Peripheral Visual Field Loss Research Articles

Characterizing visual field loss from past mercury exposure in an Indigenous riverine community (Grassy Narrows First Nation, Canada): a cluster-based approach

BackgroundBetween 1962 and 1975, a chlor-alkali plant in Canada discharged approximately 9 metric tons of mercury (Hg) into the Wabigoon River. Over the following decades, biomarkers of Hg exposure of persons from Grassy Narrows First Nation (Asubpeeschoseewagong Anishinabek), located downriver from the discharge, reflected Hg concentrations in fish. Hg exposure is known to target the calcarine fissure, resulting in visual field (VF) loss. Most studies and clinical reports focus solely on peripheral VF loss; little is known about the impact of Hg on the central and paracentral portions. The present study sought to characterize the patterns of VF loss with respect to past and current Hg.MethodsA 28-year hair-Hg (HHg) database, created from a 1970–97 government biomonitoring program, served to select study participants with ≥ 4 year-based HHg measurements (n = 81). Blood-Hg was assessed for current exposure. Light sensitivity thresholds across the VF were analyzed monocularly, using a Humphrey Field Analyzer (HFA). Following post-hoc exclusions, based on HFA interpretation indices, 65 participants were retained. Both eyes were combined for analyses (n = 130 eyes). Unsupervised hierarchical clustering of HFA plot data was used to identify patterns of VF loss. A series of mixed effects models (MEM) were performed to test the associations for current Hg exposure with respect to HFA interpretation indices and clusters, as well as for longitudinal past Hg exposure.ResultsThe clustering approach decomposed the light sensitivity deficits into 5 concentric clusters, with greatest loss in the peripheral clusters. No relation was observed between any of the cluster scores and current blood-Hg. VF deficits increased with past Hg exposure. Longitudinal MEM showed that HHg was significantly (p < 0.05) associated with all peripheral, paracentral, and central cluster scores, as well as with HFA interpretation indices.ConclusionsPast Hg exposure in Grassy Narrows First Nation was associated with present day VF loss. The cluster-based location-specific approach identified patterns of VF loss associated with long-term Hg exposure, in both the peripheral and the central areas. The functional implications of this type of visual loss should be investigated.

Apple Vision Pro’s new technology as a head-mounted perimetry device for glaucoma and other potential applications

Abstract Glaucoma is a leading cause of irreversible blindness worldwide and poses a significant public health challenge. Primary open-angle glaucoma (POAG) is the most common form of glaucoma and is marked by progressive optic nerve damage and peripheral visual field loss. Early detection and management of glaucoma are essential to prevent severe vision impairment. Perimetry measures visual field sensitivity and is a crucial tool for diagnosing and the progression of glaucoma. However, traditional perimetry devices are bulky, expensive, and require specialized settings, thereby limiting their accessibility. Studies indicate the evolving role of portable and home-based visual field testing, where the efficacy of virtual reality (VR) devices such as the VisuALL against traditional perimetry tools. Apple Vision Pro’s integration into glaucoma management could address the limitations of conventional perimetry, and thus making monitoring more feasible and less burdensome. In this manuscript, we explore the potential of Apple Vision Pro’s technology as a head-mounted perimetry device for glaucoma. The Apple Vision Pro headset leverages advances in augmented reality and wearable computing to offer a portable, cost-effective solution for visual field testing. Its compact design enables patients to perform tests at home, thus reducing the need for clinical visits and improving adherence to monitoring protocols. This portability is also particularly beneficial in space environments, such as on the International Space Station, where regular monitoring of visual health of astronauts is critical.

Retinal dystrophy associated with Birt-Hogg-Dubé syndrome

Purpose: Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant cancer syndrome characterized by skin fibrofolliculomas, lung cysts, spontaneous pneumothorax, and multifocal renal carcinomas. Ophthalmologic findings associated with BHDS include flecked chorioretinopathy, choroidal melanoma, iris melanocytosis, and eyelid fibrofolliculomas. We present the case of a retinal dystrophy associated with BHDS. Methods: Observational case report. Results: A 48-year-old woman was referred for poor night vision and peripheral visual field loss. She had a past medical history of Birt-Hogg-Dubé syndrome, manifesting as multiple pulmonary cysts and atelectasis of both lungs. Best corrected visual acuity was 20/25 OU. Posterior segment examination revealed significant vessel attenuation and peripheral retinopathy consistent with a retinal dystrophy. Conclusion: This case associates BHDS with retinal pigment epithelial changes and visual field defects. Patients with BHDS should undergo ophthalmological examination as part of their care.

