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To examine the foveal structure and vasculature in eyes with an idiopathic epiretinal membrane (ERM). Forty-nine eyes of 48 patients with an idiopathic ERM were studied. The superficial foveal avascular zone (FAZ) was measured by optical coherence tomography angiography (OCTA; RTVue XR Avanti, Optovue Inc., Fremont, CA), and the central foveal thickness (CFT) was measured by swept source OCT (DRI-OCT, Topcon, Japan). Twenty eyes underwent vitrectomy with internal limiting membrane (ILM) peeling, and the FAZ and CFT were evaluated pre- and postoperatively. Forty-nine eyes of 49 age-matched healthy subjects were also examined as control. The FAZ in eyes with an ERM was significantly smaller than that of the control eyes (0.188±0.16 mm2 vs 0.328±0.14 mm2, P<0.01). The CFT in eyes with an ERM was significantly thicker than that of control eyes (315±0.14 μm vs 193±0.14 μm, P<0.01). The size of the FAZ was strongly correlated with the CFT (ERM, R = -0.753; control, R = -0.61, both P<0.01). The postoperative size of the FAZ was not significantly different from the preoperative size (0.115 mm2 vs 0.128 mm2, P = 0.17) but the CFT was significantly thinner (370 μm vs 288 μm, P<0.01) after the vitrectomy with ILM peeling in 20 eyes. The results indicate that an ERM might affect the morphology and vasculature of not only the inner but also the outer retina before and after vitrectomy with ILM peeling. The FAZ area might have been affected by the ILM peeling.

We provide the first measures of foveal cone density as a function of axial length in living eyes and discuss the physical and visual implications of our findings. We used a new generation Adaptive Optics Scanning Laser Ophthalmoscope to image cones at and near the fovea in 28 eyes of 16 subjects. Cone density and other metrics were computed in units of visual angle and linear retinal units. The foveal cone mosaic in longer eyes is expanded at the fovea, but not in proportion to eye length. Despite retinal stretching (decrease in cones/mm2), myopes generally have a higher angular sampling density (increase in cones/deg2) in and around the fovea compared to emmetropes, offering the potential for better visual acuity. Reports of deficits in best-corrected foveal vision in myopes compared to emmetropes cannot be explained by increased spacing between photoreceptors caused by retinal stretching during myopic progression. The human eye has many different parts that enable sight. The retina is the light sensitive tissue at the back of the eye, and it contains the fovea, the region that provides the clearest vision. Light must be focused on the retina to create images, a feat achieved by the transparent parts at the front of the eye called the cornea and lens. These parts of the eye are called the optics. Between birth and adulthood, significant changes take place in the eye. Most noticeably, the distance between the optics and the fovea grows by about seven millimeters. Cells called cone photoreceptors, which provide light sensitivity, migrate and pack into the fovea. Finally, the eye’s optics adjust to maintain a sharp focus. At the same time, the brain is learning how to process inputs from the eyes to generate mental images that realistically correspond to the physical world around it. The development of the eye is fascinating in its complexity, but for more and more people, the process does not go as expected. Specifically, a growing proportion of the population has eyes that are too long. This means that, for light reflected by far away objects, the eye’s optics form an image in front of the retina instead of on it. As a result, images of distant objects cannot be seen clearly, a condition known as myopia or nearsightedness. Researchers have also discovered that nearsighted people see less clearly than those who do not use glasses, even when given a sharp image to examine at close range. It has been hypothesized that these deficits result from stretching of the retina as the eye becomes bigger. Until recently, testing this hypothesis by looking at cone photoreceptors directly in the eye was impossible. This is because the optics of all eyes have small imperfections that distort the light passing through them, including any light used to take high resolution microscopic images of the fovea. This hurdle can be overcome using adaptive optics, which means adding a deformable mirror to the instrument being used to image the eye that can adjust to correct the distortion. Wang et al. use a new generation Adaptive Optics Scanning Laser Ophthalmoscope to check the density of cones at the fovea in relation to the size of the eye. They show that although the center of the fovea has fewer cones when the eye is bigger, this effect is more than offset because the longer eye increases magnification. So, if a near-sighted person wearing contacts and someone who does not need glasses stood side-by-side admiring the full moon, the near-sighted person would most likely have more cones sampling the image and should therefore have a higher resolution view. These findings rule out reductions in the density of cone photoreceptors as the cause or effect of visual deficits associated with near-sightedness, adding to the understanding of this common condition.

