Clinical characteristics and causes of visual impairment in a low vision clinic in northern Jordan

Clinical and genetic characterization of patients with eye diseases included in the Spanish Rare Diseases Patient Registry

BACKGROUND

The low prevalence of rare diseases poses a significant challenge in advancing their understanding. This study aims to delineate the clinical and genetic characteristics of patients with rare eye diseases (RED) enrolled in the Spanish Rare Diseases Patient Registry.

METHODS

A total of 864 patients from the registry database were included. Diseases were categorized into inherited retinal dystrophies (n=688); anterior segment diseases (n=48); congenital malformations (n=27); and syndromic diseases with ocular involvement including muscular (n=46), neurological (n=34), or metabolic (n=13); inflammatory diseases (n=4); and tumors (n=4). Data on visual acuity (VA) and/or visual field (VF), symptoms and signs, concurrent diseases in syndromic cases, age of onset and at diagnosis, affected genes, disability rating, inability to work and dependency grade recognition were collected.

RESULTS

A mean diagnostic delay of 7 years from symptom onset was observed. Commonly reported symptoms included photophobia, night blindness, and progressive vision loss (≥57% of patients). Cataract was the most prevalent secondary disease (46%), with pseudophakia being the most common ocular surgery (26%). Hearing loss and cardiovascular diseases were the most prevalent concurrent systemic diseases (≥13%). Certificates of disability, incapacity for work, and dependency were held by 87%, 42%, and 19% of patients, respectively. Among the 719 patients with available VA data, 193 (27%) were blind, and 188 (26%) had moderate to severe visual impairment. Over half of the patients (54%) exhibited VF defects, and 216 (25%) had concentric contraction ≤5° or abolished VF. Most had genetic diseases with autosomal recessive (55%), autosomal dominant (30%), X-linked (9%), and mitochondrial (6%) patterns. One patient had mutations in both recessive USH2A and dominant RHO genes simultaneously. Of the 656 patients (75.7%) who underwent genetic testing, only 461 (70.3%) received a positive result (pathogenic or likely pathogenic mutations explaining the phenotype). We found 62 new gene variants related to RED not previously reported in databases of genetic variants related to specific phenotypes.

CONCLUSIONS

This study delineates the clinical and genotypic profiles of RED in Spain. Genetic diseases, particularly retinal disorders, predominate, but a significant proportion of affected patients remain genetically undiagnosed, hindering potential gene therapy endeavors. Despite notable improvements in reducing diagnosis delays, it is still remarkable. RED frequently lead to disability and blindness among young populations.

Identifying causes of vision loss and assistive technology needs among patients attending rehabilitation clinic of a tertiary care center in North India

PURPOSE

Investigating the causes of visual loss and the best corrected visual acuity (BCVA) is crucial for identifying avoidable eye problems and planning appropriate rehabilitation and assistive technology (AT) services. The study aimed to identify various causes of vision loss and determine AT required for vision rehabilitation (VR).

METHODS

The electronic records of patients who attended the VR clinic at a tertiary eyecare for the past 2 years were reviewed. Information such as demographics, BCVA, and causes of visual impairment were retrieved from the records. BCVA was categorized into better than or equal to 1/60 and less than <1/60 for AT services.

RESULTS

In total, 1723 patients, mostly male (71.2%), visited the rehabilitation clinic from 2018 to 2019. Around 58.6% of patients belonged to the age group 16-49 years, whereas 25.6% were less than 15 years old. The most frequent eye problems were retinal disorders (63.5%), followed by retinitis pigmentosa (15.2%) and rod-cone dystrophy (4.7%). In contrast, congenital disorders were the most common cause of vision loss among younger groups. Approximately 36.0% of patients had <1/60 blindness and 16.6% had ≥1/60. Around 17.1% of patients would benefit from large prints (near vision acuity N18-N12).

CONCLUSION

Early detection and timely management will prevent a significant proportion of patients from developing irreversible vision loss. Around one-third of patients would benefit from visual substitution AT.

Retrospective analysis of low vision assistive products – A 6-year review

PURPOSE

The purpose of the study was to analyze the demographics, visual acuity (VA), etiologies, recommended low vision assistive products (LVAP), and the acceptance rates of LVAP in various age groups.

METHODS

This was a long-term retrospective review of all the patients presenting to the low vision clinic of our tertiary eye care hospital from January 2011 to December 2016. Data obtained included age, gender, VA, visual fields, ocular pathology causing the low vision, and types of LVAP advised. The primary outcome was to analyze the type of LVAP prescribed in different age groups, and the secondary outcome was the acceptance rate of LVAP.

