Purpose: To find out whether there is a "hidden" group of patients with posterior capsule opacification (PCO) 5 years after cataract surgery and to establish the incidence of PCO.
Setting: Department of Ophthalmology, Sahlgrenska University Hospital, Gothenburg, Sweden.
Methods: A random sample (n = 164) was selected among patients who had extracapsular cataract extraction (ECCE) with intraocular lens implantation in 1991 (N = 1672). All surgically treated cases that required neodymium:YAG (Nd:YAG) laser capsulotomy (n = 37) within the first 5 years after surgery were recorded. Patients still alive 5 years after surgery who had not had Nd:YAG treatment were offered an eye examination to determine whether PCO requiring capsulotomy existed.
Results: Thirty-seven of 110 patients (34%) alive 5 years after surgery had an Nd:YAG capsulotomy during the first 5 postoperative years. Follow-up was possible in 51 of 73 untreated patients (70%). Clinically significant PCO according to specified criteria was found in 7 cases (14%). Half of them would benefit from treatment; the other half had visual impairment from other eye disease.
Conclusions: The estimated incidence of PCO 5 years after ECCE was 43%. Five years after surgery, there was an untreated group with clinically significant PCO, approximately 9% of the surgically treated population. This hidden group must be considered in PCO studies.