Related Experiment Video
Updated: Jan 31, 2026
Direct-Coupled Electroretinogram DC-ERG for Recording the Light-Evoked Electrical Responses of the Mouse Retinal Pigment Epithelium
Published on: July 14, 2020
Correlation between Transient Pupillary Light Reflex and Retinal Function Impairment in Patients with Retinitis
Yan He1,2, Huanyu Tang1,2, Gang Wang1,2
1Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China.
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.
Related Concept Videos
01:08Reflex Activity
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
01:26The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating...
02:20Correlations
01:27Correlation and Causation
Correlation versus Causation
If the dependent variable increases or decreases when the independent variable increases, there is a positive or negative...
01:22Somatic Spinal Reflexes
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
01:09Correlation
Two variables, for example, a and b, are said to be positively correlated if both variables move in the same direction. In other words, a positive correlation exists between two variables, a and b, if: