Ocular Brugia pahangi Filariasis Complicated by Severe Macular Damage in Thailand: Case Report and Literature Review.

Extralymphatic filariasis caused by filaria of zoonotic origins has been frequently reported in Thailand over recent years. Here, we report the first case of ocular filariasis in a 7.5-year-old Thai boy who initially presented with progressive conjunctival redness and blurred vision in his right eye. A small, slender, coiled worm was found and surgically removed from the right anterior chamber. Histopathological examination illustrated predominant eosinophilic inflammation surrounding the parasite, which showed smooth and thin cuticle, prominent lateral chords, flat and broad muscle cells, one intestine, and two reproductive tubes with unsegmented ova, typically characteristic of a female adult Brugia filarial nematode. The parasite was also molecularly identified as B. pahangi, based on mitochondrial cytochrome c oxidase subunit I sequence analysis. The patient was then empirically prescribed albendazole, systemic prednisolone, and topical methylprednisolone. Unfortunately, his vision did not recover after 2 months due to severe maculopathy, most likely resulting from parasitic infestation and subsequent vitreous inflammation. To the best of our knowledge, this is the first case of ocular infestation by B. pahangi with visual complications that occurred outside a filariasis-endemic area of Thailand. Furthermore, this report provides clinical data on preceding cases of B. pahangi filariasis formally reported in southeast Asian countries, including Thailand and Malaysia, which facilitate a better understanding of the epidemiology of this sporadic zoonotic infection for effective disease elimination.

Posterior segment manifestations of ocular metastasis.

PURPOSE OF REVIEW: This article reviewed and summarized recent published data on ocular imaging findings and treatment of posterior segment manifestations of ocular metastasis. RECENT FINDINGS: Advanced ocular imaging can help differentiate ocular metastases from other mimicking lesions, including primary intraocular tumors or infections. Recently, case reports have demonstrated the successful use of targeted systemic therapy to achieve local control of vitreous and choroidal metastases. SUMMARY: Metastasis can lead to a wide variety of posterior segment ocular manifestations. The choroid is the most common metastatic site, whereas tumor metastasizing to the retina and optic disc are rare. Patients with possible metastatic eye disease are recommended to undergo extensive investigation to determine the underlying primary cancer and ongoing systemic metastases. Currently, there is no consensus on the treatment strategy. Treatment generally includes systemic chemotherapy in combination with local treatment, such as radiotherapy, laser therapy, or anti-vascular endothelial growth factor (anti-VEGF) treatment.

Optical Coherence Tomography Angiography Biomarkers in Thai Patients With Diabetic Nephropathy: A Diabetic Eye and Kidney Diseases (DEK-D) Study.

Purpose: To identify optical coherence tomography angiography (OCTA) biomarkers to predict the diabetic nephropathy (DN) and their associations with 24-hour urine albumin levels in diabetic patients. Methods: This cross-sectional, observational study examined 186 eyes from 93 individuals subdivided into three groups according to 24-hour urine albumin levels: no DN, early DN, and late DN. Vessel density (VD), fractal dimension, foveal avascular zone area, intercapillary area, central retinal thickness, and subfoveal choroidal thickness were measured from OCTA images to determine their association with the DN stages. Results: VD values of the superficial capillary plexus, deep capillary plexus, and whole retina were significantly lower in the early DN group compared to the no DN group (adjusted P = 0.042, 0.016, and 0.008, respectively). VD values for the deep capillary plexus and whole retina were significantly decreased in the late DN group compared to the no DN group (adjusted P = 0.025 and 0.021, respectively). Mean fractal dimension, intercapillary area, foveal avascular zone area, central retinal thickness, and subfoveal choroidal thickness were not statistically different among the three groups. Conclusions: VD may be a useful parameter for the early non-invasive screening of DN. Further studies in larger populations are needed to establish a cutoff value for detection. Translational Relevance: This study investigated the association of each retinal vasculature measurement by OCTA and diabetic nephropathy status which could serve as an alternative way to screen for albuminuria.

