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International audience; Purpose: To correlate the degree of foveal hypoplasia in congenital aniridia with visual acuity, iris phenotype, and PAX6 mutations.Design: Retrospective case series.Methods: 95 consecutive patients with high quality Spectral-domain optical coherence tomography (SD-OCT) records and available genotype were included in a single referral center. Iris hypoplasia was classified as complete, presence of iris root or remnants and mild atypical aniridia. SD-OCT images were assessed to classify foveal hypoplasia as Grade 1 to 4 and to determine mean thicknesses for retinal layers. For statistical analysis one eye for each patient have been used and one member of the same family has been included (n=76 eyes).Results: Most eyes (93.5%) showed variable degree of foveal hypoplasia. PAX6-positive patients presented higher degree of foveal hypoplasia than patients negative for PAX6 (p

Aniridia is a panocular inherited rare eye disease linked to heterozygous mutations on the PAX6 gene, which fail to properly produce sufficient protein essential for normal eye development and function. Most of the patients suffer from aniridia-related keratopathy, a progressive opacification of the cornea. There is no effective treatment for this blinding disease. Here we screen for small compounds and identified Ritanserin, a serotonin 2A receptor antagonist, that can rescue PAX6 haploinsufficiency of mutant limbal cells, defective cell migration and PAX6-target gene expression. We further demonstrated that Ritanserin activates PAX6 production through the selective inactivation of the MEK/ERK signaling pathway. Our data strongly suggest that repurposing this therapeutic molecule could be effective in preventing or treating existing blindness by restoring corneal transparency.

This review updates the knowledge about the morphological assessment of the foveal hypoplasia in congenital aniridia and resumes the reported genotype-phenotype correlations known to date. Congenital aniridia is a pan ocular disease. Although iris absence is considered the hallmark of this entity, foveal hypoplasia is present in 94.7%-84% of patients. A foveal morphology assessed by optical coherence tomography in which external retina structures can be identified, with presence of the lengthening of photoreceptors outer segment and a greater external retinal thickness, is associated with a better visual outcome, regardless a foveal pit is identified or not. This analysis can be performed once the external retina has completed its differentiation, by 6 years old. PAX6 mutations that introduce premature termination codon, C terminal extension or PAX6 involving deletions have been related to lesser foveal differentiation. Better foveal differentiation has been associated to non-coding PAX6 mutations.

Aniridia is a congenital bilateral ocular disorder with dominant autosomal inheritance. More than 50% of patients will develop aniridic glaucoma (AG) during their lives. Open angle glaucoma is more common in aniridia, but a closed angle mechanism has been described in relation with anterior rotation of the rudimentary iris, occluding trabecular meshwork. Diagnosis and follow-up of AG is difficult in relation with the presence of keratopathy, nystagmus and foveal hypoplasia. Central corneal thickness usually measures more than 600 microns, which prevents achieving a reliable value of intraocular pressure. Medical treatment of AG is not different from the rest of glaucoma. It is recommended to use preservative free formulations, and combined therapy is often required. Surgical treatment is needed in many cases. There is no consensus on the first line surgery for AG, but in open angle AG, angle surgery is usually first choice, and glaucoma drainage devices are the next preferred surgical technique. In closed angle AG glaucoma drainage devices are usually the first choice, with trabeculectomy as the second preferred surgical technique.

Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, lead-ing to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease. (c) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Funding Agencies|European Union COST Action [CA-18116 ANIRIDIA-NET]

To compare the outcomes of Aurolab aqueous drainage implant (AADI; Aurolab) placement and trabeculectomy with mitomycin C (MMC) in patients with glaucoma secondary to aniridia.Retrospective comparative interventional case series.This study included patients with congenital aniridia who underwent AADI implantation or trabeculectomy with MMC. Surgical failure was defined as IOP21 mm Hg or reduced20% from baseline, IOP ≤ 5 mm Hg, reoperation for glaucoma or a complication, or loss of light perception vision.A total of 30 eyes of 30 patients underwent surgical treatment, including 18 eyes that received an AADI and 12 eyes that had a trabeculectomy with MMC. The cumulative probability of failure at 2 years was 11.1% (95% CI = 2.9%-37.6%) in the AADI group and 58.3% (95% CI = 33.5%-84.8%) in the trabeculectomy group (P = .05, log-rank). At 2 years, IOP (mean ± SD) was 14.1 ± 2.8 mm Hg in the AADI group and 19.6 ± 6.6 mm Hg in the trabeculectomy group (P = .02), and the number of glaucoma medications was 1.7 ± 0.9 in the AADI group and 2.2 ± 0.8 in the trabeculectomy group (P = .25). Surgical complications developed in 1 patient in each treatment group (P = .65). Cataract surgery was performed in 5 (42%) patients in the trabeculectomy group and no patients in the AADI group (P = .01).Placement of an AADI resulted in lower IOP and a higher rate of surgical success compared to trabeculectomy with MMC in eyes with glaucoma associated with aniridia. Cataract extraction was more frequently required after trabeculectomy with MMC than AADI implantation.

Purpose To evaluate repeat Descemet membrane endothelial keratoplasty (re-DMEK) success rates and to identify risk factors for re-DMEK failure. Design Retrospective case series. Methods Settings: Institutional. Patients and interventions: A chart review was performed, including all eyes with primary DMEK failure that underwent re-DMEK between 2013 and 2019 at the Toronto Western Hospital and the Kensington Eye Institute (Toronto, Ontario, Canada) and had at least 6 months of follow-up. Main outcome measure: Predicting factors for re-DMEK outcome. Results Of 590 consecutive DMEK surgeries, 40 eyes (6.7%) were identified for having a secondary DMEK surgery after primary DMEK failure. Etiologies for primary DMEK were Fuchs endothelial corneal dystrophy (32.5%), pseudophakic bullous keratopathy (35%), previous failed graft (27.5%), and other indications (5%). Fifty-five percent of the cohort were categorized as having a complicated anterior segment including 11 eyes with previous glaucoma surgery, 7 eyes post–penetrating keratoplasty, 4 eyes post–Descemet stripping automated endothelial keratoplasty, 3 eyes peripheral anterior synechia, 3 eyes previous pars plana vitrectomy, 2 eyes aphakia, and 1 eye each with aniridia, anterior chamber intraocular lens, and iris-fixated intraocular lens. Re-DMEK failure was documented in 12 eyes (30%) of the entire cohort. The risk factor for re-DMEK failure was the presence of a complicated anterior segment (P = .01, odds ratio = 17.0 [95% confidence interval: 1.92-150.85]), with 50% re-DMEK failure rate in this subgroup. Conclusion Re-DMEK is a viable option for cases of primary DMEK failure, especially for eyes with Fuchs endothelial corneal dystrophy as the indication for primary DMEK without other ocular morbidities; however, eyes categorized with a complicated anterior segment had high re-DMEK failure rates.