Efficacy of a wearable night-vision aid in patients with concentric peripheral visual field loss: a randomized, crossover trial.

To investigate the efficacy of our wearable night-vision aid in patients with concentric peripheral visual field loss. Prospective, single blind, three-group, and three-period crossover clinical study. The study included patients with concentric peripheral visual field loss, a best-corrected visual acuity (decimal visual acuity) of 0.1 or higher in the better eye, and the presence of a central visual field. HOYA MW10 HiKARI® (HOYA Corporation), our original wearable night-vision aid, was used as the test device with three types of camera lenses (standard-, middle-, and wide-angle lenses). Under both bright and dark conditions, the angle of the horizontal visual field was measured using each of the three lens types for each group. The baseline angle was measured when each participant wore the night-vision aid (powered off). The study included 21 participants. Under bright condition, the perceived horizontal visual field was significantly wider than the baseline setup when using the standard-angle lens ("the standard lens"); the middle-angle lens ("the middle lens") was significantly wider than both the baseline setup and the standard lens; and the wide-angle lens ("the wide lens") was significantly wider than the other lenses. Under dark condition, the perceived horizontal visual field was again significantly wider when using the middle lens than the baseline setup and the standard lens, and when using the wide lens, the perceived horizontal visual field was again wider than when using the other lenses. The control in the bright condition was significantly wider (p < 0.001) than when used in the dark condition, while the standard-angle lens in the dark condition was significantly wider (p = 0.05) than when used in the bright condition. In regards to the middle and wide lenses, there was no statistically significant result emerging from either of the illumination conditions. Our wearable night-vision aid with a middle-angle or wide-angle lens appears to provide wider visual field images in patients with concentric peripheral visual field loss, regardless of whether the illumination conditions are bright or dark.

A call for increased surveillance: monitoring the use of hydroxychloroquine to prevent retinopathy

Dear Sir / Madam. Hydroxychloroquine (HCQ) and chloroquine (CQ) are the main drugs used in the control and treatment of malaria. Although the toxicity of these drugs is rare, it has been reported in high-dose ingestions or chronic intravenous administration. Of these retinal manifestations are one of the most common following the poisoning of CQ. A recent study by Melles et al. found that the overall risk of hydroxychloroquine retinopathy is 8.6% after chronic use with higher dose of HCQ dose being associated with a progressively greater risk for incident retinopathy (1). Retinopathy can lead to serious complications in patients; in fact in most patient’s vision loss. In Melles et al’s study, it mostly led to complaints like reading difficulties, diminished vision, missing center vision, glare, hazy vision, light flashes, and metamorphopsia, while some patients were asymptomatic. The majority of patients exhibited a fundoscopic bull's-eye sign. Other signs include paracentral, central, and peripheral visual field loss, which were present in almost all patients. In the early stages of retinopathy, color vision is typically unaffected, but it too begins to be compromised in the later stages. (2) Malaria is endemic in Pakistan. In 2023 pooled malaria prevalence in Pakistan was found to be 23.3%, with Plasmodium vivax, Plasmodium falciparum, and mixed infection rates of 79.13%, 16.29%, and 3.98%, respectively. According to the World Health Organization (WHO), Pakistan is one of the seven countries in the Eastern Mediterranean Region that account for 98% of the total malaria burden in the region. Around 217 million people in Pakistan are at moderate risk of malaria and 63 million are at high risk. Approximately 0.47 million malaria cases and 800 deaths have been reported in 2020(3). The recent rise in climate change-induced flooding and other weather changes, waterborne diseases such as malaria, are also rising leading to higher HCQ use. Furthermore, CQ and HCQ are also being used in treating covid 19(4). This, combined with factors such as lack of surveillance, self-medication practises, and rampant over-the-counter use in Pakistan greatly increase the risk of patients taking improperly high doses of HCQ or CQ and, consequently, suffering from retinopathy. To prevent the HCQ-associated retinal toxicity proper surveillance methods should be employed, and the prescription and distribution of these drugs should be monitored. Patients and physicians prescribing HCQ should be aware of its toxicity risks (5). ---Continue

A novel homozygous splice site variant in ARL2BP causes a syndromic autosomal recessive rod-cone dystrophy with situs inversus, asthenozoospermia, unilateral renal agenesis and microcysts