Optogenetic therapies for vision restoration aim to confer intrinsic light sensitivity to retinal ganglion cells when photoreceptors have degenerated and light sensitivity has been irreversibly lost. We combine adaptive optics ophthalmoscopy with calcium imaging to optically record optogenetically restored retinal ganglion cell activity in the fovea of the living primate. Recording from the intact eye of a living animal, we compare the patterns of activity evoked by the optogenetic actuator ChrimsonR with natural photoreceptor mediated stimulation in the same retinal ganglion cells. Optogenetic responses are recorded more than one year following administration of the therapy and two weeks after acute loss of photoreceptor input in the living animal. This in vivo imaging approach could be paired with any therapy to minimize the number of primates required to evaluate restored activity on the retinal level, while maximizing translational benefit by using an appropriate pre-clinical model of the human visual system. Non-human primate models are important for the development of high quality vision restoration therapies for blindness. Here, the authors demonstrate restoration of light responses in foveal retinal ganglion cells of the living macaque following optogenetic gene therapy.

The primate foveola, with its high cone density and magnified cortical representation, is exquisitely specialized for high-resolution spatial vision. However, uncovering the wiring of retinal circuitry responsible for this performance has been challenging due to the difficulty in recording receptive fields of foveal retinal ganglion cells (RGCs) in vivo. In this study, we use adaptive optics scanning laser ophthalmoscopy (AOSLO) to image the calcium responses of RGCs in the living primate, with a stable, high precision visual stimulus that allowed us to localize the receptive fields of hundreds of foveal ganglion cells. This approach revealed a precisely radial organization of foveal RGCs, despite the many distortions possible during the extended developmental migration of foveal cells. By back projecting the line connecting RGC somas to their receptive fields, we have been able to define the 'physiological center' of the foveola, locating the vertical meridian separating left and right hemifields in vivo.

Silicone oil (SO) is widely used as a long-term intravitreal tamponading agent for rhegmatogenous retinal detachment (RRD) repair. This study investigated the structural changes of the foveal microvasculature using optical coherence tomography angiography (OCTA) in patients with RRD treated with vitrectomy and SO tamponade. Thirty-eight patients with unilateral RRD who were treated with vitrectomy and SO tamponade and were followed up for ≥3 months after SO removal were included. En face OCTA images were obtained and foveal avascular zone (FAZ) area and vascular density (VD) were compared between study eyes and unaffected contralateral eyes. The FAZ area in deep capillary plexus (DCP) was larger ( P  < 0.001) and the VD in DCP was lower ( P  = 0.022) in the study eyes than in the fellow eyes. The duration of SO tamponade was significantly correlated with the enlargement of FAZ area ( P  = 0.034) and reduction of VD in DCP ( P  = 0.015). These changes could reflect vascular insufficiency in eyes with SO tamponade and may represent a potential explanation for the pathogenesis of retinal thinning and unexplained visual loss.

To investigate pre-, intra-, and postoperative factors influencing postoperative visual acuity, degree of metamorphopsia, and retinal sensitivity after vitrectomy in patients with rhegmatogenous retinal detachment and foveal detachment. We reviewed retrospectively 33 consecutive eyes of 32 patients, who underwent vitrectomy for rhegmatogenous retinal detachment with foveal detachment between August 2018 and October 2020 and obtained retinal reattachment. Pre-, intra-, and postoperative characteristics were comprehensively analyzed using multivariate models to evaluate the presence of factors influencing best-corrected visual acuity, vertical/horizontal metamorphopsia scores using M-CHARTS (Inami & Co., Ltd., Tokyo, Japan), and retinal sensitivity using the MP-3 (NIDEK Co., Aichi, Japan) at 1-year postoperatively. Preoperative total retinal detachment was the only factor significantly associated with worse best-corrected visual acuity at 1-year postoperatively (β = 0.589, P<0.001). Intraoperative internal limiting membrane peeling (β = 0.443, P = 0.003) and longer duration after recognizing visual dysfunction (β = 0.425, P = 0.005) were significantly associated with higher vertical metamorphopsia scores at 1 year. The horizontal metamorphopsia score was significantly related to the duration after recognizing visual dysfunction (β = 0.457, P = 0.008). The disappearance of the EZ line on optical coherence tomography at 3 months postoperatively (β = -0.638, P<0.001) was significantly associated with lower retinal sensitivity at 1 year. Our study findings suggest that best-corrected visual acuity, metamorphopsia, and retinal sensitivity at 1 year after vitrectomy for rhegmatogenous retinal detachment with foveal detachment are influenced by distinct factors.