Purpose We evaluate the role of microscope-integrated intraoperative optical coherence tomography (i-OCT) in pediatric keratoplasty. Design: Combined prospective and retrospective, comparative, interventional study conducted at the Dr Rajendra Prasad Center for Ophthalmic Sciences in New Dehli, India. Methods: Seventy-five children ≤16 years of age undergoing planned keratoplasty were divided into 2 groups and compared regarding intraoperative course and postoperative outcome. In group 1 (prospective group, n = 56), preoperative anterior segment visualization was performed clinically, with ultrasound biomicroscopy (UBM) and i-OCT and keratoplasty was commenced under i-OCT microscope. In group 2 (retrospective group, n = 19), a conventional microscope was used during keratoplasty. Results: In group 1, i-OCT, UBM, and clinical examination detected retrocorneal membrane in 10%, 7.5%, and 5% (P = .005), iris adhesions in 62.5%, 57.5%, and 20% (P = .02), iris stump in aniridia 15%, 10%, and 0% (P = .001), shallow central anterior chamber in 22.5%, 22.5%, and 7.5% (P = .003), and shallow peripheral anterior chamber in 65%, 60%, and 17.5% (P = .004) of children, respectively. The use of i-OCT affected intraoperative surgeon decision making in 45% and 33% of cases of anterior and posterior lamellar keratoplasty, respectively. During penetrating keratoplasty, concomitant intraoperative procedures were higher in group 1 than in group 2, namely synechiolysis (19/40 vs 2/15; P = .1), pupilloplasty (4/40 vs 0/15; P = .02), lens extraction (4/40 vs 1/15; P = .5), and anterior vitrectomy (2/40 vs 1/15; P = .4). Postoperative secondary interventions were lower (P = .04) in group 1 (48.21% vs 94.74%). Conclusions: Anterior segment imaging with i-OCT and UBM immediately before surgery improves the surgical planning of children with corneal opacities. In addition, the use of i-OCT refines intraoperative steps, thereby optimizing the postoperative outcome of pediatric keratoplasty.

We sought to evaluate the 1- to 9-year safety and efficacy of colored iris reconstruction lens implantation in eyes with visual disturbances caused by partial or complete aniridia.Prospective, interventional case series.Thirty-eight patients were implanted with Ophtec 311 colored iris reconstruction lenses at the University of California, Los Angeles as part of a larger U.S. Food and Drug Administration clinical trial. Patients in group 1 lacked corneal pathology. Patients in group 2 patients had corneal pathology, such as endothelial failure, previous transplants, or scarring. Safety measures included loss of corrected distance visual acuity (CDVA), surgical complications, adverse events, secondary interventions, and corneal endothelial cell loss. Efficacy measures included improvement in uncorrected distance visual acuity (UDVA) and subjective visual disturbances.Groups 1 (n = 8) and 2 (n = 30) showed improvements in CDVA (P = .155 and .038), UDVA (P = .002 and P.001), and subjective visual disturbance scores at year 3. Median CDVA and UDVA declined slightly for both groups after 1-2 years. Group 2 experienced more adverse events, surgical complications, and secondary interventions. Endothelial cell loss was greater for group 2 (19.7%) than group 1 (8.05%), although this difference was not statistically significant (P = .067).Colored iris reconstruction lens implantation improved CDVA, UDVA, and subjective visual disturbances 3 years postoperatively and beyond. Adverse events, complications, and subsequent declines in visual acuity were common, however, in these eyes with complex medical and surgical histories.

Purpose To report the outcomes of medical and surgical management for congenital aniridia-associated keratopathy (AAK) over a long-term follow-up period. Design Retrospective, comparative case series. Methods Medical records of patients diagnosed with congenital aniridia were retrospectively reviewed. Age, sex, ethnicity, follow-up time, AAK stage, noncorneal abnormalities, ocular surgeries, and complications were recorded. The visual acuity equivalent (VAE), approximate Early Treatment Diabetic Retinopathy Study (appETDRS) letter score, was calculated using recorded Snellen visual acuities. Results A total of 92 eyes of 47 patients (31 females) with mean age of 48.0 ± 18.0 years and mean follow-up of 78.6 ± 42.2 months were included. At the initial visit, 12 eyes (13%) were classified as Stage I AAK, 33 eyes (35.9%) were Stage II, 25 eyes (27.2%) were Stage III, 17 eyes (18.5%) were Stage IV, and 5 eyes (5.4%) were Stage V. Limbal stem cell transplantation (LSCT) and Boston keratoprosthesis (KPro) were frequently performed in eyes with Stages III-V. These advanced corneal surgeries significantly improved the median (95% confidence interval [CI]) of calculated appETDRS scores from 2 (0-20) to 26 (15-41) (Snellen values, 20/20,000 to 20/300; P = 0.0004). Patients with earlier Stages (I-II) of AAK were managed medically and had stable visual acuity through their final visits (appETDRS score of 26 [20-35] to 35 [26-35]; Snellen, 20/300 to 20/200; P > 0.05). The appETDRS VAE was significantly improved from 20 (0-35) to 30 (20-55), Snellen, 20/400 to 20/250, following LSCT (P = 0.021) and from 2 (0-20) to 2 (0-41) after KPro; Snellen, 20/20,000 VAE but with improved 95% CI after follow-up (P = 0.019). Conclusions With proper characterization and staging of AAK, individualized medical and advanced surgical interventions preserves and improves visual acuity.

Disruption of any of the ocular development steps can result in ocular defects such as microphthalmia, coloboma and anterior segment dysgeneses including aniridia and cataract. All of these anomalies can be isolated or seen in association with each other. Except for aniridia (almost exclusively due to PAX6 mutations), most of these congenital ocular malformations are related to a wide genetic heterogeneity, as hundreds of genes are implied in ocular development. Here we describe a patient presenting with bilateral microphthalmia, congenital cataract, corneal dystrophy and iris hypoplasia, associated with extra-ocular features, who underwent an analysis of 119 ocular development related genes. Genetic testing revealed the presence of two truncating variants in the EPHA2 gene. While EPHA2 mutations are mainly known to be responsible for isolated dominant congenital cataract, we report here the first case of complex anterior segment dysgenesis caused by a biallelic EPHA2 mutation. This gene should be screened in case of aniridia with a negative PAX6 testing, as the ocular features of our patient clearly mimic those of PAX6 mutated patients. This observation enlarges the phenotype associated with EPHA2 variations and rise the insight of a possible PAX6-EPHA2 interaction that needs further investigations. Moreover, despite a great variability in ocular and extra-ocular phenotypes, mutations type and inheritance pattern, a possible genotype-phenotype correlation can also be drawn for this gene.

