logMAR Chart Research Articles

Does the optimal level of illumination improve both visual functions and visual comfort in schoolchildren with low vision?

Lighting modification is commonly performed by optometrists and occupational therapists to enhance visibility and visual comfort among schoolchildren with low vision. The purpose of this study is to determine the optimal illumination level for visual function and visual comfort of schoolchildren with low vision and the relationship between them. A cross-sectional study was conducted to assess five levels of illumination ranging from 125 lux to 2000 lux to determine the optimal illumination for visual functions and visual comfort in schoolchildren with low vision from a special education school for blind in Malaysia. Purposive sampling was done to recruit forty-two schoolchildren with low vision for this study. Visual functions assessed were visual acuity, measured using the Early Treatment Diabetic Retinopathy Study LogMAR chart at distance and near, contrast sensitivity (CS) measured using the Pelli-Robson chart at distance and the Mars CS chart at near. Reading speed was determined using the Universiti Kebangsaan Malaysia Malay Language Related Word Reading Text test chart. Subjects were asked to rate their visual comfort using a validated questionnaire at the end of each measurement of visual functions and reading speed for the different illumination levels. Visual acuity and contrast sensitivity at distance and near, visual comfort and reading speed improved significantly with increase in illumination levels (p<0.05). However, the interaction between illumination level and level of low vision was not significant (p>0.05). Visual comfort was significantly associated with visual function (p<0.05), while direct association between visual comfort and illumination level was not significant (p>0.05). Optimal illumination for improvement of visual function, reading speed and visual comfort range from 276.67 lux to 701.59 lux. Majority of the schoolchildren with low vision had improved visual function, reading speed and visual comfort with increased illumination. Illumination of at least 600 lux is recommended for maximum visual functioning and visual comfort of schoolchildren with low vision.

Unveiling Visual Acuity in 58,712 Four-Year-Olds: Standardized Assessment Defined Normative Visual Acuity Threshold.

The purpose was to define the threshold of normal visual acuity (VA), mean monocular and binocular VA, and interocular difference in the uniform cohort of healthy four-year-old children. All the children were recruited from the Croatian National Registry of Early Amblyopia Detection database. LEA Symbols® inline optotypes were used for VA testing at near and distance, binocularly and monocularly. The pass cut-off level was set to ≤0.1 logMAR. The final sample consisted of 58,712 four-year-old children. In total, 83.78% of the children had unremarkable results, and 16.22% of the children were referred to examination. Of those, 92% of the children were referred due to binocular, and 8% of the children due to monocular causes. The children referred due to binocular causes demonstrated a VA of 0.3 ± 0.24, while the children referred due to monocular causes 0.6 ± 0.21. The ROC curve analysis defined the uniform cut-off value for a normative VA of 0.78. We analyzed the largest uniform cohort of 58,712 children, and have determined normative data for binocular and monocular VA tested with gold standard logMAR chart in four-year-old children. The results presented here established no reasoning to further utilize historical protocols in testing VA in preschool children aged ≥ 4 years.

Ocular toxicity of daily anti-tubercular treatment regimen: A prospective observational study

Context: India carries a significant burden of TB which is the commonest cause of infectious disease-related mortality. Anti-tubercular drugs can cause serious ocular toxic effects. Optical coherence tomography (OCT) can be used as a valuable tool in the quantitative analysis of anti-tubercular treatment (ATT)-induced toxic optic neuropathy. Aims: To study the changes in visual parameters in patients on ATT and to analyze the OCT changes in patients by taking measurements once before initiation of treatment and once during ongoing treatment (between three and six months). Settings and Design: Tertiary care center, Prospective observational study. Methods and Material: A prospective observational study was conducted in 140 eyes of 70 subjects undergoing ATT as per the latest RNTCP guidelines where the following determinants were examined, and the corresponding values were taken once before initiation of treatment and once during ongoing treatment (between three and six months) and results were analyzed. Around 90% of the subjects were examined at the end fourth month. Visual acuity was taken using the Log Mar chart, color vision using Ishihara’s chart, and slit lamp examination and fundus evaluation using a 90 D lens. OCT was done and average nasal, temporal, superior, and inferior quadrant retinal nerve fiber layer (RNFL) measurements were taken. Perimetry was also done; however, findings were not included in this study. Statistical Analysis Used: Frequency and percentage were applied to study the changes in visual parameters in patients on ATT. A paired t-test was applied for numerical variables to analyze the OCT changes in patients undergoing ATT. A P value < 0.05 was considered statistically significant. Results: Despite a near-normal appearance of the fundus on ophthalmoscopy, OCT clearly demonstrated and quantified the loss of retinal nerve fibers. Statistically significant RNFL thinning (P value < 0.001) was noted in the superior, temporal, and inferior quadrants and least in the nasal quadrant (P = 0.005). Significant deterioration in visual acuity was observed following three months of ATT (P = 0.001). Red-green color vision abnormalities were detected in 14 out of 140 eyes (10%). Conclusions: RNFL thickness was reduced on OCT. RNFL thickness quantification and assessment of other visual parameters especially color vision help in the early diagnosis of ocular toxic effects of ATT. Hence, awareness and active screening are imperative in preventing visual impairment and blindness.

