Longitudinal changes of quantitative autofluorescence in the progression from intermediate to late age-related macular degeneration

Abstract

Purpose : This prospective, observational study investigated the development of quantitative autofluorescence (qAF) intensity of the retina during progression from intermediate to late age-related macular degeneration (AMD).

Methods : One hundred and fifteen eyes of 66 patients with intermediate AMD were included in the study. qAF images were longitudinally acquired every 3 months with a Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany) using a built-in autofluorescence reference. qAF intensity was evaluated using the middle 8 segment ring of the Delori pattern (qAF₈). Changes in longitudinal qAF₈ data during AMD progression were calculated using a Wilcoxon rank sum test for clustered data.

Results : Twenty-one eyes of 17 patients converted to late AMD after a median follow-up of 21 months (IQR 9-27 months). Twelve eyes progressed to atrophic AMD and 9 eyes to neovascular AMD. Patients’ mean age was 74.6 ± 4.4 years. Eleven eyes (52.4%) were pseudophakic. No difference was found between the baseline characteristics of the two groups (number of eyes, sex, pseudophakia, laterality, follow-up period (all p>0.05)). The presence of an intraocular lens did not result in a difference between the regression slopes of the two groups (p>0.05). The median change of qAF was -0.90 qAF units per 3 months. The median change for atrophic AMD eyes was -2.34 qAF units per 3 months and 0.78 qAF units per 3 months for neovascular AMD eyes. A significant difference between the two groups could be identified (p=0.009) with the group progressing towards atrophic AMD declining significantly differently from zero (p=0.012). Patients progressing towards neovascular AMD did not have a regression slope different from zero (p>0.05).

Conclusions : The autofluorescence signal detected in eyes by qAF significantly declined preceding progression to atrophic AMD, contrary to progression towards neovascular AMD. Quantitative autofluorescence imaging contributes to the identification of patients at risk of progressing to atrophic AMD and benefits individualized patient care in intermediate AMD.

This is a 2020 ARVO Annual Meeting abstract.

 

Quantitative autofluorescence (qAF) before conversion to either atrophic (blue) or neovascular age-related macular degeneration (red). Data is presented as median and interquartile range (IQR). The dashed line indicates the median slope for each group.