Microperimetric evaluation in patients with adult-onset foveomacular vitelliform dystrophy

Retinal sensitivity and fundus autofluorescence in adult-onset foveomacular vitelliform dystrophy

The present study aimed to compare retinal sensitivity (RS) at each stage and to evaluate the relationship between RS and fundus autofluorescence (FAF) pattern in adult-onset foveomacular vitelliform dystrophy (AOFVD). We retrospectively reviewed 17 eyes of 13 patients with AOFVD. In addition to best-corrected visual acuity (VA), RS within the affected lesion and optical coherence tomography (OCT) measurements were carried out in each participant. All the examined eyes were classified into 4 stages and 3 FAF patterns. RS was superimposed on OCT fundus image and RS within the affected lesion was calculated in each eye. The relationships between visual functions (VA and RS within the affected lesion) and stages and also FAF patterns were analyzed using the linear mixed model. As a result, RS within the affected lesion was significantly associated with FAF pattern, but not with stage. In contrast, VA was correlated with neither stages nor FAF patterns. Our current result suggested that RS within the affected lesion was related to FAF patterns but this was not the case with VA in eyes with AOFVD, demonstrating the usefulness of measuring RS, not only VA, to comprehend the disease status in AOFVD.

Adult-onset foveomacular vitelliform dystrophy: epidemiology, pathophysiology, imaging, and prognosis

Adult-onset foveomacular dystrophy (AOFVD) is a retinal pattern dystrophy that may affect up to 1 in 7,400 individuals. There is much that is unknown regarding this disease's epidemiology, risk factors for development, and rate of progression through its four stages. Advancements in retinal imaging over the past 15 years have enabled improved characterization of the different stages of AOFVD. These imaging advancements also offer new ways of differentiating AOFVD from phenotypically similar retinal diseases like age-related macular degeneration and Best disease. This review synthesizes the most recent discoveries regarding imaging correlates within AOFVD as well as risk factors for the development of AOFVD, complications of AOFVD, and treatment options. Our aim is to provide ophthalmologists a succinct resource so that they may offer clarity, guidance, and appropriate monitoring and treatments for their patients with suspected AOFVD.

Fotopic and scotopic retinal sensitivity and foveal fixation normal values using microperimetry in healthy population

PURPOSE

To determine normal values of fotopic and scotopic retinal sensitivity and foveal fixation obtained by microperimetry, using MP3-S microperimeter (Nidek, Gamagori, Japan), in a healthy population.

METHODS

Observational, crossectional, single centre study. Fotopic and scotopic microperimetry was performed using with a customized 13-point fovea-centered pattern in healthy volunteers without ocular pathology. A intraclass correlation coefficient (ICC) was performed to evaluate fotopic and scotopic microperimetry reliability.

RESULTS

We analyzed 102 eyes of 54 patients with a mean age of 49.8 +/- 15 years old. The fotopic and scotopic mean retinal sensitivity (MRS) was 28.55±3.3dB (95% CI=[27.87-29.23]) and 15.72±1.9dB (95% CI=[15.35-16.09]) respectively, showing a significant statistical difference (p<0.05). No differences were found when comparing SRM by gender group. However, when analyzing the SRM by age groups, statistically significant differences were found in both modalities of the test; SRM being higher in the group of subjects under 35 years of age with 30.3±1.7dB in the photopic and 16.3±1.3dB in the scotopic; and lower in the group of older than 65 years with 26.7±2.2dB in the photopic and 13.8±1.8dB in the scotopic with p=0.0001. The reliability analysis of both tests, revealed an excellent reliability of the fotopic microperimetry with a Crombach alpha of 0.958 and a good reliability of 0.841 in scotopic microperimetry.

CONCLUSIONS

Microperimetry is a test with good reliability both under photopic and scotopic conditions. SRM and fixation stability under photopic and scotopic conditions do not differ according to sex, but it does decrease with age. There is a positive correlation between photopic and scotopic SRM.