BackgroundThis report presents a clinical case of syndromic rod-cone dystrophy due to a splice site variant in the ARL2BP gene causing situs inversus, asthenozoospermia, unilateral renal agenesis and microcysts. The presence of renal agenesis and cryptorchidism expands the clinical manifestations due to ARL2BP variants. The detailed, long-term follow-up contributes valuable insights into disease progression, aiding clinical diagnosis and patient management.Case PresentationThe male patient complained of photophobia as the first symptom when he was 20 years old followed by nyctalopia, loss of central visual acuity and peripheral visual field ten years later. Genetic analysis identified a likely pathogenic homozygous variant (c.294-1G > C) involving the splicing acceptor site of intron 4. Reported symptoms together with full-field stimulus threshold testing, electroretinogram and advanced multimodal imaging allowed us to recognize the typical characteristics of a mixed retinal dystrophy. Despite the end-stage retinal disease, this patient still retained a useful residual vision at 63 years and had a slow disease progression during the last 5 years of evaluation.Discussion and conclusionsOur findings underscore the variable clinical presentation of ARL2BP variants, emphasizing the importance of a nuanced approach in diagnosing and managing patients. The presence of renal cysts warrants consideration of a differential diagnosis, particularly with Senior-Loken (SLS), Bardet-Biedl (BBS) and Joubert syndromes (JS) but also with Short Rib Thoracic Dysplasia 9, highlighting the need for careful phenotypic evaluation in these cases.

The visual field-testing maze and vision maze: Feasible techniques to evaluate visual field loss in animals

Visual field loss due to glaucoma is a severe and concerning problem, leading to limited visual range and poor quality vision. The progression of this loss begins with a para-central arcuate scotoma which eventually advances to a ring scotoma and constricted visual fields in later stages. Currently, no animal model is available for screening this pattern of vision loss. However, we have successfully developed two mazes to evaluate visual field loss - the visual field-testing maze (VFTZ) for peripheral vision loss and the vision maze (VM) for central vision loss. Our studies involved inducing glaucoma in Wistar and Sprague Dawley rats using lipopolysaccharide (LPS) and testing them in VFTZ and VM. We used Latanoprost and dorzolamide eye drops as standard drug candidates during the study. We evaluated the animals for intraocular pressure, retinal vasculature imaging, and anxiety using tonometry, ophthalmoscopy, and light and dark model techniques. Furthermore, we quantified the antioxidant parameters of the retina using UV spectroscopy. Our findings showed that animals with peripheral visual field loss in VFTZ took significantly more time to reach the goal and spent more time within the maze compared to normal or drug-treated animals (P < 0.001). Additionally, animals with compromised central visual field in VM spent more time in a particular arm and changed arms less frequently (P < 0.001) compared to normal or drug-treated animals. Moreover, we observed that glaucomatous rats exhibited elevated anxiety levels and impaired performance in the mazes, emphasizing the impact of vision loss on anxiety. Finally, the antioxidant and ATPase alterations in the retinal layers verified the glaucomatous changes in the experimental animals. Based on our remarkable findings, we strongly recommend the use of VFTZ and VM to evaluate visual field loss in animals.

SCHWARTZ-MATSUO SYNDROME : AN IMPORTANT CAUSE OF SECONDARY GLAUCOMA : RARE CASE

Introduction : Schwartz-Matsuo syndrome is a rare ocular condition characterized by rhegmatogenous retinal detachment, elevated intraocular pressure, and open anterior chamber angle with presence of aqueous cells. The prevalence of Schwartz-Matsuo syndrome is quite low and only reported through case studies.&#x0D; Case Illustration : A 63 years old female complained a visual aquity was no light perception on the left eye (LE) since 2 months ago. The symptoms are gradually getting worse, history of ocular trauma, recent surgery, photopsia, peripheral visual field loss were denied. Patient came to the hospital with IOP elevation on left eye. On Gonioscopy we interpretated as open angle chamber and USG examination we founded retinal detachment, Anti-glaucoma medication were given but no success to lower the IOP.&#x0D; Discussion : Typically, retinal detachment is associated with low IOP. In Schwartz-Matsuo syndrome the opposite is observed with elevated IOP. Hypothesized that photoreceptor outer segments pass through the retinal break allows for fluid and photoreceptor outer segments to gain access, enter the anterior chamber and block aqueous outflow at the level of the trabecular meshwork. A significant increase in IOP can lead to visual loss and blindness complicated by glaucoma requiring further medical or surgical intervention. Referred to this patient, she came with IOP elevation, open angle anterior chamber and retinal detachment that clinically diagnosed as Schwartz-Matsuo syndrome.&#x0D; Conclusion : Schwartz-Matsuo syndrome is primarily a clinical diagnosis; Early detection of disease and prompt management of increased IOP and retinal detachment is essential for a good outcome.