Intracameral Gnathostomiasis: A Case Report and Literature Review.

PURPOSE: The purpose of this article is to report a case of ocular gnathostomiasis presenting with acute anterior uveitis and uveitis glaucoma. METHODS: observational case report and literature review. RESULTS: A 56-year-old Thai male was referred to a tertiary eye center with acute anterior uveitis and uveitis glaucoma in the right eye. A nematode was found in the right anterior chamber. Surgical removal of the nematode was successfully performed. Gnathostoma spinigerum was the nematode identified on pathological examination. CONCLUSIONS: Early detection of the parasite and timely surgical removal is the key to the management of ocular gnathostomiasis.

The patterns of uveitis and the factors affecting visual outcome from Chulalongkorn University Uveitis Cohort (CU2C): A 5-year longitudinal study protocol.

BACKGROUND: In Thailand, several novel laboratory investigations are recently available to help differentiate the uveitic etiologies. The update on uveitis epidemiological data in Thailand is necessary to better understand the disease burden and provide guidance on management. The current study aims to describe the prevalence and identify factors associated with poor visual outcomes of uveitis patients at a tertiary center in Thailand. METHODS: A 5-year-prospective study of uveitis cases presented at a tertiary referral center in the central region of Thailand is conducted.

The sterility, stability and efficacy of repackaged ziv-aflibercept for intravitreal administration.

To evaluate the sterility, stability, and efficacy of repackaged ziv-aflibercept in 1-mL plastic tuberculin syringes for intravitreal injection after storage for up to 90 days at controlled (4 °C) and ambient (25.8 °C) temperature. A total of 168 tuberculin-type 1-mL syringes were prepared containing ziv-aflibercept (100 mg/4 mL). Samples were stored at 4 °C and 25.8 °C for 0, 3, 7, 14, 21, 28, 60, and 90 days. At each time point, four samples were evaluated for the stability and binding affinity of anti-VEGF to VEGF (efficacy) using enzyme-linked immunosorbent assays (ELISAs). All samples were analyzed for microbial growth. No microbial growth was obtained from any of the ziv-aflibercept samples during each time point, indicating that the repackaged ziv-aflibercept stored at 4 °C and 25.8 °C remained sterile. ELISA analysis revealed no significant decrease in concentration, and binding affinity was observed, indicating that the stability and efficacy were preserved. However, the concentration of ziv-aflibercept decreased less than the minimum expected concentration of 8 ng/mL after 60 days at 4 °C and after 30 days at 25.8 °C. The repackaged anti-VEGF drug ziv-aflibercept does not lose stability or efficacy and remains uncontaminated if prepared under sterile conditions and stored at 4 °C for up to 60 days or stored at 25.8 °C for up to 30 days.

Sensitivity and Specificity of New Visual Field Screening Software for Diagnosing Hemianopia.

PURPOSE: To assess the diagnostic accuracy of visual field results generated by the newly developed software (CU-VF) and the standard automated perimetry (SAP) for detecting hemianopia. PATIENTS AND METHODS: Forty-three subjects with hemianopia and 33 controls were tested with the CU-VF software on a personal computer and SAP. Hemianopia was defined as the presence of a hemianopic field respecting the vertical meridian on SAP with the corresponding neuroimaging pathology as evaluated by 2 neuro-ophthalmologists. Results of CU-VF were independently evaluated by 2 neuro-ophthalmologists, 1 general ophthalmologist, and 1 general practitioner in terms of the presence of hemianopia. Sensitivity, specificity, and kappa coefficient for inter-observer reliability were calculated. Satisfaction and ease of use were evaluated with a visual analog-scale questionnaire and analyzed using paired t-test. RESULTS: The sensitivity (95% CI) and specificity (95% CI) of the CU-VF to detect hemianopia was 74.42% (58.53-85.96) and 93.94% (78.38-99.94). Kappa coefficient between neuro-ophthalmologists versus general ophthalmologist and general practitioner were 0.71 and 0.84, respectively. The mean (SD) test duration was 2.25 (0.002) minutes for the CU-VF and 5.38 (1.34) minutes for SAP (p < 0.001). Subjects reported significantly higher satisfaction and comfort using the CU-VF software compared to SAP. CONCLUSION: The CU-VF screening software showed good validity and reliability to detect hemianopia, with shorter test duration and higher subject satisfaction compared to SAP.

