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Competing Interests: Competing interests: None declared.

Purpose: To evaluate the cases of corneal graft rejection following SARS-CoV-2 vaccination reported to Centers for Disease Control and Prevention Vaccine Adverse Event Reporting System., Methods: A descriptive analysis of the demographics, clinical history and presentation was performed. We evaluated the correlation between the vaccines and duration of vaccine-associated graft rejection (VAR) onset following vaccination using a one-way analysis of variance test. A post hoc analysis was performed between VAR onset-interval following vaccination dose and vaccine type. Finally, a 30-day cumulative incidence analysis was performed to assess the risk of VAR in short term following different doses, vaccines and type of corneal transplantation., Results: A total of 55 eyes of 46 patients were diagnosed with VAR following vaccination with BNT162b2 (73.91%) and mRNA-1273 (26.09%). The mean age of the patients was 62.76±15.83 years, and 28 (60.87%) were female. The patients diagnosed with VAR had undergone penetrating keratoplasty (61.82%), Descemet membrane endothelial keratoplasty (12.73%), descemet stripping endothelial keratoplasty (18.18%), anterior lamellar keratoplasty (3.64%) and corneal limbal allograft transplantation (1.82%). The mean time for VAR since penetrating and endothelial keratoplasty was 8.42±9.23 years and 4.18±4.40 years, respectively. 45.65% of the cases of VAR were reported after the second dose of vaccine. The duration of VAR onset was significantly shorter after the second dose compared with the first and booster doses (p=0.0165) and in patients who underwent endothelial keratoplasty compared with penetrating keratoplasty (p=0.041)., Conclusions: This study outlines a possible temporal relationship between corneal graft rejection and SARS-CoV-2 vaccination. An earlier onset of VAR was observed in patients who had a history of endothelial keratoplasty and following the second dose of vaccination., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To determine the degree of microbiological agreement between corneal scrapings and contact lens cultures in cases of contact lens-associated keratitis., Methods: Electronic medical records of all cases of contact lens-associated keratitis at a single institution from April 2006 to May 2019 were reviewed. Cases where both corneal scrapings and contact lens cultures were obtained were included in the study. Group 1 demonstrated agreement between corneal scrapings and contact lens cultures. Group 2 demonstrated growth on both cultures, but disagreement in isolated organism. Group 3 demonstrated negative corneal cultures but growth on contact lens cultures and the diagnostic yield of contact lens microbiological cultures and agreement between corneal and contact lens cultures., Results: A total of 80 eyes of 72 patients were included in the study. 135 total incidences of microbiological results were included for data analysis. Group 1 contained nine incidences (6.7%), group 2 contained 60 incidences (44.4%) and group 3 contained 66 incidences (49%). In group 3, 50% of the cases were treated based on contact lens culture data. There was no statistically significant difference between all three groups in terms of baseline characteristics, presenting vision, vision at last follow-up, number of antibiotics used or complications from keratitis. Pseudomonas was the most common microorganism isolated, and in 89% of these cases, there was disagreement between corneal and contact lens cultures., Conclusions: Although there was a disagreement in the microbiological yield between contact lens and corneal cultures, contact lens cultures were useful in management of patients while achieving similar outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: We aimed to investigate the refractive changes in the posterior corneal surface in keratoconus (KC) associated with wearing spherical corneal rigid gas-permeable contact lenses (corneal GPs) with apical touch or three-point touch fitting and the effect of spherical corneal GPs on corneal biomechanics., Methods: Patients with KC wearing corneal GPs every day without facing complications were enrolled as a single group. Corneal tomographic data were obtained using a three-dimensional anterior segment optical coherence tomography from the same eye with and without corneal GPs. Dioptric data from the central 3-mm zone of the posterior corneal surface were decomposed into spherical, regular astigmatism, asymmetry and higher-order irregularity components using Fourier harmonic analysis. The corneal biomechanical indices were deformation amplitude ratio within 2 mm, integrated radius, stiffness parameter at first applanation and linear Corvis Biomechanical Index. Correlations between the difference in Fourier indices with and without corneal GPs and the corneal biomechanical parameters were analysed., Results: Thirty-two eyes of 32 patients with KC were enrolled. Spherical, regular astigmatism and asymmetry components were significantly smaller with corneal GP wear than without the wear (all p<0.001). All biomechanical indices were significantly correlated with the difference in the spherical components with and without corneal GPs., Conclusion: Corneal biomechanical properties of KC were correlated with posterior corneal surface flattening induced by wearing corneal GPs on the spherical components. This effect is greater in biomechanically weaker corneas., Competing Interests: Competing interests: SK received fees from Oculus (Wetzlar, Germany) for a sponsored seminar, which was not related to this study. RI is an employee of SEED CO., LTD. (Tokyo, Japan). None of the other authors or their family members have any proprietary or financial interests in any of the material or instruments mentioned in this article., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: To compare the efficacy of compression sutures combined with intracameral air injection (CSAI) and thermokeratoplasty (TKP) for the management of acute corneal hydrops in keratoconus., Methods: In this multi-centre randomised clinical trial, 20 patients with keratoconus (20 