Femtosecond laser-assisted in situ keratomileusis versus small-incision lenticule extraction: current approach based on evidence.

PURPOSE OF REVIEW: Laser keratorefractive surgery achieves excellent visual outcomes for refractive error correction. With femtosecond laser, small incision lenticule extraction (SMILE) is an increasingly viable alternative to laser-assisted in situ keratomileusis (LASIK). Comparative studies demonstrate similar efficacy and predictability between SMILE and LASIK, making it difficult for clinicians to choose which to use. This review thus compares femtosecond-LASIK (FS-LASK) and SMILE in various scenarios, to assist clinicians in deciding which refractive surgery procedure to recommend. RECENT FINDINGS: SMILE may be superior for highly myopic eyes due to a smaller decrease in functional optical zone. SMILE further induces less spherical aberration and less overall higher order aberrations in mesopic conditions. SMIILE also has less postoperative dry eye, making it suitable those with preexisting dry eye. For low to moderate myopic astigmatism correction, FS-LASIK has less undercorrection compared to SMILE. Lastly, SMILE has not yet received Food and Drug Administration or Conformité Européenne approval for hyperopic correction, rendering FS-LASIK the choice of procedure for hyperopic correction. SUMMARY: Both FS-LASIK and SMILE demonstrate good efficacy and predictability. Understanding specific clinical scenarios where one may be superior to the other will aid clinicians in choosing the most suitable procedure for personalized care.

Cataract surgery after corneal refractive surgery: preoperative considerations and management.

PURPOSE OF REVIEW: Corneal refractive surgery (CRS) is one of the most popular eye procedures, with more than 40 million cases performed globally. As CRS-treated patients age and develop cataract, the number of cases that require additional preoperative considerations and management will increase around the world. Thus, we provide an up-to-date, concise overview of the considerations and outcomes of cataract surgery in eyes with previous CRS, including surface ablation, laser in-situ keratomileusis (LASIK), and small-incision lenticule extraction (SMILE). RECENT FINDINGS: Challenges associated with accurate biometry in eyes with CRS have been mitigated recently through total keratometry, ray tracing, intraoperative aberrometry, and machine learning assisted intraocular lens (IOL) power calculation formulas to improve prediction. Emerging studies have highlighted the superior performance of ray tracing and/or total keratometry-based formulas for IOL power calculation in eyes with previous SMILE. Dry eye remains a common side effect after cataract surgery, especially in eyes with CRS, though the risk appears to be lower after SMILE than LASIK (in the short-term). Recent presbyopia-correcting IOL designs such as extended depth of focus (EDOF) IOLs may be suitable in carefully selected eyes with previous CRS. SUMMARY: Ophthalmologists will increasingly face challenges associated with the surgical management of cataract in patients with prior CRS. Careful preoperative assessment of the ocular surface, appropriate use of IOL power calculation formulas, and strategies for presbyopia correction are key to achieve good clinical and refractive outcomes and patient satisfaction. Recent advances in CRS techniques, such as SMILE, may pose new challenges for such eyes in the future.

Electrocatalytic Hydrogen Evolution Using A Molecular Antimony Complex under Aqueous Conditions: An Experimental and Computational Study on Main-Group Element Catalysis.

Electrocatalytic hydrogen gas production is considered a potential pathway towards carbon-neutral energy sources. However, the development of this technology is hindered by the lack of efficient, cost-effective, and environmentally benign catalysts. In this study, a main-group-element-based electrocatalyst, SbSalen, is reported to catalyze the hydrogen evolution reaction (HER) in an aqueous medium. The heterogenized molecular system achieved a Faradaic efficiency of 100 % at -1.4 V vs. NHE with a maximum current density of -30.7 mA/cm2 . X-ray photoelectron spectroscopy of the catalyst-bound working electrode before and after electrolysis confirmed the molecular stability during catalysis. The turnover frequency was calculated as 43.4 s-1 using redox-peak integration. The kinetic and mechanistic aspects of the electrocatalytic reaction were further examined by computational methods. This study provides mechanistic insights into main-group-element electrocatalysts for heterogeneous small-molecule conversion.

Endothelial cell loss associated with minimally invasive glaucoma surgery.

