Abstract
Purpose:
To determine if microperimetry can detect changes in retinal sensitivity in intermediate age-related macular degeneration (AMD) over a 12-month period.
Methods:
Thirty-four intermediate AMD and 10 control participants were recruited. The Macular Integrity Assessment (MAIA) microperimeter was used to measure retinal sensitivity at 0 (baseline), 6 and 12 months for AMD participants and at 0 and 12 months for control participants. At baseline, two examinations were performed and the first test was discarded to minimize the learning effect; only one examination was performed at each follow-up. Colour fundus photographs (CFP) were graded at each time point to determine disease progression in the intermediate AMD group; spectral-domain optical coherence tomography was used to confirm that no signs of advanced AMD developed. The changes in average point-wise sensitivity (PWS) were determined using a linear mixed-effects model.
Results:
For control participants, there was no significant change in average PWS over 12 months (Baseline = 28.67 dB, 12 months = 28.56 dB; P = 0.304). For intermediate AMD participants, 15 remained stable, 14 progressed and 5 showed drusen regression based on CFP. Intermediate AMD participants who remained stable or progressed had significantly reduced average PWS sensitivity at twelve months (Baseline = 26.91 dB, 12 months = 26.51 dB; P = 0.001 and Baseline = 26.71 dB, 12 months = 26.38 dB; P = 0.007 respectively) but not at six months (6 months = 26.78 dB; P = 0.256 and 6 months = 26.60 dB; P = 0.365 respectively). Combining AMD participants who remained stable or progressed, a significant reduction in average PWS at twelve months was found for points at 2.33 degrees and 4 degrees from the fovea (P < 0.001 and P = 0.007), but not at 0 and 1 degree combined or at 6 degrees (P = 0.081 and P = 0.721). For those who showed drusen regression by the final visit, there was a significant improvement in average PWS (Baseline = 25.29 dB, 12 months = 26.31 dB; P < 0.001), although this was from a worse baseline retinal sensitivity compared to the other AMD participants.
Conclusions:
Microperimetry was able to detect subtle functional decline around the parafoveal region for those with intermediate AMD over a 12-month period, even if the fundus appearance remained stable. These changes were no evident at six months.
Keywords: 412 age-related macular degeneration •
642 perimetry