eyes) with acute corneal hydrops were enrolled and randomised to receive either CSAI or TKP and followed-up for a period of 6 months., Results: There were no significant differences in patient demographics, severity of corneal hydrops and preoperative duration of symptoms between the two groups. In both groups, corneal oedema resolved within 2 weeks. The maximum thickness of the corneal scars following CSAI and TKP was not significantly different. Best spectacle-corrected visual acuity was superior in the CSAI group at 6-month follow-up (CSAI vs TKP, 0.52 (0.37, 0.85) vs 0.96 (0.70, 1.34) LogMAR, p=0.042). CSAI resulted in greater corneal endothelial cell density (CSAI vs TKP, 2677.8±326.7 vs 1955.3±298.1 cells/mm 2 , p<0.001) and flatter corneal curvature (CSAI vs TKP: mean keratometry value, 52.13±4.92 vs 63.51±5.83D, p<0.001; maximum keratometry value, 65.21±7.42 vs 77.13±12.01D, p=0.016) at the 6-month follow-up., Conclusion: Although both CSAI and TKP resulted in resolution of acute corneal hydrops in keratoconus, CSAI was associated with superior clinical outcomes in this study., Chinese Clinical Trial Registration Number: ChiCTR-IOR-17013764., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: To investigate the chronological corneal changes associated with long-term rigid gas-permeable contact lens (RGP-CL) wear in patients with keratoconus (KC)., Methods: Clinical records of 405 patients with KC or with KC suspect were retrospectively reviewed. Patients with mild-to-moderate KC and uneventful follow-up were classified into the CL (RGP-CL wear) and non-CL (without CL wear) groups. Inclusion criteria were (1) at least 3-year follow-up and (2) Scheimpflug-based corneal imaging examination at each visit. The anterior (ARC) and posterior (PRC) radius of curvature obtained in a 3.0 mm optical zone, the thinnest pachymetry reading of the corneal thickness (Tmin), and maximum keratometry values (Kmax) were investigated as tomographic parameters., Results: Twenty-two and 15 patients who met the inclusion criteria were included in the CL and non-CL groups, respectively (31 and 20 eyes, respectively). The mean observation periods were 75 (CL group) and 63 (non-CL group) months. A multivariable non-linear regression analysis to assess the change in tomographic parameters over the follow-up period and difference of the trend between the two groups demonstrated no significant differences in the chronological change in ARC, PRC and Tmin between the CL and non-CL groups (p=0.318, p=0.280 and p=0.874, respectively)., Conclusion: Based on corneal tomographic evaluation over 5-6 years, the effects of long-term RGP-CL wear had no effect on KC progression., Competing Interests: Competing interests: SK and NM received fees from Oculus for a sponsored seminar, not related to this article. RI is an employee of SEED Co. None of the other authors or their family members have any proprietary or financial interests in any of the material or instruments mentioned in this article., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Fungal infection after corneal transplantation is a rare, yet potentially devastating, postoperative complication and has become a growing concern for the transplant surgeon and eye banking community. The Eye Bank Association of America (EBAA) has reported an increasing trend in the rate of postkeratoplasty fungal infections and a reversal in the previously documented predominance of bacterial over fungal infections. Additionally, several studies have confirmed a high correlation between positive corneoscleral donor rim fungal cultures and postoperative infections. Optisol GS (Bausch & Lomb, Irvine, California, USA), the most extensively used corneal storage solution in US eye banks, does not currently contain any antifungal supplementation. Although large randomised control trials evaluating the efficacy and safety of routine antifungal supplementation to corneal storage solution are lacking, several investigative studies have assessed the role of antifungal agents in reducing fungal contamination of donor corneas without causing undue corneal toxicity. This review will present the current epidemiology of postkeratoplasty fungal infections and evidence for obtaining routine fungal rim cultures and antifungal supplementation of storage solution., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: None declared.

Objective: To investigate the associations between 16 single-nucleotide polymorphisms (SNPs) in 14 genetic loci and keratoconus in an independent Chinese cohort., Methods: This cross-sectional, case-control association study included a Chinese cohort of 133 patients with keratoconus and 371 control subjects. In a recent meta-analysis study, we identified association of 16 SNPs in 14 gene loci with keratoconus. In this study, we genotyped these 16 SNPs in all the patients and controls and analysed their association with keratoconus, its clinical severities and progression profiles. We also analysed the genotype-phenotype correlation between individual SNPs and steep keratometry, flat keratometry (Kf), average keratometry (Avg K) and best-fit sphere diameter (BFS) of the anterior and posterior corneal surface., Results: Among the 16 selected SNPs, rs1324183 in the MPDZ-NF1B locus showed a significant association with keratoconus (OR=2.22; 95% CI 1.42 to 3.45, p=4.30×10 -4 ), especially severe keratoconus (OR=5.10, 95% CI 1.63 to 15.93, p=0.005). The rs1324183 A allele was positively associated with anterior Kf (p=0.008), anterior Avg K (p=0.017), posterior Kf (p=0.01) and negatively associated with apex pachymetry (p=0.007) and anterior BFS (p=0.023) in keratoconus. The other 15 SNPs had no significant association with keratoconus or genotype-phenotype correlations., Conclusions: This study confirmed the association of SNP rs1324183 in MPDZ-NF1B with keratoconus and revealed the association of this SNP with keratoconus severity and corneal parameters. It is thus a putative genetic marker for monitoring the progression of keratoconus to a severe form and facilitating early intervention., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: To compare the rate of disease progression in keratoconus before and after