Post Stroke, Is Perimetry Necessary? A Case Report

Abstract&#x0D; Introduction : Stroke are generally associated with peripheral visual field loss. Three out of four stroke patients report some form of disability, one of which is visual impairment. Approximately 16% of these patients have a homonymous visual field defect poststroke. These vision problems can lead to difficulty carrying out a lot of daily tasks and activities, such as driving. This report tries to define the diagnostic flow to determine the exact type and lesion.&#x0D; Case Illustration : Male, 61 years old, came to Universitas Sumatera Utara Hospital with visual field loss in both eyes. Two months ago, he was diagnosed with ischemic stroke and treated with Aspirin 80 mg, with no limbs disability right now. He also had hypertension and treated with Amlodipine 10 mg. VOD: 6/60 with BCVA S-2.00 6/7,5, VOS: 6/60 with BCVA S-2.00 6/7.5. With confrontation test and perimetry, defect was found in medial visual field OD and lateral visual field OS. Hess screen and Amsler Grid was normal. Head CT-Scan was performed with multiple infarcts, mainly in right occipital lobe. The patient was diagnosed with Incomplete Hemianopia, Left Congruous Homonymous Hemianopia with Macular Sparing, and treated with Citicholine 1000 mg once daily.&#x0D; Discussion&#x0D; Conclusion : In stroke patients with homonymous visual field loss, visual field testing with detailed evaluation of visual field defect can determine the lesion location, and neuro-radiological imaging was necessary to assess visual pathway. It’s important for educate the patients, diagnostic and prevent the stroke recurrent.

Betamethasone And Vision Loss: An Alarming Side Effect!

Madam, Betamethasone is a potent steroid medication with immunosuppressive and anti-inflammatory properties, and it is frequently prescribed in Pakistan for conditions such as eczema, psoriasis and contact dermatitis due to its availability and affordability. However, it has significant adverse effects such as skin atrophy, striae and other cutaneous symptoms, and glaucoma.[1] Glaucoma is a severe condition characterized by pathologic elevation in intraocular pressure, leading to optic nerve damage and irreversible blindness. As highlighted by Sahni et al. topical steroid use in the periorbital area for an extended peri, for treating eczema can lead to detrimental visual problems and glaucoma [2]. In this case, a woman taking high dose topical steroids since the age of 16 started to develop frequent falls and blurring of vision. She had markedly elevated intraocular pressures and extensive peripheral visual field loss, consistent with advanced glaucoma. In addition to the study above Charles et al. also published a case report about a 43-year-old male who used betamethasone ointment on his body for eight months straight. Although he had precisely denied using the ointment near his eyes, he developed painless vision loss in his left eye due to glaucoma.[3] Additionally, a 2017 study highlighted a significant rise of vision impairment in Pakistan, an increase of 55% since 1990, with glaucoma prevalent in 0.14 million individuals, and eye diseases to further increase by 2025.[4] Consequently, this medication, which is being discontinued around the world, is still frequently used in Pakistan. Through this manuscript, I would like to bring this serious issue to light so that people in Pakistan can also be educated and protected from this serious side effect. Healthcare practitioners should strictly be avoiding this medication and using less harmful alternatives.

Disturbances of Ocular Circulation in Color Doppler Imaging, Retinal Changes and Electrophysiological Tests with Neuro-Ophthalmological Clinical Symptoms in the Course of CADASIL Syndrome—A Case Report

