Correlation between Transient Pupillary Light Reflex and Retinal Function Impairment in Patients with Retinitis Pigmentosa

Abstract

Purpose To investigate the relationship between transient pupillary light reflex (PLR) and visual function in patients with retinitis pigmentosa (RP). Methods A retrospective study was performed with 137 eyes of 73 patients with RP. Transient pupillary light reflex was measured by the vision monitor system (MonColor; Metrovision, France). Dark-adapted transient PLRs were elicited by four specific levels of stimulus luminance (−5, −3, −1, and 0 log cd/m2, blue or white light). Best-corrected visual acuity (BCVA) was recorded based on Early Treatment Diabetic Retinopathy Study (ETDRS) acuity charts. Fixation stability and retinal sensitivity of radial 10° areas were measured with microperimetry. The retinal sensitivity (RS) was divided into central RS (fovea and radial 1° areas) and peripheral RS (radial 3° and 5° areas from the fovea). The patients were further classified into 2 groups (P1 > 75% and P1 < 75%) according to fixation stability. Spearman's correlation was performed to identify significant associations between BCVA, fixation stability, RS, and PLR. Results Under the stimuli of the same color light, relative pupillary constriction (RPC), latency, or velocity of constriction in the same patients was statistically different in multiple luminance, respectively. Under the same luminance, blue light induced greater RPC and velocity (except for −3 log cd/m2) than white light. Most patients showed varying degrees of threshold elevation and visual function deficiency. Besides, there was a statistically significant difference in the distribution of BCVA, MRS, or fixation stability under different thresholds. The correlation between pupillary constrictive area (PCA) and retinal sensitivity was mainly determined by the peripheral region. Moreover, patients with stable fixation showed a greater correlation between PCA and RS. Conclusion PLR induced by specific colors and luminance may serve as a promising clinical approach for assessing and monitoring rod function in advanced RP patients.

Oxidative Model of Retinal Neurodegeneration Induced by Sodium Iodate: Morphofunctional Assessment of the Visual Pathway

“…Since the mice used in this model had a mutation in the melanopsin gene ( Opn4 −/− ) that canceled its photosensitive function, the responses obtained in this reflex after the injection of sodium iodate corresponded exclusively to the photoreceptors, and their decrease was a faithful reflection of the lesion they suffered [ 40 ]. The novelty of these experiments is that their results reinforce the correlation with pupillary reflex dysfunction observed in patients suffering from various retinal disorders [ 50 , 51 , 52 , 53 ]. However, further research would be required to discern the origin of this dysfunction.…”

Chromatic pupillometry isolation and evaluation of intrinsically photosensitive retinal ganglion cell-driven pupillary light response in patients with retinitis pigmentosa

“…Many studies suggest that chromatic pupillometry is more sensitive than standard visual electrophysiological examination for detecting retinal functional activity in the later stages of retinal degeneration ( Park et al, 2010 ; Jacobson et al, 2011 ; Kardon et al, 2011 ; Lisowska et al, 2017 ; Rukmini et al, 2019 ; Krishnan et al, 2020 ; Yamamoto et al, 2023 ). In previous work, we demonstrated that chromatic pupillometry can quantitatively estimate retinal function in RP patients ( He et al, 2018 ), and we used this method to evaluate the therapeutic effect of stem cell transplantation in clinical trials ( Liu et al, 2017 ). Additionally, we found that high-intensity blue light can induce pupillary responses that are not easily attenuated ( Zhang et al, 2021 ), even in patients with NLP.…”

Dynamic and Static Pupil Changes After Near Work: Comparison Between Reading a Book and Using a Smartphone

“…One of less noticed in this regard is changes in pupillary dynamic responses while providing different stimuli. Limited studies have provided these characteristics in different eye conditions including amblyopic patients, ( 14 ) people with multiple sclerosis, ( 15 ) people with diabetic retinopathy, ( 16 ) people with retinitis pigmentosa, ( 17 ) and finally while reducing or increasing accommodation ( 10 ). However, a review of available studies shows that evaluation of dynamic pupil changes after near ocular work has not been performed yet.…”