corneal collagen crosslinking (CXL)., Methods: 145 eyes were followed without CXL (no-CXL group) for a median duration of 31 months whereas 45 eyes were followed up for 41 months before (pre-CXL) and after (post-CXL) accelerated, epithelium-off crosslinking. Progression was defined based on significant slope found in linear mixed effect models against time. Swept-source optical coherence tomography was used for measurement of anterior steep keratometry, anterior flat keratometry (Ant Kf), anterior average keratometry (Ant Avg K); posterior steep keratometry, posteriorflat keratometry (Post Kf), posterior average keratometry (Post Avg K) and corneal thickness., Results: The patients in pre-CXL group were significantly younger (26.3±5.48 years) compared with the patients in no-CXL group (32.7±10.24 years) (P=0.004). Significant differences were observed during baseline examination for all parameters (P≤0.035) between pre-CXL and no-CXL groups except Ant Cyl and Post Cyl. During observation period, statistically significant differences were noted between pre-CXL and no-CXL groups in the progression rate of Ant Kf, Ant Avg K, Post Kf and Post Avg K (P≤0.045). After CXL, the progression rate in post-CXL group was comparable to that in no-CXL group. All corneal parameters remained stable in no-CXL group throughout the follow-up period., Conclusions: Serial tomographic examination is useful to document disease progression before and after CXL. In our study, a decrease in progression rate of corneal parameters was noted after CXL. In cases with stable corneal parameters over time, careful monitoring can be considered instead of collagen crosslinking., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: We described a modified 'hydroexpression' technique for the lenticule removal during small-incision lenticule extraction (SMILE) surgery and compared the results with conventional forceps method., Methods: This was a retrospective, comparative study of 50 patients who underwent SMILE surgery by the same surgeon. We compared the 1-week and 3-months postoperative results after SMILE using the hydroexpression technique with the conventional forceps technique. Main outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive accuracy, safety index and efficacy index., Results: The baseline characteristics were comparable between both groups. At postoperative 1 week, the safety index in forceps and hydroexpression group was 0.93±0.11 and 0.97±0.10, respectively (P=0.246). At 3 months, they were 1.00±0.06 and 0.99±0.09 (P=0.850). For efficacy indices, at 1 week they were 0.84±0.17 and 0.91±0.17 (P=0.158). At 3 months, they were 0.92±0.13 and 0.94±0.19 (P=0.624). All eyes aimed for a plano target. 96% in forceps group and 90% in hydroexpression group were within ±0.50 dioptre (D) in spherical equivalent refraction (SEQ) correction at postoperative 3 months (P=0.567). The mean errors of SEQ correction were -0.10±0.21 D in forceps group and -0.08±0.30 D in hydroexpression group (P=0.705)., Conclusion: Hydroexpression was simple and safe and had early results comparable to the conventional forceps technique. This technique was particularly useful for cases with more adhesions between lenticule and anterior cap, thin lenticule cases and for the inexperienced SMILE surgeons., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

New advances in imaging allow objective measurements for dry eye as well as define new parameters that cannot be measured by clinical assessment alone. A combination of these modalities provides unprecedented information on the static and dynamic properties of the structural and functional parameters in this multifactorial disease. A literature search was conducted to include studies investigating the use of imaging techniques in dry eye disease. This review describes the application of non-invasive tear breakup time, optical coherence tomography, meibomian gland imaging, interferometry, in vivo confocal microscopy, thermography and optical quality assessment for this condition., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Aim: To compare the diagnostic ability of corneal tomography and corneal dynamic response measurements in normal and keratoconus eyes., Methods: Consecutive patients with grade II-III keratoconus and age-matched normal subjects were recruited. Corneal imaging was performed using Pentacam (Oculus Optikgeräte, Wetzlar, Germany) and Corvis (Oculus Optikgeräte). A beta version of Corvis software was used with three additional parameters: maximal change of arc length, deformation amplitude (DA) ratio 1 and DA ratio 2. Diagnostic ability of both devices to differentiate normal and keratoconus eyes was evaluated using receiver-operating characteristic (ROC) curves. The areas under the ROC curve (AUC) and partial AUC (pAUC) for specificity ≥80% for each parameter of Corvis and final D value of Belin/Ambrosio Enhanced Ectasia Display (BAD) were compared., Results: Forty-two eyes of 42 patients (21 patients with keratoconus and 21 normal subjects) were included. Both groups were age matched (p=0.760). The ROC analysis showed that the final D value of BAD had the highest AUC (0.994) and pAUC (0.194). Maximum inverse radius had the highest AUC (0.954) but a relatively lower pAUC (0.158), while DA ratio 2 had the second highest AUC (0.946) together with the highest pAUC (0.177) among Corvis parameters. There was no significant difference between AUC and pAUC of BAD compared with those of DA ratio 1 (p≥0.162) and DA ratio 2 (p≥0.208)., Conclusions: The results of our study suggest that Corvis measurements have the potential to differentiate keratoconus and normal eyes. The diagnostic ability of novel parameters on Corvis was comparable to Pentacam., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Aim: Corneal keratectasia is one of the complications associated with laser in situ keratomileusis (LASIK) that results in vision impairment. The pathogenesis of post-LASIK ectasia (PLE) remains underexplored. We report the tear cytokine profile and in vivo confocal microscopy (IVCM) findings in eyes with PLE., Methods: This retrospective study included age-matched 7 (14 eyes) post-LASIK controls (PLCs) and 6 (12 eyes) PLE