The Effect of Anti-Vascular Endothelial Growth Factor on Retinal Microvascular Changes in Diabetic Macular Edema Using Swept-Source Optical Coherence Tomography Angiography.

PURPOSE: This study evaluates the effect of anti-vascular endothelial growth factor (anti-VEGF) therapy on microaneurysm changes and foveal avascular zone (FAZ) using optical coherence tomography angiography (OCTA) in patients with diabetic macular edema (DME). DESIGN: Prospective observational study. MATERIALS AND METHODS: This study involved patients with DME undergoing anti-VEGF treatment (aflibercept, ranibizumab, and bevacizumab). Macula OCTA images were obtained before (visit 0) and 1 month after (visit 1) anti-VEGF injection. Microaneurysm counts were performed, and the FAZ was evaluated in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The differences in microaneurysms, FAZ, and clinical correlations were analyzed. RESULTS: A total of 152 eyes were analyzed. The patients' mean age was 59 years. Bevacizumab was used in 69.7%, ranibizumab in 15.1%, and aflibercept in 15.1%. There was a significant reduction in the FAZ in the SCP and DCP between visits 0 and 1. All anti-VEGF medications reduced the number of microaneurysms (p<0.01). After treatment, changes in the FAZ in SCP and DCP corresponded with changes in visual acuity (p<0.01). CONCLUSION: Microaneurysms as detected by OCTA might serve as a biomarker for a clinical response to anti-VEGF treatment in the short term. The FAZ might also predict visual acuity improvement after anti-VEGF injection. TRIAL REGISTRATION: Thai Clinical Trials Registry (TCTR20161010005).

Literature Review of Surgical Treatment in Idiopathic Full-Thickness Macular Hole.

PURPOSE: To summarize current surgical techniques for treating primary macular holes (MHs). METHODS: We reviewed publications detailing surgical approaches to primary MHs, briefly described their protocols, and outlined their results. RESULTS: Currently, the technique for primary MH repair is pars plana vitrectomy, removing the posterior cortical vitreous, stripping the epiretinal membranes, and ending with intraocular gas tamponade. The evident benefit of peeling off the internal limiting membrane (ILM) was clearly shown for MHs at stages 2 to 4 by achieving an anatomical closure rate of >90%, even in large MH up to 650 µm. Newer MH surgical techniques include modification of ILM flap techniques, placing an autologous scaffolding of tissue within the hole, and cell therapy has shown to increase the closure rate of large and chronic macular holes, resulting in modest functional improvement in complicated MHs. CONCLUSION: Since the turn of the century, the success rate of modern macular surgery has increased, even for large and chronic MHs. There seems to be no limit to novel concepts in MH surgery, which range from anatomical closure to those proposing natural restoration of visual function via stem cell therapy.

The Role of Head Elevation in Treatment of Vitreous Haemorrhage.

OBJECTIVE: To investigate the effect of head elevation on macular clearance of acute vitreous haemorrhage. DESIGN: Crossover, prospective, randomized clinical study. SETTING: University, tertiary care hospital. PARTICIPANTS: 24 vitreous haemorrhage patients, average age 55 years. METHODS: Patients with acute vitreous haemorrhage who were randomly separated into 2 groups. In group A, the patients were assigned normal head position for the first week of sleep, then switched to head elevation for the second week (n=12). In group B, the patients were assigned the head position in reverse order (n=12). A washout period of 24 hrs was used between treatments. The carryover, sequence, and treatment effects were analysed by using various mixed models. OUTCOMES: Best-corrected visual acuity (BCVA), vitreous haemorrhage grading, fundus photo colour intensity, and self-assessment scores. RESULTS: Although the mean BCVA (LogMAR) change following head elevation was higher than following normal head position, the difference was not statistically significant (-0.053 and 0.065 LogMAR, respectively, p = 0.2). Vitreous haemorrhage grading in the central region showed no statistical improvement in either group. Fundus photo colour intensity comparison in all fundus areas also showed no statistically significant differences in either group. CONCLUSION: Although head elevation is recommended to patients with acute vitreous haemorrhage, this study showed no statistically significant improvement in BCVA, vitreous haemorrhage grading, or fundus photo colour intensity between head elevation and normal head position in the early observation period.Trial registration: TCTR20150314001.