Nurse-led counselling programme on the adherence to eye patch application among children with amblyopia: a randomised control trial

ObjectiveTo assess the impact of the nurse-led counselling programme on eye patch application for improvement of adherence to eye patch application and vision among children with amblyopia.Material and methodsA randomised...

PREOPERATIVE AND POSTOPERATIVE LEVELS OF ANXIETY ACCORDING TO THE VISUAL ACUITY OF PATIENTS UNDERGOING CATARACT SURGERY

Aim: To evaluate preoperative and postoperative levels of anxiety according to visual acuity and sociodemographic characteristics in patients undergoing cataract surgery. Method: The study included 100 patients who were planned to undergo cataract surgery because of reduced vision. One day preoperatively and at one month postoperatively, all the patients were administered the sociodemographic data form and the Spielberger State-Trait Anxiety Inventory (STAI TX-1 and TX-2). All the patients underwent a detailed preoperative and postoperative ophthalmological examination. Visual acuity was evaluated with a logMAR Chart. Results: The visual acuity on the LogMAR chart of the patients was mean 1.1±0.3 preoperatively and 0.1±0.1 postoperatively. Visual acuity was determined to have significantly increased postoperatively and the STAI FORM TX-2 points significantly decreased (p=0.04). The postoperative decrease in the LogMAR chart was statistically significant (p<0.001). A significant positive correlation was determined between the preoperative STAI FORM TX-1 points and the preoperative STAI FORM TX-2 points. The mean STAI FORM TX-1 points of the patients with an education level of middle school or below were found to be significantly higher than those of patients educated to university level or higher (p=0.012). The visual acuity (LogMAR) of patients who had previously received psychiatric treatment were found to be significantly lower than those of patients who had not received any psychiatric drug treatment (p=0.027). Conclusion: Patients with cataracts are anxious in a general sense, independently of surgery. The increase in vision after cataract surgery is important in respect of decreasing levels of trait anxiety.

Comparative Analysis of Telepresence Robots’ Video Performance: Evaluating Camera Capabilities for Remote Teaching and Learning

The COVID-19 outbreak demonstrated the viability of various remote working solutions, telepresence robots (TPRs) being one of them. High-quality video transmission is one of the cornerstones of using such solutions, as most of the information about the environment is acquired through vision. This study aims to compare the camera capabilities of four models of popular telepresence robots using compact reduced LogMAR and Snellen optometry charts as well as text displayed on a projector screen. The symbols from the images are extracted using the Google Vision OCR (Optical Character Recognition) software, and the results of the recognition are compared with the symbols on the charts. Double 3 TPR provides the best quality images of optometric charts, but the OCR results of measurements of the image on the projector do not show the clear advantage of one single model over the others. The results demonstrated by Temi 2 and Double 3 TPRs are generally better than the others, suggesting that these TPRs are more feasible to be used in teaching and learning scenarios.

Significant loss of retinal nerve fibre layer and contrast sensitivity in people with well controlled HIV disease: implications for aging with HIV.