Purpose To assess outcomes and glaucoma management in eyes with aniridia following Boston type 1 Keratoprosthesis (KPro) implantation. Design Retrospective, interventional comparative case series. Methods The population included patients with aniridia and patients with other preoperative diagnoses (excluding Stevens-Johnson syndrome, mucous membrane pemphigoid, and congenital disorders) who underwent KPro implantation at Massachusetts Eye and Ear with at least 2 years of follow-up. One eye per patient was selected based on the longer follow-up time. The main outcome was intermediate and long-term outcomes related to glaucoma. Results The aniridia (n = 22) and comparison (n = 61) groups had similar preoperative visual acuity (VA, mean ± standard deviation, 1.86 ± 0.52 logMAR, P = .33) and follow-up time (65.6 ± 26.3 months, P = .25). Before KPro implantation, eyes with aniridia had more glaucoma (76.2%) and glaucoma surgery (57.1%) than comparison eyes (51.8%, P = .053; 23.2%, P = .005, respectively). More Ahmed valves were co-implanted with KPro in aniridia (47.6%) vs comparison eyes (17.9%, P = .008). At final follow-up, more aniridia eyes had glaucoma (90.5%) than comparison eyes (64.3%, P = .02), but the 2 groups had similar percentages of eyes with cup-to-disc ratio (CDR) >0.8 (23.8% vs. 30.4%, P = .57) or CDR progression of ≥0.2 (42.9% vs 44.6%, P = .89, respectively). None of the eyes with prophylactic tube implantation developed glaucoma. Eyes with and without aniridia did not differ in post-KPro VA improvement (72.7%, 72.1%, P = .96), and final VA (1.28 ± 0.79 logMAR, 1.23 ± 0.98 logMAR, P = .51). Conclusion Despite a higher glaucoma prevalence, eyes with aniridia achieved similar VA as comparison eyes with more than 5 years of mean follow-up time. Boston KPro offers satisfactory visual rehabilitation in aniridia when glaucoma is managed aggressively.

Purpose Investigate in vivo cone photoreceptor structure in familial aniridia caused by deletion in the PAX6 gene to elucidate the complexity of between-individual variation in retinal phenotype. Design Descriptive case-control study. Participants Eight persons with congenital aniridia (40–66 yrs) from 1 family and 33 normal control participants (14–69 yrs), including 7 unaffected family members (14–53 yrs). Methods DNA was isolated from saliva samples and used in polymerase chain reaction analysis to amplify and sequence exons and intron or exon junctions of the PAX6 gene. High-resolution retinal images were acquired with OCT and adaptive optics scanning light ophthalmoscopy. Cone density (CD; in cones per square millimeter) and mosaic regularity were estimated along nasal–temporal meridians within the central 0° to 5° eccentricity. Horizontal spectral-domain OCT line scans were segmented to analyze the severity of foveal hypoplasia (FH) and to measure retinal layer thicknesses. Main Outcomes and Measures Within-family variability in macular retinal layer thicknesses, cone photoreceptor density, and mosaic regularity in aniridia compared with normal control participants. Results DNA sequencing revealed a known PAX6 mutation (IV2-2delA). Those with aniridia showed variable iris phenotype ranging from almost normal appearance to no iris. Four participants with aniridia demonstrated FH grade 2, 2 demonstrated grade 3 FH, and 1 demonstrated grade 4 FH. Visual acuity ranged from 0.20 to 0.86 logarithm of the minimum angle of resolution. Adaptive optics scanning light ophthalmoscopy images were acquired from 5 family members with aniridia. Foveal CD varied between 19 899 and 55 128 cones/mm2 with overlap between the foveal hypoplasia grades. Cone density was 3 standard deviations (SDs) or more less than the normal mean within 0.5°, 2 SDs less than the normal mean at 0.5° to 4°, and more than 1 SD less than the normal mean at 5° retinal eccentricity. Conclusions The results showed considerable variability in foveal development within a family carrying the same PAX6 mutation. This, together with the structural and functional variability within each grade of foveal hypoplasia, underlines the importance of advancing knowledge about retinal cellular phenotype in aniridia.

Aniridia is a rare congenital syndrome that is associated with reduced visual acuity and progressive loss of vision. Aniridia patients may also develop systemic health issues associated with defects in the pancreas, digestive, and central nervous systems. The spectrum of symptoms associated with aniridia is due to haploinsufficiency of the paired box 6 gene (PAX6) and its role in the development and maintenance of the affected tissues. Here, we isolated pancreatic islets from mice heterozygous for Pax6 to test whether a Pax6-specific miRNA suppression (target protector) strategy can restore PAX6 protein levels. We show that miR-7 and miR-375 target specific sites within the Pax6 3′ UTR in a mouse pancreatic β-insulinoma cell line. Tough decoys (Tuds) against miR-7 and miR-375 increase expression of a mouse Pax6 3′ UTR luciferase reporter and increase PAX6 protein levels in these cells. Finally, we demonstrate that the shielding of the miR-7 binding site with a target protector restores PAX6 protein levels in the Pax6 heterozygous islets. The data presented here represent a proof of concept for RNA-based therapy for the progressive defects associated with aniridia and suggest the target protector approach may be a useful therapeutic strategy for other haploinsufficiency diseases., Graphical Abstract

There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjogren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.

PAX6 haploinsufficiency related aniridia is characterized by disorder of limbal epithelial cells (LECs) and aniridia related keratopathy. In the limbal epithelial cells of aniridia patients, deregulated retinoic acid (RA) signaling components were identified. We aimed to visualize differentiation marker and RA signaling component expression in LECs, combining a differentiation triggering growth condition with a small interfering RNA (siRNA) based aniridia cell model (PAX6 knock down). Primary LECs were isolated from corneoscleral rims of healthy donors and cultured in serum free low Ca

Purpose To determine the demographic features of patients affected by limbal stem cell deficiency (LSCD), and to identify the underlying causes of LSCD. Design Retrospective, multicenter case series. Setting: Two large tertiary care ophthalmology hospitals. Subjects: Patients with a diagnosis of LSCD presenting from January 1, 2005 to December 31, 2014. Methods Records of patients with a clinical diagnosis of LSCD were reviewed. Demographic details and clinical features at presentation, as well as the underlying cause of LSCD (if identified), were noted. Descriptive statistical analysis and chart preparation were done. Main outcome measures were type of LSCD (unilateral or bilateral), age and sex of patients, extent of LSCD (clock hours of limbus involved), and underlying cause of LSCD. Results We found 1331 patients with LSCD in the 10-year period under study. Unilateral LSCD was more common (791 patients) than bilateral LSCD (540 patients). Out of 1331 patients, 875 (65.74%) were male. The median age of patients was 24 years. Extent of LSCD could be determined in 1849 eyes, of which 1239 eyes (67.00%) had total LSCD. The underlying cause of LSCD could be identified in 1512 eyes. In cases of unilateral LSCD, ocular surface burns was the commonest identifiable cause (83.73%). The leading identifiable causes of bilateral LSCD were ocular surface burns (29.95%), allergic conjunctivitis (29.48%), Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) (23.11%), aniridia (9.43%), and mucous membrane pemphigoid (3.54%). Lime ("chuna") injury was responsible for ocular surface burns in 352 out of 567 cases in which the agent was identified (62.08%). Conclusions In our study, unilateral LSCD was more common than bilateral LSCD. Young male subjects were commonly affected, with a majority of eyes suffering from total LSCD. Overall, ocular surface burns are the leading cause of LSCD. Unilateral and bilateral LSCD had a markedly different distribution of causes, necessitating different approaches to management.

