Progressive Visual Field Loss Research Articles

What are the effects of iridotomy for slowing progression of visual field loss in people with angle-closure glaucoma?

What are the effects of iridotomy for slowing progression of visual field loss in people with angle-closure glaucoma?

Molecular genetics of inherited normal tension glaucoma.

Normal tension glaucoma (NTG) is a complex optic neuropathy characterized by progressive retinal ganglion cell death and glaucomatous visual field loss, despite normal intraocular pressure (IOP). This condition poses a unique clinical challenge due to the absence of elevated IOP, a major risk factor in typical glaucoma. Recent research indicates that up to 21% of NTG patients have a family history of glaucoma, suggesting a genetic predisposition. In this comprehensive review using PubMed studies from January 1990 to December 2023, our focus delves into the genetic basis of autosomal dominant NTG, the only known form of inheritance for glaucoma. Specifically exploring optineurin ( OPTN ), TANK binding kinase 1 ( TBK1 ), methyltransferase-like 23 ( METTL23 ), and myocilin ( MYOC ) mutations, we summarize their clinical manifestations, mutant protein behaviors, relevant animal models, and potential therapeutic pathways. This exploration aims to illuminate the intricate pathogenesis of NTG, unraveling the contribution of these genetic components to its complex development.

Prevalence of visual loss and compliance to the management plan of primary open-angle glaucoma (POAG) patients (hospital-based study)

Background Glaucoma treatment seeks to improve the patient’s health and quality of life by maintaining visual function without producing unwanted side effects. Currently, the only known and treatable risk factor for primary open-angle glaucoma (POAG) is decreased intraocular pressure. Numerous studies have shown that treating glaucoma or ocular hypertension with ocular hypotensive medications slows the onset of POAG or the progression of visual field loss. Aims The purpose of this study was to determine how much visual impairment from glaucoma correlated with how well POAG patients adhere to their care plan. Patients and methods From January 2018 to December 2019, 200 Egyptians with POAG were selected for this cross-sectional study from Tanta University’s glaucoma outpatient clinic. Results High education, regular follow-up visits, fewer prescription adverse effects, ease of medication use, good visual status, and favorable perception of their vision were all characteristics in univariate analysis that significantly improved adherence levels. Only low education levels, higher difficulty using glaucoma drops, and increased adverse drug reactions were statistically significant predictors of poor adherence to glaucoma treatment in multivariate analysis. Age, sex, visual acuity, the number of glaucoma drops used, the length of therapy, financial support, and glaucoma control did not have a statistically significant prognostic value for low compliance. Conclusion This study showed that noncompliance is mostly a multifaceted issue among Egyptian glaucoma patients.

Adherence and factors influencing adherence to glaucoma medications among adult glaucoma patients in Ethiopia: A systematic review and meta-analysis.

Intraocular pressure is the only modifiable risk factor for the development and progression of glaucoma. Raised intraocular pressure could cause progressive visual field loss and blindness if left uncontrolled. Adherence to ocular hypotensive medications is vital to prevent optic nerve damage and its consequences. This study was conducted to systematically summarize the magnitude of glaucoma medication adherence and factors influencing adherence to glaucoma medications among adult glaucoma patients in Ethiopia. Database searches to identify research articles were conducted on PubMed, EMBASE, Cochrane, AJOL, SCOPUS, and Google Scholar without restriction on the date of publication. Data extraction was done using a data extraction Excel sheet. Analysis was performed using STATA version 16. Heterogeneity was assessed using I2 statistics. Pooled prevalence and pooled odds ratio with a 95% confidence interval using a random effect model were computed. We included six studies with a total of 2101 participants for meta-analysis. The magnitude of adherence to glaucoma medication was found to be 49.46% (95% CI [41.27-57.66]). Urban residents (OR = 1.89, 95% CI; 1.29-2.49) and those with normal visual acuity (OR = 2.82, 95% CI; 0.85-4.80) had higher odds of adherence to glaucoma medications. Patients who pay for the medications themselves (OR = 0.22, 95% CI; 0.09-0.34) were found to have 78% lower odds of adherence than their counterparts. The magnitude of glaucoma medication adherence is lower than expected. Place of residence, visual acuity, and payment means had statistically significant associations with glaucoma medication adherence. Tailored health education on medication adherence and subsidization of glaucoma medication is recommended.

