Anthony Barrett¹, Hannah Kamgarpour¹, Jackson Siskovic¹, Svetlana Cherepanoff^{1, 2, 3}

¹The University of Notre Dame Australia, School of Medicine; ²St Vincent’s Hospital Sydney; ³UNSW Sydney 

Background: Soft drusen (SD) are the hallmark lesions of early Age-related macular degeneration (AMD)¹. However, SD may regress over time². This project aims to describe the lifecycle of SD by correlating their clinical appearance with their contents on histology, and the severity of AMD.

 

Methods:  49 eyes (36 patients; 29M/7F) with SD on histology were selected from a clinically and histologically validated archive of over 600 eyes. 45 eyes were prepared for LM and 4 eyes for EM according to published protocols³. SD contents and clinical fundus appearance were correlated to the known histological AMD marker, early/ late type basal lamina deposits (BLamD). 

Results:  In eyes with early BLamD, SD contents were pale and washed-out on LM, consisted of lipid rich membranous vesicles on EM, and appeared yellow and indistinct clinically. In eyes with late BLamD, SD contents were more likely to have a granular appearance on LM, appeared more electron-dense on EM, and were whiter and more distinct clinically. In eyes with geographic atrophy, SD contents were lost or replaced with calcification or fibrous tissue.   

Conclusion: SD undergo a lifecycle of formation and regression which precedes global atrophy, and is a sign of AMD disease progression.    

 

Statement of Originality: This study was conceived by Dr. Shirley Sarks, with assistance from Prof. Svetlana Cherepanoff. Data collection and analysis were carried out collaboratively by Anthony Barrett, Hannah Kamgarpour, Jackson Siskovic, Dr. Shirley Sarks, and Prof. Svetlana Cherepanoff. 

1.    Bird, A.C., Bressler, N.M., Bressler, S.B., Chisholm, I.H., Coscas, G., Davis, M.D., de Jong, P.T., Klaver, C.C.W., Klein, B., Klein, R. and Mitchell, P., 1995. An international classification and grading system for age-related maculopathy and age-related macular degeneration. Survey of ophthalmology, 39(5), pp.367-374.

2.    Klein, R., Klein, B.E., Knudtson, M.D., Meuer, S.M., Swift, M. and Gangnon, R.E., 2007. Fifteen-year cumulative incidence of age-related macular degeneration: the Beaver Dam Eye Study. Ophthalmology, 114(2), pp.253-262.

3.    Sarks, S.H., Van Driel, D., Maxwell, L. and Killingsworth, M., 1980. Softening of drusen and subretinal neovascularization. Transactions of the ophthalmological societies of the United Kingdom, 100(3), pp.414-422.