Purpose:
To investigate the efficacy of intravitreal ranibizumab injection for choroidal neovascularization (CNV) secondary to exudative Age-related Macular Degeneration (AMD) by evaluation of multifocal pupillographic objective perimetry (mfPOP).
Methods:
Pupil responses from 20 exudative AMD patients treated unilaterally with intravitreal ranibizumab were recorded before treatment and after 3 months treatment and compared with 30 normal subjects. Two multifocal stimulus ensembles consisting of 44 or 24 independent stimulus regions per eye with a mean presentation interval at each region of 1 second was presented dichoptically. Pupil responses were recorded with video cameras under infrared illumination. The stimulus layout extended from fixation to 15º eccentricity and presented stimuli at a luminance of 250 cd/m² and a background of 10 cd/m². A multivariate linear model was fitted to contraction amplitudes and time to peak responses to determine the independent effects of exudative AMD at pre and post-treatment.
Results:
Mean additional response delays for the 24 region stimulus improved significantly from a mean delay of 18.82 ± 3.0 ms (P < 0.0001) at baseline to 6.47 ± 3.13 ms (P < 0.05) after 3 months treatment. The mean effect of exudative AMD at baseline decreased constriction amplitudes by 1.3 times (-1.00 ± 0.23 µm, P < 0.0001). After 3 months of treatment exudative AMD produced smaller responses than normals by a multiplicative loss of 1.15 times (-0.63 ± 0.17 µm, P < 0.0005). Diagnostic performance was greater at baseline achieving an ROC area under the curve (AUC) of 100% ± 0.0 (mean ± SE) than at post-treatment (96.1% ± 3.8%).
Conclusions:
This study demonstrates the ability of mfPOP to detect functional improvements in eyes treated with intravitreal ranibizumab for exudative AMD and may assist in detecting progression or monitoring the effect of treatment. The 44 region stimulus ensemble demonstrated greater sensitivity for the diagnosis of exudative AMD at baseline than at post-treatment examination.
Keywords: pupil • age-related macular degeneration • perimetry