subjects. Corneal topography was used to categorise the subjects into PLC and PLE groups. Ocular Surface Disease Index (OSDI) scores obtained were based on standard questionnaire and IVCM images were used to determine corneal dendritic cells density (DCD) and sub-basal nerve plexus morphology. Inflammatory cytokines/chemokines in the tears were quantified using flow cytometry based cytometric bead array., Results: Pentacam-based scores, OSDI scores and corneal DCD were significantly (p<0.05) higher in patients with PLE compared with PLC. Discomfort-related subscale of OSDI score exhibited a positive correlation with total corneal DCD in the PLE cohort. The fold difference of chemokine (C-C motif) ligand/monocyte chemotactic protein-1 (CCL2/MCP1) (3.4±0.6) was found to be significantly (p<0.05) higher in the PLE cohorts and a positive correlation between CCL2/MCP1 levels and total corneal DCD was also observed in the PLE cohort., Conclusion: The current study found a significant difference in the tear film cytokine profile between normal and PLE eyes. Presence of increased corneal dendritic cells and altered tear cytokines suggests an ongoing inflammatory response in PLE., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objectives: To evaluate and compare the change in corneal biomechanical properties after microincision lenticule extraction (MILE) and small incision lenticule extraction (SMILE)., Methods: In this prospective study, 60 eyes received MILE surgery with 2 mm opening incision, while 64 eyes received SMILE procedure with 5 mm opening incision. Corneal hysteresis (CH), corneal resistance factor (CRF) and 37 other biomechanical waveform parameters were quantitatively assessed using ocular response analyser (ORA) preoperatively and up to 6 months postoperatively. All changes were calculated as the difference between preoperative and postoperative values (Δ)., Results: Both CH and CRF values decreased significantly after MILE and SMILE (p<0.001). ΔCRF (o=0.028) and ΔCRF index (ΔCRF/preoperative CRF) (p=0.043) were statistically lower for all eyes at 1-week follow-up. ΔCH index (ΔCH/preoperative CH) was statistically lower at 1-week (p=0.043) and 1-month (p=0.015) follow-ups in MILE group when compared with SMILE group. In both MILE and SMILE group, ΔCH index and ΔCRF index were positively correlated with preoperative manifest refraction spherical equivalent, residual stromal thickness (RST) index (RST/preoperative central corneal thickness) and negatively correlated with lenticule thickness (p<0.05)., Conclusions: Both MILE and SMILE procedures significantly altered the biomechanical characteristics of cornea. Smaller opening incision was associated with less reduction in ORA parameters during early postoperative period., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Purpose: To longitudinally compare the visual and refractive outcomes and changes in corneal thickness between femtosecond-assisted sub-Bowmen keratomileusis (SBK) and photorefractive keratectomy (PRK) with mitomycin C in eyes with high myopia., Methods: Patients with spherical equivalent ≥6 dioptres (D) who underwent femtosecond-assisted SBK or PRK with mitomycin C were recruited. All patients were examined preoperatively and after 1 week, and, 1, 3, 6 and 12 months postoperatively. Assessments included uncorrected and best-corrected distance visual acuity , and manifest refraction spherical equivalent. Corneal thickness was measured using swept source optical coherence tomography., Results: A total of 110 eyes were included (68 PRK, 42 SBK). Change in efficacy index and safety index was not significantly different between both groups beyond 1 week postoperatively (p≥0.116). Manifest refraction spherical equivalent changed significantly from -9.02±1.92 D preoperatively to -0.21±0.31 D and from -8.25±1.10 D preoperatively to -0.53±0.55 D at 1 year after PRK and SBK, respectively (p<0.0001). The variance of postoperative refraction was significantly smaller after PRK throughout the 1-year follow-up compared with SBK (p≤0.0024). The central corneal thickness stabilised at 1 week after PRK and 3 months after SBK., Conclusions: Our study showed that femtosecond-assisted SBK and PRK with mitomycin C have comparable safety and efficacy for correction of high myopia. However, better predictability of postoperative refraction was noted after PRK compared with SBK., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Aim: To evaluate the performance of a point-of-care test for detection of matrix metalloproteinase 9 (MMP-9) levels in post-laser-assisted in situ keratomileusis (LASIK) dry eyes., Methods: A comparative study between patients with mild to moderate post-LASIK dry eyes and age-matched normal subjects was conducted. Ocular surface disease index (OSDI), tear break-up time (TBUT), and tear film MMP-9 and total protein levels were compared between the two groups. A point-of-care test device (RPS InflammaDry, Sarasota, Florida, USA) was utilised to confirm elevated MMP-9 levels in tear film., Results: Fourteen post-LASIK dry eyes and 34 normal eyes were included. There was no significant difference in age and gender between both groups (p>0.175). The OSDI was significantly higher (25.5±7.7 vs 7.4±2.5; p<0.001) and TBUT levels were significantly lower (5.4±0.9 vs 13.5±2.3; p<0.001) in patients with dry eye compared with normal subjects. The tear film MMP-9 levels were 52.7±32.5 ng/mL in dry eyes and 4.1±2.1 ng/mL in normal eyes (p<0.001). MMP-9 levels were >40 ng/mL in 7/14 (50.0%) post-LASIK dry eyes. The InflammaDry was positive in 8/14 (57.1%) post-LASIK eyes. All positive cases had tear film MMP-9 levels ≥38.03 ng/mL. Agreement between InflammaDry and MMP-9 was excellent with Cohen κ value of 0.857 in post-LASIK dry eyes., Conclusions: Only half of post-LASIK dry eyes were found to have significant inflammation associated with elevated MMP-9. The OSDI is useful to non-specifically identify patients with symptomatic dry eye while the InflammaDry determined which patients with dry eye were associated with significant inflammation that may guide therapeutic management decisions., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Aim: To compare astigmatic correction between femtosecond-assisted laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE)., Methods: A total of 111 patients were included in this prospective study. Fifty-seven eyes were treated with LASIK and 54 eyes were treated with SMILE for myopia with low to moderate (-0.25 to -4.0 D) astigmatism. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity and manifest refraction were measured preoperatively and at 1 and 3 months postoperatively. Visual and refractive outcomes were reported. Changes in refractive astigmatism were evaluated using vector analysis., Results: Preoperative characteristics were similar between both groups. The UDVA at 1 and 3 months was better in the LASIK group compared with the SMILE group (p<0.009). Postoperative cylinder was higher in the SMILE group (p<0.001). Fewer eyes attained the attempted cylindrical correction in the SMILE group (p<0.029). Vector analysis showed no significant difference in target-induced astigmatism (p=0.091) and angle of error (p>0.596) between the two groups. Surgically induced astigmatism was significantly lower in the SMILE group (p<0.023), while the difference vector (p<0.001) and absolute angle of error (p<0.016) were significantly higher in the SMILE group. No significant difference was found in these parameters between 1 and 3 months in both groups (p>0.122)., Conclusions: Our results showed that SMILE offered a less favourable astigmatic correction comparable to femtosecond-assisted LASIK in eyes with low to moderate myopic astigmatism. The alignment of treatment was more variable in SMILE, leading to a lower efficacy compared with LASIK by 3 months postoperatively., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Purpose: To compare the visual outcomes of aspheric toric intraocular lens (IOL) implantation and limbal relaxing incisions (LRI) for management of coexisting age-related cataracts and astigmatism., Methods: In this prospective study, sixty eyes of 60 patients with visually significant cataract and coexisting corneal astigmatism ≤3 dioptres (D) were randomised to undergo phacoemulsification with either aspheric toric IOL or aspheric monofocal IOL with LRI. The main outcome measures were postoperative 3-month uncorrected visual acuity (UCVA), contrast sensitivity, rotational stability of the toric IOL and spectacle independence., Results: The postoperative UCVA, contrast sensitivity and refractive astigmatism were significantly better than the baseline measurements for both groups (p≤0.001). There was no significant difference detected for these parameters between LRI and toric IOL groups postoperatively (p≥0.119). At both postoperative month 1 and 3, the percentages of eyes in need of spectacles were lower in toric group than LRI group (p≤0.030). IOL misalignment was noted in three eyes in the toric IOL group (mean misalignment 7.67±4.04°). On vector analysis, magnitude of error (ME) was negative in the LRI group indicating undercorrection, whereas the ME was close to zero for toric group., Conclusions: Both toric IOL implantation and LRI were effective in correcting corneal astigmatism ≤3 D during phacoemulsification, while LRI tended to undercorrect astigmatism., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Corneal ectasias include a group of disorders characterised by progressive thinning, bulging and distortion of the cornea. Keratoconus is the most common disease in this group. Other manifestations include pellucid marginal degeneration, Terrien's marginal degeneration, keratoglobus and ectasias following surgery. Advanced ectasias usually present with loss of vision due to high irregular astigmatism. Management of these disorders is difficult due to the peripheral location of ectasia and associated severe corneal thinning. Newer contact lenses such as scleral lenses are helpful in a selected group of patients. A majority of these cases requires surgical intervention. This review provides an update on the current treatment modalities available for management of advanced corneal ectasias., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background/aims: To compare the long-term outcomes of primary pterygium surgery with combined conjunctival rotational autograft and mitomycin C (CRA-MMC), mitomycin C alone (MMC) and limbal conjunctival autograft (LCAU)., Methods: The outcomes of primary pterygium excision followed by conjunctival rotational autograft (CRA) combined with intraoperative 0.02% MMC for 5 min (group 1, CRA-MMC, n=61) were compared with historical control groups consisting of, pterygium excision with MMC (group 2, n=47), and, pterygium excision with limbal conjunctival autograft (LCAU) (group 3, n=29). The main outcome measures were recurrence rate and complications., Results: The mean follow-up period was 101±3 months, 138±2 and 137±2 months in the CRA-MMC, MMC and LCAU groups respectively. Recurrence was noted in one patient (1.6%) in the CRA-MMC, 12 patients with MMC (25.5%) and 2 patients with LCAU (6.9%). The difference in recurrence rate between CRA-MMC and MMC was statistically significant (p<0.001). Early postoperative complications included 3 conjunctival cysts (1 from the CRA-MMC, 2 with MMC alone), 2 symblephara (1 in the MMC group, 1 in the LCAU group), and 1 granuloma in the CRA-MMC group., Conclusions: Pterygium excision followed by CRA-MMC or LCAU are effective means of preventing recurrence. The use of CRA-MMC in pterygium excision may be considered for cases where conventional autograft harvesting is contraindicated or when large grafts for double-head pterygium are required., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Purpose: To comparatively evaluate the image quality in normal and forme fruste keratoconus patients using a double-pass system., Methods: Fourteen normal eyes and 15 eyes with forme fruste keratoconus were included. Corneal tomographic parameters were obtained with optical coherence tomography. Image quality characteristics were determined by an optical quality analysis system (OQAS). Two readings were obtained from each eye. The following parameters were analysed: modulation transfer function cutoff frequency (MTF), Strehl ratio and OQAS values (OV) at contrasts of 