The purpose of the current study was to investigate the effect of topical atropine on choroidal thickness using spectral-domain optical coherence tomography. A total of 30 healthy eyes from 30 children were analyzed in this study. A single drop of 1% atropine gel was administered twice daily for a week. Choroidal thickness (CT) was measured using SD-OCT, and changes in CT before and after administration of the eye drops were analyzed at the subfovea and at 1.0-mm intervals (up to 3.0 mm) from the fovea at superior, inferior, nasal, and temporal locations. Pre- and post-cycloplegic axial length (AL) was also measured using the IOLMaster. We observed that administration of 1% atropine gel led to a significant increase in the choroidal thickness under the fovea and at all intervals from the fovea. The greatest change in CT was observed in the inferior meridian, while the nasal meridian exhibited the least change. AL did not significantly differ before and after cycloplegia, and there was no significant correlation between the changes in AL and subfoveal CT. It was concluded that administration of 1% atropine gel can significantly increase CT in the eyes of young Chinese children, albeit with different magnitude at different locations.

We have used recent measurements of mammalian cone light responses and voltage-gated currents to calculate cone ATP utilization and compare it to that of rods. The largest expenditure of ATP results from ion transport, particularly from removal of Na⁺ entering outer segment light-dependent channels and inner segment hyperpolarization-activated cyclic nucleotide-gated channels, and from ATP-dependent pumping of Ca2+ entering voltage-gated channels at the synaptic terminal. Single cones expend nearly twice as much energy as single rods in darkness, largely because they make more synapses with second-order retinal cells and thus must extrude more Ca2+. In daylight, cone ATP utilization per cell remains high because cones never remain saturated and must continue to export Na⁺ and synaptic Ca2+ even in bright illumination. In mouse and human retina, rods greatly outnumber cones and consume more energy overall even in background light. In primates, however, the high density of cones in the fovea produces a pronounced peak of ATP utilization, which becomes particularly prominent in daylight and may make this part of the retina especially sensitive to changes in energy availability.

To determine the influence of residual submacular fluid (SMF) on the recovery of function and structure of the retina after successful rhegmatogenous retinal detachment (RRD) reattachment. We reviewed the medical records of all patients who had undergone successful RRD repair by scleral buckling (SB) surgery or by pars plana vitrectomy (PPV) from March 2011 to August 2014. Spectral-domain optical coherence tomographic images of the macular regions were used at 1, 2, 3, 6, 9, and 12 months following the surgery. The best-corrected visual acuities (BCVA) were evaluated at the same times. The eyes with a macula-off RRD that were treated by SB surgery had a significant higher incidence of residual SMF (52%) than those treated by PPV (6.8%; P <0.001). Nevertheless, the postoperative BCVA was significantly improved in the eyes that had undergone SB surgery (P = 0.007). The postoperative BCVAs were not significantly different between the groups in which the SMF was absorbed (12 eyes) and not absorbed (13 eyes) within 1 month after the SB surgery. The photoreceptor outer segment length and the presence of a foveal bulge were not significantly different between these two groups at 12 months. Multiple regression analyses showed that the presence of a foveal bulge (β = 0.531, P = 0.001) and the duration of the retinal detachment before surgery (β = 0.465, P = 0.002) but not the duration of the SMF were independent factors significantly correlated with the final BCVA. These results suggest that the postoperative residual SMF does not significantly disrupt the functional and structural recovery of eyes with macula-off RRD treated by SB surgery.

This study investigated alterations in the foveal microvasculature following the administration of 0.125% atropine in myopic children. In this prospective study, 63 eyes from 36 individuals aged 5–18 years with myopia were administered 0.125% atropine for myopia control. After administration, foveal microvascular parameters such as the area and perimeter of the foveal avascular zone (FAZ), the acircularity index (AI) of FAZ, and foveal vessel density were evaluated longitudinally. The effect of atropine on foveal microvasculature was analyzed using a linear mixed model. One month after atropine application, the area and perimeter of FAZ significantly decreased ( p  = 0.014 and 0.041). A significant decrease in vessel density within the 300-µm wide annulus around FAZ and an increase in the AI of the FAZ were observed in the initial 3-month period ( p  = 0.035 and p  = 0.047, respectively). However, changes in the FAZ area, perimeter, AI and foveal vessel density throughout the follow-up were not significant. These findings suggest that 0.125% atropine may induce transient changes in FAZ size and foveal vessel density, but its overall safety in managing myopia is supported by the stability of foveal parameters over time.