Topical Atropine for Childhood Myopia Control: The Atropine Treatment Long-Term Assessment Study.

Importance: Clinical trial results of topical atropine eye drops for childhood myopia control have shown inconsistent outcomes across short-term studies, with little long-term safety or other outcomes reported. Objective: To report the long-term safety and outcomes of topical atropine for childhood myopia control. Design, Setting, and Participants: This prospective, double-masked observational study of the Atropine for the Treatment of Myopia (ATOM) 1 and ATOM2 randomized clinical trials took place at 2 single centers and included adults reviewed in 2021 through 2022 from the ATOM1 study (atropine 1% vs placebo; 1999 through 2003) and the ATOM2 study (atropine 0.01% vs 0.1% vs 0.5%; 2006 through 2012). Main Outcome Measures: Change in cycloplegic spherical equivalent (SE) with axial length (AL); incidence of ocular complications. Results: Among the original 400 participants in each original cohort, the study team evaluated 71 of 400 ATOM1 adult participants (17.8% of original cohort; study age, mean [SD] 30.5 [1.2] years; 40.6% female) and 158 of 400 ATOM2 adult participants (39.5% of original cohort; study age, mean [SD], 24.5 [1.5] years; 42.9% female) whose baseline characteristics (SE and AL) were representative of the original cohort. In this study, evaluating ATOM1 participants, the mean (SD) SE and AL were -5.20 (2.46) diopters (D), 25.87 (1.23) mm and -6.00 (1.63) D, 25.90 (1.21) mm in the 1% atropine-treated and placebo groups, respectively (difference of SE, 0.80 D; 95% CI, -0.25 to 1.85 D; P = .13; difference of AL, -0.03 mm; 95% CI, -0.65 to 0.58 mm; P = .92). In ATOM2 participants, the mean (SD) SE and AL was -6.40 (2.21) D; 26.25 (1.34) mm; -6.81 (1.92) D, 26.28 (0.99) mm; and -7.19 (2.87) D, 26.31 (1.31) mm in the 0.01%, 0.1%, and 0.5% atropine groups, respectively. There was no difference in the 20-year incidence of cataract/lens opacities, myopic macular degeneration, or parapapillary atrophy (ß/γ zone) comparing the 1% atropine-treated group vs the placebo group. Conclusions and Relevance: Among approximately one-quarter of the original participants, use of short-term topical atropine eye drops ranging from 0.01% to 1.0% for a duration of 2 to 4 years during childhood was not associated with differences in final refractive errors 10 to 20 years after treatment. There was no increased incidence of treatment or myopia-related ocular complications in the 1% atropine-treated group vs the placebo group. These findings may affect the design of future clinical trials, as further studies are required to investigate the duration and concentration of atropine for childhood myopia control.

Cost of Myopia Correction: A Systematic Review.

Myopia is one of the leading causes of visual impairment globally. Despite increasing prevalence and incidence, the associated cost of treatment remains unclear. Health care spending is a major concern in many countries and understanding the cost of myopia correction is the first step eluding to the overall cost of myopia treatment. As cost of treatment will reduce the burden of cost of illness, this will aid in future cost-benefit analysis and the allocation of healthcare resources, including considerations in integrating eye care (refractive correction with spectacles) into universal health coverage (UHC). We performed a systematic review to determine the economic costs of myopia correction. However, there were few studies for direct comparison. Costs related to myopia correction were mainly direct with few indirect costs. Annual prevalence-based direct costs for myopia ranged from $14-26 (USA), $56 (Iran) and $199 (Singapore) per capita, respectively (population: 274.63 million, 75.15 million and 3.79 million, respectively). Annually, the direct costs of contact lens were $198.30-$378.10 while spectacles and refractive surgeries were $342.50 and $19.10, respectively. This review provides an insight to the cost of myopia correction. Myopia costs are high from nation-wide perspectives because of the high prevalence of myopia, with contact lenses being the more expensive option. Without further interventions, the burden of illness of myopia will increase substantially with the projected increase in prevalence worldwide. Future studies will be necessary to generate more homogenous cost data and provide a complete picture of the global economic cost of myopia.

Role of anterior segment optical coherence tomography angiography in the assessment of acute chemical ocular injury: a pilot animal model study.

