Wavefront aberrometry repeatability and agreement-A comparison between Pentacam AXL Wave, iTrace and OPD-Scan III.

INTRODUCTION: To compare intrasession agreement and repeatability of wavefront aberration measurements from three different aberrometers obtained using Hartmann-Shack, ray tracing and automated retinoscopy methods, as well as their interdevice agreement. METHODS: Three consecutive measurements were obtained using the Pentacam AXL Wave, the iTrace and the OPD-Scan III in 47 eyes of 47 patients. Wavefront refractions, root mean square of total aberrations (RMS total), RMS of higher-order aberrations (HOA) and second-, third- and fourth-order HOAs were exported for 4-mm pupils. Wavefront refractions were converted into vector components: M, J0 and J45 . Intrasession agreement and repeatability were evaluated using intraclass correlation coefficients (ICCs) and repeatability coefficients (RCs); interdevice agreement was assessed using the Bland-Altman method. RESULTS: The intrasession agreement and repeatability of RMS HOA were comparable between the three devices; both the Pentacam AXL Wave and the OPD-Scan III had better intrasession agreement and repeatability for the RMS total than the iTrace (p ≤ 0.02). Intrasession repeatability for the majority of second- and third-order aberrations was better on the Pentacam AXL Wave than on the iTrace (p ≤ 0.01) and OPD-Scan III (p ≤ 0.04), although their agreement and repeatability in spherical aberration were comparable (p ≥ 0.24). Significant systematic differences and proportional bias were detected for almost all refraction power vectors and Zernike coefficients among the three devices. CONCLUSIONS: In this study, all three devices provided good-to-excellent agreement for aberration measurements. Most of the individual Zernike's components were not exchangeable between different aberrometers. Their relative intrasession performance in agreement and repeatability varied significantly across different ocular aberration parameters.

Transepithelial corneal collagen cross-linking using iontophoresis versus the Dresden protocol in progressive keratoconus: A meta-analysis.

BACKGROUND: Standard epithelium-off collagen cross-linking using Dresden protocol (S-CXL) is the standard of care for progressive keratoconus. Despite its efficacy, epithelial debridement is associated with pain, delayed visual rehabilitation, stromal oedema and haze. Minimising these complications while achieving a comparable efficacy remains an unmet need. METHODS: Comparative studies between transepithelial iontophoresis-assisted CXL (I-CXL) and S-CXL reporting the outcomes of visual, refractive, topographic, aberrometry, demarcation line, endothelial cell density, confocal microscopy or complications were identified from databases. Assessments of publication bias, meta-analyses, sensitivity analysis, subgroup analysis, and meta-regressions were performed. RESULTS: In this meta-analysis, 586 eyes from three randomised controlled trials and seven comparative studies were analysed. No differences were found in the change in uncorrected/corrected distance visual acuities, mean/maximum keratometry, central corneal thickness, higher order aberration, spherical aberration, coma, subbasal nerve/anterior stromal keratocyte density and demarcation line depth in both CXL protocols (P ≥ .052). However, I-CXL resulted in less thinning at the minimum pachymetry (standardised mean difference 0.25; 95% confidence interval [CI] 0.06-0.44). More importantly, there was a significant reduction in complications following I-CXL (odds ratio 0.30; 95% CI 0.12-0.75). Meta-regression analyses on demarcation line depth and complication suggested that I-CXL was more effective than S-CXL when baseline maximum keratometry was >55.2 D and the risk of complication was independent of other baseline covariates. CONCLUSION: I-CXL has a more favourable safety profile, as evidenced by the available literature, with less thinning at the minimum pachymetry and reduced risk of complications while achieving comparable effects on visual, refractive, topographic, aberrometry, and morphological outcomes as S-CXL.

Outcomes of cataract operations in extreme high axial myopia.

