Morphology, Fundus Autofluorescence, and Retinal Sensitivity of Photocoagulated Lesions in Proliferative Diabetic Retinopathy.

Purpose: To evaluate the relationships among morphology, fundus autofluorescence (FAF), and retinal sensitivity of photocoagulated lesions more than 1 year after panretinal photocoagulation in patients with proliferative diabetic retinopathy and good vision. Methods: This retrospective cohort study included patients with proliferative diabetic retinopathy who had undergone panretinal photocoagulation more than 1 year ago. The photocoagulated lesions were classified according to FAF levels: group A, no FAF; group B, diffuse FAF; group C, white-dotted centers with diffuse FAF; group D, white-dotted centers without FAF; and group E, controls. The main outcome measures were FAF, retinal sensitivity, and morphology of the photocoagulated lesions. Results: The median sensitivity values and number of photocoagulated lesions in groups A (n = 37), B (n = 39), C (n = 4), D (n = 15), and E (n = 39) were 0 dB, 18.0 dB, 13.9 dB, 0.3 dB, and 21.5 dB, respectively. EZ lines were absent in 93.5%, 18.1%, 50%, 93.3%, and 0% of lesions in groups A, B, C, D, and E, respectively. The inner retinal layer was damaged in 45.2%, 3.0%, 50%, 73.3%, and 0% lesions in groups A, B, C, D, and E, respectively. Statistically significant between-group differences were observed in the retinal sensitivities of the photocoagulated lesions, presence of EZ lines, and damage to the inner retinal layer (p < 0.05). Conclusions: The photoreceptors in most photocoagulated lesions with diffuse FAF retain their morphology and function. Translational Relevance: Using fundus autofluorescence, the damage to photoreceptors after panretinal photocoagulation in patients with diabetes can be estimated in a noninvasive manner. This process can help in determining the need for additional panretinal photocoagulation.

Two Japanese Families with Pigmented Paravenous Retinochoroidal Atrophy and HK1 Mutation: A Case Report.

Hexokinase 1 (HK1) gene is the cause of autosomal dominant retinitis pigmentosa (RP) 79. To date, only E874K mutation has been reported as the causative mutation in patients with nonsyndromic RP. As a Caucasian RP case with a pathological variant of HK1 exhibiting pigmented paravenous retinochoroidal atrophy (PPRCA) phenotype was recently reported, we reviewed RP79 cases in our Japanese RP cohort. Consequently, 2 Japanese patients, who were diagnosed with RP79 by genetic tests in our RP cohort, were included in this study. Patient 1 was a 60-year-old woman. Fundus examination revealed symmetrical donut-shaped retinal degeneration, with pigment deposition avoiding the macula. Moreover, degeneration extended in a peripheral direction along the vessels like a starfish, and degeneration was observed around the veins and arteries. Patient 2 was a 75-year-old man. Fundus examination revealed symmetric macula-avoiding donut-shaped retinal degeneration, with paravenous protruding degeneration along the blood vessels like in case 1. Both Japanese cases, which belonged to two separate families, had the same HK1 pathogenic mutation, with a phenotype of PPRCA. Furthermore, atrophy along retinal arteries was noted. Reviewing previous nonsyndromic RP79 cases revealed symptoms that are believed to be those of PPRCA. Ultra-widefield fundus imaging, especially ultra-widefield fundus autofluorescence, has been useful in detecting PPRCA. If these devices become widely available, more cases may be discovered in the future because PPRCA can be used as a clue to suspect RP79, and Sanger sequencing may be used to identify pathogenic mutations in HK1 at a lower cost and more easily than using whole-exome sequencing.

Assessment of myopic rebound effect after discontinuation of treatment with 0.01% atropine eye drops in Japanese school-age children.