A double masked randomised 4-week, placebo-controlled study in the USA, Thailand and Taiwan to compare the efficacy of oral valganciclovir and topical 2% ganciclovir in the treatment of cytomegalovirus anterior uveitis: study protocol.

INTRODUCTION: Cytomegalovirus (CMV) anterior uveitis is a recognised cause of anterior uveitis in immunocompetent patients and is preventable cause of vision loss. Ocular sequelae include corneal endothelial damage which can cause corneal oedema and failure, as well as glaucoma. Recurrences of inflammation are common and therefore patients are often exposed to long-term therapy. Oral therapy is available in the form of valganciclovir, although with the caveat of systemic side effects such as bone marrow suppression and renal failure necessitating regular interval laboratory monitoring. Recent reports have demonstrated that topical 2% ganciclovir solution may offer promising treatment outcomes in patients with CMV anterior uveitis with superior safety, cost-effectiveness and convenience profiles. An investigation into the relative equipoise of these therapies is warranted for these reasons. METHODS AND ANALYSIS: The Systemic and Topical Control of Cytomegalovirus Anterior uveitis: Treatment Outcomes (STACCATO) trial is designed as a multicentre, block randomised by site, double-masked, placebo-controlled trial comparing the efficacy of oral valganciclovir, 2% topical ganciclovir and placebo in treating PCR-proven CMV anterior uveitis. Participant clinical evaluation will occur at three study time points by a masked study ophthalmologist over a 28-day period to assess resolution of ocular inflammation (secondary outcome). A control group will provide additional information about the possible impact that the infected host's immune response may play in controlling local viral replication. The primary analysis is an analysis of covariance (three arms) correcting for baseline to compare quantitative CMV viral load in the anterior chamber (AC) aqueous fluid before and 7 days after treatment. ETHICS AND DISSEMINATION: The University of California San Francisco Committee on Human Research and the Khon Kaen University Institutional Review Board have given ethical approval. The results of this trial will be presented at local and international meetings and submitted for peer-reviewed journals for publication. TRIAL REGISTRATION NUMBER: NCT03576898.

Ocular manifestations of dengue.

PURPOSE OF REVIEW: There are an increasing number of publications related to dengue ophthalmic manifestations and multimodality imaging related to dengue. This review summarizes the current literature, describe ocular manifestations, current using of ocular imaging/investigations, and management of ocular dengue. RECENT FINDINGS: Ocular manifestations of dengue can be present in many stages of dengue fever including after the resolution of systemic disease. Most cases of ocular dengue will exhibit an improvement in vision spontaneously over time. Multimodal imaging such as optical coherence tomography, optical coherence tomography angiography, near-infrared imaging, and microperimetry plays an important role in the diagnosis, follow-up, quantitative measure, and help to understand the disease progression. SUMMARY: Dengue fever can lead to a variety of ocular manifestations. The mechanisms underlying dengue-related ocular complications remain unclear. Immune-mediated mechanisms and direct viral invasion are thought to play an important role. Ophthalmologists should carefully assess patients with dengue-related ophthalmic disease because some patients may have poor visual acuity and exhibit refractoriness to treatment. Treatment with systemic corticosteroids may benefit those patients with poor presenting visual acuity, progressive ocular symptoms, and lesions involving the optic nerve and/or threatening the macula.

Foveal and parafoveal choroidal thickness pattern measuring by swept source optical coherence tomography.