PURPOSE: To analyse the outcomes of phacoemulsification in extreme axial myopia METHODS: Consecutive cases of phacoemulsification in eyes with axial length ≥ 30.0 mm from January 1, 2010 to Dec 31, 2013 in a tertiary referral eye hospital were retrospectively reviewed. A single intraocular lens (IOL) type was used for all cases. Main outcome measures included perioperative complications and refractive outcome. RESULTS: Two hundred and twenty-one eyes were identified. Intraoperatively, two eyes (0.9 %) had unstable capsular bag and three (1.4 %) had posterior capsular rupture. At a mean follow-up duration was 27.4 ± 14.6 months, three eyes (1.5 % of 198 eyes with no history of retinal detachment or macular hole) developed retinal detachment. There was an overall hyperopic shift with a mean biometry error of 0.45 ± 1.21 D in all eyes. The mean absolute biometry prediction error was 0.98 ± 0.83 D in all eyes, 1.11 ± 0.86 D and 0.85 ± 0.82 D in eyes receiving negative- and positive-power IOL, respectively (p = 0.042). A total of 61.2 % of eyes had refractive outcome within ± 1.0 D of target spherical equivalent. Regression analysis showed low IOL power as an independent predictor for greater postoperative absolute biometry error (p = 0.014). CONCLUSIONS: We showed no increase in perioperative complications in eyes with extreme high axial myopia. In eyes with long axial length, implantation of IOL with lower power was associated with more hyperopic shift, which was more pronounced with negative-power IOL.

Photokeratitis in Outdoor Event Participants Exposed to UV Radiation Display.

Importance: While UV radiation displays may be used for recreational purposes at outdoor events, unprotected eyes have been reported to have symptoms consistent with photokeratitis. Such symptoms warrant documentation and evaluation in ophthalmic peer reviewed literature. Objective: To describe a case series of photokeratitis associated with a single ultraviolet radiation display at an outdoor event. Design, Setting, and Participants: This case series involved a retrospective record review of 8 patients who presented in public and private health sectors in November 2023 after developing photokeratitis following UV radiation exposure at an outdoor event in Hong Kong on the night of November 4, 2023. Main Outcomes and Measures: Clinical symptoms, signs, and clinical course of patients who were diagnosed acute photokeratitis following exposure to UV radiation. Results: The mean time of UV display exposure for the 8 patients (mean [SD] age, 33.12 [5.19] years; 4 [50%] female) was 3.00 (1.41) hours, and symptoms presented at a mean (SD) 8.88 (8.24) hours after the exposure. None of the patients were wearing spectacles during the exposed period. All patients were affected bilaterally. All patients experienced eye pain, 6 experienced red eye, and 5 experienced tearing and photophobia. Mean (SD) presenting visual acuity was logMAR 0.10 (0.14) (approximate Snellen equivalent, 20/25) for right eyes and 0.06 (0.89) (approximate Snellen equivalent, 20/25) for left eyes. On examination, there were findings of cornea and conjunctival involvement with punctate epithelial erosions and ciliary vasodilation, but none of the patients presented with anterior chamber reaction. Corticosteroids, lubricants, and antibiotics, all provided topically, were prescribed. Five patients were not scheduled for a review, and 3 had follow-up visits, with the length of follow-up ranging from 7 to 10 days. All patients had undergone a complete recovery. Conclusions and Relevance: These findings provide evidence of an association between UV radiation used for recreational purposes and photokeratitis, which may help guide evaluation and management of future cases.

Outcomes and prognostic factors of cataract surgery in cytomegalovirus-related anterior uveitis.

PURPOSE: To evaluate the outcomes of cataract surgery in patients with cytomegalovirus (CMV) anterior uveitis and factors associated with final visual outcome. SETTING: Hong Kong Eye Hospital, Hong Kong. DESIGN: Retrospective case series. METHODS: History, clinical characteristics, corrected distance visual acuity (CDVA), medications, and complications of CMV anterior uveitic eyes that underwent cataract surgery between 2010 and 2020 were reviewed. RESULTS: This study included 26 eyes of 26 patients undergoing phacoemulsification. The median duration of disease was 4.8 years, and the median quiescent period preoperatively was 2.3 years. None required pupil manipulation or had significant intraoperative complications. The median CDVA improved from 20/100 (interquartile range [IQR] 20/200 to 20/50) preoperatively to 20/30 (IQR 20/40 to 20/25) at 1 year and 20/35 (IQR 20/50 to 20/30) at the last follow-up at a median of 4.9 years postoperatively ( P < .001). CDVA improved in 19 eyes (73.1%) and was ≥20/40 in 18 eyes (69.2%). In the multivariate regression model, preoperative use of topical 0.15% ganciclovir (ß = 0.33, 95% CI 0.17 to 0.48, P < .001) and adjunctive intraoperative intracameral dexamethasone 0.4 mg (ß = 0.19, 95% CI 0.01 to 0.36, P = .043) were associated with a better final CDVA. Loss of CDVA and poor postoperative CDVA visual acuity were mostly attributed to uveitic glaucoma, but preoperative glaucoma or the number of antiglaucoma medications did not affect final CDVA. CONCLUSIONS: Cataract surgery in eyes with CMV anterior uveitis was safe and CDVA significantly improved and remained sustained postoperatively. Topical ganciclovir 0.15% preoperatively and intracameral corticosteroid intraoperatively seem to maximize the final visual outcome.