Progression of retinitis pigmentosa on static perimetry, optical coherence tomography, and fundus autofluorescence

In retinitis pigmentosa (RP), photoreceptor degeneration leads to progressive visual field loss and visual impairment. Several therapeutic trials are ongoing aiming to establish effective treatments. Although functional evaluations are commonly used in clinical trials, residual ellipsoid zone (EZ) measurement on optical coherence tomography has been shown to be more sensitive to detect disease progression. Establishment of sensitive outcome measurement is essential to develop new therapeutic strategies. In the current study, we evaluated the progression rates of the disease in 76 eyes of 76 patients with RP, using the residual EZ length, ring-shaped macular hyperautofluorescent (AF), and visual field. Decrease rates measured by the residual EZ area and by the hyper-AF ring area were strongly positively correlated (P < 0.0001, r = 0.71). The reduction rates of the residual EZ length and hyper-AF ring radius were constant regardless of their baseline measurements. Faster annual reduction rates of the hyper-AF ring area or radius were significantly correlated with faster visual field progression (P = 0.03, r = 0.25 and P = 0.004, r = 0.33, respectively). These findings support the usage of morphological measurements such as EZ or hyper-AF ring measurements as outcome measurement for future clinical trials for RP.

El espacio supracoroideo en pacientes afectados por retinosis pigmentaria

Background and objectiveThe suprachoroidal space (SCS) is a theoretical structure which can be demonstrated between the inner border of the sclera and the outer boundary of the choroid. SCS is being studied for its potential uses as a route for drug delivery and innovative surgical techniques for the treatment of many retinal diseases. Retinitis pigmentosa (RP) is a group of inherited eye disorders characterized by a gradual loss of photoreceptors, resulting in vision impairment, which typically presents as night blindness and progressive visual field loss. The purpose of the study is to define the morphology of outer choroidal margins by means of SS-OCT in RP. Material and methodThis is a retrospective observational study designed to evaluate the presence of SCS in RP. We performed swept source optical coherence tomography (SS-OCT) in a group of 55 patients affected by RP (26 males and 29 females, 110 eyes) with a mean age of 51.8±13.7 years. In the control group, we included 28 healthy subjects (6 males and 22 females, 56 eyes) with a mean age of 48.8±16.6 years. ResultsOCT scans allowed the outer choroidal margin and inner scleral margin to be delineated with certainty in all 110 eyes. In the RP group SCS was detected in 47 of 110 eyes (42.7%), in the control group SCS was detected in 11 eyes (19.6%).Subjects with SCS visible (RP group) had reduced retinal thickness (168.4μm) compared to those with not visible SCS (211.2μm, p=0.007). ConclusionsSS-OCT can be successfully applied to assess the presence of SCS in RP and the high rate of SCS found in the RP patients is encouraging when considering future innovative therapies.

Familial normal tension glaucoma genetics.

Glaucoma is defined by characteristic optic nerve damage and corresponding visual field defects and is the leading cause of irreversible blindness in the world. Elevated intraocular pressure (IOP) is a strong risk factor for developing glaucoma. However, glaucoma can occur at any IOP. Normal tension glaucoma (NTG) arises with IOPs that are within what has been defined as a normal range, i.e., 21mm Hg or less, which may present challenges in its diagnosis and management. Identifying inheritance patterns and genetic mutations in families with NTG has helped elucidate mechanisms of NTG, however the pathophysiology is complex and not fully understood. Approximately 2% of NTG cases are caused primarily by mutations in single genes, optineurin (OPTN), TANK binding kinase 1 (TKB1), or myocilin (MYOC). Herein, we review pedigree studies of NTG and autosomal dominant NTG caused by OPTN, TBK1, and MYOC mutations. We review identified mutations and resulting clinical features of OPTN-associated and TBK1-associated NTG, including long-term follow up of these patients with NTG. In addition, we report a new four-generation pedigree of NTG caused by a Glu50Lys OPTN mutation, including six family members with a mean follow up of 17 years. Common features of OPTN -associated NTG due to Glu50Lys mutation included early onset of disease with an IOP <21mm Hg, marked optic disc cupping, and progressive visual field loss which appeared to stabilize once an IOP of less than 10mm Hg was achieved. Lastly, we review risk factor genes which have been identified to contribute to the complex inheritance of NTG.