OBJECTIVE: To evaluate the choroidal thickness (CT) in foveal and parafoveal regions in Thai adults using swept-source optical coherence tomography (SS-OCT). METHODS: We enrolled healthy volunteers ≥18 years of age from King Chulalongkorn Memorial Hospital, Thailand, during September 2015 to March 2016. Optical coherence tomography (OCT) of the macula was performed, and subfoveal CT was measured manually using a line scan. Average thicknesses of retinal and choroidal layers in regions of the Early Treatment Diabetic Retinopathy Study grid were measured automatically. A multivariate analysis was conducted to determine correlations between CTs in the foveal and parafoveal regions and retinal layers. RESULTS: Altogether, 144 eyes from 144 subjects (29 men, 115 women; mean age 41 years) were studied. The mean foveal CT was 282.4 ± 13.8 µm. It was thicker in the temporal fovea than in the nasal fovea (p < 0.001) and thicker in men than in women. Multivariate analysis showed that age and sex were significantly negatively correlated with the thickness of the retina, ganglion cell layer, outer retinal layer, and choroid but not of the nerve fiber layer. Regression analysis revealed that the CT decreased approximately 1.5 µm per year. CONCLUSIONS: Age and sex significantly influence choroidal thickness. Macular CT in a healthy eye thins with age. CT decreases with age faster at distances away from the foveal center than at the center. Subfoveal CT was greater than the mean CT. Parafoveal CT should be evaluated to identify specific retinal-choroidal disease.

Catching the therapeutic window of opportunity in early initial-onset Vogt-Koyanagi-Harada uveitis can cure the disease.

PURPOSE: Vogt-Koyanagi-Harada (VKH) disease is a primary autoimmune granulomatous choroiditis that begins in the choroidal stroma. The aim of this review was to gather a body of evidence for the concept of a window of therapeutic opportunity, defined as a time interval following initial-onset disease during which adequate treatment will substantially modify the disease outcome and possibly even lead to cure, similar to what has been described for rheumatoid arthritis. METHODS: We reviewed the literature and consulted leading experts in VKH disease to determine the consensus for the notion of a therapeutic window of opportunity in VKH disease. RESULTS: We found a substantial body of evidence in the literature that a therapeutic window of opportunity exists for initial-onset acute uveitis associated with VKH disease. The disease outcome can be substantially improved if dual systemic steroidal and non-steroidal immunosuppressants are given within 2-3 weeks of the onset of initial VKH disease, avoiding evolution to chronic disease and development of "sunset glow fundus." Several studies additionally report series in which the disease could be cured, using such an approach. CONCLUSIONS: There is substantial evidence for a therapeutic window of opportunity in initial-onset acute VKH disease. Timely and adequate treatment led to substantial improvement of disease outcome and prevented chronic evolution and "sunset glow fundus," and very early treatment led to the cure after discontinuation of therapy in several series, likely due to the fact that the choroid is the sole origin of inflammation in VKH disease.

School-Based versus Community-Based Sampling for Trachoma Surveillance.

Trachoma surveillance is typically performed via random sampling of endemic districts. This strategy minimizes bias and allows examination of preschool children, but is also expensive. Surveillance for some other neglected tropical diseases is carried out in schools, which is logistically easier. In the present study, the prevalence of trachomatous inflammation-follicular (TF) from a population-based sample of children from each of 70 communities in Ethiopia was compared with the corresponding school-based estimate, which was calculated for each community by performing examinations in all primary schools in the district. The overall prevalence of TF was 39.1% (95% confidence interval [CI]: 35.0-43.1%) among children aged 1-9 years in the community-based sample and 18.8% (95% CI: 15.9-21.7%) among children in grades 1-3 of the school-based sample. School-based estimates of TF explained 35% of the variation in the community-based prevalences (P < 0.001). When TF prevalence was used as a diagnostic test for detecting a community with > 5% prevalence of ocular chlamydia, the area under the receiver operating characteristic curve was 0.73 (95% CI: 0.60-0.85) for the school-based sample and 0.71 (0.58-0.83) for the community-based sample (P = 0.76). Thus, although school-based monitoring was necessarily biased relative to population-based monitoring of 1- to 9-year olds, the two methods provided a similar amount of information about the community burden of ocular chlamydia in this trachoma-hyperendemic setting. The generalizability of these findings to areas with less prevalent trachoma is unclear.