Aniridia is a rare disease of the eye that affects the iris, lens and the cornea. In about 90% of the cases, patients showed a loss of PAX6 function. Patients with aniridia often develop aniridia-related keratopathy (ARK), due to limbal stem cell insufficiency. The aim of this study was to determine the differentiation status of limbal epithelial cells (LECs) in patients with ARK. Epithelial cells were isolated from the limbus region of two patients with aniridia and cultured in KSFM medium supplemented with EGF and BPE. Normal cells were obtained from limbus region of cadaveric control patients. Cells were analyzed with RT-PCR, qPCR and Western blot to evaluate expression of the developmental transcription factor, PAX6, potential stem cell markers, ΔNp63α and ABCG2, and corneal differentiation markers, keratin 12 (K12) and K3. Conjunctival differentiation markers, keratin 13 (K13) and K19 were also investigated. Cells were immunostained to evaluate K3, PAX6, and p63α protein expression. Protein coding sequence of PAX6 from patient LEC-cDNA was cloned and sequenced. RT-PCR showed that K3 and K12 transcripts were absent from patient cells, but present in healthy control preparations. Transcription levels of PAX6, ABCG2, and p63α of aniridia patients show no differences compared to normal control cells. Western blot showed reduced PAX6, protein levels in aniridia-LECs compared to control-LECs. Immunostaining also showed reduced PAX6 and K3 expression in aniridia-LECs compared to control-LECs. One aniridia patient showed a loss of stop codon in half of the cloned transcripts. In the second aniridia patient mRNA degradation through nonsense mediated decay seems to be very likely since we could not identify the mutation c.174C > T (Refseq. NM_000280), or misspliced transcripts in cDNA. We identified decreased PAX6 protein levels in aniridia patients in addition to decreased K12 mRNA levels compared to control cells. This result indicates an altered differentiation of limbal epithelial cells of aniridia patients. Further studies are necessary to evaluate the mechanism of differentiation of limbal epithelial cells in aniridia.

Purpose To relate central corneal epithelial phenotype to degree of keratopathy in a limbal stem cell deficient population. Methods 37 patients (67 eyes) with aniridia-associated keratopathy (AAK) underwent corneal examination including slit lamp biomicroscopy to determine the Grade of AAK, Cochet-Bonnet esthesiometry, and in vivo confocal microscopy (IVCM) to assess morphology of the central corneal epithelium and subepithelial region. Results AAK Grade ranged from 1 (limbal involvement only) to 4 (total conjunctivalization), with progression from Grade 1 occurring after the age of 20. 30% of subjects had an asymmetric Grade between eyes. In early-stage AAK (Grades 1–2), central epithelial cells had mixed corneal-conjunctival phenotype, touch sensitivity and subbasal nerves diminished, and mature dendritic cells, inflammatory leukocytes, and blood vessels were present despite central transparency in the slit lamp. In later stages (Grades 3–4) of the LSCD, neural deficit and nerve function worsened, immune cell invasion increased, and lymphatic vessels were detected in several cases. Goblet cells and epithelial cysts were observed to varying degrees in all stages, but without clear association to AAK severity. The clinical grade and progression of AAK was strongly associated with the central corneal epithelial phenotype. Conclusions AAK is associated with degradation of epithelial phenotype, a neural deficit, and immune compromised status even in the clear central cornea in the earliest stages. IVCM can aid in assessing whether the conditions for limbal stem cell maintenance are likely to exist, based on morphology of the central epithelial microenvironment.

To clinically characterize and compare 2 types of corneal abnormalities in patients with congenital aniridia: (1) congenital central corneal opacity from birth (CCO) and (2) aniridia-associated keratopathy (AAK) that develops progressively with age.Retrospective cohort study.Medical records of Korean patients who were diagnosed with congenital aniridia at Seoul National University Hospital between 1991 and 2016 were reviewed. Prevalence of corneal abnormalities (CCO and AAK), other ocular and systemic comorbidities, severity of AAK depending on the age, logarithm of the minimum angle of resolution (logMAR) visual acuities, and types and results of surgical intervention were collected.Among a total of 275 eyes (138 patients), 13% (35 eyes, 20 patients) had CCO and 25% (68 eyes, 35 patients) developed AAK. The AAK became prominent at a mean of 21.6 years of age, and the severity progressed with age. Glaucoma was more prevalent in aniridia patients with CCO (74%), compared to those with AAK (37%) (P = .0003). Cataract frequently occurred in patients with AAK (78%), who required cataract surgeries at mean 26.6 years. The logMAR visual acuity was worse in patients with CCO (2.04 ± 0.71) than in those with AAK (1.29 ± 0.62) (P.0001). Penetrating keratoplasty was performed in 6 eyes with CCO, and the graft survival was 33.3% during mean 45 months of follow-up (range 14-79 months).In total, 13% of aniridia patients had CCO at birth, while 25% progressively developed clinically significant AAK with age. The visual outcome was worse in patients with CCO than in those with AAK.

Objective To describe the clinical presentation and genotype of subjects with aniridia with a particular focus on foveal hypoplasia. Design Prospective cohort study. Participants Thirty-three Canadian participants with aniridia and of various ethnic backgrounds residing in British Columbia. Methods Full ophthalmic examinations and posterior segment spectral domain-optical coherence tomography (SD-OCT) imaging were performed. Foveal hypoplasia was graded independently by 2 staff ophthalmologists. PAX6 sequencing was performed and chromosomal 11p anomalies investigated. Candidate gene and single-nucleotide polymorphism sequencing in genes functionally related to PAX6 were also studied. Results Best corrected visual acuities in the cohort ranged from 0.0 logMAR to no light perception. Total absence of iris tissue was seen in the majority (42 of 66 eyes). In those in whom SD-OCT was possible, foveal hypoplasia was seen in the majority (45 of 56 eyes, 80%). Molecular genetic defects involving PAX6 were identified in 30 participants (91%), including 4 novel PAX6 mutations (Gly18Val; Ser65ProfsX14; Met337ArgfsX18; Ser321CysfsX34) and 4 novel chromosome 11p deletions inclusive of PAX6 or a known PAX6 regulatory region. Conclusions The number of PAX6 mutations associated with aniridia continues to increase. Variable foveal architecture despite nearly identical anterior segment disease in 4 participants with an Ex9 ELP4-Ex4 DCDC1 deletion suggested that molecular cues causing variation in disease in the posterior segment differ from those at play in the anterior segment. Results in 3 patients without identifiable PAX6 mutations and a review of the literature suggest that such cases be described as phenocopies rather than actual cases of the syndrome of aniridia.

Purpose To report on the implantation of a XEN 45 gel implant in a patient with glaucoma associated with congenital aniridia. Observations A 60-year old man with familial congenital aniridia and glaucoma presented with intraocular pressure of 30 mmHg in his right eye despite maximal topical treatment with four medications. Implantation of a XEN gel stent was performed without complications after subconjunctival injection of mitomycin-C (0.1 mL of 0.02%). At the two-year follow-up, the patient's intraocular pressure was 12 mmHg with one topical medication. No needling of the filtering bleb was required. No excessive fibrosis of the conjunctiva or worsening of the existing keratopathy was noted. Conclusions The XEN 45 implant could be an option in the treatment of aniridia-associated glaucoma.