Antiretroviral therapy has decreased the prevalence of retinal opportunistic infections in people living with HIV (PLWH). However, abnormalities in visual function are evident and may be associated with an early onset of aging in PLWH. In this study, we examined the Retinal Nerve Fibre Layer (RNFL) thickness and visual function in PLWH and HIV non-infected controls in Malaysia. Cross-sectional study. Two hundred and two (202) PLWH without retinal opportunistic infection and 182 age-matched, HIV seronegative individuals were enrolled. PLWH were recruited from the Infectious Disease clinic at the University Malaya Medical Centre. Controls were recruited among the hospital staff and community volunteers. RNFL thickness was measured with spectral domain optical coherence tomography (SDOCT). Visual functions include visual acuity using LogMAR chart and contrast sensitivity using Pelli- Robson Chart. All PLWH (mean age 46.1 years ± 9.9 years) in the study were on ART and 61.2% had a CD4+ T-cell count more than 500 cell/μl. The mean visual acuity was similar between the two groups (LogMAR 0.05 vs. 0.07, p = 0.115). Contrast sensitivity was lower in PLWH compared to HIV seronegative individuals (1.90 vs 1.93, p = 0.032). RNFL thickness was significantly thinner in the temporal quadrant for PLWH compared to controls (68.89 μm vs 74.08 μm, p = 0.001). Changes in RNFL thickness and contrast sensitivity were seen in PLWH despite their relatively young age and well controlled HIV disease. The changes reflect structural and functional deficits, and could have long-term implications on their health trajectory.

A STUDY TO ASSESS CHANGE IN CONTRAST SENSITIVITY AND VISUAL ACUITY IN PROLIFERATIVE DIABETIC RETINOPATHY PATIENTS UNDERGOING ANTI-VEGF TREATMENT AND ROLE OF LOW VISION AID IN SUCH PATIENTS

Objective: The aim of this study was to study the effect of intravitreal anti-vascular endothelial growth factor (VEGF) on the visual acuity (VA) using logMAR charts and the contrast sensitivity (CS) using the pelli-robson chart in patients of advanced diabetic retinopathy. Design: We performed a retrospective study to assess the change in CS and VA in diabetic retinopathy (DR) with or without proliferative DR patients receiving intra-vitreal anti VEGF. Methods: The study was done at our institution where 40 patients of DR were included in the study, 20 cases (20 eyes) and 20 controls (20 eyes). Moreover, it comes under the criteria of low vision and above 18 years of age and VA >6/60. VA and CS were compared before injection and after injection at 14 days, 30 days, and 90 days, respectively. Results: On comparing the mean of CS change before injections and after injections at 14 days (p=0.036), 30 days (p=0.012), and 90 days (p=0.012), respectively, showed a significant association between change in CS change within group but on comparing with control group at 14 days (p=0.195), 30 days (p=0.247), 90 days (p=0.247), respectively, showed no significant association. Another comparison of mean VA before injection and after injection in the case group at 14 days, 30 days, and 90 days, respectively, (p=0.329) remains the same. Which is insignificant but on comparison with the control group (p=0.02) showed a significant association. Conclusion: Whatever VA and CS are achieved with anti-VEGF was completed at 14 days of injection.

Visual parameter status as a predictive factor for the outcomes of occlusion therapy in anisometropic amblyopia.

The purpose is to compare visual parameters between normal and amblyopic eyes in anisometropic amblyopia and to find predictive factors for occlusion therapy. Sixty patients with anisometropic amblyopia between the ages of 5 and 25 years were enrolled in the prospective, longitudinal, and interventional study. Patients were selected based on no improvement with spectacle correction alone after 1 month of follow-up. Baseline parameters such as LogMAR visual acuity, LEA contrast sensitivity, TNO stereopsis test, online Farnsworth D-15 test for color vision, accommodation with RAF ruler, +2.00/-2.00 flipper test, and dynamic retinoscopy were recorded. All patients were treated with occlusion therapy depending on their grades of amblyopia. After 6 months of follow-up, improvement in visual acuity was recorded with a LogMAR chart and correlated with initial visual parameters. Paired "t" test, Chi-square test, independent "t" test, analysis of variance test were used as statistical analysis. Visual functions such as contrast sensitivity, accommodative facility, near point of accommodation, and accommodative amplitude showed a statistically significant difference between normal and amblyopic eyes of anisometropic amblyopia patients, whereas color vision did not differ significantly between normal and amblyopic eyes. Sixty-seven percentage of patients had poor stereopsis. Eighty percentage of patients who were younger had improvement in final best-corrected visual acuity and these patients had better stereopsis, contrast sensitivity, and mild-to-moderate amblyopia on initial testing. The age of the patient, degree of anisometropia, spherical equivalent in amblyopic eyes, stereopsis, contrast sensitivity values at initial presentation, and compliance to occlusion therapy were found to be positive predictive factors of occlusion therapy.