Barriers to Low-Vision Rehabilitation Services for Visually Impaired Patients in a Multidisciplinary Ophthalmology Outpatient Practice

Low-vision rehabilitation (LVR) has significant benefit in improving the quality of life of visually impaired patients. However, these services are highly underutilized in ophthalmology practices. A quality improvement study was performed to investigate barriers to LVR services for patients at the University of Texas Medical Branch (UTMB) between 2010 and 2020. Low vision was defined as the best corrected visual acuity of 20/70 or worse in the better-seeing eye or a visual field less than 20 degrees. Potential subjects were screened (n = 577) from the electronic medical record using International Classification of Disease (ICD) codes for legal blindness, impaired vision, and low vision. Chart review identified 190 subjects who met criteria for low-vision analysis. Patients who received LVR referrals to attend at least one LVR service visit from the eligible subjects were contacted for participation in phone interviews regarding their LVR experience. Practicing eye care providers (ECPs) at UTMB completed a questionnaire to capture their referral patterns. Of the eligible subjects, 64% were referred to LVR services by ECPs. Reported patient barriers included mental health issues (76%), denial of need for low-vision aid (71%), poor physical health (67%), lack of transportation (57.1%), and lack of referrals (36%). EPCs reported patient's overall health (67%), older age (44%), lack of social support (44%), poor cognitive function (44%), and low likelihood of follow-up (44%) as barriers to referring patients to LVR. This study identified several modifiable barriers that can be addressed to access LVR services for low-vision patients. Changing referral patterns, eliminating variations in referral criteria, and increasing patient awareness and knowledge of LVR resources may tremendously improve the quality of life of low-vision patients.

NOVEL BEST1 MUTATIONS DETECTED BY NEXT-GENERATION SEQUENCING IN A CHINESE POPULATION WITH VITELLIFORM MACULAR DYSTROPHY

PURPOSE

To characterize novel BEST1 mutations and the phenotype-genotype correlations in vitelliform macular dystrophy in a Chinese population.

METHODS

Seventeen individuals affected by vitelliform macular dystrophy underwent detailed ophthalmic examinations, including a best-corrected visual acuity test, slit-lamp biomicroscopy, fundus photography, spectral-domain optical coherence tomography, fundus autofluorescence, fluorescein angiography, and optical coherence tomography angiography. Next-generation sequencing was used to screen 790 genes frequently involved in common inherited nonsyndromic eye diseases in all participants. Sanger sequencing was used to identify possible disease-causing variants.

RESULTS

The mean ± SD age of the patients was 44.20 ± 15.09 (range: 16-69) years. Seven novel BEST1 mutations were identified: six heterozygous missense (p.Thr307Asn, p.Ile295The, p.Leu75Pro, p.Thr2Ser, p.Ser79Tyr, and p.Val81Leu) and one frameshift (p.Glu115GlufsX120) mutation. Choroidal neovascularization was detected in two probands. One individual presented with subfoveal focal choroidal excavation. Arden ratios obtained by electrooculography were less than the 1.5 cutoff value in 7 patients. No mutations were identified in 2 patients, one of whom had a fundus appearance typical of vitelliform macular dystrophy and a decreased Arden ratio (1.2/1.2).

CONCLUSION

Patients with the same heterozygous BEST1 mutations exhibited varying phenotypes. Our results have expanded the BEST1 mutation spectrum in a Chinese population with vitelliform macular dystrophy.

Comparison of Perimetric Outcomes from Melbourne Rapid Fields Tablet Perimeter Software and Humphrey Field Analyzer in Glaucoma Patients

Purpose

To compare visual field results obtained using Melbourne Rapid Fields (MRF) iPad-based perimeter software and Humphrey Field Analyzer (HFA) 24-2 Swedish Interactive Threshold Algorithm (SITA) standard program in glaucoma patients.

Design

A cross-sectional observational study.

Methods

In this single-centre study involving patients diagnosed with glaucoma, the perimetric outcomes of MRF were compared against those returned from the HFA 24-2 SITA standard. Outcomes included mean deviation (MD), pattern standard deviation (PSD), visual field index (VFI)/visual capacity (VC), foveal threshold, test time, number of points depressed at P < 5% on PSD probability plot, and glaucoma hemifield test/color coded indicator.

Results

The study included 28 eyes of 28 glaucoma patients. Mean (standard deviation) test times were 342.07 (56.70) seconds for MRF and 375.11 (88.95) for HFA 24-2 SITA standard (P=0.046). Mean MD was significantly lower for MRF (Δ = 3.09, P < 0.001), and mean PSD was significantly higher for MRF (Δ = 1.40, P=0.005) compared with HFA. The mean foveal threshold for the MRF was significantly lower than the mean HFA foveal threshold ((Δ = 9.25, P < 0.001). The number of points depressed at P < 5% on the PSD probability plot was significantly less for MRF (P < 0.001). Other perimetric outcomes showed no significant differences between both. Bland–Altman plots showed that considerable variability existed between the programs.

Conclusion

MRF is a good cost-effective, time-saving, user-friendly tool for monitoring visual fields in settings where access to traditional perimetry is limited. The lack of Internet strength in rural areas and questionable detection of early cases may be two points in MRF fields requiring an upgrade.