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The rise of primary topical monotherapy with chemotherapeutic drugs and immunomodulatory agents represents an increasing recognition of the medical management of ocular surface squamous neoplasia (OSSN), which may replace surgery as the standard of care in the future. Currently, there is no consensus regarding the best way to manage OSSN with no existing guidelines to date. This paper seeks to evaluate evidence surrounding available treatment modalities and proposes an approach to management. The approach will guide ophthalmologists in selecting the most appropriate treatment regime based on patient and disease factors to minimize treatment related morbidity and improve OSSN control. Further work can be done to validate this algorithm and to develop formal guidelines to direct the management of OSSN. Published version Publication fees associated with this article have been funded through the ExxonmobileNUS grant awarded to Chris Lim.

Background Descemet's stripping endothelial keratoplasty (DSEK) is the most common procedure for corneal transplantation. The effect of a pre-existing glaucoma drainage device on long-term surgical outcomes is uncertain. Methods A retrospective chart review of all DSEK cases at an academic hospital over a 10-year period was conducted. Results 37 eyes who had undergone DSEK were included for analysis. These consist of 12 eyes with pre-existing GDD (GDD group), 13 eyes with glaucoma but no previous GDD (no-GDD group), and a control group of 12 patients with no ocular comorbidities apart from the indication for DSEK (control group). Visual acuity (VA) was significantly improved amongst all 3 groups, and there was no significant difference in VA between the GDD and no-GDD groups. There were no significant differences in absolute or increase in IOP between all three groups at 3 years. Graft survival rates of the 3 groups were not significantly different at 12 months. However, at 36 months, graft survival was 63% in the GDD group compared to 81% in the no-GDD group and 92% in the control group. In the GDD group, an increase in number of preoperative glaucoma drops, and a tube location in the anterior chamber were associated with an increased hazard ratio for failure. Conclusions Presence of a GDD adversely affects graft survival whereas glaucomatous eyes which were medically managed or surgically managed without a GDD had survival rates comparable to controls. Glaucoma-filtering surgeries may confer graft survival advantage over tube shunt surgeries after DSEK.

Corneal cross-linking (CXL) using riboflavin and ultraviolet A (UVA) light has become a useful treatment option for not only corneal ectasias, such as keratoconus, but also a number of other corneal diseases. Riboflavin is a photoactivated chromophore that plays an integral role in facilitating collagen crosslinking. Modifications to its formulation and administration have been proposed to overcome shortcomings of the original epithelium-off Dresden CXL protocol and increase its applicability across various clinical scenarios. Hypoosmolar riboflavin formulations have been used to artificially thicken thin corneas prior to cross-linking to mitigate safety concerns regarding the corneal endothelium, whereas hyperosmolar formulations have been used to reduce corneal oedema when treating bullous keratopathy. Transepithelial protocols incorporate supplementary topical medications such as tetracaine, benzalkonium chloride, ethylenediaminetetraacetic acid and trometamol to disrupt the corneal epithelium and improve corneal penetration of riboflavin. Further assistive techniques include use of iontophoresis and other wearable adjuncts to facilitate epithelium-on riboflavin administration. Recent advances include, Photoactivated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL) for treatment of infectious keratitis, customised protocols (CurV) utilising riboflavin coupled with customised UVA shapes to induce targeted stiffening have further induced interest in the field. This review aims to examine the latest advances in riboflavin and UVA administration, and their efficacy and safety in treating a range of corneal diseases. With such diverse riboflavin delivery options, CXL is well primed to complement the armamentarium of therapeutic options available for the treatment of a variety of corneal diseases.

Purpose To compare the outcome in patients with Fuchs endothelial dystrophy (FED) who underwent standard phacoemulsification vs femtosecond laser–assisted cataract surgery (FLACS) in the treatment of visually significant cataracts. Design Retrospective, comparative, interventional case series. Methods Patient or Study Population : Between April 2013 and December 2016, 140 FED eyes with cataracts of all densities were included. Seventy-two eyes underwent phacoemulsification and 68 eyes underwent FLACS. Intervention or Observation Procedures : Automated noncontact specular microscopy was performed at baseline and postoperatively over a mean of 17.91 ± 10.47 months. Parameters collected include visual acuity, slit-lamp examination findings, and intraoperative findings. Main Outcome Measures : Pachymetry, endothelial cell density (ECD), and coefficient of variance (COV) were compared. Results Phacoemulsification had significantly greater postoperative median loss of ECD of 229.0 cells/mm2 (14.2%) compared to FLACS ECD of 133.0 cells/mm2 (6.5%) (U = 1343.0, Z = -2.241, P = .025). Mean loss of ECD was 346.524 ± 420.472 cells/mm2 and 119.964 ± 434.882 cells/mm2 for phacoemulsification and FLACS, respectively (P = .005). Mean percentage loss of ECD was 15.3% ± 17.5% for phacoemulsification and 4.4% ± 25.0% for FLACS (P = .006). Eyes that underwent phacoemulsification had 10.7% ± 15.4% mean ECD loss in the mild cataract group, and in the moderate/hard cataract group 19.5% ± 18.0%, P = .045. Eyes that underwent FLACS had 0.9% ± 22.5% mean ECD loss in the mild cataract group, and 8.2% ± 26.3% in the moderate/hard cataract group, P = .291. Comparison between procedures of mean ECD loss for moderate/hard cataracts was significant (P = .043). Conclusions FLACS is shown to be superior to phacoemulsification in reducing postoperative endothelial cell loss in FED patients, which translates to a lower risk of corneal decompensation, especially in patients with moderate/hard cataract densities.

