Retinitis pigmentosa in Laurence-Moon-Bardet-Biedl syndrome in India: Electronic medical records driven big data analytics: Report II

Purpose:

To describe the clinical presentation and demographic distribution of retinitis pigmentosa (RP) in Laurence–Moon–Bardet–Biedl (LMBB) syndrome patients.

Methods:

This is a cross-sectional observational hospital-based study wherein 244 patients with RP in LMBB syndrome presenting to our hospital network between March 2012 and October 2020 were included. An electronic medical record database was used for data retrieval.

Results:

There were 244 patients in total, with a hospital-based prevalence rate of 0.010% or 1000/100,000 population. The mean and median age of patients was 15.22 ± 7.56 and 14 (IQR: 10–18.5) years, respectively, with the majority being in the age group of 11–20 years (133/244 patients; 54.50%). Males were more commonly affected (164 patients; 67.21%), and the majority (182 patients; 74.59%) were students. All 244 patients (100%) complained of defective central vision at presentation. More than one-fourth of the patients had severe visual impairment to blindness at presentation. Prominent retinal feature at presentation was diffuse or widespread retinal pigment epithelial degeneration in all patients.

Conclusion:

Patients with RP in LMBB syndrome present mainly in the first to second decade of life with severe visual acuity impairment to blindness early in life. It is important to rule out LMBB syndrome in early-onset RP with central visual acuity impairment. On the contrary, all patients diagnosed or suspected with LMBB syndrome systemic features at physician clinic should also be referred for ophthalmic evaluation, low vision assessment, rehabilitation, and vice versa.

Spectrum of Eye Disease in Diabetes (SPEED) in India: A prospective facility-based study. Report # 3. Retinal vascular occlusion in patients with type 2 diabetes mellitus

Purpose

To determine the proportion of people with type 2 diabetes mellitus (T2DM) attending large eye care facilities across India who have retinal vascular occlusion (RVO).

Methods

A 6-month descriptive, multicenter, observational hospital-based study of people was being presented to the 14 eye care facilities in India. The retina-specific component of comprehensive eye examination included stereoscopic biomicroscopy, binocular indirect ophthalmoscopy, and fundus fluorescein angiography, and optical coherence tomography was also available when needed. Data recording of the duration of diabetes, hypertension (HTN), stroke, and other variables was obtained from the medical history. The statistical analysis included frequencies, mean, and standard deviations for continuous variables. Odds ratio (OR) and multivariate analysis were undertaken to assess the associations between risk factors and RVO.

Results

The study recruited 11,182 consecutive patients (22,364 eyes) with T2DM. About 59.0% (n = 6697) were male. The mean age was 58.2 ± 10.6 years. In this cohort, RVO was detected in 3.4% (n = 380) of patients; 67.6% (n = 257) of them had branch retinal vein occlusion (BRVO) and the remaining 32.4% (n = 123) had central retinal vein occlusion (CRVO). The frequency of unilateral BRVO (n = 220, 85.6%) and unilateral CRVO (n = 106, 86.18%) was much common. Unilateral RVO was more frequent (n = 326, 85.8%) than bilateral diseases (n = 54, 14.2%) (χ2 = 126.95, P < 0.001). Ischemic CRVO was more common (n = 103, 73.6%) than nonischemic CRVO (n = 37, 26.4%). Macula-involving BRVO was found in 58.5% (n = 172) of cases, suggesting more than 50% of cases in RVO carries a risk of severe vision loss. The duration of diabetes apparently had no influence on the occurrence of RVO. On the multivariate analysis, a history of HTN [OR: 1.7; 95% confidence interval (CI): 1.3-2.1; P = 0.001) and stroke (OR: 5.1; 95% CI: 2.1-12.4; P < 0.001) was associated with RVO.

Conclusion

RVO is a frequent finding in people with T2DM. History of stroke carries the highest risk followed by HTN. The management of people with T2DM and RVO must also include comanagement of all associated systemic conditions.

VMAT1 deletion causes neuronal loss in the hippocampus and neurocognitive deficits in spatial discrimination

Vesicular monoamine transporters (VMAT) are involved in presynaptic storage and release of neurotransmitters. While it was thought initially that only VMAT2 is brain expressed and VMAT1 is present only in the periphery, recent data have challenged the exclusive expression of VMAT2 in the brain. To further elucidate the role of VMAT1 brain expression and its potential role in neuropsychiatric disorders, we have investigated mice lacking VMAT1. Comparison of wildtype and knock-out (KO) mice using qPCR and immunohistochemistry documents the expression of VMAT1 in the brain. Deletion of VMAT1 leads to increased hippocampal apoptosis and reduced neurogenesis as assessed by caspase-3-labeling and 5-bromo-deoxy-uridine-labeling. Behavioral data show that mice lacking VMAT1 have neurocognitive deficits. VMAT2 expression is not altered in VMAT1 KO mice, suggesting a distinct role of VMAT1. Our data support VMAT1 brain expression and suggest that VMAT1 plays a key role in survival of hippocampal neurons and thus might contribute to neurocognitive deficits observed in neuropsychiatric disorders.