ITPR1 encodes an intracellular receptor for inositol 1,4,5-trisphosphate (InsP3) which is highly expressed in the cerebellum and is involved in the regulation of Ca2 + homeostasis. Missense mutations in the InsP3-binding domain (IRBIT) of ITPR1 are frequently associated with early onset cerebellar atrophy. Gillespie syndrome is characterized by congenital ataxia, mild to moderate intellectual disability and iris hypoplasia. Dominant or recessive ITPR1 mutations have been recently associated with this form of syndromic ataxia. We performed next generation sequencing in two simplex families with Gillespie syndrome and identified de novo pathological mutations localized in the C-terminal channel domain of ITPR1 in both patients: a recurrent deletion (p.Lys2596del) and a novel missense mutation (p.Asn2576Ile) close to a point of constriction in the Ca2 + pore. Our study expands the mutational spectrum of ITPR1 and confirms that ITPR1 screening should be implemented in patients with congenital cerebellar ataxia with or without iris hypoplasia., Highlights • De novo ITPR1 mutations were identified in two patients with Gillespie syndrome. • The Asn2576Ile mutation is located close to a point of constriction in the Ca2 + pore. • ITPR1 is frequently involved in congenital ataxias with or without iris hypoplasia.

Resume Objectif Evaluer le resultat a long terme des implants intraoculaires a iris artificiel incorpore sutures a la sclere dans la prise en charge de l’aphakie et de l’aniridie traumatiques. Materiels et methodes L’ensemble des patients ayant ete operes d’un implant combine Morcher® entre juin 2008 et fevrier 2016 a l’Hopital Edouard-Herriot (Lyon, France) a ete inclus dans cette etude retrospective monocentrique. L’acuite visuelle, le degre subjectif d’eblouissement autoevalue, la qualite de vie et les complications chirurgicales ont ete evalues. Resultats Dix-sept yeux de 17 patients ont ete inclus, parmi lesquels 82 % d’hommes. L’âge moyen etait de 42 ans. On denombrait 23,5 % de contusion et 70,5 % de traumatismes a globe ouvert dont 41 % de ruptures de globe, et un cas survenu dans un contexte postoperatoire. Une keratoplastie transfixiante a ete realisee dans le meme temps operatoire pour huit yeux. Le suivi moyen etait de 32 mois. La meilleure acuite visuelle corrigee s’est amelioree pour 41,2 %, est restee stable pour 17,6 % et s’est degradee pour 41,2 % de nos cas. Le gain moyen d’acuite visuelle etait d’1 ± 0,25 ligne en vision de loin et de 2,2 ± 0,32 lignes en vision de pres lorsque l’acuite visuelle preoperatoire etait chiffrable. L’eblouissement s’est ameliore chez 80 % des patients evalues et est reste stable pour 20 % d’entre eux, passant en moyenne de 3,3/5 [min. 3–max. 4 ; SD : 0,48] en preoperatoire a 1,9/5 [min. 0–max. 4 ; SD : 1,197] en postoperatoire. Concernant les resultats esthetiques, 78 % des patients se declaraient assez a tres satisfaits ; 57 % rapportaient ne subir aucune limitation des activites de la vie quotidienne et 43 % une faible limitation. L’hypertonie intraoculaire et le glaucome, retrouves chez 40 % des yeux, etaient les principales complications postoperatoires. Conclusion L’implantation d’un dispositif d’iris prothetique combine a une lentille intraoculaire semble etre une methode sure et efficace pour reduire l’eblouissement et ameliorer l’acuite visuelle. Une surveillance etroite et a long terme est essentielle pour le succes de cette chirurgie.

Purpose To determine the incidence rate, principal causes, and clinical course of eyes developing no light perception (NLP) visual acuity (VA) following Boston Keratoprosthesis (B-KPro) type 1 surgery. Secondary objectives include determining the incidence rate, relative risk (RR), and survival probability with respect to NLP outcomes among eyes with congenital aniridia. Design Retrospective, interventional case series. Subjects All patients undergoing B-KPro type 1 surgery between October 2008 and June 2016 by a single surgeon at CHUM – Hopital Notre-Dame. Methods Records of patients having undergone B-KPro implantation were reviewed. Eyes with a final outcome of NLP were further reviewed to determine best recorded postoperative VA, time to NLP onset, clinical course, and principal cause. Descriptive statistics, incidence rates, Kaplan-Meier survival curves, and the RR of NLP outcomes among eyes with aniridia were determined. Statistical significance was defined as P Results Records of 119 patients were included, with an average follow-up of 49.1 ± 26.8 months postoperatively. Nineteen eyes had a final outcome of NLP, representing 16.0%. The incidence rate of NLP was 0.04 cases per eye-year of follow-up. The most common principal causes were inoperable retinal detachment (n = 7, 36.8%), terminal glaucoma (n = 6, 31.6%), and carrier graft melt-related complications (n = 5, 26.3%). The RR of developing NLP among eyes with aniridia was 3.04 ( P = .01). Conclusions No light perception is a devastating but uncommon outcome of B-KPro surgery. Patients with aniridia seem to be at increased risk. In spite of all available medical and surgical interventions, some eyes may still suffer this outcome.

The Pax6 transcription factor is essential for development of the brain, eye, olfactory and endocrine systems. Haploinsufficiency of PAX6 in humans and mice causes the congenital condition aniridia, with defects in each of these organs and systems. Identification of the PAX6 transcription networks driving normal development is therefore critical in understanding the pathophysiology observed with loss-of-function defects. Here we have focused on identification of the downstream targets for Pax6 in the developing iris and ciliary body, where we used laser capture microdissection in mouse eyes from E12.5-E16.5, followed by chromatin immunoprecipitation, promoter-reporter assays and immunohistochemistry. We identified 6 differentially expressed genes between wildtype and Pax6 heterozygous mouse tissues and demonstrated that Bmp4, Tgfβ2, and Foxc1 were direct downstream targets of Pax6 in developing iris/ciliary body. These results improve our understanding of how mutations in Bmp4, Tgfβ2, and Foxc1 result in phenocopies of the aniridic eye disease and provide possible targets for therapeutic intervention.

Adaptive optics (AO) imaging tools enable direct visualization of the cone photoreceptor mosaic, which facilitates quantitative measurements such as cone density. However, in many individuals, low image quality or excessive eye movements precludes making such measures. As foveal cone specialization is associated with both increased density and outer segment (OS) elongation, we sought to examine whether OS length could be used as a surrogate measure of foveal cone density. The retinas of 43 subjects (23 normal and 20 albinism; aged 6-67years) were examined. Peak foveal cone density was measured using confocal adaptive optics scanning light ophthalmoscopy (AOSLO), and OS length was measured using optical coherence tomography (OCT) and longitudinal reflectivity profile-based approach. Peak cone density ranged from 29,200 to 214,000cones/mm2 (111,700±46,300cones/mm2); OS length ranged from 26.3 to 54.5μm (40.5±7.7μm). Density was significantly correlated with OS length in albinism (p

We report the case of a 12-year-old boy with fovea plana discovered on a systematic work-up. His best-corrected visual acuity was limited to 20/25 in both eyes. Anterior segment examination showed no evidence of iris transillumination or aniridia. Macular OCT revealed persistence of the inner nuclear layers in the foveolar area and an absence of foveal pits, suggesting a diagnosis of fovea plana. Fluorescein angiography revealed that the foveal avascular zone (FAZ) was absent. OCT angiography revealed persistence of the superficial and deep capillary plexi. Our case confirms that OCT angiography affords additional insights into macular exploration and the diagnosis of fovea plana by revealing absence of the foveal pit associated with persistence of both superficial and deep capillary plexi in the foveal area.