Pars plana vitrectomy with internal limiting membrane flap versus pars plana vitrectomy with conventional internal limiting membrane peeling for large macular hole.

Macular hole (MH) is a full-thickness defect in the central portion of the retina that causes loss of central vision. According to the usual definition, a large MH has a diameter greater than 400 µm at the narrowest point. For closure of MH, there is evidence that pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling achieves better anatomical outcomes than standard PPV. PPV with ILM peeling is currently the standard of care for MH management; however, the failure rate of this technique is higher for large MHs than for smaller MHs. Some studies have shown that the inverted ILM flap technique is superior to conventional ILM peeling for the management of large MHs. To evaluate the clinical effectiveness and safety of pars plana vitrectomy with the inverted internal limiting membrane flap technique versus pars plana vitrectomy with conventional internal limiting membrane peeling for treating large macular holes, including idiopathic, traumatic, and myopic macular holes. The Cochrane Eyes and Vision Information Specialist searched CENTRAL, MEDLINE, Embase, two other databases, and two trials registries on 12 December 2022. We included randomized controlled trials (RCTs) that evaluated PPV with ILM peeling versus PPV with inverted ILM flap for treatment of large MHs (with a basal diameter greater than 400 µm at the narrowest point measured by optical coherence tomography) of any type (idiopathic, traumatic, or myopic). We used standard methodological procedures expected by Cochrane and assessed the certainty of the body of evidence using GRADE. We included four RCTs (285 eyes of 275 participants; range per study 24 to 91 eyes). Most participants were women (63%), and of older age (range of means 59.4 to 66 years). Three RCTs were single-center trials, and the same surgeon performed all surgeries in two RCTs (the third single-center RCT did not report the number of surgeons). One RCT was a multicenter trial (three sites), and four surgeons performed all surgeries. Two RCTs took place in India, one in Poland, and one in Mexico. Maximum follow-up ranged from three months (2 RCTs) to 12 months (1 RCT). No RCTs reported conflicts of interest or disclosed financial support. All four RCTs enrolled people with large idiopathic MHs and compared conventional PPV with ILM peeling versus PPV with inverted ILM flap techniques. Variations in technique across the four RCTs were minimal. There was some heterogeneity in interventions: in two RCTs, all participants underwent combined cataract-PPV surgery, whereas in one RCT, some participants underwent cataract surgery after PPV (the fourth RCT did not mention cataract surgery). The critical outcomes for this review were mean best-corrected visual acuity (BCVA) and MH closure rates. All four RCTs provided data for meta-analyses of both critical outcomes. We assessed the risk of bias for both outcomes using the Cochrane risk of bias tool (RoB 2); there were some concerns for risk of bias associated with lack of masking of outcome assessors and selective reporting of outcomes in all RCTs. All RCTs reported postoperative BCVA values; only one RCT reported the change in BCVA from baseline. Based on evidence from the four RCTs, it is unclear if the inverted ILM flap technique compared with ILM peeling reduces (improves) postoperative BCVA measured on a logarithm of the minimum angle of resolution (logMAR) chart at one month (mean difference [MD] -0.08 logMAR, 95% confidence interval [CI] -0.20 to 0.05; P = 0.23, I2 = 65%; 4 studies, 254 eyes; very low-certainty evidence), but it may improve BCVA at three months or more (MD -0.17 logMAR, 95% CI -0.23 to -0.10; P < 0.001, I2 = 0%; 4 studies, 276 eyes; low-certainty evidence). PPV with an inverted ILM flap compared to PPV with ILM peeling probably increases the proportion of eyes achieving MH closure (risk ratio [RR] 1.10, 95% CI 1.02 to 1.18; P = 0.01, I2 = 0%; 4 studies, 276 eyes; moderate-certainty evidence) and type 1 MH closure (RR 1.31, 95% CI 1.03 to 1.66; P = 0.03, I² = 69%; 4 studies, 276 eyes; moderate-certainty evidence). One study reported that none of the 38 participants experienced postoperative retinal detachment. We found low-certainty evidence from four small RCTs that PPV with the inverted ILM flap technique is superior to PPV with ILM peeling with respect to BCVA gains at three or more months after surgery. We also found moderate-certainty evidence that the inverted ILM flap technique achieves more overall and type 1 MH closures. There is a need for high-quality multicenter RCTs to ascertain whether the inverted ILM flap technique is superior to ILM peeling with regard to anatomical and functional outcomes. Investigators should use the standard logMAR charts when measuring BCVA to facilitate comparison across trials.