PURPOSE: Having previously demonstrated the efficacy of 0.01% atropine eye drops for inhibiting progression of childhood myopia, we conducted additional analyses to assess post-treatment changes in myopia progression. STUDY DESIGN: Analysis of follow-up data from a previously reported randomized controlled trial METHODS: A mixed-effects model was used to compare intergroup changes in spherical equivalent (SE) and axial length (AL) at 1 month and 12 months after discontinuation of 2-year treatment with atropine or placebo in 167 school-age children. RESULTS: Follow-up measurements were available for 149 participants at 1 month after discontinuation of treatment and for 51 participants at 12 months after discontinuation. At 1 month post-treatment, differences between the atropine and placebo groups in least squares (LS) mean changes in SE and AL, respectively, from 24 months were -0.06 diopters (D) (95% CI: -0.21, 0.08; P = .39) and 0.02 mm (95% CI: -0.05, 0.08; P = .60). At 12 months post-treatment, intergroup differences (atropine vs placebo) in LS mean changes in SE and AL, respectively, were -0.13 D (95% CI: -0.35, 0.10; P = .26) and -0.02 mm (95% CI: -0.12, 0.09; P = .75). LS mean changes in SE and AL from treatment discontinuation did not differ between the groups at 1 or 12 months post-treatment. CONCLUSION: Axial elongation was significantly less in the atropine group than in the placebo group. The suppression effect obtained at 2 years was maintained after 12 months. The absence of intergroup differences in myopia progression since treatment cessation suggests that myopic rebound did not occur.

The influence of stimulating electrode conditions on electrically evoked potentials and resistance in suprachoroidal transretinal stimulation.

PURPOSE: To determine the influence of stimulating electrode conditions on the amplitudes and latencies of electrically evoked potentials (EEPs) and the resistance at the electrode-tissue interface in the suprachoroidal transretinal stimulation (STS) system. STUDY DESIGN: Experimental study. METHODS: A scleral pocket (3 × 5 mm) was created just over the visual streak in anesthetized pigmented rabbits (weight, 1.9-2.7 kg), and STS stimulating electrodes were implanted into the pocket. Measurements were obtained with stimulating electrodes of different lengths (0.3 or 0.5 mm) and different surface characteristics (smooth or porous). EEPs elicited with a fixed current under each set of electrode conditions were recorded; three measurement sessions were performed for each rabbit. The resistance at each electrode-tissue interface was measured. RESULTS: The latencies and amplitudes of the EEPs did not differ significantly with changes in the height and surface characteristics of the stimulating electrodes, but the resistances at the electrode-tissue interface differed significantly (P = 0.001; the resistance values for the 0.3-mm-long electrode with a porous surface was 5.24 ± 0.67 kΩ and with the 0.3- and 0.5-mm-long electrodes with smooth surfaces were 7.63 ± 0.12 kΩ and 6.77 ± 0.20 kΩ). CONCLUSION: Being shorter did not affect the EEPs of the stimulating electrodes with a porous surface while decreasing the resistance at the electrode-tissue interface.

Evaluation of ocular biometry in the Japanese population using a multicenter approach: Prospective observational study.

This prospective observational study aimed to evaluate the ocular biometry of Japanese people through a multicenter approach. The uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) in the log minimum angle of resolution (logMAR), subjective and objective spherical equivalent values (SE) of ocular refraction, anterior and posterior corneal curvature (ACC and PCC, respectively), anterior and posterior corneal asphericity (ACA and PCA, respectively), central corneal thickness (CCT), anterior chamber depth (ACD), and ocular axial length (AL) were measured in the eyes of 250 participants (mean age = 46.5 ± 18.0 years, range: 20-90 years) across five institutions in Japan. The mean UDVA, CDVA, subjective SE, objective SE, ACC, PCC, ACA, PCA, CCT, ACD, and AL were 0.68, -0.08, -2.42 D, -2.66 D, 7.77 mm, 6.33 mm, -0.31, -0.39, 0.55 mm, 2.92 mm, and 24.78 mm, respectively. Age-related changes and sex-based differences were noted in the visual acuity, refraction, corneal shape, ACD, and AL. Our results serve as basis for future studies aiming to develop refractive correction methods and various vision-related fields.

Extensive Macular Atrophy with Pseudodrusen in a Japanese Patient Evaluated by Wide-Field OCTA.

