Phenotypic heterogeneity in family members of patients with retinitis pigmentosa

Purpose: To describe the phenotypic variations in family members of patients with retinitis pigmentosa (RP) with different modes of inheritance and to assess the ocular abnormalities in RP families. Methods: A descriptive analysis of three types of inheritance of RP was carried out, where 64 family members were examined at a tertiary eye care center, South India. They underwent comprehensive eye examination, fundus photography, fundus autofluorescence (FAF), full?field electroretinogram (FFERG), and spectral domain optical coherence tomography (SD?OCT). Analysis was performed between mild and severe forms of abnormalities to delineate retinal structural and functional defects in RP families. Results: The mean age was 38.55 ± 17.95 years. Males were 48.4%. In autosomal recessive and X?linked recessive groups, 74.2% and 77.3%, respectively, were asymptomatic, whereas in autosomal dominant group, 27.3% were asymptomatic. The proportion of the cases with abnormalities in all three groups was higher on ERG (59.6%), followed by OCT (57.5%), visual acuity (43.7%), peripheral FAF (23.5%), and macular FAF (11.8%). However, these abnormalities and the clinical pictures of the family members had no statistical difference across the three groups of inheritance. Conclusion: Structural and functional retinal alterations were noted in four out of five asymptomatic members, suggesting the need for careful screening of RP families and the pressing need for pre?test (genetic) counseling

Inhibition of photoreceptor apoptosis in mice with retinitis pigmentosa through NF-κB/NLRP3 pathway suppression with Lycium barbarum polysaccharide / 数字中医药（英文）

Objective@# To explore whether Lycium barbarum polysaccharide (LBP) can reduce the apoptosis of retinal photoreceptor cells in retinitis pigmentosa (RP) mice by inhibiting nuclear factor-kappa B (NF-κB)/NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) signaling pathway. @*Methods@# (i) In vitro experiments, mouse retinal ganglion cells (661W cells) were divided into normal, model, LBP low-dose (LBP-L, 40 mg/L), LBP middle-dose (LBP-M, 80 mg/L), LBP high-dose (LBP-H, 160 mg/L), and positive drug control (NLRP3 inhibitor, 160 mg/L) groups. And the 661W cells were exposed to varying concentrations of H2O2 ranging from 50 to 400 μmol/L to determine the optimal concentration for inducing apoptosis (200 μmol/L). Then the cell viability was assessed using Cell Counting Kit-8 (CCK-8), while the apoptosis rate was detected by flow cytometry; the expression of NLRP3 was detected by immunofluorescence; and the expression of apoptosis markers was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB). (ii) In vivo assays were carried out with the use of C57/BL6 and Rd10 mice. The animal experimental groups were divided into normal, model, LBP-L, LBP-M, LBP-H, and NLRP3 inhibitor groups, in which the normal group was C57/BL6 mice and the other groups were Rd10 mice. Ten mice were included in each group, and the corresponding drugs were administered intragastrically for a duration of four weeks. NF-κB/NLRP3 pathway and the expression of apoptosis markers were observed by electroretinogram, histopathological examination, and WB to assess the effects of LBP on retinal photoreceptor cell apoptosis.@*Results@#(i) In vitro experiments, compared with the normal group, the apoptosis rate of 661W cells in model group was significantly increased (P < 0.01), and the expression levels of key proteins of NF-κB/NLRP pathway, such as NLRP3, NF-κB, p-NF-κB, and pro-apoptotic protein caspase-3, were up-regulated (P < 0.01). The rate of Bax/Bcl-2 was increased (P < 0.01), and the concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were significantly increased (P < 0.01). Compared with the model group, high dose of LBP decreased the apoptosis rate of 661W cells (P < 0.01), and down-regulated the expression levelsof the key proteins of NF-κB/NLRP3 pathway, including NF-κB, NLRP3, p-NF-κB, and caspase-3 (P < 0.01). The rate of Bax/Bcl-2 was decreased (P < 0.01), and the concentrations of IL-1β and TNF-α were decreased (P < 0.01). (ii) In vivo experiments, high dose of LBP significantly increased morphological changes in the outer nuclear layer (ONL) thickness of Rd10 mice, as well as functional changes in the amplitudes of the a-wave and b-wave (P < 0.01), which also down-regulated the expression levels of NF-κB (P < 0.05), NLRP3, p-NF-κB, and caspase-3 (P < 0.01), reduced the Bax/Bcl-2 rate (P < 0.01), and decreased the concentrations of IL-1β (P < 0.01) and TNF-α (P < 0.05). @*Conclusion@#LBP could improve both retinal morphology and function, providing protection to photoreceptors from apoptosis through the inhibition of the NF-κB/NLRP3 pathway.