To study the effect of intraocular pressure (IOP) on refractive outcomes after deep anterior lamellar keratoplasty (DALK).This retrospective study included eyes which underwent DALK. DALK technique involved either modified Anwar big-bubble if possible or manual anterior lamellar dissection. Our main outcome measures are postoperative IOP and refractive outcomes at postoperative week and months 1, 3, 6, and 12.Fifty-nine eyes of 59 patients were included. DALK was performed for optical (93.2%) and tectonic (6.8%) purposes. 76.3% of the patients had keratoconus. Anwar's big-bubble technique was successful in 30 cases. Linear mixed-model was used to analyze the effect of the highest postoperative IOP measured prior to measurement of postoperative cylinder. Patients with greater maximum postoperative IOP measured had worse postoperative cylinder (Our study shows a positive correlation between postoperative IOP and worse spherical equivalent and cylinder post-DALK, emphasizing the need for good IOP control with IOP-lowering medication(s).

Purpose To investigate the disease patterns of Microbial Keratitis(MK) in patients seen in a tertiary referral hospital, to evaluate the clinical outcomes of MK and the risk factors for poorer visual outcomes. Methods This is a retrospective case series of all culture-positive corneal scrapings between April 2012 and October 2016. A total of 230 patients(n = 230) were included into this study. Patient demographics, clinical information and microbiological characteristics of organisms are collected. Results 64.3% of patients with MK are contact lens(CL) users. Among CL users, there is a preponderance of females(68.9%) and they tend to be younger (27.1 ± 10.6 years). The most frequently isolated organism in this study is Pseudomonas aeruginosa(51.7%) with 69.6% of cases belonging to CL users. MK in non-CL users tend to involve other organisms, such as coagulase-negative Staphylococci, Staphylococcus aureus and Streptococcus pneumoniae. Pseudomonas aeruginosa exhibits good sensitivity rates to ciprofloxacin, levofloxacin and gentamicin. Non-Pseudomonas organisms display similar sensitivities to ciprofloxacin, levofloxacin and gentamicin. MK in non-CL users is related to predisposing factors of prior ocular trauma and concomitant ocular pathology. They tend to have worse visual acuity(VA) on presentation and after treatment compared to CL users. Poorer VA outcome is associated with larger ulcers, increasing age, trauma and non-CL wearers. Successful clinical outcome is achieved in 97.8% of patients, with only 2.2% requiring further surgical intervention. Conclusion CL use alters the disease patterns of MK as well as the underlying microbiological etiology. Fluoroquinolones and aminoglycosides are good empirical antibiotics for MK treatment. Early referral to a tertiary centre will likely allow for earlier treatment, which can result in better VA outcome, especially so in patients who are older, non-CL wearers and have larger ulcers with associated trauma.

Introduction: This study aimed to describe and compare corneal graft survival and optical outcomes following deep anterior lamellar keratoplasty (DALK) and Descemet's stripping automated endothelial keratoplasty (DSAEK) with penetrating keratoplasty (PK), and to document tectonic success of patch grafts. Materials and Methods: This was a retrospective, non-randomised, comparative and descriptive cohort study. A total of 139 eyes that underwent primary keratoplasty between 2000 and 2016 were included, and the following data was extracted: demographics, clinical diagnosis and primary indication, pre- and intraoperative risk factors, postkeratoplasty outcomes, and complications. Optical success was defined as good graft clarity and best corrected visual acuity (BCVA) of 6/12 or better. Graft failure was defined as irreversible corneal oedema and loss of clarity. Tectonic success in patch grafts was defined as tectonic integrity with no repeat tectonic surgical procedure required in the postoperative period. Results: The mean follow-up duration was 3.24 ± 3.47 years in the PK group (n = 16), 1.89 ± 0.86 years in the DALK group (n = 37), 2.36 ± 1.24 years in the DSAEK group (n = 53), and 2.17 ± 1.09 years in the patch graft group (n = 33). The 3-year probabilities of survival for PK, DALK, DSAEK and patch graft were 60.9%, 94.1%, 89.9%, and 67.1%, respectively. The overall percentage of complications was significantly higher for PK (81.3%), compared to DALK (48.6%), DSAEK (49.1%), and patch graft (21.2%). In the PK and DALK groups, 100% achieved BCVA of 6/12 or better, while in the DSAEK group, 96.43% achieved BCVA of 6/12 or better. Conclusion: From a similar study cohort of Asian eyes, graft survival was superior and complications were reduced for DALK and DSAEK compared to PK, but optical outcomes were comparable. Graft survival for patch graft was expectedly lower, but the incidence of complications was low. Key words: Cornea, Keratoplasty, Survival