Extensive macular atrophy with pseudodrusen (EMAP) is a relatively newly proposed clinical entity that was first reported in 2009. Although no definitive diagnostic criteria have been defined, characteristic findings can distinguish it from other diseases, especially dry age-related macular dystrophy (AMD). Herein, we present the case of a patient with EMAP who underwent a comprehensive ophthalmic examination and whole-exome sequencing (WES). A 72-year-old Japanese man complained of progressive visual impairment in his right eye and nyctalopia. Ophthalmic examination revealed that the best-corrected visual acuity (BCVA) in decimal units was 0.08 on the right and 0.8 on the left. Fundoscopy and fundus autofluorescence (FAF) revealed well-demarcated symmetrical macular atrophy, with a vertical axis larger than the horizontal axis, which reached the vascular arcade inferiorly and exceeded it superiorly. Pseudodrusen were widespread throughout the retina in both eyes. Paving-stone degeneration was not observed in the extreme periphery of either eye. Seven months later, his left BCVA decreased to 0.3 without major changes on multimodal imaging. Based on the above findings, we diagnosed EMAP. Wide-field optical coherence tomography angiography (OCTA) showed no significant changes in the retinal vessels, but the density of choroidal vessels was reduced in the degenerated areas. We thought that this finding suggests that EMAP originates between the deep retina and choroid. WES did not reveal any candidate mutations in known pathogenic genes. To the best of our knowledge, this is the first report of a Japanese patient with EMAP, and no data for analysis of wide-field OCTA or equatorial OCT images of EMAP cases have been found in previous reports. EMAP is not well recognized in Asia and may be incorrectly diagnosed as dry-type AMD. EMAP should be included in the differential diagnosis of dry AMD, and this may lead to more Asians being diagnosed with EMAP in the future.

Spatial Resolution of Suprachoroidal-Transretinal Stimulation Estimated by Recording Single-Unit Activity From the Cat Lateral Geniculate Nucleus.

Retinal prostheses are devices used to restore visual sensation in patients suffering from photoreceptor degeneration, such as retinitis pigmentosa. Suprachoroidal-transretinal stimulation (STS) is a prosthesis with retinal electrodes located in the sclera. STS has the advantage that it is safer than epiretinal or subretinal prostheses, as the implant is not directly attached to the retinal tissue. We have previously reported feasibility of STS with animal experiments and clinical trials. However, functional evaluation with neurophysiological experiments is still largely missing. To estimate the spatial resolution of STS, single-unit activities in response to STS were recorded from relay cells in the dorsal lateral geniculate nucleus of cats, and the response probability of the units was analyzed in relation to the distance between the stimulus location and the receptive field of each recorded unit. A platinum electrode was attached to the sclera after lamellar resection, and the return electrode was placed in the vitreous. The stimulating current, which ranged from 50 to 500 µA, was applied between these electrodes, and the probability of spike responses occurring just after retinal stimulation was measured. The distance at half-maximum of response was determined from the collected response probabilities as a function of stimulus intensity for all units characterized by their distances from the receptive field center to the stimulation point. As the stimulation became weaker, this distance decreased to 1.8° at 150 and 100 µA. As another estimation, the radius of 25% response probability was 1.4° at 100 µA. The diameter of the stimulated cat retinal area, 3.6° or 2.8°, corresponds to human visual acuity of 0.005 or 0.007, or finger counting. Considering the lower hazard to the retina of STS and its potentially large visual field coverage, STS is an attractive method for retinal prosthetic device development.

Depth Perception with a Newly Developed Microscope Stereotest.

PURPOSE: We aimed to compare the depth perception under a microscope between binocular and monocular conditions using a newly developed microscopic stereotest (M-stereotest) and examine the effect of anisometropia on depth perception under a microscope. SUBJECTS AND METHODS: Thirty young and healthy subjects were examined. A manipulator attached with a stainless wire was placed under the objective lens of a stereomicroscope. The wire was moved up manually, and the subjects were instructed to stop the knob movement once the wire reached the same height as the fixed two wires. The deviation from the height of the fixed wires was measured under a best optically corrected binocular, a best optically corrected monocular, or an anisometropic binocular [±3 diopters (D) in the dominant or nondominant eye] condition. RESULTS: The deviation was significantly smaller in the binocular condition than in the monocular dominant eye condition (0.38 ± 0.26 mm vs 1.89 ± 1.15 mm, p < 0.001) and was also significantly smaller in the best optically corrected binocular than in the anisometropic binocular condition [1.07 ± 1.00 mm (-3.0 D), p = 0.003; 0.85 ± 0.67 mm (+3.0 D), p < 0.001]. CONCLUSION: Depth perception under the microscope is more accurate under the binocular than in the monocular condition, indicating the potential role of stereopsis. Anisometropia deteriorates depth perception, suggesting that refractive error should be corrected during microscopic work, such as during ophthalmic surgery.

