Oxygen metabolic retinal function in retinitis pigmentosa correlates with disease severity

Abstract

AbstractPurpose: The aim of our study was to evaluate retinal function with white light dark‐adapted full‐field sensitivity threshold (FST) and find possible correlations with metabolic function measured with retinal oximetry (RO) in patients with retinitis pigmentosa (RP).Methods: In this prospective observational study (BASEC 2020–00122), FST and RO measurements were performed on 66 RP eyes (33 subjects, 12♀ 21♂) aged between 18 and 80 years (mean 43.2 years); all eyes were graded for disease severity. Main outcome parameters were white FST thresholds using the Diagnosys Espion system with the ColorDomeTM LED full‐field stimulator (Diagnosys LLC, Lowell, MA) as well as the main RO parameters: the mean arterial (A‐SO2; %), venular (V‐SO2; %) oxygen saturation, their difference (A‐V SO2; %), and the corresponding mean diameters of the peripapillary retinal arterioles (D‐A; μm) and venules (D‐V; μm) recorded with the oxygen saturation tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). In addition, semi‐automated kinetic perimetry (V4e, III4e, I4e, III3e isopters, Octopus 900®, Haag‐Streit AG Bern, Switzerland) was performed and included in the linear mixed‐effects models analysis calculated with SPSS®.Results: Neither the oxygen saturation parameters (p > 0.21) nor the D‐A and D‐V (p > 0.13) showed significant correlations with the FST. However, when compared systematically with the visual field (VF) areas of the different isopters, RO parameters V‐SO2 (p = 0.024) and A‐V SO2 (p < 0.02) showed significant correlations. Furthermore, both V‐SO2 and A‐V SO2 showed gradual changes with more pronounced impairment in oxygen metabolic function in advanced stages of RP when analysed in subgroups of disease severity grades.Conclusions: In advanced stages of RP, RO showed a significant association with standardized VF testing parameters and presented with gradual changes of more pronounced impairment in retinal oxygen metabolic function. Unlike standardized VF parameters, white dark‐adapted FST does not appear to correlate with retinal oxygen metabolic function in RP patients, implying that the two examinations may capture unrelated aspects of the retinal pathological process.