One-Year Results of Photorefractive Keratectomy for Myopia and Compound Myopic Astigmatism with 210 nm Wavelength All Solid-State Laser for Refractive Surgery.

To examine the 12-month clinical and refractive outcomes of PRK performed with a UV all-solid-state laser. The study included healthy patients with myopia and/or compound myopic astigmatism enrolled for refractive surgery and treated with PRK using a 210 nm wavelength, 2 kHz repetition rate, UV all-solid-state laser (LaserSoft, Katana Technologies GmbH, Kleinmachnow, Germany). All subjects were examined at baseline and after 1, 3, 6, and 12 months after the treatment with a slit lamp, refraction, visual acuity assessment (logMAR chart), tonometry, ophthalmoscopy, and corneal tomography with a Scheimpflug camera. The outcome measures considered were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, central corneal thickness, and transparency. The efficacy, safety, predictability, and stability were determined. The study included 34 eyes of 19 patients. The mean UDVA changed from 1.20 ± 0.43 to -0.05 ± 0.10 logMAR at 12 months, and the mean CDVA changed from -0.03 ± 0.06 to -0.06 ± 0.09 logMAR, respectively. The mean spherical equivalent (SE) changed from -4.90 ± 2.12 D to -0.01 ± 0.40 D and was within ±0.50 D of the intended correction in 91% of eyes and within ±1.00 D in 97% of eyes at 12 months. No eyes lost lines of visual acuity, and 64% of eyes gained one or more lines. PRK with the 210 nm wavelength, 2 kHz repetition rate, all-solid-state laser LaserSoft system proved to have good visual, refractive, and clinical outcomes after the follow-up at 12 months. The emerging gas-free, solid-state technology might be considered a valid alternative for the gas operating lasers for corneal refractive surgery.

Need of optical aids for schools for blind students in Pune and Nasik districts and compliance of their use.

To assess the need for spectacles and low-vision aids (LVA) in students attending schools for the blind and study their compliance with use. Comprehensive ocular evaluation was performed using a hand-held slit lamp and ophthalmoscope. Vision acuity was measured using a logarithm of the minimum angle of resolution (logMAR) chart for distance, as well as for near. Spectacles and LVAs were dispensed after refraction and LVA trial. Follow-up was performed to assess the vision using the LV Prasad Functional Vision Questionnaire (LVP-FVQ) along with compliance with use after 6 months. Of the 456 students examined from six schools, 188 (41.2%) were female; 147 (32.2%) were <10 years of age. In all, 362 (79.4%) were blind since birth. The students dispensed only LVAs were 25 (5.5%), only spectacles were 55 (12.1%), and both spectacle and LVAs were 10 (2.2%). The vision improved using LVAs in 26 (5.7%) and using spectacles in 64 (9.6%). There was a significant improvement in LVP-FVQ scores (P < 0.001). Also, 68/90 students were available for follow-up, of whom 43 (63.2%) were compliant to use. Causes of not wearing spectacles or LVA in 25 were left somewhere or lost 13 (52%), broken 3 (12%), uncomfortable to use 6 (24%), not interested to use 2 (8%), and got operated 1 (4%). Although the dispensing of LVA and spectacles improved the visual acuity and vision function of 90/456 (19.7%) students, nearly a third were not using them after 6 months. Efforts need to be taken to improve the compliance of use.

A clinical trial on phakic intraocular lens for the treatment of refractive amblyopia in children and adolescents.