Late-Onset Nontuberculous Mycobacterial Keratitis After Small Incision Lenticule Extraction.

PURPOSE: The purpose of this article was to report a case of unilateral late-onset nontuberculous mycobacterial keratitis after small incision lenticule extraction (SMILE). METHODS: This was a case report. RESULTS: A 27-year-old woman presented with Mycobacterium chelonae keratitis 3 weeks after uncomplicated SMILE with a solitary interface infiltrate. The keratitis worsened after an initial response to topical fortified and interface antibiotic irrigation. Despite repeated interface irrigation and topical and oral antibiotics, progressive, diffuse stromal infiltrates followed by melting of the cap ensued over the next 6 weeks. Cap amputation and intrastromal antibiotic injection followed by prolonged topical and oral antibiotics usage for the following 5 weeks led to infiltrate resolution and re-epithelization of the residual stromal bed. All medications were tapered off over 6 months after initial presentation without recurrence, but anterior stromal scarring and corneal neovascularization persisted. CONCLUSIONS: Cap amputation and intrastromal antibiotic injection for intractable post-SMILE keratitis can prevent the need for therapeutic keratoplasty.

Accelerated corneal collagen cross-linking in progressive keratoconus: Five-year results and predictors of visual and topographic outcomes.

Purpose: To analyze the 5-year results of accelerated corneal collagen crosslinking (CXL) for progressive keratoconus and identify preoperative characteristics predictive of visual and topographic outcomes. Methods: A prospective interventional case series. Nineteen eyes of 19 patients receiving accelerated CXL with settings of 18 mW/cm2 for 5 min were included. Clinical and topographic parameters were assessed. Linear regression and logistic regression were used to compare the R2 and odds ratio (OR), respectively, between baseline characteristics and postoperative outcomes. Results: Corrected distance visual acuity (CDVA) remained stable from 0.28 ± 0.21 to 0.25 ± 0.18 logMAR (P = 0.486). The mean cylindrical refraction was stable (P = 0.119). The maximal keratometry (Kmax) decreased from 61.99 ± 10.37 to 59.25 ± 7.75 D (P < 0.001), flattening in the flattest and steepest meridians and mean keratometry were also observed (P ≤ 0.040). The mean anterior elevation at the apex reduced from 21.42 ± 16.69 to 18.53 ± 12.74 µm (P = 0.013) and changes in posterior elevation were non-significant (P = 0.629). Preoperative Kmax best predicted the postoperative change in Kmax (R2 = 0.55, P < 0.001) compared to the other baseline characteristics (P ≤ 0.028), whereas preoperative CDVA was the only significant predictor of postoperative change in CDVA (R2 = 0.41, P = 0.003). Accelerated CXL is less likely to fail in eyes with a steeper preoperative Kmax (OR = 0.74, P = 0.040) or greater posterior elevation at the apex (OR = 0.91, P = 0.042). Conclusion: Kmax significantly decreased following accelerated CXL. Eyes with worse preoperative CDVA and higher Kmax were more likely to have an improvement in visual acuity and corneal flattening.

Enhanced Monofocal Versus Conventional Monofocal Intraocular Lens in Cataract Surgery: A Meta-analysis.

PURPOSE: To compare different outcomes of an enhanced monofocal intraocular lens (IOL) versus a conventional monofocal IOL implantation after cataract surgery. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline was used for abstracting data and assessing quality. Comparative studies between enhanced monofocal versus conventional monofocal IOL implantations reporting outcomes in monocular and binocular visual acuities at various distances, spectacle independence, contrast sensitivity, optical quality, and adverse effects were identified from three databases. Meta-analysis, sensitivity analysis, and subgroup analysis were performed. RESULTS: A total of 680 eyes implanted with an enhanced monofocal IOL (Tecnis Eyhance ICB00; Johnson & Johnson) and 647 eyes with a conventional monofocal IOL from 3 randomized controlled trials and 9 comparative studies were included. The enhanced monofocal IOL showed better monocular uncorrected intermediate visual acuity (UIVA) (mean difference [MD]: -0.11 logMAR; 95% CI: -0.12 to -0.09), binocular UIVA (MD: -0.17 logMAR; 95% CI: -0.23 to -0.11), and binocular uncorrected near visual acuity performance (MD: -0.17 logMAR; 95% CI: -0.29 to -0.04) than the conventional monofocal IOL. More patients were spectacle free at intermediate distance with the enhanced monofocal IOL (odds ratio: 12.9; 95% CI: 6.2 to 27.0). Both monocular (MD: -0.002 logMAR; 95% CI: -0.01 to 0.01) and binocular (MD: 0.01 logMAR; 95% CI: -0.02 to 0.03) uncorrected distance visual acuity revealed non-significant differences between the IOL designs. Contrast sensitivity, photic phenomenon, and adverse effects were comparable. CONCLUSIONS: Enhanced monofocal IOLs effectively improved unaided intermediate vision with similar distance performance relative to conventional monofocal IOLs. This was achieved without compromising the contrast sensitivity or inducing photic phenomena. [J Refract Surg. 2022;38(8):538-546.].