The authors present a new paper examining the disturbances in ocular circulation and electrophysiological changes in the presence of neuro-ophthalmic manifestations in a patient with cerebral autosomal dominant arteriopathy with subcortical infracts and leucoencephalopathy (CADASIL). Symptoms reported by the patient included: transient vision loss (TVL), migraines, diplopia, bilateral peripheral visual field loss and convergence insufficiency. CADASIL was confirmed by the presence of NOTCH3 gene mutation (p.Cys212Gly), the presence of granular osmiophilic material (GOM) in cutaneous vessels in an immunohistochemistry test (IHC) and bilateral focal vasogenic lesions in the white matter of the cerebral hemisphere, with micro-focal infarct in the left external capsule on a magnetic resonance imaging test (MRI). Color Doppler imaging (CDI) confirmed decreased blood flow and increased vascular resistance in the retinal and posterior ciliary arteries, with reduced P50 wave amplitude on a pattern electroretinogram (PERG). An eye fundus examination and fluorescein angiography (FA) revealed the constriction of retinal vessels and a peripheral retinal pigment epithelium (RPE) atrophy with focal drusen. The authors suggest that the cause of TVL may be changes in the hemodynamics of the retinochoroid vessels associated with the narrowing of small vessels and the presence of druses in the retina-which is supported by a decrease in the amplitude of the P50 wave in PERG, changes in OCT correlating simultaneously with changes in MRI imaging and other neurological symptoms.

Importance of two-dimensional gaze analyses in the assessment of reading performance in patients with retinitis pigmentosa.

The causes of reading difficulties in people with peripheral visual field loss are not fully understood. We conducted a two-dimensional gaze analysis on eye movements during reading in patients with retinitis pigmentosa to investigate the causes of reading difficulties in relation to the central visual field using a binocular eye mark recorder (EMR-9). Twenty-seven patients with retinitis pigmentosa whose central visual field narrowed to ≤ 20° using Goldmann kinetic perimetry (I/4 target) and this present study included eight healthy participants. The participants' visual acuities were corrected to better than +0.4 logMAR. Correlations and multivariate regression analyses were investigated between the number of letters read correctly, the I/4 central visual field, V/4 perifoveal and peripheral visual field, and visual acuity. Multivariate regression analysis revealed that all these parameters played almost equal roles in the number of letters read correctly. In the two-dimensional gaze analysis, the task performance time of patients during reading increased as the I/4 central visual field narrowed. The task performance time was more clearly correlated with the rotation saccade (r = 0.428, p <0.05) and the distance of the vertical direction (ΣY) of eye movements (r = 0.624, p < 0.01), but not with regressive saccade and the distance of the horizontal direction (ΣX). Visual acuity was correlated with the task performance time (-0.436, <0.05) but not with eye movement directionality. Reading difficulties in patients with retinitis pigmentosa result from impaired eye movement directionality. Understanding eye measurements for people with tunnel vision required a two-dimensional gaze analysis. The two-dimensional gaze analysis also showed that the involvement of the perifoveal and peripheral visual fields, visual acuity, and I/4 central visual field was important for reading in people with tunnel vision.

PMON126 Null Cell Adenoma With Low Ki-67 Presenting as Recurrent Pituitary Mass

Abstract Background Pituitary adenomas account for 10% to 15% of all intracranial masses. Among these, approximately one-third are identified as nonfunctioning pituitary adenomas (NFPA) which have a heterogenous profile and an increased potential for relapse one to five years after pituitary surgery. In a retrospective analysis by Almeida et al,multiple surgical resections, elevated ki-67 and cavernous sinus invasion were predictive of recurrence. They typically present with symptoms of mass effect and most are macroadenomas at time of diagnosis. Clinical Case A 65-year-old female initially presented with bitemporal hemianopsia, galactorrhea and amenorrhea 28 years prior. She subsequently underwent transsphenoidal hypophysectomy with resolution of symptoms post operatively. She was clinically stable until 12 years after the surgery when she noted new onset peripheral visual field loss. Upon reevaluation, she was diagnosed with non-functioning pituitary macroadenoma for which she was advised gamma knife surgery but she opted a repeat transsphenoidal pituitary surgery. Her vision improved and she remained asymptomatic thereafter. Sixteen years after her second surgery, she developed blurring of vision. Cranial MRI was done which showed lobulated, heterogeneous hyperdense sellar-suprasellar mass measuring 55×36×47 mm extending to the bilateral sphenoid and ethmoid sinuses, left pterygopalatine fossa, left superior orbital fissure, probably the left foramen lacerum, and left cavernous sinus with encasement of the left internal carotid artery and associated erosion of the adjacent osseous structures. Visual field testing showed mild reduction in field sensitivity with consideration of media opacity and/or uncorrected error of refraction. Baseline hormonal work up was unremarkable. Hence, endoscopic endonasal transphenoidal, transethmoidal parasellar excision of sellar mass, with reconstruction via Hadad Flap was done. There were no intraoperative nor postoperative complications. The specimen was sent for histopathology with provisional anatomic diagnosis of pituitary adenoma. Immunohistochemistry stained negative for chromogranin and any of the pituitary hormones which was consistent with null cell adenoma. The Ki-67, an independent marker of tumor progression and recurrence, was low at less than 1%. However, after 1 month, repeat MRI showed  no significant change in the lobulated, heterogeneously enhancing mass centered in the sellar-suprasellar region. Thus, she received adjuvant radiotherapy with total dose of 5040cGy divided in 28 fractions and was advised close monitoring of pituitary MRI and/or development of any new symptoms. Conclusion In this case, although with low Ki-67, the presence of multiple surgeries and high Knosp grade were recognized as risk factors for its recurrence.Treatment of recurrent NFPA is multimodal which includes re-operation, radiosurgery and radiation therapy. A multidisciplinary team approach is required for its comprehensive management and long-term follow-up. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Rapid Quantification of the Binocular Visual Field for Clinical Trials: Performance of a Modified Esterman Supra-Threshold Test Implemented with the Open Perimetry Interface.

