Reliability of Mesopic Measures of Visual Acuity and Contrast Sensitivity and Their Correlation with Rod and Cone Function in Retinitis Pigmentosa
Overview
Authors
Affiliations
Background: Mesopic conditions elicit both rod and cone responses, and they are more commonly encountered in daily life than are scotopic conditions; yet visual function outcome measures of mesopic visual acuity (VA) or contrast sensitivity (CS) are rarely evaluated.
Objective: In retinitis pigmentosa (RP), we explored whether visual reductions in mesopic versus photopic conditions were correlated with cone or rod function, as well as the between-visit test-retest variability in mesopic measures.
Methods: At each of two visits, 22 RP subjects completed mesopic and photopic ETDRS VA and Pelli-Robson chart CS tests obtained with and without a U23 NoIR 4% transmission filter; testing of perifoveal scotopic cone or rod sensitivity with the AdaptDx; and the Rabin Cone Contrast Test (CCT).
Results: A greater CS reduction in mesopic versus photopic conditions was significantly related to absence of scotopic rod function (p = 0.038) or longer self-reported duration of night vision loss (p = 0.044). VA reductions >0.2 logMAR in mesopic versus photopic conditions were significantly related to reduced cone-mediated scotopic sensitivity (p = 0.038). Significant predictors of the CCT ratio of S-cone to M- and L-cone sensitivity were mesopic VA (p = 0.038) and absence of AdaptDx rod function (p = 0.008). Test-retest 95% coefficients of repeatability were not significantly different when comparing between photopic and mesopic tests of VA (0.16 and 0.12 logMAR, respectively) or CS (0.21 and 0.24 logCS, respectively).
Conclusions: Perifoveal scotopic rod and cone function measured with the AdaptDx was significantly correlated with mesopic CS and VA, respectively, which had good, acceptable test-retest repeatability; thus, they appear to be suitable outcome measures to monitor mesopic visual function in clinical practice or trials. RP subjects with reduced mesopic VA and no perifoveal rod function had a greater loss of sensitivity for S-cones than for L-/M-cones.
Real-world outcomes of Voretigene Neparvovec: a single-centre consecutive case series.
Jalil A, Ferrara M, Lippera M, Parry N, Black G, Banderas S Eye (Lond). 2025; .
PMID: 39900645 DOI: 10.1038/s41433-025-03637-0.
MNREAD Reading Vision in Adults With Glaucoma Under Mesopic and Photopic Conditions.
Goddin T, Yu H, Friedman D, Owsley C, Kwon M Invest Ophthalmol Vis Sci. 2023; 64(15):43.
PMID: 38153749 PMC: 10756241. DOI: 10.1167/iovs.64.15.43.
Kwon M, Owsley C Transl Vis Sci Technol. 2023; 12(9):7.
PMID: 37676678 PMC: 10494985. DOI: 10.1167/tvst.12.9.7.
Age-related normal limits for spatial vision.
Keuken A, Subramanian A, Mueller-Schotte S, Barbur J Ophthalmic Physiol Opt. 2022; 42(6):1363-1378.
PMID: 35979702 DOI: 10.1111/opo.13037.
Miura G, Baba T, Tatsumi T, Yokouchi H, Yamamoto S J Ophthalmol. 2021; 2021:2281834.
PMID: 34820138 PMC: 8608543. DOI: 10.1155/2021/2281834.