100% (OV-100), 20% (OV-20) and 9% (OV-9). Repeatability coefficient (RC), coefficient of variation (CVw) and intraclass correlation coefficient (ICC) were evaluated., Results: There were no significant differences in central corneal thickness, anterior best-fit sphere and posterior best-fit sphere in both groups. There was a significant difference between the mean MTF (p=0.001), Strehl ratio (p<0.001), OV-100 (p=0.001), OV-20 (p<0.001) and OV-9 (p<0.001) values between both groups. The coefficients of variation were 4.10 (MTF) and 13.77 (Strehl ratio) in normal eyes and 14.53 (MTF) and 14.97 (Strehl ratio) in eyes with forme fruste keratoconus. The ICC values were 0.99 and 0.95 for MTF and, 0.80 and 0.91 for Strehl ratio, in normal and forme fruste keratoconus eyes, respectively. The corresponding repeatability values were 3.53 and 6.15 for MTF and, 0.06 and 0.04 for Strehl ratio, respectively., Conclusions: OQAS has the potential to be a useful diagnostic tool in cases with early keratoconus. The repeatability of a double-pass (DP) system was good in normal as well as forme fruste keratoconus eyes., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Purpose: To describe the outcomes of cataract surgery in adult patients with Down's syndrome at a tertiary eye hospital in Hong Kong., Methods: Retrospective case-file analysis was performed to identify patients with Downs's syndrome who underwent cataract surgery between January 2002 and December 2012. Morphology of cataract, associated ocular features and surgical and visual outcomes were analysed., Results: Cataract surgery was performed in 33 eyes of 20 patients (12 males, 8 females, mean age 42.9±10.6 years) over a 10-year period. Nine patients (9/20, 45.0%) had bilateral cataracts at the time of diagnosis. White cataracts were noted in 12 eyes of 10 patients (12/33, 36.3%) at the time of presentation. Associated ocular problems included myopic maculopathy (18 eyes, 54.5%), keratoconus (12 eyes, 36.3%), nystagmus (2 eyes, 6.0%), corneal scar (2 eyes, 6.0%) and glaucoma (2 eyes, 6.0%). Five eyes (15.1%) underwent extracapsular cataract extraction whereas a phacoemulsification was performed in 28 (84.9%) eyes. Intraocular lens implantation was performed in 32/33 eyes. The most common postoperative complication was posterior capsular opacification (8 eyes, 24.2%). The mean best-corrected visual acuity improved from 0.07±0.11 preoperatively to 0.17±0.19 at 3 months postoperatively (p=0.000)., Conclusions: A high incidence of bilateral cataracts as well as white cataracts was observed in patients with Down's syndrome in our study. Although the surgical outcomes of cataract surgery were good, the visual outcomes were suboptimal in our cases due to associated ocular comorbidities., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aim: To compare the efficacy of alcohol delamination (ALD) and phototherapeutic keratectomy (PTK) for the treatment of recurrent corneal erosion syndrome (RCES) in a prospective, randomised, controlled trial., Methods: Patients with RCES not responding to conservative treatment were recruited and randomised to undergo ALD or PTK. Patients were masked to their treatment group. The primary outcome measure was the intensity of pain on waking, using a numerical rating scale between 0 and 10 to record a subjective pain score., Results: 17 eyes were treated with ALD and 16 eyes were treated with PTK. The mean follow-up period was 16.25 and 17.25 months, respectively. There were no differences in baseline parameters or pain scores at 3, 6, 12 and 24 months between the groups. The pain score improved from baseline at 3 months (ALD, p=0.022; PTK, p=0.014) and 6 months (ALD, p=0.033; PTK, p=0.036) in both groups, but only in the ALD group at 24 months (ALD, p=0.035; PTK, p=0.500). Overall, there was complete or partial resolution of symptoms in 11 (65%) eyes in the ALD group and 10 (63%) eyes in the PTK group. Recurrence of symptoms was observed in five eyes in the ALD group and six eyes in the PTK group. There was one treatment failure in the ALD group. There were no long-term complications., Conclusions: ALD should be considered as an alternative treatment for the management of RCES with promising results compared with PTK.

An 80-year-old Chinese man with high myopia and a history of right eye cataract extraction and superior peripheral iridectomy developed peripheral corneal oedema after a period of aphakia. The peripheral corneal oedema was static over years and did not progress to involve central cornea hence his visual acuity remained stable. The condition was compatible with the relatively rare Brown-McLean syndrome. Specular microscopy showed normal endothelial cell density in the oedematous peripheral as well as central cornea. While anterior segment optical coherence tomography demonstrated the cross-sectional architecture of cornea, Scheimpflug imaging was used to measure the peripheral corneal thickening and to demonstrate increased corneal density as compared with the contralateral normal eye. These investigations not only help better characterise the rare disease, but also in precisely monitoring any disease progression by periodic measurements.

A 60-year-old Chinese patient was seen multiple times in the ophthalmology outpatient department due to persistent anterior-chamber inflammation and raised intraocular pressure. The patient was being treated with topical corticosteroids and oral acyclovir. Signs of corneal endotheliitis were observed in subsequent follow-ups. A clinical diagnosis could be made on slit-lamp examination, but aetiology could not be specified. An anterior-chamber diagnostic tap performed 18 months after the initial presentation revealed cytomegalovirus (CMV). Prompt response was noted with oral valganciclovir treatment. Our case highlights the importance of performing anterior-chamber tap in cases with persistent anterior-chamber inflammation. There was a long interval between the presentation and diagnosis mainly due to the absence of any concurrent ocular signs. An anterior-chamber tap was delayed until the ocular signs were suggestive of CMV endotheliitis. Timely diagnosis in such cases can improve the outcome as well as the prognosis.

Aims: To describe a new technique of corneal stab incision with intracameral air injection for management of patients with acute corneal hydrops., Methods: Five patients with acute corneal hydrops with large Descemet's membrane (DM) detachment and multiple stromal clefts underwent the procedure. The technique entailed anterior segment optical coherence tomography guided intrastromal fluid drainage through multiple corneal stromal venting incisions along with anterior chamber air tamponade. The time taken for the DM to reattach, resolution of corneal oedema and the best-corrected visual acuity (BCVA) were assessed postoperatively., Results: Five patients (age range, 10-25 years) with large DM detachment underwent the procedure. The presenting visual acuity varied from hand motions close to face to 1/60. No intraoperative complications were encountered. The DM attached on first postoperative day in four out of five cases. The corneal oedema resolved over 2-3 weeks in all cases. Repeat air injection was not required in any of the cases. All patients had a final BCVA of ≥3/60 with two of them achieving a BCVA of ≥6/24 at three months postoperatively., Conclusions: The technique of intrastromal drainage of fluid combined with air tamponade can be effectively used as a treatment modality for the management of severe cases of acute corneal hydrops.

Aims: To report the refractive error difference (RED) between parents and their children and the estimated single generational myopic shift in an urban area in China., Methods: 395 children aged 6-17 years and their parents, who had been enrolled in the Beijing Myopia Progression Study were included. Cycloplegic and non-cycloplegic refraction of the children and parents were performed, respectively. RED was defined as the difference between the average parental spherical equivalent (SE) and the average SE of their children. Binomial fitted curves of RED were plotted as a function of the children's age. Generational myopic shift was defined as the estimated RED according to the prediction model at the age of 18 years., Results: 395 families were enrolled. The RED was positively correlated with the children's age (rspearman=0.58, p<0.001). The RED (median (25th and 75th percentile)) was -1.88 (-3.23 to -1.00) dioptres (D) in children at 6.0-7.9 years of age, and it increased to 1.53 (-0.12 to 3.44) D in children at 16.0-17.9 years of age. The SE of the children approached the average SE of their parents at the age of 11 years. At the age of 18 years, the children's estimated myopic shift would be 1.94 D., Conclusions: In this sample, children's refractive errors at the age of 11 years were already similar to their parents. Moreover, the estimated myopia in children at the age of 18 years would be up to 2.0 D higher than their parents. This remarkable single-generation myopic shift indicates that there are likely effects of environmental factors on myopia development in urban Chinese children.

Purpose: To analyse the types of systematic reviews and meta-analyses published in the field of ophthalmology., Methods: The systematic reviews and meta-analysis in ophthalmology published in peer-reviewed journals were retrieved. The distribution of systematic reviews and meta-analyses in various ophthalmic subspecialties, type of study and country of origin were determined., Results: A total of 533 records were identified as systematic reviews and meta-analysis in ophthalmology. Overall, retina and glaucoma were the two major subspecialties accounting for 35% and 21% of the published systematic reviews and meta-analyses, respectively. The major topics published in retina were age-related macular degeneration (37%), tumours (14%), and diabetic retinopathy (12%). More than half (56%) the systematic reviews and meta-analyses were interventional. The author affiliations of these studies were largely from the USA (30%) and the UK (22%). About 60% of the systematic reviews and meta-analyses were published in ophthalmology journals, followed by the Cochrane Library (15.75%) and other non-ophthalmic journals (25.14%), respectively. The number of publications increased from 3 per year in 1994 to almost 100 per year in 2010., Conclusions: The number of published systematic reviews and meta-analyses has been increasing progressively over the past few years. Retina and glaucoma are the two most commonly published topics. Non-ophthalmology journals form a sizeable proportion of avenues for ophthalmic publications.

Aim: To determine if residual corneal stroma remains on the recipient posterior lamella in big-bubble deep anterior lamellar keratoplasty (DALK)., Methods: Pneumodissection using the big-bubble technique was carried out on eye-bank corneas mounted on an artificial anterior chamber. Samples that had a successful big-bubble formation were sent for histological evaluation to determine if any residual stroma remained on the Descemet membrane (DM)., Results: Big-bubble formation was achieved in 32 donor corneas. Two distinct types of big-bubble were seen: the bubble had either a white margin (30 corneas) or a clear margin (two corneas). The posterior lamellae of all the white margin corneas showed residual stroma on DM with a mean central thickness of 7.0 μm (range 2.6-17.4 μm). The clear margin corneas showed no residual stroma on DM., Conclusion: It should no longer be assumed that big-bubble DALK, where the bubble has a white margin, routinely bares DM. True baring of DM may only occur with the less commonly seen clear margin bubble.