RESULTS

We analyzed the results of 8309 patients, out of which 2844 (34%. 2) were <15 years of age, 2425 (29.5%) were between 16-40 years, and 3013 (36.3%) were above 40 years. A total of 5522 (66.4%) had best-corrected visual acuity (BCVA) ranging from 6/18-3/60, and 2796 (33.6%) had BCVA from 3/60-No PL. Approximately 38% improved with LVAPs. The most common etiology was retinitis pigmentosa in 1545 (18.6%) patients, followed by congenital nystagmus in 1482 (17.8%), and the least was albinism 383 (4.6%). Maximum prescribed and accepted LVAP were hand and stand magnifiers among 1017 (44.3%) and 512 (52.6%) patients, respectively.

CONCLUSION

Products that are easy to use, require lesser adaptability, are cheap, and require lower maintenance have maximum acceptance rates. We suggest that great emphasis should be laid on training, education, and guidance for low vision rehabilitation centers.

Vision-Related Quality of Life in Patients with Inherited Retinal Dystrophies

Purpose

To evaluate the effect of inherited retinal dystrophies (IRDs) on vision-related quality of life (VRQoL) among IRDs' patients in Iran.

Methods

This cross-sectional study was conducted on 192 patients with different types of IRDs who were randomly selected from registered patients in the Iranian National Registry for Inherited Retinal Dystrophy (IRDReg®). All ophthalmic findings were collected based on the recorded data in IRDReg®. Moreover, the eligible participants were interviewed to fill out the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) to assess their VRQoL. Ordinal logistic regression was used to evaluate the possible association of the different clinical and nonclinical factors such as demographic information, socioeconomic status, and visual function with VRQoL.

Results

The overall mean of a composite score of VRQoL was 45. All subscales obtained from the NEI VFQ-25 questionnaire except general health, mental health, and ocular pain had a significant negative correlation with logMAR best corrected visual acuity (BCVA) and near visual acuity variables. There was a statistically significant relationship between VRQoL and factors like age (odds ratio [OR] = 0.91, 95% confidence interval [CI]: 0.87-0.94), employment status (OR = 1.37, 95% CI: 1.05-4.74), logMAR BCVA (OR = 0.31, 95% CI: 0.19-0.49) and normal color vision (OR = 1.92, 95% CI: 1.74-5.01).

Conclusion

The VRQoL of patients with IRDs in this study was low. BCVA could be an indicator to show VRQoL.

Characteristics of Visual Impairment and the Impact of Low Vision Assessment in a Tertiary Academic Hospital in Jordan

PURPOSE

This project aims to describe the characteristics of patients with visual impairment referred from a tertiary academic hospital in Jordan for a comprehensive low vision evaluation and to study its impact on their functional needs.

METHODS

A retrospective analysis of the records of 108 patients from the ophthalmology clinic at Jordan University Hospital over the period from January 2014 to December 2018 was performed. Gathered information included age, gender, clinical diagnosis, family history of ocular disease, and type of low vision aid prescribed and its impact on patients' functional needs.

RESULTS

The mean age was 44.64 years (range 4-88). Most participants were in the 19-60 years age group (50.0%). Fifty percent of the participants were the offspring of consanguineous marriages. The main cause of visual impairment in this cohort was retinitis pigmentosa, followed by diabetic retinopathy. The majority of low vision aids were prescribed for near distance tasks, and reading spectacles were the most prescribed visual aid. Eighty-nine percent of patients reported functional improvement and retained their visual aids upon follow-up.

CONCLUSION

Retinitis pigmentosa was the main cause of visual impairment in this cohort of patients referred from a tertiary academic hospital for low vision assessment. We report a consanguinity rate of 50%. The overwhelming majority of patients reported functional improvement and retained their visual aids upon follow-up. Awareness and integration of low vision services into a multidisciplinary approach and improving referral protocols is essential to better address the needs of patients with visual impairment. Familial counselling regarding consanguineous marriages and emerging research to treat inherited retinal diseases should be pursued.

A retrospective study of causes of visual impairment and use of low vision devices in the low vision clinic in Trinidad and Tobago

PURPOSE

To determine the causes of visual impairment and the use of low vision devices in patients attending the low vision clinic in Trinidad and Tobago.

METHODS

A retrospective study of the 222 patients attending the low vision clinic at the University of the West Indies, St Augustine Campus was conducted. The presenting visual acuity, causes of low vision and blindness, and prescribed low vision devices were recorded and analysed to determine the major causes of visual impairment and improvement in visual acuity with low vision aids.

RESULTS

Out of the total 222 participants, 66.66% (n = 148) had low vision while the rest (33.33%, n = 74) were legally blind. Glaucoma was the major cause of low vision (31.08%) and blindness (28.38%) followed by diabetic retinopathy (20.94%, low vision and 20.27%, blindness). A total of 193 low vision devices were prescribed, 79.79% (n = 154) near devices and 20.20% (n = 39) distance devices. The low vision devices were effective in improving both near visual acuity (120 participants reading 1M or 2M) and distance visual acuity (VA better than 3/60).