PurposeWe aimed to assess the performance of the modified-Esterman test (mET) as a rapid suprathreshold binocular quantification tool for the assessment of peripheral visual fields. The mET consists of an even spread of test points across the visual field.Materials and MethodsThe mET was implemented on the Octopus 0900 perimeter using the Open Perimetry Interface (OPI) and consisted of 160 points. Patients with choroideremia, a rod-cone dystrophy, Stargardt disease, a cone-rod dystrophy, and healthy volunteers underwent both the mET and the standard Esterman tests twice. Disease severity (mild/moderate/severe) was graded on both tests independently. Voronoi tessellation was utilised to compare the tests.ResultsThe Voronoi visualisation was able to demonstrate that the mET was able to provide more information about the disease state at all stages of diseases. This was confirmed by the agreement statistic, which showed that the mET detected 27% more points of visual field loss compared to the Esterman test, being most useful in patients with rod-cone dystrophies.ConclusionThe mET provides a speedy quantitative measure of the peripheral visual field loss, which can be used in clinical trials to monitor longitudinal assessment of peripheral visual function. The mET provides a more even coverage across the visual field compared to the Esterman test points, making it more suitable for this purpose. This is a key part of safety monitoring in retinal clinical trials. The mET can easily be implemented on commercially available perimeters that allow Open Perimetry.

Choroideremia: molecular mechanisms and therapies.

Choroideremia (CHM) is a monogenic X-linked chorioretinal dystrophy affecting the photoreceptors, retinal pigment epithelium (RPE), and choroid; it is caused by mutations involving the CHM gene. CHM is characterized by night blindness in early childhood, progressing to peripheral visual field loss and eventually to complete blindness from middle age. CHM encodes the ubiquitously expressed Rab escort protein 1 (REP1), which is responsible for prenylation of Rab proteins and is essential for intracellular trafficking of vesicles. In this review we explore the role of REP1 in the retina and its newly discovered systemic manifestations, and discuss the therapeutic strategies for tackling this disease, including the outcomes from recent clinical trials.

Spatial Characteristics of Peripheral Visual Islands in Retinitis Pigmentosa.

PurposeRetinitis pigmentosa (RP) is typified by progressive peripheral visual field (pVF) loss in patterns that can vary between individuals. Greater understanding of pVF preservation may inform research on therapeutic targets. However, characteristics of retained pVF are incompletely understood. We aimed to evaluate the spatial characteristics of retained pVF in RP.MethodsWe developed a computational platform to generate a probability map of the spatial distribution of retained pVF loci using the Goldmann V4e isopter. RP subjects were grouped into cross-sectional and longitudinal datasets. Probability maps of retained pVF were generated for categories of symptomatic disease duration (SDD). We applied a mathematical model to determine the anatomical correlate of the retained pVF.ResultsA total of 152 subjects were included. The mean age was 46.7 years. SDD was <20 years (47.4%), 20 to 40 years (39.5%), or >40 years (13.2%). Longitudinal data (3.2–5.7 years of follow up) were available for 65 subjects. In the cross-sectional dataset, retained pVF loci were most likely to be located between the 50° and 80° isoeccentric meridians and between the 30° to 50° radial axes. In the longitudinal dataset, inferotemporal pVF loci were the most likely to be preserved over time. The area of pVF retention corresponded anatomically to the pre-equatorial superonasal retina.ConclusionsSemiautomated quantitation of pVF may be a useful tool to analyze spatial characteristics of VF in RP. Retinal cells in the superonasal periphery may be resilient to RP-related functional decline. Understanding the cellular and molecular basis of pVF resilience in the retina may inform efforts to develop treatment modalities for RP.