PURPOSE OF REVIEW: Minimally invasive glaucoma surgery (MIGS) represents a safer, albeit moderately effective surgical option for intraocular pressure control. However, the CyPass Micro-Stent (Alcon Laboratories) was withdrawn from the market in 2018 as the COMPASS-XT study demonstrated greater cornea endothelial cell (CEC) loss in patients who received the CyPass Micro-Stent with phacoemulsification compared with phacoemulsification alone. This led to the increased attention on MIGS-associated CEC loss and thus, this review will summarise the recent, available evidence on MIGS-associated CEC loss. RECENT FINDINGS: Prospective clinical trials and retrospective observational studies published between 2011 and 2021 reported a wide range of 12 month CEC loss from 'insignificant', and up to 14.6%, for phacoemulsification combined with various MIGS procedures. Recent clinical trials over the same time period reported CEC loss of 12.8-15.2% associated with phacoemulsification alone. SUMMARY: Apart from the CyPass Micro-Stent clinical trial, no other studies on combined phacoemulsification with MIGS that is 'phaco-plus' procedures have reported a higher short-term CEC loss compared with phacoemulsification alone. However, studies that specifically examine postprocedural CEC loss following phacoemulsification compared to 'phaco-plus' procedures over a longer follow-up period are required.

MACULAR SENSITIVITY AND CAPILLARY PERFUSION IN HIGHLY MYOPIC EYES WITH MYOPIC MACULAR DEGENERATION.

PURPOSE: To evaluate the interrelationship between macular sensitivity and retinal perfusion density (PD) in eyes with myopic macular degeneration (MMD). METHODS: One hundred and thirty-eight highly myopic eyes from 82 adult participants were recruited. Macular sensitivity was evaluated using the Microperimeter MP-3. Retinal PD was measured using the PLEX Elite 9000 swept source optical coherence tomography angiography. Macular sensitivity values between different categories of MMD and its relationship with optical coherence tomography angiography measurements were evaluated using multivariable linear mixed models, adjusting for age and axial length. RESULTS: Macular sensitivity reduced with increasing severity of MMD (ß ≤ -0.95, P < 0.001), whereas the best-corrected visual acuity was not associated with MMD severity (P > 0.04). Persons who were older (ß = -0.08, P < 0.001), with longer axial length (ß = -0.32, P = 0.005), presence of macular diffuse choroidal atrophy (ß = -2.16, P < 0.001) or worse MMD (ß = -5.70, P < 0.001), and presence of macular posterior staphyloma (ß ≤ -2.98, P < 0.001) or Fuchs spot (ß = -1.58, P = 0.04) were associated with reduced macular sensitivity. Macular sensitivity was significantly associated with deep retinal PD in MMD (ß = 0.15, P = 0.004) but not with superficial retinal PD (P = 0.62). CONCLUSION: There was a strong correlation between reduced macular sensitivity and increasing MMD severity, even in mild MMD independent of the best-corrected visual acuity. Furthermore, macular sensitivity was correlated with deep retinal PD, suggesting a vasculature-function relationship in MMD.

Hydrodechlorination of Dichloromethane by a Metal-Free Triazole-Porphyrin Electrocatalyst: Demonstration of Main-Group Element Electrocatalysis*.

In this work, the electrocatalytic reduction of dichloromethane (CH2 Cl2 ) into hydrocarbons involving a main group element-based molecular triazole-porphyrin electrocatalyst H2PorT8 is reported. This catalyst converted CH2 Cl2 in acetonitrile to various hydrocarbons (methane, ethane, and ethylene) with a Faradaic efficiency of 70 % and current density of -13 mA cm-2 at a potential of -2.2 V vs. Fc/Fc+ using water as a proton source. The findings of this study and its mechanistic interpretations demonstrated that H2PorT8 was an efficient and stable catalyst for the hydrodechlorination of CH2 Cl2 and that main group catalysts could be potentially used for exploring new catalytic reaction mechanisms.

Artificial intelligence in myopia: current and future trends.

PURPOSE OF REVIEW: Myopia is one of the leading causes of visual impairment, with a projected increase in prevalence globally. One potential approach to address myopia and its complications is early detection and treatment. However, current healthcare systems may not be able to cope with the growing burden. Digital technological solutions such as artificial intelligence (AI) have emerged as a potential adjunct for myopia management. RECENT FINDINGS: There are currently four significant domains of AI in myopia, including machine learning (ML), deep learning (DL), genetics and natural language processing (NLP). ML has been demonstrated to be a useful adjunctive for myopia prediction and biometry for cataract surgery in highly myopic individuals. DL techniques, particularly convoluted neural networks, have been applied to various image-related diagnostic and predictive solutions. Applications of AI in genomics and NLP appear to be at a nascent stage. SUMMARY: Current AI research is mainly focused on disease classification and prediction in myopia. Through greater collaborative research, we envision AI will play an increasingly critical role in big data analysis by aggregating a greater variety of parameters including genomics and environmental factors. This may enable the development of generalizable adjunctive DL systems that could help realize predictive and individualized precision medicine for myopic patients.