To examine the use of anterior segment-optical coherence tomography angiography (AS-OCTA) in the assessment of limbal ischemia in an animal model chemical ocular injury. We conducted a prospective study using an established chemical ocular injury model in 6 rabbits (12 eyes), dividing the cornea limbus into 4 quadrants. Chemical injury grade was induced based on extent of limbal injury (0 to 360 degrees) and all eyes underwent serial slit-lamp with AS-OCTA imaging up to one month. Main outcome measure was changes in AS-OCTA vessel density (VD) comparing injured and control cornea limbal quadrants within 24 h and at one month. AS-OCTA was able to detect differences in limbal VD reduction comparing injured (3.3 ± 2.4%) and control quadrants (7.6 ± 2.3%; p < 0.001) within 24 h of ocular chemical injury. We also observed that AS-OCTA VD reduction was highly correlated with the number of quadrants injured (r = - 0.89; p < 0.001; 95% CI - 5.65 to - 1.87). Corneal vascularization was detected by AS-OCTA in injured compared to control quadrants (10.1 ± 4.3% vs 7.0 ± 1.2%; p = 0.025) at 1 month. Our animal pilot study suggests that AS-OCTA was able to detect limbal vessel disruption from various severities of acute chemical insult, and in the future, could potentially serve as an adjunct in providing objective grading of acute ocular chemical injury once validated in a clinical trial.

Post-keratoplasty Infectious Keratitis: Epidemiology, Risk Factors, Management, and Outcomes.

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2-11.9%) than developed countries (0.02-7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

Anterior Segment Optical Coherence Tomography Angiography Assessment of Corneal Vascularisation After Combined Fine-Needle Diathermy with Subconjunctival Ranibizumab: A Pilot Study.

INTRODUCTION: To describe anterior segment optical coherence tomography angiography (AS-OCTA) imaging to monitor corneal vascularisation (CoNV) and scar reduction after combined fine-needle diathermy (FND) with subconjunctival ranibizumab. METHODS: Prospective clinical study of six eyes from six subjects with corneal scar and CoNV which underwent combined FND with subconjunctival ranibizumab. All eyes were imaged using slit-lamp photography (SLP) and AS-OCTA (Optovue, Inc., Fremont, CA, wavelength: 840 nm) before and after the operation, with two independent masked assessors analysing all images. Main outcome measures were changes in median corneal scar area and vessel density (AS-OCTA) comparing pre- and postoperative imaging up to month 3 and 6. RESULTS: The mean age of the subjects was 60 ± 23 years, with three males and three females. CoNV and corneal scarring involving the visual axis were present in all eyes, secondary to previous infective keratitis (n = 3), severe blepharokeratoconjunctivitis (n = 2), or chemical injury (n = 1). Follow-up time frame ranged from 2 to 6 months postoperation. There was a reduction in median corneal scar area from 30.2 mm2 (IQR 18.7-38.5) before surgery to 14.8 mm2 (IQR 7.1-19.6) after surgery, with a median reduction of 37.1% (IQR = - 3.1-86.9, p = 0.046). There was also a reduction in median cornea vessel density (AS-OCTA) from 20.8% (IQR 16.1-20.8) before surgery to 17.6% (IQR 14.0-17.6) after surgery, with a median reduction of 15.1% (IQR 13.2-15.1, p < 0.001). CONCLUSIONS: Combined imaging of SLP and AS-OCTA is useful for monitoring treatment response of corneal scarring and CoNV after combined FND with subconjunctival Ranibizumab.

Assessment of the Macular Microvasculature in High Myopes With Swept Source Optical Coherence Tomographic Angiography.

Background: The risk of pathologic myopia (PM) increases with worsening myopia and may be related to retinal microvasculature alterations. To evaluate this, we analyzed the macular microvasculature of myopes with swept source-optical coherence tomographic angiography (SS-OCTA) in adolescent and young adult Singaporeans. Methods: This is a prevalent case-control study including 93 young Chinese from the Strabismus, Amblyopia and Refractive error in Singaporean children (STARS, N = 45) study and the Singapore Cohort Study of Risk Factors for Myopia (SCORM, N = 48) studies. Macular vessel density (VD) measurements were obtained from 3 × 3 mm SS-OCTA scans and independently assessed using ImageJ. These measurements were compared between individuals with non-high myopia [non-HM, N = 40; SE >-5.0 diopter (D)] and HM (SE ≤-5.0D, N = 53). Results: The mean macular VD was 40.9 ± 0.6% and 38.2 ± 0.5% in the non-HM and HM, groups, respectively (p = 0.01 adjusted for age and gender). Mean FAZ area in the superficial layer was 0.22 ± 0.02 mm2 in the HM group, which was smaller compared to non-HM group (0.32 ± 0.03 mm2, p = 0.04). Mean deep FAZ area was similar between the two groups (0.45 ± 0.03 mm2 and 0.48 ± 0.04 mm2 in the HM and non-HM groups, respectively, p = 0.70). Conclusions: VD was lower and superficial FAZ area was smaller, in adolescents and young adults with HM compared to non-HM. These findings require validation in prospective studies to assess their impact on the subsequent development of PM.