Progressive Visual Field Loss and Subsequent Quality of Life Outcomes in Glaucoma

To evaluate the association between baseline severity of visual field (VF) damage and the initial rates of VF progression with quality of life (QOL) outcomes over an extended follow-up in glaucoma. Retrospective cohort study. Both eyes of 167 glaucoma or suspected glaucoma patients were followed for 10.0±0.3 years. The National Eye Institute Visual Function Questionnaire (NEI-VFQ)-25 was performed at the end of the follow-up. Separate linear regression models included the VF parameters of the better eye, the worse eye, and the central and peripheral points of the integrated binocular VF to evaluate the association of baseline and initial rates of change of VF parameters (first half of the follow-up) with NEI-VFQ-25 Rasch-calibrated disability scores over an extended follow-up. All models demonstrated association of worse baseline severity of VF damage with worse subsequent NEI-VFQ-25 scores. Faster rates of decline in VF mean deviation of the better eye and the mean sensitivity of the central and peripheral test locations of the integrated binocular VF were significantly associated with worse subsequent NEI-VFQ-25 scores. VF parameters of the better eye performed better than those of the worse eye (R2 of 0.21, and 0.15, respectively), and the VF parameters of the central test locations performed better than those of the peripheral test locations (R2 of 0.25, and 0.20, respectively). Baseline severity and initial rates of change of VF damage are associated with QOL outcomes over an extended follow-up. Assessment of longitudinal VF changes, especially in better eye, provides prognostic utility to identify glaucoma patients at a higher risk for developing disease-related disability.

Incidence and risk factors of early transient intraocular pressure elevation after canaloplasty for primary open-angle glaucoma.

Glaucoma is one of the most common optic neuropathies, featuring progressive retinal ganglion cell damage and visual field loss (Tham et al., 2014; Xu et al., 2020). Currently, the only effective treatment for this condition is the reduction of intraocular pressure (IOP) (Palmberg, 2001; Heijl et al., 2002). Canaloplasty is a proven bleb-independent surgery with good efficacy and safety profiles in primary open-angle glaucoma (POAG) (Gołaszewska et al., 2021). However, early transient postoperative IOP elevation has been reported in up to 30% of cases (Riva et al., 2019), similar to that commonly observed in other internal drainage glaucoma surgeries such as implantation using iStent (0%-21.0%), CyPass (10.8%), and Hydrus (4.8%-6.5%) (Lavia et al., 2017). This complication may be a predictor of poor reserve in the outflow system and is potentially associated with surgical failure. Nonetheless, the exact pathophysiology of glaucoma remains unknown, and studies clarifying the risk factors for postoperative IOP elevation have been scarce.

The use of Nicotinamide and Nicotinamide riboside as an adjunct therapy in the treatment of glaucoma.

Glaucoma is an optic neuropathy characterized by death of retinal ganglion cells (RGCs), which leads to progressive visual field loss and may result in blindness. Currently, the only available treatment to avoid or delay progression in glaucoma patients is to decrease intraocular pressure (IOP). However, despite adequate IOP control, approximately 25% of the patients continue to progress. To delay or prevent optic nerve damage in glaucoma, two forms of vitamin B3, nicotinamide (NAM) and nicotinamide riboside (NR) are emerging as viable adjuvant therapies. These compounds are nicotinamide adenine dinucleotide (NAD) precursors. NAD is essential for proper cell functioning and is involved in several metabolic activities, including protection against reactive oxygen species, contribution to the performance of various enzymes, and maintenance of mitochondrial function. Due to its beneficial effects and to the evidence of the reduction of NAD bioavailability with aging, researchers are seeking ways to replenish the cellular NAD pool, by administrating its precursors (NAM and NR), believing that it will reduce the RGC vulnerability to external stressors, such as increased IOP. This article attempts to analyze the current knowledge regarding the use of NAM and NR for the prevention and/or treatment of glaucoma.

Iridotomy to slow progression of visual field loss in angle-closure glaucoma.