Ophthalmic manifestations and risk factors for mortality of HIV patients in the post-highly active anti-retroviral therapy era.

BACKGROUND: To evaluate the ophthalmic manifestations and risk factors for mortality in HIV patients in the post-highly active anti-retrovirus therapy (HAART) era. DESIGN: Retrospective study. SAMPLES: 151 patients with HIV infection. METHODS: Review of all HIV patients who have attended the Hong Kong Eye Hospital between 2000 and 2007. MAIN OUTCOME MEASURES: Ocular findings especially opportunistic infections and medical information including mortality during follow up. RESULTS: At presentation, 139 (92.1%) patients were already diagnosed with HIV and 58 (41.7%) had an AIDS indicator condition. Fifty-one (33.8%) patients had HIV-related eye disease on presentation and the leading manifestations were cytomegalovirus (CMV) retinitis and HIV microangiopathy. Low baseline CD4 cell count <100 cells/L was significantly related with HIV-related ophthalmic manifestations and CMV retinitis at presentation (P < 0.013). 105 patients were followed for 6 months or more and the mean follow-up was 4.8 years. There was no significant change in visual acuity compared with baseline (P = 0.13). 20 (19.0%) patients had one eye with final visual acuity of 20/200 or worse and the leading cause for poor vision was CMV retinitis. 11 (10.5%) patients died during the follow-up due to complications of HIV/AIDS. The presence of HIV retinal microangiopathy was significantly associated with mortality (P = 0.005). CONCLUSIONS: CMV retinitis remains the main HIV-related ocular disease in the post-HAART era. HIV retinal microangiopathy might be an important prognostic factor for mortality. Appropriate ophthalmic monitoring is justified to detect for ophthalmic complications in HIV patients regardless of HAART use in order for prompt initiation of treatment.

Collagen Cross-linking With Photoactivated Riboflavin (PACK-CXL) for Bacterial Keratitis After Small Incision Lenticule Extraction (SMILE).

PURPOSE: To report a case of infectious keratitis after small incision lenticule extraction (SMILE) treated with collagen cross-linking with photoactivated riboflavin (PACK-CXL). METHODS: Case report and literature review. RESULTS: A patient presented with culture-proven bacterial keratitis 5 days after SMILE was treated with fortified topical antibiotics and PACK-CXL. Irrigation of the corneal cap-stromal bed interface, which can be difficult and affect visual outcomes, was not performed. Clinical improvement was seen shortly after treatment and resolution of keratitis was achieved at 2 weeks. CONCLUSIONS: This is the first reported use of PACK-CXL in the management of infectious keratitis after SMILE. PACK-CXL may help sterilize the infection and limit its spread within the interface. [J Refract Surg. 2017;33(4):278-280.].

Comparative evaluation of aspheric toric intraocular lens implantation and limbal relaxing incisions in eyes with cataracts and ≤3 dioptres of astigmatism.

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.

Different Topographic Response Between Mild to Moderate and Advanced Keratoconus After Accelerated Collagen Cross-linking.