A vision 'bolt-on' increases the responsiveness of EQ-5D: preliminary evidence from a study of cataract surgery.

OBJECTIVES: (1) To evaluate the effect of adding a vision dimension ('bolt-on') to the 5-level EQ-5D (EQ-5D-5L) and 3-level EQ-5D (EQ-5D-3L) on their responsiveness, and (2) to compare the responsiveness of a vision 'bolt-on' EQ-5D-3L (EQ-5D-3L + V) with SF-6D and Health Utilities Index Mark 3 (HUI3) to the benefit of cataract surgery. METHODS: Sixty-three patients were assessed before and after their cataract surgery using the EQ-5D-3L, EQ-5D-5L, SF-6D, HUI3, as well as a 3-level and a 5-level vision dimension. Preference-based indices were calculated using available value sets for EQ-5D-3L, EQ-5D-3L + V, EQ-5D-5L, SF-6D, and HUI3, and non-preference-based indices were calculated using the sum-score method for EQ-5D-5L and EQ-5D-5L + V (vision bolt-on EQ-5D-5L). Responsiveness was assessed using the standardized response mean (SRM) and F-statistic. RESULTS: Among preference-based indices, mean changes from pre to post-surgery in EQ-5D-3L + V and EQ-5D-3L indices were 0.031 and 0.018, respectively. The mean changes for EQ-5D-5L, SF-6D and HUI3 indices were 0.020, 0.012 and 0.105, respectively. The SRM (F-statistic) for EQ-5D-3L + V and EQ-5D-3L indices were 0.458 (13.2) and 0.098 (0.6), respectively. The responsiveness of EQ-5D-3L + V was better than EQ-5D-5L, SF-6D; the responsiveness of HUI3 was better than all other measures. Using non-preference-based indices, mean change for EQ-5D-5L + V and EQ-5D-5L were 0.067 and 0.017, respectively. The corresponding SRM (F-statistic) were 0.709 (31.7) and 0.295 (5.4). CONCLUSIONS: Preliminary evidence from our study suggests that a vision 'bolt-on' may increase the responsiveness of EQ-5D-3L and EQ-5D-5L to change in health outcomes experienced by patients undergoing cataract surgery. In absence of the preference-based vision bolt-on EQ-5D-5L index, HUI3 was the most responsive measure.

Optical coherence tomography angiography for the assessment of choroidal vasculature in high myopia.

AIMS: To assess specific layers of the choroid in highly myopic young adults and to examine their associations with levels of myopia. METHODS: We recruited 51 young myopes (n=91 eyes) from the Singapore Cohort of Risk Factors for Myopia cohort. We performed standardised optical coherence tomography (OCT) and OCT angiography imaging and developed a novel segmentation technique assessing choroidal layers' thickness (overall choroidal thickness (CT), medium-vessel choroidal layer (MVCL) thickness, large-vessel choroidal layer (LVCL)) and vasculature (choroidal vessel density (%), choroidal branch area (CBA, %) and mean choroidal vessel width (MCVW, mm)). RESULTS: We found that eyes with extreme myopia (EM) had thinner vascular layers compared with high myopia (HM), that is, LVCL (36.0±1.5 vs 39.2±1.2 µm, p=0.002) and MVCL (185.5±5.7 vs 198.2±4.6 µm, p=0.014). Overall CT was thinnest in the nasal and inferior quadrants in EM (nasal: 157.1±9.6 vs 187.2±8.3 µm, p<0.001; superior: 236.6±11.1 vs 257.0±9.5 µm, p=0.02; temporal: 228.0±10.6 vs 254.3±8.8 µm, p=0.012; and inferior quadrant: 198.7±10.0 vs 239.8±8.3 µm, p=<0.001) when compared with HM. We also observed significantly more vessel branching in eyes with EM as compared with eyes with HM (CBA, 10.2%±0.7% vs 9.95%±0.8%, p=0.018). CONCLUSIONS: The novel segmentation technique and introduced choroidal parameters may serve as new biomarkers to study disease conditions in myopia.