Refractive surgery.

Refractive surgery has evolved beyond laser refractive techniques over the past decade. Laser refractive surgery procedures (such as laser in-situ keratomileusis), surface ablation techniques (such as laser epithelial keratomileusis), and photorefractive keratectomy have now been established as fairly safe procedures that produce excellent visual outcomes for patients with low-to-moderate amounts of ametropia. Additionally, a broader selection of options are now available to treat a wider range of refractive errors. Small incision lenticule extraction uses a femtosecond laser to shape a refractive lenticule, which is removed through a small wound. The potential advantages of this procedure include greater tectonic strength and less dry eye. In the future, intracorneal implants could be used to treat hyperopia or presbyopia. Phakic intraocular implants and refractive lens exchange might be useful options in carefully selected patients for correcting high degrees of ametropia. Thus, physicians are now able to provide patients with the appropriate refractive corrective option based on the individual's risk-benefit profile.

Randomized Clinical Trial Comparing Femtosecond LASIK and Small-Incision Lenticule Extraction.

PURPOSE: To compare femtosecond LASIK with small-incision lenticule extraction (SMILE) for the treatment of myopia and myopic astigmatism. DESIGN: Prospective, randomized, paired-eye, single-masked clinical trial. PARTICIPANTS: Consecutive eligible patients were randomized to undergo SMILE and LASIK in either eye at a single tertiary referral eye center. METHODS: Patients were treated in each eye using the VisuMax (Carl Zeiss Meditec, Jena, Germany) 500-kHz femtosecond laser system. Excimer ablation was subsequently performed using the WaveLight EX500 excimer laser (Alcon Laboratories, Inc, Fort Worth, TX) in the eye for LASIK. MAIN OUTCOME MEASURE: Refractive predictability at 3 months. Secondary outcomes were refractive outcomes, that is, efficacy and safety at 3 and 12 months. RESULTS: We recruited 70 consecutive patients (mean age, 28±5 years; 64% women; all Asian) with no difference in preoperative spherical equivalent (SE) between eyes (-5.3±1.8 diopters [D] vs. -5.2±1.7 D; P = 0.87). At 3 months, 99% of SMILE eyes and 97% of LASIK eyes achieved SE within ±1.0 D of attempted correction (P = 1.0). Small-incision lenticule extraction achieved similar results as LASIK in terms of efficacy index (0.97±0.20 vs. 0.99±0.20; P = 0.56), uncorrected distance visual acuity (UDVA) of 20/40 or better (100% vs. 100%; P = 1.0), and UDVA of 20/20 or better (84% vs. 87%; P = 0.63). Safety index (1.1±0.2 vs. 1.1±0.2; P = 0.57) was similar between SMILE and LASIK eyes at 3 months. At 12 months, SMILE was similar to LASIK in terms of efficacy (85% vs. 83% UDVA ≥20/20; P = 0.81), predictability (99% vs. 99% ±1.0 D of attempted correction SE; P = 1.0), and safety (1.15±0.20 vs. 1.15±0.20; P = 0.93). CONCLUSIONS: The results from this randomized trial suggest that SMILE produced promising refractive outcomes in terms of predictability, efficacy, and safety at 3 and 12 months of follow-up.

Myopic optic disc changes and its role in glaucoma.

PURPOSE OF REVIEW: Optic nerve head (ONH) changes such as tilt and torsion are associated with the progression of myopia, and may in turn predispose toward glaucoma. At the same time, these ONH deformations also make the structural assessment for glaucoma difficult. Here, we review the mechanisms and changes to the myopic optic disc, and the advances in structural imaging to better evaluate the ONH in myopia. RECENT FINDINGS: The distance, depth, and angle between the optic disc and the deepest point of the elongated eyeball may be related to the degree and direction of optic disc tilt and torsion. It is hypothesized that as the eyeball grows axially, the disc is pulled toward its most protruded point. These ONH deformations in myopia are thought to induce strain on the lamina cribrosa and the axons passing through it. Recent studies have shown unique characteristics of the lamina cribrosa in myopia that may account for susceptibility toward glaucoma. New developments in imaging the ONH in myopia, including the use of optical coherence tomography-angiography may also further our understanding of the relationship between myopia and glaucoma. SUMMARY: Optic disc changes in myopia are secondary to the configuration of the posterior globe. These ONH deformations may predispose toward glaucoma, although the causative relationship between myopia and glaucoma remains to be further clarified.