To analyze the demographics and clinical outcomes of posterior chamber phakic intraocular (IOL) implantation for refractive amblyopia in children and adolescents. A prospective interventional study was performed on children and adolescents with amblyopia at a tertiary eye care center from January 2021 to August 2022. Twenty-three eyes of 21 anisomyopic and isomyopic amblyopia patients operated for posterior chamber phakic IOL (Eyecryl phakic IOL) as a treatment for amblyopia were included in the study. Patient demographics, pre- and postoperative visual acuity, cycloplegic refraction, anterior and posterior segment examination, intraocular pressure, pachymetry, contrast sensitivity, endothelial count, and patient satisfaction scores were evaluated. Patients were followed up at day 1, 6 weeks, 3 months, and 1 year after surgery, and visual outcomes and complications were documented. The mean age of patients was 14.16 ± 3.49 years (range: 10-19 years). The mean intraocular lens power was - 12.20 diopter spherical (DS) in 23 eyes and - 2.25 diopter cylindrical (DC) in four patients. The mean unaided distant visual acuity (UDVA) and best-corrected visual acuity (BCVA) were 1.39 ± 0.25 and 0.40 ± 0.21 preoperatively on the log of minimum angle of resolution (logMAR) chart. Postoperatively, the visual acuity improved by 2.6 lines in 3 months period and maintained till 1 year. Postsurgery, contrast sensitivity in the amblyopic eyes significantly improved, and the average endothelial loss recorded was 5.78% at 1 year, which was statistically insignificant. Patient satisfaction score was statistically significant, with 4.736/5 recorded on the Likert scale. Posterior chamber phakic IOL is a safe, effective, and alternative method for treating amblyopia patients who are noncompliant with glasses, contact lenses, and keratorefractive procedures.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

Prevalence and Risk Factors of Refractive Errors and Effective Spectacle Coverage in Emiratis and Non-Emiratis Aged 40 Years or Older: the Dubai Eye Health Survey.

The aim was to investigate the prevalence and risk factors of refractive errors (REs) and the effective spectacle coverage in Emiratis and non-Emiratis in Dubai. The Dubai Eye Health Survey was a population-based cross-sectional study of participants aged 40 years or older. Distance and near visual acuity (VA), and noncycloplegic automated refraction were tested according to a standardized protocol. Distance VA was tested using the Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR chart at 3m and near VA was measured using the near vision logMAR chart at 40cm under ambient lighting. Myopia was defined as spherical equivalent of refraction of less than -0.50 diopters (D), and hypermetropia as spherical equivalent of more than +0.50D. Astigmatism was defined as cylinder power of 0.5D or greater. Effective spectacle coverage for distance vision was computed as met need/(met need+unmet need+under-met need)×100%. Multivariable logistic regression models were used to examine associations between sociodemographic factors and RE. The authors included 892 participants (446 Emiratis and 446 non-Emiratis) in the analysis. The prevalence of hypermetropia was 20.4% [95% confidence interval (CI): 16.8%-24.4%] in Emiratis and 20.6% (95% CI: 20.0%-24.7%) in non-Emiratis. The prevalence of myopia and high myopia was 27.4% (95% CI: 23.3%-31.7%) and 1.8% (95% CI: 0.8%-3.5%) in Emiratis, and 19.5% (95% CI: 15.9%-23.5%) and 0.9% (95% CI: 0.2%-2.3%) in non-Emiratis, respectively. High education (P=0.02) and not currently working (P=0.002) were risk factors of myopia in non-Emiratis only. The prevalence of astigmatism was 7.4% (95% CI: 5.1%-10.2%) in Emiratis and 1.6% (95% CI: 0.6%-3.2%) in non-Emiratis. This prevalence was higher in individuals aged over 60 years (P<0.001) and men (P=0.014) among Emiratis. The prevalence of anisometropia and uncorrected presbyopia was 11.4% (95% CI: 8.6%-14.8%) and 0.7% (95% CI: 0.1%-2.0%) in Emiratis, and 9.2% (95% CI: 6.7%-12.3%) and 0.4% (95% CI: 0.05%-1.6%) in non-Emiratis, respectively. The effective spectacle coverage was 62.3% (95% CI: 54.0%-70.6%) and 69% (95% CI: 60.5%-77.5%) in Emiratis and non-Emiratis, respectively. A high proportion of Emiratis and non-Emiratis was affected by RE without optimal effective spectacle coverage, highlighting the imperativeness of intervention to alleviate the burden. The findings may help facilitate evidence-based policymaking concerning the delivery of eye care services and allocation of medical resources in Dubai.