EQ-5D-5L is More Responsive than EQ-5D-3L to Treatment Benefit of Cataract Surgery.

BACKGROUND: It is not clear whether 5-level EQ-5D (EQ-5D-5L) utilities based on recently developed value sets are more responsive than 3-level EQ-5D (EQ-5D-3L) utilities. OBJECTIVES: The study aims were to compare (1) the responsiveness of EQ-5D-5L and EQ-5D-3L utilities and (2) the responsiveness of these utilities with the Short Form-6 Dimension (SF-6D) and Health Utilities Index Mark 3 (HUI3) utilities to the treatment benefit of cataract surgery. METHODS: A total of 148 patients were interviewed before and after their cataract surgery using EQ-5D-3L, EQ-5D-5L, SF-6D, and HUI3. Responsiveness was assessed for all measures using the mean change (post-treatment-pre-treatment), standardized effect size (SES), standardized response mean (SRM), and F-statistic. RESULTS: Using the Singapore value sets, mean change for EQ-5D-3L and EQ-5D-5L utilities was 0.016 and 0.028, SES was 0.097 and 0.199; SRM was 0.091 and 0.196; and F-statistic was 1.2 and 5.7, respectively. Similar trends were observed using the UK/England EQ-5D value sets, although the magnitude was slightly smaller. The mean change, SES, SRM and F-statistics for SF-6D (UK value set) were 0.020, 0.234, 0.249, and 9.2, respectively. The values of mean change, SES, SRM and F-statistics for HUI3 (Canada value set) were 0.080, 0.472, 0.474, and 33.3, respectively. CONCLUSIONS: The EQ-5D-5L utilities tend to be more responsive than the EQ-5D-3L utilities to treatment benefits of cataract surgery. The HUI3 utilities are more responsive than both the EQ-5D-5L and SF-6D, and SF-6D utilities may be slightly more responsive than the EQ-5D-5L for assessing patients undergoing cataract surgery.

A Vision "Bolt-On" Item Could Increase the Discriminatory Power of the EQ-5D Index Score.

BACKGROUND: Recently, a vision "bolt-on" EuroQol five-dimensional questionnaire (EQ-5D) was developed and tentative utility values (i.e., a "value set") for this new descriptive system were estimated. OBJECTIVES: To compare the discriminatory power of this bolt-on and standard utility-based EQ-5D health indices. METHODS: Cross-sectional data on the (3-level) vision bolt-on EQ-5D were collected through face-to-face interviews with 500 and 336 individuals with and without visual impairment, respectively. To assess the discriminatory power of the vision bolt-on index relative to the standard EQ-5D index developed in the vision bolt-on valuation study, 16 pairs of mutually exclusive subgroups of individuals defined by the individuals' visual acuity and responses to the 14-item visual function questionnaire were compared pairwise. The absolute mean difference in the two index scores and the corresponding F statistic derived from the comparisons were used as measures of discriminatory power. RESULTS: The absolute mean difference in the bolt-on index score was larger than that in the standard EQ-5D index score in 14 of the 16 comparisons. The bolt-on index score exhibited a larger F-statistic value than did the standard EQ-5D index score in all known-group comparisons, with the F-statistic ratio ranging from 0.415 to 0.770. CONCLUSIONS: The vision bolt-on EQ-5D appears to be more discriminative than the standard EQ-5D in measurement of vision problems. Future studies should investigate the extent to which the vision bolt-on item can increase the sensitivity of the EQ-5D to vision change in interventional studies.

Validation of an Objective Scoring System for Forme Fruste Keratoconus Detection and Post-LASIK Ectasia Risk Assessment in Asian Eyes.