Primary angle-closure glaucoma is a type of glaucoma associated with a physically obstructed anterior chamber angle. For example, contact between the iris and lens at the pupillary margin creates a pupillary block that increases resistance to aqueous outflow. Obstruction of the anterior chamber angle blocks drainage of fluids (aqueous humor) within the eye and may raise intraocular pressure (IOP). Elevated IOP is associated with glaucomatous optic nerve damage and visual field loss. Laser peripheral iridotomy ('iridotomy') is a procedure to eliminate pupillary block by allowing aqueous humor to pass directly from the posterior to anterior chamber, which is achieved by creating a hole in the iris using laser. Iridotomy is used to treat patients with primary angle-closure glaucoma, patients with primary angle-closure (narrow angles and no signs of glaucomatous optic neuropathy), and patients who are primary angle-closure suspects (patients with reversible obstruction). However, the effectiveness of iridotomy on slowing progression of visual field loss is uncertain. To assess the effects of iridotomy compared with no iridotomy for primary angle-closure glaucoma, primary angle-closure, and primary angle-closure suspect. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 10), which contains the Cochrane Eyes and Vision Trials Register; MEDLINE Ovid; Embase Ovid; PubMed; LILACS; ClinicalTrials.gov; and the WHO ICTRP. The date of the most recent search was 10 October 2021. Randomized or quasi-randomized controlled trials that compared iridotomy with no iridotomy in primary angle-closure suspects, people with primary angle-closure, or people with primary angle-closure glaucoma in one or both eyes were eligible. We used standard Cochrane methodology and assessed the certainty of the body of evidence for prespecified outcomes using the GRADE approach. We identified four studies (3086 eyes of 1543 participants) that compared iridotomy with no iridotomy in participants (range of mean age 59.6 to 62.9 years) who were primary angle-closure suspects from China, Singapore, or the UK. Study investigators randomized one eye of each participant to iridotomy and the other to no iridotomy. Two studies provided long-term (five or more years) results. We judged the certainty of the evidence as moderate to low across the prespecified outcomes, downgrading for high risk of bias (e.g. performance and detection biases) and imprecision of results. Meta-analyses of data from two studies suggest that iridotomy probably results in little to no difference in IOP compared with no iridotomy at one year (mean difference (MD) 0.04 mm Hg, 95% confidence interval (CI) -0.17 to 0.24; I2 = 65%; 2598 eyes of 1299 participants; moderate certainty evidence) and five years (MD 0.12 mm Hg, 95% CI -0.11 to 0.35; I2 = 0%; 2016 eyes of 1008 participants), and in best-corrected visual acuity measured as logMAR at one year (MD 0.00, 95% CI -0.01 to 0.01; I2 = 69%; 2596 eyes of 1298 participants; moderate certainty evidence) and five years (MD 0.01, 95% CI -0.01 to 0.03; I2 = 0%; 2002 eyes of 1001 participants). In terms of gonioscopic findings, eyes treated with iridotomy likely had wider angles in Shaffer grading scale (MD 4.93 units, 95% CI 4.73 to 5.12; I2 = 59%; 2598 eyes of 1299 participants at one year; MD 5.07, 95% CI 4.78 to 5.36; I2 = 97%; 2016 eyes of 1008 participants at five years; moderate certainty evidence) and experienced fewer peripheral anterior synechiae (PAS) than eyes that received no iridotomy at five years (risk ratio (RR) 0.41, 95% CI 0.24 to 0.67; I2 = 28%; 2 studies, 2738 eyes of 1369 participants), but the evidence was less conclusive at one year (RR 0.62, 95% CI 0.25 to 1.54; I2 = 57%; 3 studies, 2896 eyes of 1448 participants; low certainty evidence). No studies reported data on the proportion of participants with progressive visual field loss during follow-up (the primary outcome of this review), mean number of medications to control IOP, or quality of life outcomes. Low certainty evidence suggests that iridotomy may result in little to no difference in the incidence of acute angle-closure (RR 0.29, 95% CI 0.07 to 1.20; I2 = 0%; 3 studies, 3006 eyes of 1503 participants). Other ocular adverse events (e.g. eye pain, dry eye, redness of eyes, and ocular discomfort), although rare, were more common in eyes treated with iridotomy than in eyes in the control group. AUTHORS' CONCLUSIONS: We did not find sufficient evidence to draw any meaningful conclusions on the use of iridotomy for the purpose of slowing progression of visual field loss. No study reported on progressive visual field loss, the primary outcome of this review. Although there is moderate certainty evidence that iridotomy results in improved gonioscopic findings, in is unclear if these findings translate to clinically meaningful benefits.