Pupil constriction via the parasympathetic pathway precedes perceptual switch of ambiguous stimuli.

Perceptual rivalry of ambiguous stimuli reflects the interaction of neural activity among multiple cortical regions. However, it remains unclear what drives a spontaneous perceptual alteration. We hypothesized that increased fluctuations in spontaneous neural activity due to arousal reduction drive the perceptual switch. Here, we show that the pupils shrank a few seconds prior to the onset of the spontaneous perceptual switch. Such pupil constriction was not observed before the exogenous perceptual switch. Pharmacological experiments confirmed that the pupil constriction disappeared when the peripheral parasympathetic pathway (pupil sphincter muscle) was blocked, but it remained intact when the peripheral sympathetic pathway (pupil dilator muscle) was manipulated. Furthermore, rapid pupil dilations with behavioral response are also mediated by the peripheral parasympathetic pathway. The present findings suggested that transient arousal drops, as denoted by the autonomic nervous modulation of pupil size, are involved in inducing the spontaneous perceptual switch of bistable stimuli.

Testing of Newly Developed Wide-Field Dual-Array Suprachoroidal-Transretinal Stimulation Prosthesis in Dogs.

Purpose: This study was conducted to investigate the feasibility of a newly developed wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis in dogs and to examine its biocompatibility and stability over a 4-month period. Methods: Three types of STS dual arrays were designed and tested. The STS dual-array was implanted into a scleral pocket of the left eye of six healthy beagle dogs. Ophthalmic examinations, fundus photography, fluorescein angiography (FA), electroretinography (ERG), and functional testing of this system were conducted postoperatively. The dogs were euthanatized at the end of the experiment, and their eyes were enucleated and histologically examined. Results: All prostheses were successfully implanted without complications, and no serious adverse event occurred during the postoperative period. Fundus photographs and FA showed no serious damage in the retina surrounding the arrays. The ERGs recorded from the implanted eyes showed no significant differences from those from control eyes. Histological evaluations demonstrated good preservation of the retina over the array. However, system failure occurred in 50% of the dogs owing to dog-specific habits. Conclusions: Implantation of this prosthesis system in dogs is feasible and can be performed without significant damage to the eye. The biocompatibility and stability of the array were good during the observation period, but the low durability of the system against dogs (not humans) is an issue to be resolved in the future. Translational Relevance: This study suggests that this wide-field dual-array prosthesis might widen the visual field and might be useful for patients with retinitis pigmentosa.

Efficacy and safety of 0.01% atropine for prevention of childhood myopia in a 2-year randomized placebo-controlled study.

PURPOSE: Atropine eye drops prevent the progression of myopia, but their use has not been tested in the Japanese schoolchildren population. Here, we evaluate the efficacy and safety of 0.01% atropine eye drops for myopia control in Japanese children. STUDY DESIGN: Multicenter (7 university hospitals), randomized, double-masked, placebo-controlled trial. METHODS: Participants were 171 Japanese schoolchildren aged 6 to 12 years, with progressive myopia, spherical equivalence (SE) of -1.00 to -6.00 diopters (D), and astigmatism of ≤1.5 D. They were randomized to receive either 0.01% atropine (n=85) or placebo (n=86) eye drops once nightly OU for 24 months. Primary and secondary efficacy endpoints were changes in SE and axial length (AL), respectively, from baseline to month 24. RESULTS: Data from 168 subjects were analyzed. At month 24, compliance was similar in both groups (atropine: 83.3%; placebo: 85.7%). The least squares mean change in SE and AL from baseline were, respectively, -1.26 D (95% confidence interval [CI]: -1.35, -1.17) and 0.63 mm (0.59, 0.67) for atropine and -1.48 D (- 1.57, -1.39) and 0.77 mm (0.73, 0.81) for placebo. Inter-group differences were 0.22 D (95% CI: 0.09, 0.35; P < 0.001) for SE and - 0.14 mm (-0.20, -0.08; P < 0.001) for AL. Three patients experienced mild allergic conjunctivitis side effects, with no inter-group difference in incidence (atropine: 2.4%; 2/84 patients; placebo: 1.4%; 1/84 patients). CONCLUSION: With good compliance, 0.01% atropine is effective and safe for preventing the progression of childhood myopia.

