Evaluation of Two Systems for Fundus-Controlled Scotopic and Mesopic Perimetry in Eye with Age-Related Macular...

The purpose of this study was to evaluate and compare the MP-1S (Nidek Technologies, Padova, Italy) and the S-MAIA (CenterVue, Padova, Italy) for mesopic and scotopic fundus-controlled perimetry (FCP) in age-related macular degeneration (AMD).

Eleven eyes from 11 patients underwent mesopic and, after 30 minutes of dark adaptation, scotopic (MP-1S: Goldmann V, 200 ms, background luminance 0.0032 cd/m²; S-MAIA: Goldman III, 200 ms, background luminance <0.0001 cd/m²) FCP. For the S-MAIA device, cyan (505 nm) and red (627 nm) scotopic FCP were performed. For both devices, a grid of 56 stimulus points covering 16° of the central macula was used. Examination time, fixation stability, and threshold values were analyzed.

The upper end of the dynamic range (≤4 dB of lowest threshold) was frequently reached by the MP-1S for mesopic testing (median 34 of 56 stimuli), while threshold values within the lower 4 dB of the dynamic range were occasionally found with the S-MAIA for scotopic testing (median 3 for cyan, median 2 for red). After correction of the stimulus intensity for the S-MAIA results, the median difference for all stimuli between both devices for mesopic testing was -2.0 dB (interquartile range [-4;0], range -14 to 6).

The results indicate that robust testing of mesopic and scotopic function is feasible with both devices in patients with AMD, although both devices are susceptible to floor and ceiling effects.

The interpretation and particularly the comparison of both scotopic and mesopic FCP results between the MP-1S and the S-MAIA in AMD eyes need to consider variable susceptibility of floor and ceiling effects. Further software updates are desirable as FCP captures visual functional loss that is not noted with best-corrected central visual acuity and is important for clinical trials in AMD.