Assessment of Vascular Change Using Swept-Source Optical Coherence Tomography Angiography: A New Theory Explains Central Visual Loss in Behcet's Disease.

OBJECTIVE: To evaluate retinal vascular structural change in ocular Behcet's using optical coherence tomography angiography (OCTA) and fluorescein angiography (FA). METHODS: An analytic cross-sectional study of 37 eyes of 21 Behcet's uveitic patients was performed. Foveal retinal thickness (FRT), perifoveal hypoperfusion areas in superficial capillary plexus (SCP), and deep capillary plexus (DCP) were measured with swept-source optical coherence tomography and OCTA. FA images were used for assessing the vascular features and correlation. RESULTS: Twenty-one patients were enrolled (52.4% males). The average age at onset was 36.7 ± 12.93 years. The median of disease duration was 5 years (1-25). FRT was 118.1 ± 52.35 µm, which correlated with visual acuity (95% CI -60.47, -13.92). Using OCTA, the area of hypoperfusion in SCP (0.47 ± 0.17 mm2) was smaller than that in DCP (1.94 ± 3.87 mm2) (p < 0.001). Superficial to deep capillary plexus nonperfusion (SCP : DCP) ratio was 0.57 ± 0.27 which had the positive coefficient correlation with visual acuity (95% CI -0.644, -0.015). CONCLUSIONS: OCTA is an alternative noninvasive method to monitor macular ischemia in Behcet. Behcet's uveitis affects DCP more than SCP. Decreasing SCP : DCP ratio and decrease FRT correlates with poor visual acuity. Macular ischemia and DCP loss can be found early and can explain vision loss in Behcet.

Conjunctival Sensation in Scleritis.

PURPOSE: To investigate conjunctival sensation in patients with scleritis. METHODS: Retrospective cross-sectional study of patients with scleritis. Conjunctival sensation was tested by Cochet-Bonnet aesthesiometer in four quadrants of the bulbar conjunctiva plus the area(s) of active or previously active inflammation; sensation was compared with the contralateral eye. RESULTS: Of 28 patients with scleritis, nine had active scleritis and 19 had inactive scleritis. Eleven patients had a systemic autoimmune condition and five had infectious scleritis. The mean conjunctival sensation score of areas of inactive scleritis was significantly less than that of corresponding normal areas in the contralateral eye (p<0.001). Among patients with presumed herpetic scleritis, conjunctival sensation was significantly lower in the affected eye than in the unaffected eye (p<0.001). CONCLUSIONS: Conjunctival sensation is decreased in areas of previously active inflammation from scleritis. Eyes with herpetic scleritis had reduced conjunctival sensation, even in areas without previous active inflammation.

Multifocal choroiditis and panuveitis presenting with progressive equatorial linear streaks: evolution of Schlaegel lines documented with multimodal imaging.

PURPOSE: To describe the progressive, peripheral linear streaks of the equatorial retina, known as Schlaegel lines, in multifocal choroiditis and panuveitis (MCP). METHODS: A case report of a 13-year-old girl with MCP showed progression of retinal linear streaks. Extensive systemic and ophthalmologic investigations were performed. RESULTS: Linear streaks in MCP showed progression before the institution of immunomodulatory treatment. Infrared imaging showed hyperreflectivity of the lesions with surrounding hyporeflectivity. Optical coherence tomography showed elevated and irregular hyperreflectivity of the retinal pigment epithelium and choroidal hyperreflectivity. These findings, including the clinical progression before immunomodulatory therapy and negative systemic evaluation for infectious entities, are consistent with MCP. CONCLUSION: Patients with linear streaks in the setting of atypical MCP can progress and should be treated with adequate systemic corticosteroids and immunomodulatory agents. This case is unique in that it shows the evolution of Schlaegel lines using a multimodal imaging approach. Multimodal imaging can provide ancillary evidence of disease activity.

