Factors associated with extended remission in neovascular age-related macular degeneration on pro re nata treatment protocol.

AimTo show the characteristics and outcomes of patients with neovascular age-related macular degeneration (nAMD) who had extended remission (ER) while on a pro re nata (PRN) treatment protocol.MethodsThis was a retrospective case-control study of a consecutive series of patients with nAMD treated with a PRN antivascular endothelial growth factor (anti-VEGF) drug regimen. ER was defined as the absence of haemorrhage, intraretinal/subretinal fluid on optical coherence tomography and leakage on fluorescein angiography for 52 weeks after cessation of anti-VEGF therapy. Matching patients with nAMD who did not achieve ER were included as control group. Cox regression analysis was fitted to identify predictors of time to achieve ER and time to recurrence. A logistic regression analysis of baseline characteristics was used to identify predictors of achieving ER.ResultsOf 830 eyes treated with anti-VEGF monotherapy, 77 (9.2%) eyes achieved ER during a median follow-up of 236 weeks (range 70-525 weeks). Cox regression analysis showed that ER was achieved earlier in eyes with isolated intraretinal fluid (HR, 2.05; 95% CI 1.929 to 4.520; p=0.045) at presentation. Logistic regression analysis showed that type 3 choroidal neovascularisation (OR, 0.090; 95% CI 0.021 to 0.382; p=0.001), thinner choroid (OR, 0.993; 95% CI 0.988 to 0.998; p=0.004) and absence of macular atrophy (OR, 0.233; 95% CI 0.065 to 0.839; p=0.026) at baseline increased the likelihood of achieving ER.ConclusionER is achievable in 9.2% of patients under PRN therapy for nAMD. At presentation with nAMD, anatomical features on retinal imaging may predict the likelihood of achieving ER and a shorter time to achieve ER

In Vivo Photovoltaic Performance of a Silicon Nanowire Photodiode-Based Retinal Prosthesis.

Purpose:For more than 20 years, there has been an international, multidisciplinary effort to develop retinal prostheses to restore functional vision to patients blinded by retinal degeneration. We developed a novel subretinal prosthesis with 1512 optically addressed silicon nanowire photodiodes, which transduce incident light into an electrical stimulation of the remaining retinal circuitry. This study was conducted to evaluate the efficacy of optically driving the subretinal prosthesis to produce visual cortex activation via electrical stimulation of the retina. Methods:We measured electrically evoked potential responses (EEPs) in rabbit visual cortex in response to illumination of the subretinal nanowire prosthesis with pulsed 852-nm infrared (IR) light. We compared the EEP responses to visually evoked potential responses (VEPs) to pulsed 532-nm visible light (positive control) and pulsed 852-nm IR light (negative control). Results:Activating the devices with IR light produced EEP responses with a significantly higher trough-to-peak amplitude (54.17 ± 33.4 μV) than IR light alone (24.07 ± 22.1 μV) or background cortical activity (23.22 ± 17.2 μV). EEP latencies were significantly faster than focal VEP latencies. Focal VEPs produced significantly higher amplitudes (94.88 ± 43.3 μV) than EEPs. We also demonstrated how an electrode placed on the cornea can be used as a noninvasive method to monitor the function of the implant. Conclusions:These results show that subretinal electrical stimulation with nanowire electrodes can elicit EEPs in the visual cortex, providing evidence for the viability of a subretinal nanowire prosthetic approach for vision restoration

A study on a feasible no-root approach on Android

National Research Foundation (NRF) Singapor

A degenerative retinal process in HIV-associated non-infectious retinopathy

HIV retinopathy is the most common non-infectious complication in the eyes of HIV-positive individuals. Oncotic lesions in the retinal nerve fiber layer, referred to as cotton wool spots (CWS), and intraretinal (IR) hemorrhages are frequently observed but are not unique to this pathology. HIV-positive patients have impaired color vision and contrast sensitivity, which worsens with age. Evidence of inner-retinal lesions and damage have been documented ophthalmoscopically, however their long term structural effect has not been investigated. It has been hypothesized that they may be partially responsible for loss of visual function and visual field. In this study we utilized clinical data, retinal imaging and transcriptomics approaches to comprehensively interrogate non-infectious HIV retinopathy. The methods employed encompassed clinical examinations, fundus photography, indirect ophthalmoscopy, Farmsworth-Munsell 100 hue discrimination testing and Illumina BeadChip analyses. Here we show that changes in the outer retina, specifically in the retinal pigment epithelium (RPE) and photoreceptor outer segments (POS) contribute to vision changes in non-infectious HIV retinopathy. We find that in HIV-positive retinae there is an induction of rhodopsin and other transcripts (including PDE6A, PDE6B, PDE6G, CNGA1, CNGB1, CRX, NRL) involved in visual transduction, as well as structural components of the rod photoreceptors (ABCA4 and ROM1). This is consistent with an increased rate of renewal of rod outer segments induced via increased phagocytosis by HIV-infected RPE previously reported in culture. Cone-specific transcripts (OPN1SW, OPN1LW, PDE6C, PDE6H and GRK7) are uniformly downregulated in HIV positive retina, likely due to a partial loss of cone photoreceptors. Active cotton wool spots and intraretinal hemorrhages (IRH) may not affect photoreceptors directly and the interaction of photoreceptors with the aging RPE may be the key to the progressive vision changes in HIV-positive patients