Choroidal Melanoma: A Mini Review

Choroidal melanoma is a rare malignant tumour, yet it is the most common primary intra-ocular neoplasm and second on the list of top ten most malignant melanoma sites in the body. Clinical presentation can be non-specific and includes photopsia, floaters, progressive visual field loss, and blurry vision. The tumour is quite often diagnosed clinically during fundus examination; however, the most valued diagnostic tests are A- and B-scan ultrasonography (US). Several factors affect prognosis, including the patient's age, tumour size, histological features, and presence of metastases. Still, with primary treatment and tight surveillance, around 50% of choroidal melanoma patients metastasise.

Commentary: Rethinking 10-2 visual fields in early diagnosis of glaucoma for a glided glaucoma practice: The right choice to pick up a feeble noise?

Commentary: Rethinking 10-2 visual fields in early diagnosis of glaucoma for a glided glaucoma practice: The right choice to pick up a feeble noise?

Autophagy in glaucoma pathogenesis: Therapeutic potential and future perspectives.

Glaucoma is a common blinding eye disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons, progressive loss of visual field, and optic nerve atrophy. Autophagy plays a pivotal role in the pathophysiology of glaucoma and is closely related to its pathogenesis. Targeting autophagy and blocking the apoptosis of RGCs provides emerging guidance for the treatment of glaucoma. Here, we provide a systematic review of the mechanisms and targets of interventions related to autophagy in glaucoma and discuss the outlook of emerging ideas, techniques, and multidisciplinary combinations to provide a new basis for further research and the prevention of glaucomatous visual impairment.

Full-Thickness Macular Hole Following Selective Laser Trabeculoplasty

Glaucoma is the second leading cause of blindness worldwide and is predicted to affect nearly 80 million people globally by the end of the decade [1]. Characterized by progressive optic nerve damage and visual field loss, the cornerstone of glaucoma treatment involves reduction of intraocular pressure (IOP) by means of topical therapy, lasers or surgery in a bid to slow or prevent further progression of optic nerve damage and visual loss [1].

Inverse Problem Reveals Conditions for Characteristic Retinal Degeneration Patterns in Retinitis Pigmentosa Under the Trophic Factor Hypothesis.

Retinitis pigmentosa (RP) is the most common inherited retinal dystrophy with a prevalence of about 1 in 4,000, affecting approximately 1.5 million people worldwide. Patients with RP experience progressive visual field loss as the retina degenerates, destroying light-sensitive photoreceptor cells (rods and cones), with rods affected earlier and more severely than cones. Spatio-temporal patterns of retinal degeneration in human RP have been well characterised; however, the mechanism(s) giving rise to these patterns have not been conclusively determined. One such mechanism, which has received a wealth of experimental support, is described by the trophic factor hypothesis. This hypothesis suggests that rods produce a trophic factor necessary for cone survival; the loss of rods depletes this factor, leading to cone degeneration. In this article, we formulate a partial differential equation mathematical model of RP in one spatial dimension, spanning the region between the retinal centre (fovea) and the retinal edge (ora serrata). Using this model we derive and solve an inverse problem, revealing for the first time experimentally testable conditions under which the trophic factor mechanism will qualitatively recapitulate the spatio-temporal patterns of retinal regeneration observed in human RP.

ISK Factors for Progressive Visual Field Loss in Primary Open-Angle Glaucoma: A Retrospective Cross-Sectional Study

Aim: To assess the risk factors of visual field defects in primary open-angle glaucoma Study design: A retrospective cross-sectional study Place and Duration: Institute of Ophthalmology LUMHS, Jamshoro from May 2020 to April 2021 Methodology: This study comprised a total of 100 participants with glaucoma. Males outnumbered females in the gender distribution. Instead of using a formal definition defined by the investigators, a clinical diagnosis of POAG was used in this investigation. In the presence of gonioscopically open anterior chamber angles in both eyes, POAG was pragmatically defined as glaucomatous visual field defects (GVFD). Results: Primary open-angle glaucoma affected 80 percent of men and 20 percent of women. The prevalence of open-angle glaucoma was 44 percent in the 55-65-year-old group, and 30 percent in the 45-54-year-old group. In 44 percent of instances, the eyesight loss lasted two years, whereas 31 percent had a one-year history. Hypertension was observed in 23.5 percent of patients with primary open-angle glaucoma, followed by myopia and diabetes. Conclusion: It was observed that hypertension was the leading risk factor of Primary Open angle glaucoma, followed by myopia, family history, diabetes, and smoking. Keywords: Glaucoma, risk factors, hypertension, diabetes