Descemet membrane endothelial keratoplasty and glaucoma.

PURPOSE OF REVIEW: The aim of this review is to describe the relationship between Descemet membrane endothelial keratoplasty (DMEK) and glaucoma. RECENT FINDINGS: Glaucoma after DMEK is a serious complication that may cause permanent visual loss, affect donor endothelial cells and graft survival. The mechanisms of raised intraocular pressure (IOP) after DMEK include reverse pupillary block in the early postoperative period, and steroid response in the late phase. The reduced risk of immunogenic graft rejection after DMEK necessitates a shorter duration of steroids, which may in turn reduce the risk of steroid response. On the other hand, eyes with preexisting glaucoma that undergo DMEK may have a poorer prognosis than those without glaucoma. SUMMARY: Early recognition and treatment of raised IOP is important after DMEK. Accurate IOP measurements after DMEK may be difficult to obtain because of the presence of an air bubble, corneal oedema, and corneal irregularities. A prophylactic peripheral iridectomy is recommended to prevent reverse pupillary block. Patients should posture face-up and be evaluated in the early postoperative period, as patients may be asymptomatic despite raised IOP. In order to reduce the risk of steroid response, weaker steroids may be prescribed after 1-3 months without adverse effects on DMEK outcomes.

Optical coherence tomography angiography: a review of current and future clinical applications.

Optical coherence tomography angiography is a non-invasive imaging technique that now allows for simultaneous in vivo imaging of the morphology as well as the vasculature in the eye. In this review, we provide an update on the existing clinical applications of optical coherence tomography angiography technology from the anterior to posterior segment of the eye. We also discuss the limitations of optical coherence tomography angiography technology, as well as the caveats to the interpretation of images. As current optical coherence tomography angiography systems are optimized for the retina, most studies have focused on interpreting images from conditions such as age related macular degeneration and retinal vascular diseases. However, the interpretation of these optical coherence tomography angiography images should be taken in consideration with other multi-modal imaging to overcome the limitations of each technique. In addition, there are a growing variety of clinical applications for optical coherence tomography angiography imaging in optic nerve head evaluation for glaucoma and optic neuropathies. Further developments in anterior optical coherence tomography angiography have now allowed for evaluation of anterior segment pathology such as glaucoma, ocular surface diseases, corneal vascularisation, and abnormal iris vasculature. Future developments in software could allow for improved segmentation and image resolution with automated measurements and analysis.

Randomized controlled trial evaluating a novel community eye care programme for elderly individuals with visual impairment.

IMPORTANCE: The novel intervention was effective at improving compliance to appropriate tertiary eye care after community eye screening. BACKGROUND: Elderly individuals from low socio-economic background with visual impairment (VI) often do not attend tertiary care, even if significant eye diseases are detected while in the community. We evaluate a novel incentive care scheme (ICS) to improve compliance to appropriate follow-up after community eye screening. DESIGN: Randomized controlled trial in a population-based setting was conducted. PARTICIPANTS: A total of 140 elderly individuals with VI (visual acuity <6/12, mean age ± SD = 66.6 ± 8.9 years, 46.4% female) were included. METHODS: Participants were randomized to either ICS (N = 72) or usual care (UC; N = 68). ICS incorporated patient education, social support and financial assistance to assist individuals in attending tertiary eye care. UC comprised of a standard referral letter and advice. MAIN OUTCOME MEASURE: Primary outcome included compliance to eye care referral. Secondary outcomes included best-corrected visual acuity and vision-related quality of life assessed at baseline and 3 months. RESULTS: Participants receiving the ICS intervention had higher rates of compliance to tertiary eye care attendance compared to UC (31.9% vs. 16.2%, respectively, P = 0.027). While we observed an overall significant improvement in best-corrected visual acuity at 3 months in both groups (P < 0.05), we found no significant differences in Rasch-transformed vision-related quality of life scores between groups (all P > 0.05). Identified barriers for tertiary healthcare access included patient attitudes and financial- and health-related barriers. CONCLUSION AND RELEVANCE: Our pilot RCT found that ICS improved adherence to appropriate tertiary eye care referrals after community eye screening in elderly people with VI.

Central corneal thickness in glaucoma.

PURPOSE OF REVIEW: The purpose of this review is to summarize the role of central corneal thickness (CCT) in the clinical management of a glaucoma patient. RECENT FINDINGS: The prognostic value of CCT is well recognized in patients with ocular hypertension. However, its predictive value in other glaucoma suspects and patients with established glaucoma is less certain. Tonometry artefacts can result from variations in CCT. However, an adequately validated correction algorithm for Goldmann applanation tonometry measurements does not exist. Newer methods of tonometry are potentially less influenced by CCT but are limited in their clinical use. There may also be biological and genetic associations between corneal thickness and glaucoma. Demographics, environmental factors, glaucoma treatment and the measurement device used have a significant influence on CCT, and should be considered when interpreting the effect of cornea thickness in patients with glaucoma. New measurements of the biomechanical properties of the cornea are likely to be better approximations of the globe biomechanics than CCT, but these require further evaluation. SUMMARY: The clinical significance of CCT is well recognized in the context of glaucoma diagnosis and management, though the extent of its importance remains debatable. Corneal biomechanical properties may be more significantly associated with glaucoma than CCT.

Serial optical coherence tomography angiography for corneal vascularization.

PURPOSE: Recently, optical coherence tomography angiography (OCTA) has been used to successfully delineate vessels within the retina. This current study aims to assess corneal vascularization secondary to herpetic keratitis pre- and post-treatment using serial OCTA imaging adapted for the anterior segment. METHODS: All eyes were scanned using the split-spectrum amplitude decorrelation angiography (SSADA) algorithm on the AngioVue OCTA system (Optovue Inc. Fremont, CA, USA) with an anterior segment lens adapter. Multiple scans in the regions of interest (ROI) before and after treatment were analysed to assess change in corneal vascularization in response to each treatment modality. RESULTS: We analyzed a total of 12 OCTA scans in three eyes with corneal vascularization, comparing images pre- and 3 months post-treatment. We found that the OCTA was able to detect a significant decrease in area of vascularization in all eyes: including fine-needle diathermy (48 ± 7 to 41 ± 5 %, P = 0.048), subconjunctival bevacizumab (45 ± 7 to 38 ± 5 %, P = 0.015) and systemic steroid treatment following graft rejection (38 ± 1 to 32 ± 2 %, P = 0.003). CONCLUSIONS: Our preliminary study of serial OCTA scans suggests that this may be a useful tool for objective quantification of corneal vascularization. Future development of image processing software will be needed for clinical use or trials to evaluate anti-vascular therapies.

Five-Year Graft Survival Comparing Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty.

PURPOSE: To compare 5-year graft survival after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in Asian eyes. DESIGN: Prospective, nested, cohort study. PARTICIPANTS: Consecutive patients who underwent DSAEK (423 eyes) or PK (405 eyes) for Fuchs' endothelial dystrophy (FED) or bullous keratopathy (BK). METHODS: Clinical data and donor and recipient characteristics were recorded from our prospective cohort from the Singapore Corneal Transplant Registry. All surgeries were performed by the corneal surgeons at our center, which included cases performed or partially performed by corneal fellows in training under direct supervision. MAIN OUTCOME MEASURES: Five-year cumulative graft survival. RESULTS: Overall mean age was 67.8±9.8 years, and 50.1% of patients were men. There were no significant differences in age (P = 0.261) or gender (P = 0.78) between PK and DSAEK groups in our predominantly Chinese (76.6%) Asian cohort, with more BK compared with FED (68.1% vs. 31.9%; P < 0.001). Overall 5-year graft survival was superior for DSAEK compared with PK (79.4% vs. 66.5%; P < 0.001, log-rank test). Median 5-year percent endothelial cell density loss was significantly greater in PK compared with DSAEK (60.9% vs. 48.7%; P = 0.007). Cox regression analysis revealed that BK was a significant factor associated with graft failure (hazard ratio [HR], 3.30; 95% confidence interval [CI], 2.05-5.33; P < 0.001), and PK was more likely to fail compared with endothelial keratoplasty (HR, 1.61; 95% CI, 1.08-2.41; P = 0.02) adjusting for confounders such as recipient age, gender, and donor factors. Five-year cumulative incidence of complications such as graft rejection (P < 0.001), epitheliopathy (P < 0.001), suture-related corneal infections (P < 0.001), and wound dehiscence (P = 0.002) were greater in the PK group compared with the DSAEK group. CONCLUSIONS: In Asian eyes from the same study cohort with standardized surgical and postoperative regimes, 5-year graft survival was superior for DSAEK compared with PK in eyes with FED and BK.