Aim: To explore the antiangiogenic property of isoliquiritigenin (ISL) on in vivo and in vitro models., Design: Laboratory investigation., Methods: The effect of ISL on angiogenesis development was investigated using ex ovo chick chorioallantoic membrane model. Its effect on pathological angiogenesis was examined by (1) silver nitrate cauterisation-induced corneal neovascularisation in BALB/c mice, followed by topical ISL (0.2-50 μM) and CD31 immunofluorescence of corneal blood vessels; (2) argon laser photocoagulation-induced choroidal neovascularisation in C57BL/6 mice, followed by intravitreal ISL (10-200 μM) and fundus fluorescein angiography and immunofluorescence with Griffonia simplicifolia isolectin-B4 (GSA I-B4); and (3) oxygen-induced retinopathy in C57BL/6J mice pups, followed by intravitreal ISL (1-100 μM) and GSA I-B4 immunofluorescence. The vascular area was quantified and analysed by one-way analysis of variance and Student t test. Expression of vascular endothelial growth factor (VEGF) and pigment-epithelium-derived factor in human umbilical vein endothelial cells was analysed by western blotting., Results: Ex ovo chick chorioallantoic membrane assay showed that ISL dose-dependently suppressed VEGF-induced vessel growth. In vivo experiments illustrated that topical ISL alleviated corneal neovascularisation (IC(50)=7.14 μM, day 7) and intravitreal ISL reduced vessel leakage and GSA I-B4-positive vascular area in choroidal and retinal neovascularisation. ISL was found to dose-dependently suppress VEGF and induce pigment epithelium derived factor expression in cultured endothelial cells., Conclusion: Using various experimental models of ocular neovascularisation, the authors have demonstrated that ISL from licorice extract has an antiangiogenic effect. The authors' findings suggest that ISL may be a potential antiangiogenic molecule in the development of therapy for neovascularisation diseases.

Keratoconus is an ectatic corneal dystrophy and is a leading indication for corneal transplantation surgery worldwide. The disease was first described in detail more than 150 years ago by Dr John Nottingham, but the understanding of the disease and its management have undergone significant changes over the last few decades. Corneal specialists have adopted new techniques and technologies for the effective management of keratoconus, while adhering to the age-old concepts of contact lens fitting and penetrating keratoplasty. Lamellar keratoplasty has been revived with improved outcomes and devices such as intracorneal ring segments are being used to treat cases of early keratoconus effectively. This review article discusses the current scenario on the surgical as well as non-surgical management of keratoconus with a focus on the established, novel and emerging treatment modalities.

Aim: To study the microbiological and clinical profile of patients with microbial keratitis living in nursing homes., Methods: A retrospective analysis of hospital records from 1996 to 2006 of patients who had microbial keratitis, and were living in nursing homes, was undertaken. The main parameters evaluated were clinical and microbiological profile and final visual outcome., Results: Of 66 patients included in this study, 39 were female and 27 were male, with mean age of 81(SD 11) (range 46-97) years. The major ocular and systemic factors associated with the occurrence of microbial keratitis were the presence of dry eyes (26%) and rheumatoid arthritis (81%), respectively. A positive bacterial culture was obtained in 54 (82%) cases with Staphylococcus being the most prevalent isolate (48%). Seven patients had positive culture for herpes virus. Surgical intervention had to be performed in 31(47%) of cases mainly in the form of botox injection for induction of ptosis (n = 9, 27%), keratoplasty (n = 8, 24%), tarsorrhaphy (n = 5, 15%) or glue (n = 3, 9%). The mean pre-treatment and post-treatment visual acuity was counting fingers and 6/60 respectively., Conclusions: Microbial keratitis in patients living in nursing homes is usually caused by Staphylococcus and is associated with dry eyes and ocular surface disease. Surgical intervention is required in majority of cases with poor visual outcome.

Aim: To examine the clinical profile of cases requiring resuturing following penetrating keratoplasty (PKP) at a tertiary care eye hospital., Methods: The medical records of 947 consecutive patients who had undergone PKP between 1998 and 2006 were reviewed retrospectively and cases that were resutured during this period were analysed. The main parameters studied were indications for PKP, suturing techniques, causes of resuturing, visual acuity outcome and post-resuturing complications., Results: The incidence of resuturing was 5.4% (51 eyes). The number of cases requiring resuturing was higher in corneal grafts performed for microbial keratitis (12%) than those for keratoconus (10%) and corneal endothelial decompensation (2.5%; p = 0.08). Wound dehiscence was the leading cause for resuturing (43%), followed by loose or broken sutures (37.3%). The most common complications after resuturing were occurrence of microbial keratitis (7.8%) and graft failure (5.9%)., Discussion: Resuturing may have to be performed more commonly for corneal transplantation surgery done for microbial keratitis and keratoconus. The major indications for resuturing are wound dehiscence and loose/broken sutures.

Aims: Evaluation of a new surgical technique for the management of corneal ectasia with peripheral corneal involvement., Methods: Twelve eyes of 12 patients with corneal ectasias and peripheral corneal thinning requiring surgical intervention, including eight patients with combined keratoconus and PMD and four patients of keratoglobus, were enrolled for the study in a tertiary care hospital. All patients were contact lens intolerant and had a best corrected visual acuity (BCVA) /=20/60, and all patients had BCVA >/=20/80. The mean keratometry decreased from 57.54 (SD 6.89) D preoperatively to 46.36 (2.39) D (p = 0.003), and the mean spherical equivalent (SEQ) refractive error decreased from -7.8 (4.6) D preoperatively to 1.23 (1.88) D (p = 0.007). A significant decrease was also seen in mean refractive astigmatism which decreased from 5.93 (3.06) D preoperatively to 3.23 (1.14) D (p = 0.037)., Conclusion: Our technique of TILK is an effective surgical modality for the management of ectatic corneal dystrophies with peripheral corneal thinning.