CONCLUSION

The major causes of vision impairment in Trinidad and Tobago were glaucoma and diabetic retinopathy and low vision devices are effective in improving visual acuity. A comprehensive approach to dealing with the causes of low vision and low vision services are required to mitigate the burden of visual impairment in the country.

Descriptive Study of a Cohort of 488 Patients with Inherited Retinal Dystrophies

Purpose

To analyze the distribution of inherited retinal diseases (IRDs), describe the clinical characteristics of patients, and determine the percentages of patients with genetic diagnosis in the Castilla y Leon region of Spain.

Methods

All patients with an IRD seen in the two major referral units of Castilla y Leon during a 20-year period were included. The ages at symptom onset, diagnosis, and the last visit; sex; family history; history of consanguinity; type of inheritance; status of the fundus and electroretinogram findings; lens and macular status, visual acuity; and visual field data were recorded. Patients were divided into those with retinitis pigmentosa (RP) and all others. Gene mutations were gathered when available.

Results

Four hundred eighty-eight patients with IRDs were studied: 216 (44.26%) with RP of which 34 (15.74%) had syndromic diseases, and 272 had other conditions being 161 (59,19%) macular dystrophies. The mean delay in diagnosis was 6–16.2 years respectively. For the RP group the mean age at the last visit was 47.96±17,26; mean age of cataract surgery was 48.30 ± 12.01 years; and the foveal area was preserved in 74 (35.07%) patients, atrophic in 101 (47.87%), and edematous in 36 (17.06%). A genetic study had been performed in 58 (26.85%) of patients with RP and 71 (26,1%) of the rest, being indeterminate in 17 (29.31%) out of RP group and 20 (28.16%) out of the others.

Conclusion

Clinical characteristics are comparable to other published series. There is a significant delay in diagnosis. The number of patients with IRDs and available genetic diagnosis, thus being possible candidates for undergoing personalized treatments including gene therapy in our region is low and must be improved.

Clinical heterogeneity in retinitis pigmentosa caused by variants in RP1 and RLBP1 in five extended consanguineous pedigrees

Purpose

The aim of this study is to identify disease-causing variants in five consanguineous Jordanian families with a history of autosomal recessive retinitis pigmentosa (RP), and to investigate the clinical variability across the affected individuals.

Methods

Exome sequencing (ES) and ophthalmic examinations were performed to classify the underlying RP-causative variants and their pathogenic consequences. The candidate variants in the affected and unaffected family members underwent segregation analyses with Sanger sequencing.

Results

We described four variants in the RP1 and RLBP1 genes as disease-causing across the five families, including novel (c.398delC; p.Pro133GlnfsTer126) and recurrent (c.79delA; p.Thr27ProfsTer26) variants in RLBP1 and two previously reported variants in RP1 ((c.1126C>T; p.Arg376Ter) and (c.607G>A; p.Gly203Arg)). The consequent clinical manifestations were thoroughly investigated using a battery of ophthalmic tests, including electroretinography (ERG), optical coherence tomography (OCT), visual acuity (VA), and fundus examination. The phenotypes indicated clinical heterogeneity, typical RP for variants in RP1, and retinitis punctata albescens (RPA) for variants in RLBP1.

Conclusions

This study extends the pathogenic variant spectrum for the RP1 and RLBP1 genes. The study also revealed the consequent clinical progression, severity, and presentation of RP. Furthermore, we confirm that ES is an efficient molecular diagnostic approach for RP.

Application of neural network model in assisting device fitting for low vision patients

Background

To explore the application of neural network models in artificial intelligence (AI)-aided devices fitting for low vision patients.

Methods

The data of 836 visually impaired people were collected in southwestern Fujian from May 2014 to May 2017. After a full eye examination, 629 low vision patients were selected from this group. Based on the visual functions, rehabilitation needs, and living quality scores of the selected patients, the professionals chose assistive devices that were the best fit for the patients. The data of these three factors were then subjected to the quantitative analysis, and the results were digitized and labeled. The final datasets were used to train a fully connected deep neural networks to obtain an AI-aided model for assistive device fitting.

Results

In this study, the main causes of low vision in southwestern Fujian were congenital diseases, among which congenital cataract was the most common. During the low vision AI-aided devices fitting, we found that the intermediate distance magnifier was suitable for the largest number of patients. Through quantitative analysis of the research results, it was found that AI-aided devices fitting was closely related to visual function, rehabilitation needs and quality of life. If this complex relationship can be mapped into the neural network model, AI-aided device fitting can be realized. We built a fully connected neural network model for AI-aided device fitting. The input of the model was the characteristic data of low vision patients, and the output was the forecast of suitable devices. When the threshold of the model was 0.4, the accuracy was about 80% and the F1 value was about 0.31. This threshold can be used as the classification judgment threshold of the model.

Conclusions

Low vision AI-aided device fitting is closely related to visual function, rehabilitation needs, and quality of life scores. The neural network model based on full connection can achieve high accuracy in AI-aided devices fitting. It has a great impact on clinical application.