Optical coherence tomography angiography in dural carotid-cavernous sinus fistula.

BACKGROUND: Recently, applications of optical coherence tomography angiography (OCTA) have been limited to the retina and posterior segment. Although early studies have described its use for other clinical applications, its role in anterior segment vasculature and optic disc imaging has been limited thus far. CASE PRESENTATION: We describe a novel clinical application of OCTA in a patient with dural carotid-cavernous sinus fistula (CCF), which was complicated by increased intra-ocular pressure (IOP). In this case report, we used the OCTA to delineate increased epsicleral venous flow in the affected eye with secondary raised IOP. Current measurements of episcleral venous pressure are either invasive or provide highly variable results, thus the OCTA may have the potential to provide a more reliable approach to assess episcleral vasculature. We also describe the use of OCTA to detect early glaucomatous nerve damage, associated with focal reductions in peripapillary retinal perfusion. CONCLUSIONS: We present an early report of using OCTA of the anterior segment to allow rapid, non-invasive delineation of abnormal episcleral venous plexus secondary to dural CCF. The OCTA was also useful for detecting early reduction in peripapillary retinal perfusion, which suggests early glaucomatous optic neuropathy. This suggests that OCTA may have a role for determining risk of glaucoma in patients with CCF in future.

Optical Coherence Tomography Angiography for Anterior Segment Vasculature Imaging.

PURPOSE: To evaluate the application of an optical coherence tomography angiography (OCTA) system adapted for the assessment of anterior segment vasculature. DESIGN: Cross-sectional, observational study. PARTICIPANTS: Consecutive subjects with normal eyes on slit-lamp clinical examination and patients with abnormal corneal neovascularization. METHODS: All scans were performed using a commercially available AngioVue OCTA system (Optovue, Inc., Fremont, CA) using an anterior segment lens adapter and the split-spectrum amplitude decorrelation angiography algorithm. Each subject underwent scans from 4 quadrants (superior, inferior, nasal, and temporal) in each eye by 2 trained, independent operators. MAIN OUTCOME MEASURES: Analysis of signal strength, image quality, and reproducibility of corneal vascular measurements was performed. RESULTS: In our study of 20 normal subjects (10 men, 10 women; mean age, 25.3±7.8 years), we found good repeatability (κ coefficient, 0.76) for image quality score and good interobserver agreement for vasculature measurements (intraclass coefficient, 0.94). After optimization of the angiography scan protocol, vascular measurements within the regions of interest were compared in the superior versus inferior quadrants (mean vascular loops, 3.34±1.16 vs. 3.12 ± 0.90 [P = 0.768]; segment-to-loop ratio, 4.18±0.71 vs. 4.32±0.87 [P = 0.129]; fractal dimension [Df] value, 1.78±0.06 vs. 1.78±0.06 [P = 0.94]; vascular loop area, 25.9±14.5 vs. 25.9±10.7 × 10(-3) mm(2) [P = 0.21]) and nasal versus temporal quadrant (mean vascular loops, 2.89±0.98 vs. 3.57±0.99 [P < 0.001]; segment-to-loop ratio, 3.94±0.69 vs. 4.55±0.78 [P = 0.897]; Df value, 1.78±0.06 vs. 1.77±0.06 [P = 0.14]; vascular loop area, 29.7±15.7 vs. 22.1±7.1 × 10(-3) mm(2) [P = 0.38]. We then used the established OCTA scanning protocol to visualize abnormal vasculature successfully in 5 patients with various corneal pathologic features, including graft-associated neovascularization, postherpetic keratitis scarring, lipid keratopathy, and limbal stem cell deficiency. CONCLUSIONS: This preliminary study describes a method for acquiring OCTA images of the cornea and limbal vasculature with substantial consistency. This technique may be useful for the objective evaluation of corneal neovascularization in the future.

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.