Abstract
Purpose :
Rhegmatogenous retinal detachment (RRD) is a threatening visual condition. Despite successful reattachment surgery, vision does not fully recover, due to subretinal fluid (SRF) accumulation and subsequent photoreceptor cell death. Various molecular components of SRF could exert toxicity on retinal neurons. With increased RRD duration, SRF protein concentration increases and visual prognosis worsens, but the direct effect of proteins on photoreceptors has not been evaluated. The aim of this study is to analyze the effect of proteins on photoreceptors as well as the role of protein concentration in SRF on functional outcome in RRD patients.
Methods :
First, human cones cell line were treated by albumin from 2.5 to 40 g/L and cultured during 24 hours. Cell Titer was assessed to determine viable cells. Secondly, SRF from 21 consecutive patients underwent vitrectomy for RRD repair were collected and protein concentration was measured by Micro BCA protein assay. Clinical data was recorded at baseline and at 6 months after surgery. Finally, rat retinal explants were created to mimic retinal detachment and treated by albumin at 12 mg/ml. LDH release was measured in medium after 6 hours of culture.
Results :
Albumin reduced cone viability in dose-dependent manner. Albumin concentrations higher than 5g/L significantly reduced viability of cone cells, when compared to the control (p<0.05, Mann-Whitney test). At 20 mg/ml, albumin reduced 40% of cone cells viability.
Mean protein concentration in SRF from patients with RRD was 3.1 ± 2.9 mg/ml (range: 0.6-12.1 mg/ml). The protein concentration, measured in the SRF at the time of surgery correlated with lower best-corrected visual acuity (BCVA) at baseline (r=0.5, p=0.0004, Spearman correlation), as well as with lower BCVA recovery 6 months after surgery (r=0.6, p=0.0001, Spearman correlation).
Rat retinal explants treated by albumin, at concentration ranges found in SRF of patients, showed significantly higher LDH release in culture medium compared to control retinas (p=0.01, Mann-Whitney test).
Conclusions :
Lower visual outcome in RRD patients is associated with higher protein concentration in SRF that could be explained by a direct toxic effect of albumin on photoreceptors.
This is a 2021 ARVO Annual Meeting abstract.