Multimodal imaging of white and dark without pressure fundus lesions.

PURPOSE: To describe multimodal imaging findings in patients with dark or white without pressure lesions of the fundus. METHODS: Retrospective observational case series of 10 patients with white or dark without pressure lesions. We analyzed multimodal imaging using spectral domain optical coherence tomography, color and near-infrared fundus photography, and fundus autofluorescence imaging to explore the findings associated with these lesions. RESULTS: All patients had geographic dark or white lesions on clinical examination and color photography, which were either hyporeflective or hyperreflective on near-infrared reflectance imaging, respectively. On optical coherence tomography, these lesions correlated with an abrupt change of the photoreceptor reflectivity, with relative hyporeflectivity of photoreceptor zones (ellipsoid and interdigitation zones, as well as outer segments) within the dark, and relative hyperreflectivity within white lesions. Ten patients underwent fundus autofluorescence, which showed well-defined zones of relative hypo-autofluorescence within the lesion, compared with neighboring uninvolved regions, whether dark or white without pressure. In two patients who had a lesion combining white and dark without pressure, we observed the transition in photoreceptor reflectivity from the dark lesion (hyporeflective) to the white lesion (hyperreflective), relative to the surrounding retina. CONCLUSION: Both white and dark without pressure lesions are associated with changes in outer retinal reflectivity on optical coherence tomography, which occur in opposite directions compared with the surrounding unaffected areas. In the face of normal visual field testing to date, the clinical significance of this finding remains uncertain. Recognition of the optical coherence tomography appearance will help clinicians avoid unnecessary workup of these patients for outer retinal dystrophy or degeneration.

Reliability of visual acuity measurements taken with a notebook and a tablet computer in participants who were illiterate to Roman characters.

BACKGROUND: Electronic measurement of visual acuity (VA) has been proposed and adopted as a method of determining VA scores in clinical research. Characters (optotypes) are displayed on a monitor screen and the examinee selects a match and inputs his choice to another electronic device. Unfortunately, the optotypes, called Sloan letters, in the standard protocol are 10 Roman characters. This limits their practicabilityfor measuring VA of patients who are illiterate to these characters. The authors introduced a method of displaying the Sloan letters one by one on a notebook and all 10 Sloan letters on a tablet computer screen. The former is for testing the patients whereas the latter is for them to input their responses by tapping on a letter that matches the one on the notebook screen. OBJECTIVE: To assess test-retest reliability of VA scores determined with this method. MATERIAL AND METHOD: Participants without ocular abnormality were recruited to have their right eyes measured with the same VA measurement method twice, one week apart. Those who were illiterate to Roman characters were enrolled for the aforementioned method for measuring their VA (Tablet group). A 15-inch display notebook computer and a 9-inch display tablet computer (iPad) communicated via a local wireless data network provided by a Wi-Fi router. Those who understood Roman characters were enrolled to have measurements with a 17-inch desktop computer and an infrared wireless keyboard (Keyboard group). Both methods used the same protocols and software for VA measurements. Reliability of VA scores obtained from each group was assessed by the confidence interval (CI) of the difference of the scores from the test and retest. The t test was used to analyze differences in mean VA scores between the test and retest in each group with p < 0.05 determined as statistically significant. RESULTS: There were 49 and 50 participants in the Tablet and Keyboard group respectively. The 95% CI of the difference between the scores from the test and retest in each group was 2 letters. Approximately 95% of participants in each group had an absolute difference of the scores between the test and retest of 7 letters. The mean of VA scores from the first test was significantly different from that of the second test in the Keyboard group (one-letter difference, p = 0.049); there was no significant difference between these scores in the Tablet group (0.1-letter difference, p = 0.86). CONCLUSION: Tablet computers may be used to assist patients who are illiterate to Roman characters in having their VA measured with the standard electronic protocol. This preliminary study suggested that the proposed method should be useful for reliable measuring VA outcome in multicenter international clinical trials without encountering a language barrier