Optimizing correction of coma aberration in keratoconus with a novel soft contact lens.

PURPOSE: To report on a second-generation prototype contact lens (modified lens) with enhanced optics to correct coma aberration and compare its performance with that of the prototype contact lens (conventional lens) used to optimise correction of coma aberration in keratoconus (KC). METHODS: Both lenses were designed as a set of standardised soft contact lenses (SCLs) with asymmetric powers along the posterior surface. The modified lens differs from the conventional lens in that the optical zone is decentred superiorly by 0.7 mm. The on-eye performance was compared between the SCLs and no-lens wearing in terms of manifest refraction, corrected distance visual acuity (CDVA), ocular aberrations, subjective quality of vision, and on-eye lens position relative to the pupil. RESULTS: Thirty-four KC eyes were included. SCLs significantly decreased coma aberration compared to no-lens wear (none, 0.68 ± 0.27 µm; conventional lens, 0.37 ± 0.28 µm; modified lens, 0.19 ± 0.15 µm; P < 0.001), with the reduction in coma aberration being significantly greater with the modified lens than with the conventional lens (P = 0.018). No significant difference in manifest refraction or CDVA was found among the three conditions. Quality of vision was significantly better with the modified lens than with no SCL wear (P < 0.05) but no differences were found between the SCLs. The on-eye optical center position relative to the pupil was closer to the pupil centre using the modified lens than the conventional lens (P < 0.001). CONCLUSION: Optimisation of the location of the optical zone in a standardised asymmetric SCL improves correction of coma aberrations and on-eye optical centration.

Efficient measurements for the dynamic range of human lightness perception.

PURPOSE: Patients with an eye disease often report nyctalopia, hemianopia, and/or photophobia. We hypothesized that such symptoms are related to the disease impacting the dynamic range of lightness perception (DRL). However, there is currently no standardized approach for measuring DRL for clinical use. We developed an efficient measurement method to estimate DRL. STUDY DESIGN: Clinical trial METHODS: Fifty-five photophobic patients with eye disease and 46 controls participated. Each participant judged the appearance of visual stimuli, a thick bar with luminance that gradually changed from maximum to minimum was displayed on uniform background. On different trials the background luminance changed pseudo-randomly between three levels. The participants repeatedly tapped a border on the bar that divided the appearance of grayish white/black and perfect white/black. We defined the DRL as the ratio between the luminance values at the tapped point of the border between gray and white/black. RESULTS: The mean DRL of the patients was approximately 15 dB, significantly smaller than that of the controls (20 dB). The center of each patient's DRL shift depending on background luminance, which we named index of contextual susceptibility (iCS), was significantly larger than controls. The DRL of retinitis pigmentosa was smaller than controls for every luminance condition. Only the iCS of glaucoma was significantly larger than controls. CONCLUSIONS: This measurement technique detects an abnormality of the DRL. The results support our hypothesis that the DRL abnormality characterizes lightness-relevant symptoms that may elucidate the causes of nyctalopia, hemeralopia, and photophobia.

Complete Visual Recovery From Severe Outer Retinitis After Tonsillitis.

BACKGROUND: To report a case of severe acute bilateral outer retinitis after tonsillitis and rapid morphologic and functional recovery after steroid treatment. METHODS: Observational case report. RESULTS: A 26-year-old woman with acute bilateral blurred vision that developed after tonsillitis underwent spectral-domain optical coherence tomography (SD-OCT) that showed photoreceptor outer segment damage. Full-field electroretinography (ERG) and multifocal ERG were nonrecordable. The patient had a remarkable anatomic and functional recovery in response to steroid treatment; however, partial damage remained around the macula on SD-OCT, and an adaptive optics imaging system showed damaged cone photoreceptors. CONCLUSIONS: Prednisolone is an effective treatment for a disease that is believed to be due to suspicious involvement of the autoimmune system. Even severe outer retinitis can recover completely with rapid diagnosis and treatment.

Simultaneous Measurement of Objective and Subjective Accommodation in Response to Step Stimulation.