PURPOSE: To investigate the efficacy of the SCORE Analyzer (Bausch+Lomb TechnoLas, Germany) in detecting forme fruste keratoconus (FFKC) in Asian eyes and validate its usefulness as a risk assessment system for post-laser in situ keratomileusis (LASIK) keratectasia. METHODS: We retrospectively evaluated corneal topographies with the Orbscan IIz system and independently tested them with the SCORE Analyzer through masked investigators. Eyes were classified into 2 groups: (1) The FFKC group included clinically and topographically normal eyes with definite keratoconus in the contralateral eye. (2) The control group included normal preoperative topographies of patients with LASIK performed at least 4 years before with no resultant keratectasia. The main outcome measures were accuracy indicators: sensitivity, specificity, positive, and negative predictive values. Parameters in the calculation of the SCORE including irregularity at 3 mm, thinnest pachymetry, the difference between central and thinnest pachymetry (CP - TP), vertical decentration of the thinnest point, maximum posterior elevation, and anterior elevation of the thinnest point were compared in both groups. RESULTS: We analyzed 128 Orbscans of 128 Asian patients. There were 24 FFKC eyes and 104 control eyes. SCORE was negative in 7 eyes (false negative) in the FFKC group and was positive in 2 eyes in the control group (false positive). The sensitivity was 70.8%, specificity 98.1%, positive predictive value 89.5%, and negative predictive value 93.6%. Irregularity at 3 mm, thinnest pachymetry, CP - TP, thinnest point decentration, maximum posterior elevation, and anterior elevation of the thinnest point were significantly different in both groups. CONCLUSIONS: The SCORE Analyzer algorithm, developed and validated in eyes of white subjects, was found to be valid and consistent in Asian eyes, showing good sensitivity and specificity in FFKC detection, and to be useful in objectively identifying cases at risk of post-LASIK keratectasia.

Cost-effectiveness of alternative strategies for interferon-γ release assays and tuberculin skin test in tuberculous uveitis.

BACKGROUND: Although tuberculous uveitis remains a major cause of ocular morbidity in the developing world, there is no consensus on which diagnostic test or testing strategy is the most cost effective. In this study we carried out a cost-effectiveness analysis to determine the most cost-effective diagnostic test strategy. METHODS: In this prospective study, we recruited 102 patients from Singapore National Eye Centre with signs suggestive of tuberculous uveitis. Using prospective data from this cohort and from published meta-analyses, we modelled the incremental cost effectiveness of the following strategies: tuberculin skin test (TST) only; interferon-γ release assay (IGRA) only; IGRA following a positive TST result; and dual-test strategy, conducting TST and IGRA at presentation. Incremental cost-effectiveness ratios (ICERs) were calculated for each strategy and analysed using a willingness-to-pay threshold of $50,000 per quality-adjusted life year (QALY) gained. RESULTS: In our population, the least cost effective was the IGRA-only strategy. The dual-test strategy was the most cost effective, with an improvement of 0.017 QALY at an incremental cost of $190 relative to the TST-only strategy (ICER $11,500); while the TST-only strategy was more cost effective than the third strategy, using IGRA following a positive TST result (ICER $3610). This remained consistent while varying the costs of IGRA and TST, the incidence of tuberculosis and tuberculous uveitis, as well as the diagnostic accuracy of IGRA and TST found in previous studies in various populations. CONCLUSIONS: The dual-test strategy (performing TST and IGRA at presentation) was the most cost effective strategy for the diagnosis of tuberculous uveitis in our population.

Health burden associated with visual impairment in Singapore: the Singapore epidemiology of eye disease study.

OBJECTIVE: To assess the impact of visual impairment (VI) on health-related quality of life and to compare the health burden of VI and other health conditions in Singapore. DESIGN: Population-based cross-sectional study. PARTICIPANTS: We studied the 10 009 adults (3353 Chinese, 3397 Indians, and 3259 Malays) who underwent a comprehensive eye assessment and completed the European Quality of Life-5 Dimensions (EQ-5D) questionnaire in the Singapore Epidemiology of Eye Disease Study. METHODS: We estimated the effects of VI, obesity, hypertension, diabetes, and hyperlipidemia on the EQ-5D index score using linear regression models and the association between VI and self-reported EQ-5D health problems using logistic regression models. We compared prevalence-based quality-adjusted life-year (QALY) loss associated with VI and other health conditions. For each condition, QALY loss was calculated for 100 000 persons in 1 year using associated reduction in EQ-5D index score estimated in regression analysis as disutility. MAIN OUTCOME MEASURES: The EQ-5D index score and annual QALY loss. RESULTS: The EQ-5D index score decreased with increasing VI severity in all 3 ethnicities. For example, after adjusting for sociodemographic characteristics, the difference in EQ-5D index score between adults with bilateral severe VI and those without VI was -0.044 (95% confidence interval [CI], -0.089 to 0.001) in Chinese, -0.127 (95% CI, -0.237 to -0.017) in Indians, and -0.085 (95% CI, -0.148 to -0.022) in Malays. In all 3 ethnicities, VI was associated with reporting of problems in mobility (e.g., odds ratio [OR], 3.69 for Chinese with bilateral severe VI; 95% CI, 1.21-12.13) and usual activities (e.g., OR, 6.51 for Chinese with bilateral severe VI; 95% CI, 1.59-26.58). In Indians, VI was also associated with anxiety or depression (e.g., OR, 2.68 for bilateral severe VI; 95% CI, 1.11-6.50). The annual QALY loss associated with VI was 511.8 in Chinese, 608.8 in Indians, and 706.7 in Malays, greater than that associated with other health conditions examined in this study. CONCLUSIONS: Visual impairment is associated with substantial health burden among Asians in Singapore. The relatively high burden of VI highlights the importance of VI prevention. The ethnic difference exhibited in this burden warrants further study.