PURPOSE: To evaluate the clinical and topographic effects after accelerated corneal collagen cross-linking (CXL) in keratoconus. METHODS: This was a prospective interventional study in 25 eyes of 24 Asian patients with keratoconus, where 10 eyes in group 1 had mild to moderate keratoconus with the steepest keratometry reading (Kmax) < 58 diopters (D), and 15 eyes in group 2 had advanced keratoconus with Kmax ≥ 58.0 D. The patients underwent accelerated CXL with 18 W/cm UV-A light for 5 minutes. Clinical and topographic parameters were obtained before and 1 year after treatment. RESULTS: Overall, spectacle-corrected distance visual acuity, refraction, average keratometry readings, Kmax, anterior elevation at the apex, and corneal endothelial cell density remained stable (P < 0.102). Posterior elevation at the apex increased at 1 year (P = 0.002). The thinnest pachymetry readings also showed significant reduction (P < 0.001). Kmax in group 1 increased by 1.00 ± 1.63 D (range, -2.2 to 5.4 D; P = 0.012), whereas Kmax in group 2 reduced by 1.69 ± 2.61 D (range, -8.4 to 3.2 D; P = 0.013) at 1 year after accelerated CXL. The change in Kmax between the 2 groups was significantly different (P < 0.001). There was no intergroup difference for the change in other parameters. A significant correlation was found between the preoperative Kmax and postoperative change in Kmax at 1 year (r = -0.648; P < 0.001). CONCLUSIONS: Accelerated CXL seems to be effective in preventing progression and causing topographic flattening in advanced cases of keratoconus but not as effective in the less progressed counterparts.

One-year outcomes of conventional and accelerated collagen crosslinking in progressive keratoconus.

We compared one-year outcomes of conventional (3 mW/cm(2), 365-nm ultraviolet-A light, 30 minutes) and accelerated (18 mW/cm(2), 365-nm ultraviolet-A light, 5 minutes) collagen crosslinking (CXL) in patients with progressive keratoconus. Main outcome measures were change in keratometry, uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA). Nineteen patients in each group completed 1-year follow-up. Preoperatively, there were no inter-group differences for age, keratometry, corneal thickness, and spherical equivalent (p > 0.127). One year postoperatively, maximum and minimum keratometry were flattened by 1.6 diopters (p < 0.023) and 2 diopters (p < 0.047) respectively after conventional CXL, and, 0.47 diopters (p = 0.471) and 0.19 diopters (p = 0.120) respectively after accelerated CXL. Association analysis showed significant negative association between baseline maximum keratometry and change in maximum keratometry after accelerated CXL (p = 0.002) but not after conventional CXL (p = 0.110). Corneal thickness was reduced significantly in both groups (p = 0.017). An improvement in UCVA (p < 0.001) and BCVA (p < 0.022) was noted in both groups along with a reduction in spherical equivalent postoperatively (p < 0.026). There were no inter-group differences for any of the parameters postoperatively (p > 0.184). Although no statistically significant differences were observed between both treatment modalities, a more effective topographic flattening was observed with conventional CXL as compared to accelerated CXL in this study.

Intraoperative pachymetry using spectral-domain optical coherence tomography during accelerated corneal collagen crosslinking.

PURPOSE: To evaluate the role of spectral-domain optical coherence tomography (SDOCT) to measure corneal thickness during accelerated corneal crosslinking (CXL). METHODS: Intraoperative pachymetry was performed using SDOCT and ultrasound pachymetry (USP) in 6 eyes of 6 patients with keratoconus. Pachymetry readings were obtained at baseline, after epithelium removal and after 30 minutes of riboflavin instillation. SDOCT measurements of eyes with and without lid speculum during riboflavin instillation were compared. RESULTS: There was no statistically significant difference in central corneal thickness (CCT) measurements between SDOCT and USP (P > 0.05 for all). A significant decrease in both CCT (P = 0.031) and the thinnest corneal thickness (TCT) (P = 0.031) was observed during CXL. There was a greater reduction in CCT (38 ± 6%) with the use of lid speculum as compared to the no-speculum eyes (18 ± 9%) (P = 0.100). TCT was also reduced by a greater extent with the use of lid speculum (40 ± 5% versus 26 ± 7%; P = 0.100). CONCLUSION: SDOCT can be successfully used to measure intraoperative corneal pachymetry during corneal CXL. SDOCT measurements demonstrated corneal thinning intraoperatively during CXL, which was further accentuated by the use of a lid speculum during the procedure.

Use of Anterior Segment OCT in the Evaluation and Management of Congenital Aphakia.

Anterior segment optical coherence tomography (AS-OCT) is a noninvasive technology capable of capturing high-resolution images of the anterior segment. With AS-OCT, a 7-year-old boy with nystagmus was diagnosed as having secondary congenital aphakia. The presence of lens capsules on the AS-OCT was of significant prognostic and management value and the child later benefited from bilateral sulcus-fixated intraocular lens implantation surgery. AS-OCT also required less cooperation from the patient compared to ultrasound biomicroscopy. To the authors' knowledge, this is the first reported case of congenital aphakia diagnosed by AS-OCT.