Anterior segment dysgeneses (ASDs) comprise a spectrum of developmental disorders affecting the anterior segment of the eye. Here, we describe three unrelated families affected by a previously unclassified form of ASD. Shared ocular manifestations include bilateral iris hypoplasia, ectopia lentis, corectopia, ectropion uveae, and cataracts. Whole-exome sequencing and targeted Sanger sequencing identified mutations in CPAMD8 (C3 and PZP-like alpha-2-macroglobulin domain-containing protein 8) as the cause of recessive ASD in all three families. A homozygous missense mutation in the evolutionarily conserved alpha-2-macroglobulin (A2M) domain of CPAMD8, c.4351T>C (p. Ser1451Pro), was identified in family 1. In family 2, compound heterozygous frameshift, c.2352_2353insC (p.Arg785Glnfs∗23), and splice-site, c.4549-1G>A, mutations were identified. Two affected siblings in the third family were compound heterozygous for splice-site mutations c.700+1G>T and c.4002+1G>A. CPAMD8 splice-site mutations caused aberrant pre-mRNA splicing invivo or invitro. Intriguingly, our phylogenetic analysis revealed rodent lineage-specific CPAMD8 deletion, precluding a developmental expression study in mice. We therefore investigated the spatiotemporal expression of CPAMD8 in the developing human eye. RT-PCR and insitu hybridization revealed CPAMD8 expression in the lens, iris, cornea, and retina early in development, including strong expression in the distal tips of the retinal neuroepithelium that form the iris and ciliary body, thus correlating CPAMD8 expression with the affected tissues. Our study delineates a unique form of recessive ASD and defines a role for CPAMD8, a protein of unknown function, in anterior segment development, implying another pathway for the pathogenicity of ASD.

A human induced pluripotent stem cell (hiPSC) line (UCLi013-A) was generated from fibroblast cells of a 34-year-old donor with multiple ocular conditions including severe microphthalmia and aniridia. The patient had a heterozygous missense mutation in PAX6 c.372C>A, p.(Asn124Lys), validated in the fibroblasts through Sanger sequencing. Fibroblasts derived from a skin biopsy were reprogrammed using integration free episomal reprogramming. The established iPSC line was found to express pluripotency markers, exhibit differentiation potential in vitro and display a normal karyotype. This cell line will act as a tool for disease modelling of microphthalmia and aniridia, identification of therapeutic targets and drug screening.

Mutations in the Pax6 gene cause ocular defects in both vertebrate and invertebrate animal species, and the disease aniridia in humans. Despite extensive experimentation on this gene in multiple species, including humans, we still do not understand the earliest effects on development mediated by this gene. This prompted us to develop pax6 mutant lines in Xenopus tropicalis taking advantage of the utility of the Xenopus system for examining early development and in addition to establish a model for studying the human disease aniridia in an accessible lower vertebrate. We have generated mutants in pax6 by using Transcription Activator-Like Effector Nuclease (TALEN) constructs for gene editing in X. tropicalis. Embryos with putative null mutations show severe eye abnormalities and changes in brain development, as assessed by changes in morphology and gene expression. One gene that we found is downregulated very early in development in these pax6 mutants is myc, a gene involved in pluripotency and progenitor cell maintenance and likely a mediator of some key pax6 functions in the embryo. Changes in gene expression in the developing brain and pancreas reflect other important functions of pax6 during development. In mutations with partial loss of pax6 function eye development is initially relatively normal but froglets show an underdeveloped iris, similar to the classic phenotype (aniridia) seen in human patients with PAX6 mutations. Other eye abnormalities observed in these froglets, including cataracts and corneal defects, are also common in human aniridia. The frog model thus allows us to examine the earliest deficits in eye formation as a result of pax6 lesions, and provides a useful model for understanding the developmental basis for the aniridia phenotype seen in humans.

AGR syndrome (the clinical triad of aniridia, genitourinary anomalies, and mental retardation, a subgroup of WAGR syndrome for Wilm's tumor, aniridia, genitourinary anomalies, and mental retardation) is a rare syndrome caused by a contiguous gene deletion in the 11p13-14 region. However, the mechanisms of WAGR syndrome pathogenesis are elusive. In this study we provide evidence that LGR4 (also named GPR48), the only G-protein-coupled receptor gene in the human chromosome 11p12-11p14.4 fragment, is the key gene responsible for the diseases of AGR syndrome. Deletion of Lgr4 in mouse led to aniridia, polycystic kidney disease, genitourinary anomalies, and mental retardation, similar to the pathological defects of AGR syndrome. Furthermore, Lgr4 inactivation significantly increased cell apoptosis and decreased the expression of multiple important genes involved in the development of WAGR syndrome related organs. Specifically, deletion of Lgr4 down-regulated the expression of histone demethylases Jmjd2a and Fbxl10 through cAMP-CREB signaling pathways both in mouse embryonic fibroblast cells and in urinary and reproductive system mouse tissues. Our data suggest that Lgr4, which regulates eye, kidney, testis, ovary, and uterine organ development as well as mental development through genetic and epigenetic surveillance, is a novel candidate gene for the pathogenesis of AGR syndrome.

Congenital iris defects may usually present either as subtotal aniridia or colobomatous iris defects. Acquired iris defects are secondary to penetrating iris injury, iatrogenic after surgical excision of iris tumours, collateral trauma after anterior segment surgery, or can be postinflammatory in nature. These iris defects can cause severe visual disability in the form of glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The structural loss of iris can be reconstructed with iris suturing, use of prosthetic iris implants, or by a combination of these, depending on the relative amount of residual iris stromal tissue and health of the underlying pigment epithelium. Since the first implant of a black iris diaphragm posterior chamber intraocular lens in 1994, advances in material and design technology over the last decade have led to advances in the prosthetic material, surgical technique, and instrumentation in the field of prosthetic iris implants. In this article, we review the classification of iris defects, types of iris prosthetic devices, implantation techniques, and complications.

Aniridia is a congenital disorder, predominantly caused by heterozygous mutations of the PAX6 gene. While ocular defects have been extensively characterized in this population, brain-related anatomical and functional abnormalities are emerging as a prominent feature of the disorder. Individuals with aniridia frequently exhibit auditory processing deficits despite normal audiograms. While previous studies have reported hypoplasia of the anterior commissure and corpus callosum in some of these individuals, the neurophysiological basis of these impairments remains unexplored. This study provides direct assessment of neural activity related to auditory processing in aniridia. Participants were presented with tones designed to elicit an auditory steady-state response (ASSR) at 22 Hz, 40 Hz, and 84 Hz, and infrequent broadband target tones to maintain attention during electroencephalography (EEG) recording. Persons with aniridia showed increased early cortical responses (P50 AEP) in response to all tones, and increased high-frequency oscillatory entrainment (84 Hz ASSR). In contrast, this group showed a decreased cortical integration response (P300 AEP to target tones) and reduced neural entrainment to cortical beta-band stimuli (22 Hz ASSR). Collectively, our results suggest that subcortical and early cortical auditory processing is augmented in aniridia, while functional cortical integration of auditory information is deficient in this population.