Asymptomatic Unexplained Visual Field Loss Diagnosed as Early Retinitis Pigmentosa without Pigmentation: A Case Report

PURPOSE: We report a case of asymptomatic unexplained visual field loss diagnosed as early retinitis pigmentosa (RP) without pigmentation. CASE SUMMARY: A 33-year-old woman was referred to us with a constricted visual field (C24-2) before laser-assisted in-situ keratomileusis surgery. The visual field test (C30-2) revealed significantly decreased sensitivity between 15 to 25 degrees in both eyes. Close fundus examination revealed a subtle greyish retinal atrophic lesion along the vascular arcade and fluorescein angiography revealed a window defect in accordance with a retinal atrophic lesion in both eyes. Optical coherence tomography showed decreased retinal thickness around the macula. Electroretinogram revealed decreased b waves in rod response. Based on these findings, we diagnosed the patient with early RP without pigmentation. CONCLUSIONS: The possibility of early RP without pigmentation presenting as slight atrophy around the macula without significant pigmental degeneration should also be considered if a patient presents with peripheral visual field constriction without other symptoms. The ophthalmologist should ensure that the location of the visual field defect matches the location of the lesion. In addition, a detailed fundus examination with macular optical coherence tomography can be helpful to diagnose such a lesion.

Electrophysiological and Histologic Evaluation of the Time Course of Retinal Degeneration in the rd10 Mouse Model of Retinitis Pigmentosa

Among several animal models of retinitis pigmentosa (RP), the more recently developed rd10 mouse with later onset and slower rate of retinal degeneration than rd1 mouse is a more suitable model for testing therapeutic modalities. We therefore investigated the time course of retinal degeneration in rd10 mice before adopting this model in our interventional studies. Electroretinogram (ERG) recordings were carried out in postnatal weeks (PW) 3~5 rd10 (n=23) and wild-type (wt) mice (n=26). We compared the amplitude and implicit time of the b-wave of ERG records from wt and rd10 mice. Our results showed that b-wave amplitudes in rd10 mice were significantly lower and the implicit time of b-waves in rd10 mice were also significantly slower than that in wt mice (20~160 microV vs. 350~480 microV; 55~75 ms vs. 100~150 ms: p<0.001) through PW3 to PW5. The most drastic changes in ERG amplitudes and latencies were observed during PW3 to PW4. In multichannel recording of rd10 retina in PW2 to PW4.5, we found no significant difference in mean spike frequency, but the frequency of power spectral peak of local field potential at PW3 and PW3.5 is significantly different among other age groups (p<0.05). Histologic examination of rd10 retinae showed significant decrease in thickness of the outer nuclear layer at PW3. TUNEL positive cells were most frequently observed at PW3. From these data, we confirm that in the rd10 mouse, the most precipitous retinal degeneration occurs between PW3~PW4 and that photoreceptor degeneration is complete by PW5.

Retinitis Pigmentosa Complicated by Vitreous Hemorrhage in a Young Patient: A Case Report

PURPOSE: To report a case of a young male patient with retinitis pigmentosa (RP) accompanied by vitritis and neovascularization of the optic disk in both eyes who underwent unilateral vitrectomy for the treatment of vitreous hemorrhage in the right eye. CASE SUMMARY: An 8-year-old boy visited our clinic with a complaint of night blindness. Both eyes showed inflammatory cells in the anterior vitreous and neovascularization of the optic disk confirmed by fluorescein angiography. Extensive vitreous hemorrhage developed in his right eye and he underwent unilateral vitrectomy. His final visual acuity was 0.6 in both eyes. CONCLUSIONS: Vitreous hemorrhage may be related to chronic inflammation in the vitreous and is a very rare RP complication. Vitrectomy can be an effective treatment option for RP complicated by vitreous hemorrhage.