In-Office Sulfur Hexafluoride (SF6) Injection to Close Recently Operated or Reopened Macular Holes: A Minimal Approach Technique.

To describe an in-office minimal approach technique for closing recently operated full thickness macular holes (FTMH), when closure was not fully achieved or there was macular hole re-formation, without performing another pars plana vitrectomy (PPV). Retrospective case series study. Nine patients were included in this case series. All patients were diagnosed with FTMH characterized by a decrease in visual acuity (VA) and metamorphopsias. All patients initially underwent a standard PPV procedure with 20% sulfur hexafluoride (SF6) injection. After 1-16 weeks, no closure or reformation of the macular hole was observed. Fluid-SF6 exchange was performed in the slit lamp, with the aim of injecting a 50% gas bubble of pure SF6 into the vitreous cavity, according to a minimally invasive in-office technique. Postoperatively, all patients achieved successful macular hole closure and VA showed an average improvement of approximately 4 lines on the EDTRS logarithm of the minimum angle of resolution (logMAR) chart. In particular, the mean corrected distance visual acuity improved from 0.99 ± 0.27 logMAR to 0.33 ± 0.23 logMAR (P = 0.03). The minimal surgical in-office technique of SF6 injection for the management of reopened macular holes after a recent PPV procedure shows promising results.

Subjective refractions determined by Dyop® and LogMAR chart as fixation targets

Background: Dyop® is a dynamic optotype with a rotating and segmented visual stimulus. It can be used for visual acuity and refractive error measurement. The objective of the study was to compare refractive error measurement using the Dyop® acuity and LogMAR E charts.

Tomographic prognostic factors for visual improvement after pars plana vitrectomy for epiretinal membrane

AbstractPurpose: To evaluate postoperative changes and investigate tomographic prognostic factors of visual impairment after vitrectomy for epiretinal membrane (ERM).Methods: A retrospective observational study on patients who underwent pars plana vitrectomy for ERM by a single experimented surgeon. Best corrected visual acuity (BCVA) on the logMAR chart and optical coherence tomography (OCT) features were recorded before surgery and at the last visit. Tomographic parameters analysed were: central foveal thickness (CFT), foveal contour morphology, external limiting membrane (ELM), ellipsoid zone (EZ) and interdigitation zone (IZ) integrity, the presence of intraretinal fluid (IRF), subretinal fluid, disorganization of retinal inner layers (DRIL) and subfoveal deposits. Student's t‐test and Pearson's correlation coefficients were used for statistical analysis. p Values &lt;0.05 were considered statistically significant.Results: Forty‐seven eyes of 43 patients were included. The mean age was 61.7 years (range 13–87). The ERM was idiopathic in 49% and secondary in 51%. The mean BCVA was 1.02 before and 0.5 after surgery and improved significantly (p &lt; 0.001) with a mean gain of 5.2 lines. The postoperative BCVA correlated strongly with the preoperative one (R2 = 0,764, p &lt; 0.001). Tomographic factors associated with worse final BCVA were higher baseline CFT (p = 0.004), abnormal foveal profile (p = 0.02), the presence of IRF (p &lt; 0.001), DRIL (p = 0.01) and subfoveal deposits (p = 0.04). The disruption of ELM, EZ and IZ were as well associated with a poorer visual outcome (p &lt; 0.001, p = 0.03 and p &lt; 0.001 respectively).Conclusions: ERM surgery provides functional and anatomical improvement. Preoperative OCT is an essential tool to evaluate morphological retinal changes and identify prognostic factors for visual recovery.