Purpose: This paper describes a modified technique for the Descemet's Stripping Automated Endothelial Keratopasty (DSAEK) surgery in eyes with abnormal or altered anatomy. Certain anatomic abnormalities increase the level of surgical complexity, and lead to increased risk of donor lenticule detachment. These challenges include aniridia, abnormal iris, aphakia and hypotony from previous vitrectomy. Observations: The Sheets glide was trimmed to 4mm in width and inserted into the clear-corneal wound. The “needle-push”/Fichman glide technique was used to insert the DSAEK donor graft. The modification of the technique involves maintaining the Sheets glide in the eye for the duration of the intraoperative air bubble. After confirming desired orientation of the graft, air was injected into the anterior chamber, creating a large air bubble between the graft and the Sheets glide. After 10 minutes, the Sheets glide was removed, and the main wound was closed. Conclusions and Importance: This technique overcomes the challenges of posterior air bubble migration and posterior dislocation of the donor lenticule in eyes with altered anatomy. Keywords: DSAEK, DSEK, Endothelial keratoplasty, Sheets glide, Surgical technique

The strictly regulated expression of most pleiotropic developmental control genes is critically dependent on the activity of long-range cis-regulatory elements. This was revealed by the identification of individuals with a genetic condition lacking coding-region mutations in the gene commonly associated with the disease but having a variety of nearby chromosomal abnormalities, collectively described as cis-ruption disease cases. The congenital eye malformation aniridia is caused by haploinsufficiency of the developmental regulator PAX6. We discovered a de novo point mutation in an ultraconserved cis-element located 150 kb downstream from PAX6 in an affected individual with intact coding region and chromosomal locus. The element SIMO acts as a strong enhancer in developing ocular structures. The mutation disrupts an autoregulatory PAX6 binding site, causing loss of enhancer activity, resulting in defective maintenance of PAX6 expression. These findings reveal a distinct regulatory mechanism for genetic disease by disruption of an autoregulatory feedback loop critical for maintenance of gene expression through development.

Introduction Aniridia is a panocular disorder which occurs in 1/50,000 to 1/100,000 live births and can appear either in isolated form or in the context of a syndrome. Isolated aniridia is inherited as an autosomal dominant condition and is caused by mutations of the PAX6 gene. A variety of techniques and methodologies within molecular genetics and cytogenetics are used to study these mutations. Objective To identify the different aspects of this disease and to provide a guide for proper genetic diagnosis leading to improved clinical management of the disease. Development Aniridia is an autosomal dominant disease that primarily affects the iris, though it can impact most of the ocular structures. The disease is mainly caused by mutations in the PAX6 gene located on chromosome 11p13 which encodes a transcription factor that is involved in the development of the eye. Genetic analysis of aniridia is complex and requires the use of both molecular genetics and cytogenetics techniques. These procedures are indicated in all cases of aniridia. It is important to bear certain clinical and technical aspects in mind prior to starting analysis or providing genetic counseling for patients and their families. Conclusions The use of molecular genetic techniques in the genetic diagnosis of aniridia enables patients and their families to receive better clinical management.

Individuals who are carriers of deletions of various sizes that cause haploinsufficiency in the contiguous WT1 and PAX6 genes, located on chromosome 11p13 approximately 4 Mb centromeric to the BDNF gene, are susceptible to Wilms tumor, aniridia, mental retardation, genitourinary anomalies and obesity (WAGRO syndrome). The molecular characterization of the wide deletion 11p15.1p12 arr (18676926–36576388) x1 dn in a child with 3 years and 4 months of age only affected by aniridia, predicts not only other serious associated diseases, but also allows us to hypothesize a specific phenotype of mental impairment, conduct alterations and childhood obesity, possibly added to the onset of metabolic alterations. The variable appearance and/or description of haploinsufficiency for obesity susceptibility in the WAGR syndrome mainly depends on the critical region located within 80 kb of exon 1 of BDNF . The relationship between genetic variation based on the genotype combinations of the 4 gene SNPs tagging the BDNF gene and the body mass index (BMI) was studied. The polymorphic variability was similarly distributed in 218 children suffering a severe and non-syndromic obesity from families at high risk for obesity, as compared with 198 controls. The corroborated role of the BDNF gene as highly susceptible to severe syndromic obesity has not already been evidenced in the molecular basis of overweight attributed to the common polygenic principles. Its potential role as risk modifier variant to provoke more severe phenotype has not yet been demonstrated. Some genetic variants of brain-derived neurotrophic factor ( BDNF ) have resulted in important disorders of energy balance, but it is essential to know exactly their deleterious human capacity because they play a fundamental role in the development and plasticity of the central nervous system in regulating food intake. The existence of polymorphic amino acid changes of unknown functional significance in patients carrying the haploinsufficiency of the BDNF gene could constitute an adequate model to study in depth their effects.

Fatty acid transport protein 4 (FATP4) is one of a family of six transmembrane proteins that facilitate long- and very long-chain fatty acid uptake. FATP4 is expressed in several tissues, including skin. Mutations in human SLC27A4, which encodes FATP4, cause ichthyosis prematurity syndrome, characterized by a thick desquamating epidermis and premature birth. Mice lacking FATP4, which genetically model the human disease, are born with tight, thick skin and a defective skin barrier; they die neonatally due to dehydration and restricted movements. Both the skin phenotype and the lethality are rescued by transgene expression of FATP4 in suprabasal keratinocytes. Sebaceous glands in Fatp4 null skin grafted onto nude mice were found to be dystrophic and enwrapped by thick layers of epithelial cells. Consistent with these results, transgene-rescued Fatp4 null mice showed a subnormal level of FATP4 expression in sebocytes and exhibited abnormal development of both sebaceous glands and meibomian glands, specialized sebaceous glands of the eyelids. Sebum from these mice contained a reduced level of type II diester wax, a major mouse sebum lipid species, and showed perturbations in mass spectrometric profiles of diester wax and cholesteryl ester species. In addition, these mice showed an impaired ability to repel water and regulate body temperature after water immersion. Taken together, our results suggest that FATP4 plays crucial roles in the development and maturation of both sebaceous and meibomian glands, as well as in the formation and composition of sebum, likely by regulating the trafficking of fatty acids necessary for proper synthesis of sebum lipids.