Purpose: This study aimed to evaluate differences in objective and subjective accommodation dynamically and simultaneously. Methods: Thirty-four pre-presbyopic healthy volunteers (mean age ± SD, 41.0 ± 3.2 years) participated in this study. Initially, the reaction time for detecting a change in the target was measured at near. Dynamic accommodation was then monocularly recorded using an open-view Shack-Hartmann aberrometer and compared with the amplitude and velocity of subjective accommodation. Results: The objective amplitude of accommodation (0.97 ± 0.32 diopter [D]) was significantly greater than the subjective amplitude of accommodation (0.62 ± 0.43 D; P < 0.001). The accommodative velocity was significantly faster for the "before the accommodation" response time (0.47 ± 0.38 D/s) than the "after the accommodation" response time (0.21 ± 0.22 D/s; P = 0.007). Conclusions: The human eye under the monocular condition quickly adjusts to the focal plane to clearly archive the nearby object, and the focal plane thereafter is slowly and accurately adjusted to the visual target after visual recognition.

Novel mutation identified in Leber congenital amaurosis - a case report.

BACKGROUND: Leber congenital amaurosis (LCA) is the earliest onset and the most severe form of all inherited retinal degenerative disorders, characterized by blindness, or severe visual impairment from birth, and typically exhibits clinical and genetic heterogeneity. Recently, 14 causative genes of LCA were reported. We performed whole-exome sequencing (WES) for Japanese siblings, and identified a novel homozygous nonsense mutation in the RPGR-interacting protein 1 (RPGRIP1) gene. We also report their follow-up data over 27 years. CASE PRESENTATION: Patient 1 is a 37-year-old male. In 1992, his eye position indicated orthophoria, however, horizontal nystagmus was evident, and he complained of photophobia. His best corrected decimal visual acuity (BCVA) was 0.2 (S + 6.5/C-3.5/170°) OD and 0.1 (S + 6.0/C-2.5/10°) OS. Fundus examination revealed bisymmetrical inferior focal retinal pigment epithelium (RPE) mottling. Bright-flash electroretinogram (ERG) revealed a subnormal pattern, while 30 Hz flicker ERG was non-recordable in both eyes. At his final visit in 2019, his BCVA was 0.09 (S + 3.5/C-3.5/180°) OD and 0.09 (S + 3.0/C-4.0/10°) OS. Patient 2, a 34-year-old female, is the sibling of patient 1. In 1992, her BCVA was 0.05 (S + 6.0) OD and 0.06 (S + 5.0) OS. She was in a chin-up position during visual acuity testing. Horizontal nystagmus was evident, and she also complained of photophobia. Bright-flash ERG was severely attenuated, and 30 Hz flicker ERG was non-recordable in both eyes. At her final visit in 2019, her BCVA was 0.02 (uncorrectable) OD and 0.03 (uncorrectable) OS. There were no other patients with LCA in their family and their parents were non-consanguineous. WES revealed a homozygous, consecutive, two-nucleotide variation in the RPGRIP1 gene (NM_020366: exon15:c.G2294A and c.C2295A, p.C765X), resulting in a premature stop codon. We interpreted this variation as a novel pathogenic mutation of RPGRIP1 that contributes to LCA6 development. CONCLUSIONS: Herein, we report a novel nonsense mutation of RPGRIP1 in two patients with LCA6 and present their long-term follow-up data. These clinical data linked to genotypes provide important information for the development of new treatments, such as gene therapy, as well as for genetic counseling.

Objective evaluation of visual fatigue in patients with intermittent exotropia.

PURPOSE: The purpose of this study was to evaluate the degree of visual fatigue in patients with intermittent exotropia (IXT) using the binocular fusion maintenance (BFM) test. METHODS: Fourteen patients with IXT (32.1 ± 16.4 years) and 15 age-matched healthy volunteers (31.2 ± 9.3 years) participated in the study. BFM was assessed by measuring the transmittance of liquid crystals placed in front of the subject's nondominant eye at the instance when binocular fusion was broken and vergence eye movement was induced. A questionnaire on subjective symptoms was administered to the subjects before and after the visual task. The visual task consisted of a reciprocal movement between 67 and 40 cm. RESULTS: The change [post-pre] of BFM was significantly lower in the IXT group (-0.185 ± 0.187) than in the control group (-0.030 ± 0.070) (P = 0.010). The change of total subjective eye symptom score was significantly greater in the IXT group (2.28 ± 1.43) than in the control group (0.93 ± 1.27) (P = 0.018). The reduction in BFM rate with increasing total subjective eye symptom score was significantly greater in the IXT group (-0.106 ± 0.017) than in the control group (-0.030 ± 0.013) (P = 0.006). CONCLUSION: The present findings objectively showed that patients with IXT are at a greater risk of visual fatigue in comparison with healthy individuals.

Binocular Coordination during Smartphone Reading in Esophoric Patients.

Purpose: To evaluate binocular coordination using video-oculography (VOG) during smartphone reading in patients with esophoria (EP) compared with control subjects.Patients and methods: Ten young and adult patients with EP (25.3 ± 7.3 years) and seven orthophoric or small-angle exophoric control subjects (25.7 ± 4.8 years) were examined. Eye movements were recorded during smartphone reading at 20, 30, and 50 cm using VOG. Differences in the horizontal fixation disparity at each distance between and within the groups were analyzed.Results: Horizontal esodeviation at 20 cm in the EP group (1.23° ± 2.00°) was significantly greater than that at 30 cm (-0.39° ± 0.73°; P = .027) and was significantly greater than horizontal exodeviation at 20 cm in the control group (-0.21° ± 0.17°; P < .001).Conclusion: The current findings suggest that the horizontal fixation disparities in the patients with EP deviate to eso-direction during smartphone use.

An update on retinal prostheses.

Retinal prostheses are designed to restore a basic sense of sight to people with profound vision loss. They require a relatively intact posterior visual pathway (optic nerve, lateral geniculate nucleus and visual cortex). Retinal implants are options for people with severe stages of retinal degenerative disease such as retinitis pigmentosa and age-related macular degeneration. There have now been three regulatory-approved retinal prostheses. Over five hundred patients have been implanted globally over the past 15 years. Devices generally provide an improved ability to localize high-contrast objects, navigate, and perform basic orientation tasks. Adverse events have included conjunctival erosion, retinal detachment, loss of light perception, and the need for revision surgery, but are rare. There are also specific device risks, including overstimulation (which could cause damage to the retina) or delamination of implanted components, but these are very unlikely. Current challenges include how to improve visual acuity, enlarge the field-of-view, and reduce a complex visual scene to its most salient components through image processing. This review encompasses the work of over 40 individual research groups who have built devices, developed stimulation strategies, or investigated the basic physiology underpinning retinal prostheses. Current technologies are summarized, along with future challenges that face the field.

Insufficient accommodation during binocular near viewing in eyes with intermittent exotropia.

PURPOSE: To investigate the changes in spherical equivalent and pupil response during near viewing in patients with intermittent exotropia (IXT) who have complaints of blurred vision or asthenopia from near viewing in daily life using a novel binocular wavefront aberrometer. STUDY DESIGN: A cross-sectional study. METHODS: Ten IXT patients and ten healthy subjects wearing full-correction lenses at far sight (5 m) were instructed to fixate on a near target at 67 cm, which was then moved to 40 cm three times. Serial changes in the spherical equivalent (SE) refractive error (SE) were measured during this task using a laboratory-made open-field binocular Hartmann-Shack wavefront aberrometer and compared between patients and healthy subjects. In the IXT patients, regression analysis was performed between ∆SE and exodeviation angles, as measured by an alternate prism and cover test. Pupil-diameter and pupil-constriction ratios were also compared between patients and healthy subjects, and the correlation of constriction ratio with ∆SE was calculated for both groups. RESULTS: Compared to healthy subjects, IXT patients demonstrated significantly lower ∆SE of convergence (mean ± SD, 0.91 ± 0.26 D vs. 1.15 ± 0.19 D; P < 0.05) and divergence (0.93 ± 0.28 D vs. 1.16 ± 0.20 D; P < 0.05). Angle of exotropia was negatively correlated with ∆SE during far-sight and near-sight convergence and divergence (P < 0.05). Pupil-constriction ratio was also reduced in patients compared to healthy subjects (6.67% ± 3.31% vs. 11.9% ± 5.96%; P<0.05). Pupil-constriction ratio was positively correlated with ∆SE during convergence in both groups (P < 0.05). CONCLUSION: Insufficient accommodation and pupil constriction during near viewing were observed in patients with IXT who had complaints of blurred vision or asthenopia from near viewing. These conditions might contribute to symptoms, such as fatigue, eye strain and impaired visual performance.