Topical Treatment for Open Angle Glaucoma

Glaucoma refers to a group of conditions that lead to damage of the optic nerve head, typically caused by raised intra-ocular pressure. Primary open angle glaucoma is the commonest glaucoma type in the UK and affects 8% of people at 80 years old. In open angle glaucoma the iridocorneal angle is open but aqueous flow is diminished. As glaucoma progresses, it can lead to peripheral visual field loss. The mainstay of treatment initially is with eye drops with the aim of lowering intraocular pressure. Intraocular pressure is determined by the production, circulation and drainage of aqueous humour and is considered normal if between 11-21mmHg. If treated, glaucoma progression can be delayed and most people will not have severe visual impairment.

Molecular Therapy for Choroideremia: Pre-clinical and Clinical Progress to Date.

Choroideremia is an inherited retinal disease characterised by a degeneration of the light-sensing photoreceptors, supporting retinal pigment epithelium and underlying choroid. Patients present with the same symptoms as those with classic rod-cone dystrophy: (1) night blindness early in life; (2) progressive peripheral visual field loss, and (3) central vision decline with a slow progression to legal blindness. Choroideremia is monogenic and caused by mutations in CHM. Eight clinical trials (three phase 1/2, four phase 2, and one phase 3) have started (four of which are already finished) to evaluate the therapeutic efficacy of gene supplementation mediated by subretinal delivery of an adeno-associated virus serotype 2 (AAV2/2) vector expressing CHM. Furthermore, one phase 1 clinical trial has been initiated to evaluate the efficiency of a novel AAV variant to deliver CHM to the outer retina following intravitreal delivery. Lastly, a non-viral-mediated CHM replacement strategy is currently under development, which could lead to a future clinical trial. Here, we summarise the rationale behind these various studies, as well as any results published to date. The diversity of these trials currently places choroideremia at the forefront of the retinal gene therapy field. As a consequence, the trial outcomes, regardless of the results, have the potential to change the landscape of gene supplementation for inherited retinal diseases.

Choroideremia Gene Therapy.

Choroideremia Gene Therapy.

Brimonidine is Neuroprotective in Animal Paradigm of Retinal Ganglion Cell Damage.

To investigate the neuroprotective effect of brimonidine after retinal ischemia damage on mouse eye. Glaucoma is an optic neuropathy characterized by retinal ganglion cells (RGCs) death, irreversible peripheral and central visual field loss, and high intraocular pressure. Ischemia reperfusion (I/R) injury model was used in C57BL/6J mice to mimic conditions of glaucomatous neurodegeneration. Mouse eyes were treated topically with brimonidine and pattern electroretinogram were used to assess the retinal ganglion cells (RGCs) function. A wide range of inflammatory markers, as well as anti-inflammatory and neurotrophic molecules, were investigated to figure out the potential protective effects of brimonidine in mouse retina. In particular, brain-derived neurotrophic factor (BDNF), IL-6, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its death receptor DR-5, TNF-α, GFAP, Iba-1, NOS, IL-1β and IL-10 were assessed in mouse retina that underwent to I/R insult with or without brimonidine treatment. Brimonidine provided remarkable RGCs protection in our paradigm. PERG amplitude values were significantly (p < 0.05) higher in brimonidine-treated eyes in comparison to I/R retinas. Retinal BDNF mRNA levels in the I/R group dropped significantly (p < 0.05) compared to the control group (normal mice); brimonidine treatment counteracted the downregulation of retinal BDNF mRNA in I/R eyes. Retinal inflammatory markers increased significantly (p < 0.05) in the I/R group and brimonidine treatment was able to revert that. The anti-inflammatory IL-10 decreased significantly (p < 0.05) after retinal I/R insult and increased significantly (p < 0.05) in the group treated with brimonidine. In conclusion, brimonidine was effective in preventing loss of function of RGCs and in regulating inflammatory biomarkers elicited by retinal I/R injury.