Intraoperative anterior segment optical coherence tomography: a novel assessment tool during deep anterior lamellar keratoplasty.

PURPOSE: To describe the use of high-resolution anterior segment optical coherence tomography (AS-OCT) during deep anterior lamellar keratoplasty (DALK). DESIGN: Prospective case series. METHODS: At the Singapore National Eye Centre we performed sequential intraoperative AS-OCT scans using iVue 100-2 (Optovue, Fremont, CA, USA) during various DALK techniques. RESULTS: In case 1 (corneal scarring) the OCT images helped to guide manual dissection, showed the depth of the needle track before air injection, and identified the location of a small bubble when the big bubble failed. In cases 2 (macular dystrophy) and 3 (lattice), viscodissection was undertaken, but in case 2 the OCT showed the viscoelastic trapped intrastromally, compared to case 3, in which the viscobubble dissection was successful. In case 4 (irregular corneal thinning and scarring), AS-OCT enabled accurate decision on initial trephination and guided dissection. In case 5 (keratoconus), the OCT showed the achieved big-bubble and detached Descemet membrane. Case 6 was a repeat DALK; the OCT guided the manual dissection of the residual stroma underlying the failed graft. In case 7, the OCT showed an intrastromal retention of fluid that was not detectable by the operating microscope due to diffuse scarring following alkaline injury. The OCT helped to assess the location of the Descemet membrane and guided the manual dissection. CONCLUSIONS: Intraoperative high-definition AS-OCT obtained good-quality images of the cornea during DALK and proved useful in various cases of DALK to help the surgeon decide on a number of surgical steps.

Utility of EQ-5D to assess patients undergoing cataract surgery.

PURPOSE: To assess the construct validity and responsiveness of the EuroQoL-5D (EQ-5D) instrument in Asian patients undergoing cataract surgery in Singapore. METHODS: In this prospective study, English- or Chinese-speaking patients (n = 216) completed the EQ-5D and the VF-14 questionnaires before and 3 months after they underwent cataract surgery. The impact of cataracts on patients was assessed using two standard gamble (SG) questions before surgery. Construct validity of the EQ-5D index and the visual analog scale (VAS) was assessed by examining their correlation with the VF-14 and SG scores. Responsiveness of the EQ-5D was compared with that of the VF-14 in terms of the magnitude of score change associated with cataract surgery. RESULTS: We found that the EQ-5D index correlated with VF-14, SG (death), and SG (blindness) (Pearson r = 0.30, 0.23 and 0.24, respectively; p < 0.01). In contrast, we found no correlation between the EQ-VAS, VF-14, and SG scores. The mean EQ-5D index (difference, 0.06; effect size, 0.35) and VF-14 score (difference, 1.75; effect size, 0.97) of patients improved after cataract surgery (p < 0.0001). CONCLUSIONS: Our study demonstrated that the EQ-5D utility index is a valid and responsive outcome measure for evaluating the impact of cataract surgery in our Asian population. However, the implications of using the generic EQ-5D instrument to assess the cost-effectiveness of surgical interventions for visual impairment require further investigation.

Cost-effectiveness of Descemet's stripping endothelial keratoplasty versus penetrating keratoplasty.