Visual impairment in Malta ‐ preliminary data from the Malta eye study

AbstractPurpose: The Malta Eye Study is a cross‐sectional ophthalmic epidemiology study of the Maltese population aged between 50–80 years. We report preliminary data on visual impairment, and the leading causes of visual loss among the Maltese population.Methods: Data is being collated over 2 years from a randomized sample of 2000 subjects from the Maltese Electoral Register, using postal invitations for assessments. The assessments include questionnaires (National Eye Institute Visual Function Questionnaire, EuroQoL, Ocular Surface Disease Index, the Quick Mild Cognitive Impairment Score), anthropometrics, visual assessment, a slit lamp based ophthalmological examination, OCT scanning, Visionix and saliva collection for DNA analysis. The visual examination involves the use of logMAR chart calibrated at 4 m. This is performed for either eye with occlusion of the other eye. The WHO definitions of mild, moderate, severe visual impairment and blindness have been used.Results: Up until the date of submission of this abstract, 500 participants were assessed (25% of the target data). The overall prevalence of visual impairment, that is, any vision &gt;0.3 logMAR in the better eye, is 5.8% (95% CI 3.9–8.2%). The prevalence of mild, moderate, severe visual impairment and blindness of the better eyes are 3.6% (95% CI 2.1–5.6%), 1.6% (95% CI 0.7–3.1%), 0.2% (95% CI 0.0–1.1%) and 0.4% (95% CI 0.0–1.4%) respectively. 22.4% (95% CI 18.8–26.3%) of the population have at least one eye with visual impairment, i.e. visual acuity &gt;0.3 logMAR. In the population with visual impairment in at least one eye, the leading causes for such impairment in descending order include uncorrected refractive error, amblyopia, untreated cataract, age related macular degeneration, diabetic retinopathy and glaucoma with prevalence of 29.5% (95% CI 21.2–38.8%), 21.4% (95% CI 14.2–30.2%), 20.5% (95% CI 13.5–29.2%), 7.1% (95% CI 3.1–13.6%), 4.5% (95% CI 1.5–10.1%) and 4.5% (95% CI 1.5–10.1%) respectively.Conclusions: The findings from this preliminary dataset compare well with large epidemiological surveys of similar populations in Europe and the US.

Ocular biometrics and uncorrected visual acuity for detecting myopia in Chinese school students

The study is to evaluate the performance of ocular biometric measures and uncorrected visual acuity (UCVA) for detecting myopia among Chinese students. Among 5- to 18-year-old Chinese students from two cities of China, trained eye-care professionals performed assessment of ocular biometrics (axial length (AL), corneal curvature radius (CR), anterior chamber depth) under noncycloplegic conditions using NIDEK Optical Biometer AL-Scan, distance visual acuity using retro-illuminated logMAR chart with tumbling-E optotypes, and cycloplegic refractive error using NIDEK autorefractor with administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder, and myopia was defined as SER ≤ − 0.5 D. Performances of ocular biometrics and UCVA (individually and in combination) for detecting myopia were evaluated using sensitivity and specificity, predictive values, and area under ROC curve (AUC) in both development dataset and validation dataset. Among 3436 students (mean age 9.7 years, 51% female), the mean (SD) cycloplegic SER was − 0.20 (2.18) D, and 1269 (36.9%) had myopia. Cycloplegic SER was significantly correlated with AL (Pearson Correlation coefficient r = − 0.82), AL/CR ratio (r = − 0.90), and UCVA (r = 0.79), but was not correlated with CR (r = 0.02, p = 0.15). The AL/CR ratio detected myopia with AUC 0.963 (95% CI 0.957–0.969) and combination with UCVA improved the AUC to 0.976 (95% CI 0.971–0.981). Using age-specific AL/CR cutoff (> 3.00 for age < 10 years, > 3.06 for 10–14 years, > 3.08 for ≥ 15 years) as myopia positive, the sensitivity and specificity were 87.0% (95% CI 84.4–89.6%) and 87.8% (86.0–89.6%), respectively, in the development dataset and 86.4% (95% CI 83.7–89.1%) and 89.4% (95% CI 87.3–91.4%), respectively, in the validation dataset. Combining AL/CR and UCVA (worse than 20/32 for age < 10 years, and 20/25 for ≥ 10 years) provided 91.9% (95% CI 90.4–93.4%) sensitivity and 87.0% (95% CI 85.6–88.4%) specificity, positive value of 80.6% (95% CI 78.5–82.6%) and negative value of 94.8% (95% CI 93.8–95.8%). These results suggest that AL/CR ratio is highly correlated with cycloplegic refractive error and detects myopia with high sensitivity and specificity, AL/CR ratio alone or in combination with UCVA can be used as a tool for myopia screening or for estimating myopia prevalence in large epidemiological studies with limited resources for cycloplegic refraction.