Purpose To describe clinical and molecular characteristics of Korean patients with aniridia and to compare the clinical phenotype between those having an identifiable PAX6 mutation and those not. Design Comparative case series. Participants A total of 14 Korean patients from 10 families with aniridia. Methods Complete ophthalmologic examinations were performed for all patients. PAX6 analysis included direct sequencing of all coding regions and multiplex ligation-dependent probe amplification (MLPA) to detect large deletions when the sequencing was negative. If the PAX6 analysis failed to reveal any identifiable mutations, genomic copy number variation analysis via array comparative genomic hybridization (CGH) and candidate gene PITX3 and FOXE3 sequencing were then performed. Main Outcome Measures Severity of ocular abnormalities and genetic findings. Results Sequencing of PAX6 exhibited 5 different heterozygous mutations in 8 patients from 5 families; 2 (p.Ser43Phe, IVS8-9C>G) were novel, and 3 (p.Arg208Trp, p.Arg317X, and p.X423L) have been previously reported. Among the remaining 6 patients in whom the PAX6 sequencing was negative, MLPA identified large deletions in 2 sporadic patients. However, the array CGH and candidate gene sequencing found no genomic or genetic abnormalities. The mutation detection rate was therefore 70%. Patients harboring an identifiable mutation in PAX6 had either a severe or a mild variant phenotype depending on the type of mutations. Likewise, among patients without an identifiable PAX6 mutation, their phenotypes varied widely from severe to very mild. Conclusions This study adds 2 novel PAX6 mutations to those previously reported, providing further evidence for genetic and phenotypic heterogeneity in aniridic ocular malformation. There was no difference in the clinical phenotype between patients with and without detectable mutations in the PAX6 gene. The wide variability of ocular phenotype regardless of the presence or absence of PAX6 mutations calls for a further appreciation of the complexity in the molecular diagnosis of aniridia and suggests that this ocular malformation may be better regarded as a group of heterogeneous disorders, rather than a single disease entity, associated with mutations in PAX6 and/or other genes located elsewhere in the human genome. Financial Disclosure(s) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Objective To present the technique and report the results of up to 36 months after allogenic central penetrating limbo-keratoplasty in conjunction with conjunctivoplasty, mitomycin C (MMC), and amniotic membrane (AM) transplantation in patients with bilateral limbal stem cell deficiency (LSCD). Design Retrospective, consecutive subject cohort study. Participants Case records of 20 eyes from 20 patients who presented with bilateral LSCD due to aniridia, chemical/thermal burn, cicatrizing pemphigoid, and chronic ocular surface inflammation and who were treated at the University Eye Hospital, Freiburg. Methods All eyes were treated with central limbo-keratoplasty in conjunction with conjunctivoplasty, MMC, and AM. There were 20 human leukocyte antigen-typed allolimbal transplants from cadaveric donors. All patients received systemic immunosuppression with mycophenolate mofetil or cyclosporine A. Main Outcome Measures Surgical success was measured by the duration for which a healthy corneal epithelium was maintained. Visual success was measured by an improvement in visual acuity (VA) in the eye during follow-up and directly correlated with central clear graft survival. Results The follow-up period was up to 34 months (mean, 20 months; median, 22.4 months). Mean VA, measured in decimal fractions, increased from 0.029 (∼20/400; median, 0.005; first quartile 0.005; third quartile 0.005) before surgery to 0.281 (20/70; median, 0.2; first quartile 0.04; third quartile 0.55) after surgery. Healthy corneal epithelium showing survival of limbal stem cells was observed in 14 eyes (70%) during complete follow-up. Conclusions Penetrating limbo-keratoplasty with conjunctivoplasty, MMC, and AM transplantation is a promising new surgical technique for improving vision and conjunctivalization in patients with severe bilateral LSCD necessitating allogenic transplants. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Ocular coloboma is a developmental defect of the eye and is due to abnormal or incomplete closure of the optic fissure. This disorder displays genetic and clinical heterogeneity. Using a positional cloning approach, we identified a mutation in the ATP-binding cassette (ABC) transporter ABCB6 in a Chinese family affected by autosomal-dominant coloboma. The Leu811Val mutation was identified in seven affected members of the family and was absent in six unaffected members from three generations. A LOD score of 3.2 at θ = 0 was calculated for the mutation identified in this family. Sequence analysis was performed on the ABCB6 exons from 116 sporadic cases of microphthalmia with coloboma (MAC), isolated coloboma, and aniridia, and an additional mutation (A57T) was identified in three patients with MAC. These two mutations were not present in the ethnically matched control populations. Immunostaining of transiently transfected, Myc-tagged ABCB6 in retinal pigment epithelial (RPE) cells showed that it localized to the endoplasmic reticulum and Golgi apparatus of RPE cells. RT-PCR of ABCB6 mRNA in human cell lines and tissue indicated that ABCB6 is expressed in the retinae and RPE cells. Using zebrafish, we show that abcb6 is expressed in the eye and CNS. Morpholino knockdown of abcb6 in zebrafish produces a phenotype characteristic of coloboma and replicates the clinical phenotype observed in our index cases. The knockdown phenotype can be corrected with coinjection of the wild-type, but not mutant, ABCB6 mRNA, suggesting that the phenotypes observed in zebrafish are due to insufficient abcb6 function. Our results demonstrate that ABCB6 mutations cause ocular coloboma.

Purpose To evaluate retention of visual acuity and development of complications after Boston type 1 keratoprosthesis implantation over a longer follow-up period than previously reported. Design Cohort study. Participants Forty eyes of 35 patients who underwent Boston type 1 keratoprosthesis surgery at the University of California, Davis, between 2004 and 2010. Methods Preoperative, intraoperative, and postoperative parameters were collected and analyzed. Main Outcome Measures Best-corrected visual acuity (BCVA) and postoperative complications. Results Preoperative visual acuity ranged from 20/150 to light perception and was ≤20/400 in 38 eyes (95%). Preoperative diagnoses included failed corneal transplants (19 eyes, 47.5%), chemical injury (10 eyes, 25%), and aniridia (5 eyes, 12.5%). Mean follow-up duration was 33.6 months (range, 5–72 months). Of 36 eyes followed for ≥1 year, 32 eyes (89%) achieved postoperative BCVA ≥20/200. Of eyes that achieved BCVA ≥20/200, at last follow-up, 19 of 32 eyes (59%) followed for ≥1 year retained BCVA ≥20/200; 16 of 27 eyes (59%) followed for ≥2 years retained BCVA ≥20/200; 7 of 14 eyes (50%) followed for ≥3 years retained BCVA ≥20/200; and 2 of 7 eyes (29%) followed for ≥4 years retained BCVA ≥20/200. End-stage glaucoma most commonly caused vision loss (7 of 13 eyes, 54%) when BCVA ≥20/200 was not retained (follow-up ≥1 year). Glaucoma was newly diagnosed in 11 eyes (27.5%); progression was noted in 9 eyes (22.5%). Glaucoma drainage device erosion occurred in 9 eyes (22.5%). Retroprosthetic membrane formed in 22 eyes (55%), 5 eyes (12.5%) developed endophthalmitis, 6 eyes (15%) developed corneal melt, 7 eyes (17.5%) underwent keratoprosthesis replacement, and 23 eyes (57.5%) required major surgery to treat postoperative complications. The initial keratoprosthesis was retained in 32 eyes (80%). Conclusions Keratoprosthesis implantation remains a viable option for salvaging vision. A significant number of patients lost vision over the postoperative course. Glaucoma and complications related to glaucoma surgery are significant challenges to maintaining good vision after keratoprosthesis surgery. Our study highlights the need for long-term follow-up and a team approach to management, and points to a more guarded long-term visual prognosis after surgery. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.