PURPOSE: Selective endothelial transplantation in the form of Descemet's stripping endothelial keratoplasty (DSEK) is rapidly replacing traditional full-thickness penetrating keratoplasty (PK) for endothelial disease. An incremental cost-effectiveness analysis was performed to determine whether the benefits of DSEK are worth the additional costs. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients at the Singapore National Eye Center, a tertiary eye center in Singapore, with Fuchs' dystrophy or bullous keratopathy who underwent either PK or DSEK. INTERVENTION: Patients underwent either PK (n = 171) or DSEK (n = 93) from January 2001 through December 2007. Data were collected from inpatient and outpatient notes corresponding to the time immediately before the procedure to up to 3 years after. MAIN OUTCOME MEASURES: Improvements in best spectacle-corrected visual acuity were used to calculate the increase in quality-adjusted life years (QALYs) 3 years after the procedure. This was combined with hospital charges (a proxy for costs) to determine incremental cost-effectiveness ratios (ICERs) comparing PK with no intervention and DSEK with PK. RESULTS: Three-year charges for DSEK and PK were $7476 and $7236, respectively. The regression-adjusted improvement in visual acuity for PK relative to no intervention was -0.613 logarithm of the minimum angle of resolution (logMAR) units (P<0.001), and for DSEK relative to PK, it was -0.199 logMAR units (P = 0.045). The regression-adjusted marginal gain in utility for PK relative to no intervention was 0.128 QALYs (P<0.001) and for DSEK relative to PK was 0.046 QALYs (P = 0.031). This resulted in ICERs of $56 409 per QALY for PK relative to no intervention and $5209 per QALY for the more expensive DSEK relative to PK. CONCLUSIONS: If the goal is to maximize societal health gains given fixed resources, DSEK should be the preferred strategy. For a fixed budget, it is possible to achieve greater QALY gains by providing DSEK to as many patients as possible (and nothing to others), rather than providing PK.

Quantitative assessment of changes in trabeculectomy blebs after laser suture lysis using anterior segment coherence tomography.

PURPOSE: To quantify changes in bleb morphology after laser suture lysis (LSL) using anterior segment optical coherence tomography (AS-OCT). PATIENTS AND METHODS: This was a prospective observational case series of patients who underwent trabeculectomy surgery with mitomycin-C and required subsequent LSL. Subjects were assessed before and immediately after LSL, and at 3 months after LSL. At each visit, a standardized cross-sectional AS-OCT image of the bleb was obtained, from which a masked observer measured bleb height (hB), cavity height (hC), wall cross sectional area (AW), cavity cross sectional area (AC), and bleb cross sectional area (AB) using custom software. RESULTS: Twenty-five subjects (25 eyes) were examined. LSL was performed at a mean of 21.5±16.3 days after trabeculectomy. Immediately after LSL, there was a significant increase in mean hB (P=0.026) and mean hC (P=0.45) from pre-LSL. At 3 months after LSL, there was a significant increase in mean hB (P=0.003), mean AC (P=0.047), and mean AB (P=0.006) as compared with before LSL. Increase in hB and hC immediately after LSL was predictive of outcome at month 3. CONCLUSIONS: AS-OCT was able to quantify changes in bleb morphology after LSL, some of which were predictive of eventual outcome.

National survey of ophthalmologists in Singapore for the assessment and management of asymptomatic angle closure.

PURPOSE: Approximately 10% of Chinese people older than 50 years in Singapore have asymptomatic narrow angles [also termed primary angle closure suspects (PACS)]. The aim of this study was to determine the attitudes and practices of ophthalmologists in Singapore regarding the management of these patients. METHODS: A nation wide questionnaire-based survey was conducted on all registered, practicing ophthalmologists in Singapore by electronic mail and post. An ophthalmologist was defined as a doctor who had completed at least 3 years of specialist training in ophthalmology and had passed the Master's Degree in Ophthalmology or equivalent examinations. The survey asked the ophthalmologists about the methods and criteria used for the diagnosis of angle closure. It also inquired about the management of PACS and opinions on the effectiveness of prophylactic laser peripheral iridotomy (LPI) in preventing both acute and chronic angle closure. RESULTS: A total of 126 out of 158 ophthalmologists responded (79.7% response rate). Of the respondents, 84.9% would advise prophylactic LPI for asymptomatic PACS; 84.9% believed that prophylactic LPI would prevent acute angle closure but only 44% thought that it could prevent the development of glaucomatous optic nerve damage. The preferred method of prophylactic LPI was sequential argon-YAG LPI. In assessing patients for angle closure, 85.4% used gonioscopy, 92.9% assessed anterior chamber depth, and 17.5% performed provocative tests. CONCLUSIONS: Ophthalmologists in Singapore vary in the method of assessment of patients with angle closure. Most believe that prophylactic LPI should be performed for asymptomatic PACS.