Novel biallelic USH2A variants in a patient with usher syndrome type IIA- a case report

BackgroundUsher Syndrome is the commonest cause of inherited blindness and deafness. The condition is clinically and genetically heterogeneous, with no current treatment. We report a case carrying novel biallelic variants in USH2A causing progressive early adolescent onset visual and hearing impairment consistent with Usher Syndrome Type IIA.Case presentationOur patient presented at age 13 with progressive visual field loss and hearing loss, associated with early onset of cataract in her 40s requiring lens extraction. Now 52 years old, latest best corrected visual acuity (BCVA) stands at Logmar Right Eye (RE) 0.8 and Left Eye (LE) 0.2, with significantly constricted visual fields bilaterally. She was registered partially sighted age 46. Clinical and molecular genetic assessment of the proband was consistent with a diagnosis of Usher Syndrome Type IIA. Genetic testing identified two novel USH2A variants, resulting in the premature termination codon p.Leu30Ter and a missense mutation p.Cys3251Tyr. Segregation analysis confirmed that these variants were biallelic in the affected case. Comprehensive in silico analysis confirmed that these mutations are the probable cause of Usher Syndrome Type IIA in this individual.ConclusionsThe identification of novel mutations in USH2A increases the spectrum of genetic variations that lead to Usher Syndrome, aiding genetic diagnosis, assessment of patient prognosis, and emphasising the importance of genetic testing to identify new mutations in patients with undiagnosed progressive visual loss.

Evaluation of neuroprotective and immunomodulatory properties of mesenchymal stem cells in an ex vivo retinal explant model

BackgroundGlaucoma is a blinding degenerative neuropathy in which the death of retinal ganglion cells (RGCs) causes progressive loss of visual field and eventually vision. Neuroinflammation appears to be a key event in the progression and spread of this disease. Thus, microglial immunomodulation represents a promising therapeutic approach in which mesenchymal stem cells (MSCs) might play a crucial role. Their neuroprotective and regenerative potentials have already raised hope in animal models. Yet no definitive treatment has been developed, and some safety concerns have been reported in human trials. In the present study, we investigated the neuroprotective and immunomodulatory properties as well as the safety of MSCs in an ex vivo neuroretina explant model.MethodsLabeled rat bone marrow MSCs were placed in coculture with rat retinal explants after optic nerve axotomy. We analyzed the neuroprotective effect of MSCs on RGC survival by immunofluorescence using RBPMS, Brn3a, and NeuN markers. Gliosis and retinal microglial activation were measured by using GFAP, CD68, and ITGAM mRNA quantification and GFAP, CD68, and Iba1 immunofluorescence stainings. We also analyzed the mRNA expression of both ‘M1’ or classically activated state inflammatory cytokines (TNFα, IL1β, and IL6), and ‘M2’ or alternatively activated state microglial markers (Arginase 1, IL10, CD163, and TNFAIP6).ResultsThe number of RGCs was significantly higher in retinal explants cultured with MSCs compared to the control group at Day 7 following the optic nerve axotomy. Retinal explants cultured with MSCs showed a decrease in mRNA markers of gliosis and microglial activations, and immunostainings revealed that GFAP, Iba1, and CD68 were limited to the inner layers of the retina compared to controls in which microglial activation was observed throughout the retina. In addition, MSCs inhibited the M1 phenotype of the microglia. However, edema of the explants was observed in presence of MSCs, with an increase in fibronectin labeling at the surface of the explant corresponding to an epiretinal membrane-like phenotype.ConclusionUsing an ex vivo neuroretina model, we demonstrated a neuroprotective and immunomodulatory effect of MSCs on RGCs. Unfortunately, the presence of MSCs also led to explant edema and epiretinal membrane formation, as described in human trials. Using the MSC secretome might offer the beneficial effects of MSCs without their potential adverse effects, through paracrine signaling.

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.