Purpose: To classify the morphologic appearance of posterior capsule opacification (PCO) and to observe and document the changes over longer periods of time.
Setting: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
Methods: Eighty-one pseudophakic eyes of 53 patients with PCO of varying degrees were included in this prospective study. Digital retroillumination images of the posterior capsule were taken in a standardized fashion 1, 2, and 3 years after cataract surgery. The PCO morphology was classified, and changes among the 3 follow-up images were analyzed.
Results: At 1, 2, and 3 years, pearls occurred in 16 (20%), 41 (51%), and 57 (63%) eyes. Pearls increased in size and number. Cases with thin layers of PCO decreased from 53 to 33 to 16 eyes. Conversely, cases with thick layers increased from 18 to 45 and 64 eyes. "Cheese holes" appeared most frequently as the predominant structure (range 47% to 51%), followed by plates (range 28% to 31%), islands (range 15% to 20%), and traces of PCO (range 1% to 5%). Changes in expansion of the PCO area were observed in 61 eyes (75%) during period 1 (1 to 2 years) and period 2 (2 to 3 years). Regions of expansion and regression in the same eye occurred in periods 1 and 2 in 11 eyes (14%) and 9 eyes (11%), respectively. The phenomenon of thinning bridges, a regression of syncytial extensions of PCO, occurred in 22 eyes (27%) and 32 eyes (40%), respectively. An overlapping growth of 2 layers was observed in 18 eyes (22%).
Conclusions: The morphology of PCO is multifaceted. Apart from the Elschnig pearls, categories such as cheese holes, plates, islands, and traces of PCO were distinguished. Over the years, pearls increased in frequency, size, and number. Expansion and regression occurred simultaneously in some cases. Two or more layers grew on top of each other in some eyes.