Changing trends in ocular cysticercosis over two decades: An analysis of 118 surgically excised cysts

Purpose : To evaluate the frequency of ocular cysticercosis and to demonstrate the changing trends in localisation of ocular cysticercosis along with a brief review of literature. Methods : A retrospective analysis of histology proven ocular cysticercosis cases seen over a period of 20 years (1981 through 2000) was done. The pathology record forms were reviewed for demographics, clinical features with specific reference to the location of cysts in four subgroups: subconjunctival; intraocular orbit and eyelid. The distribution of cases in four five-year periods namely group A: 1981-1985, group B: 1986-1990, group C: 1991-1995 and group D: 1996-2000 and the changing trends in the location of cysts was evaluated. Results : One hundred eighteen cysts from 118 patients aged 4-72 (mean 17.1) years were submitted to the pathology service of S D Eye Hospital, Hyderabad. Male to female ratio was 1: 1.2. Total number of cases in groups A, B, C and D were 33, 41, 16 and 25 respectively. Location of cysts was subconjunctival - 74 (62.7%); intraocular-31 (26.3%); orbital-8 (7%) and lid-5 (4%). In last 20 years, significant decrease ( P =0.0001) was noted in subconjunctival cases (85% vs. 28%) with a significant rise ( P =0.0001) in intraocular cysticercosis (6% vs. 60%). Conclusions : Frequency of surgically excised ocular cysticercosis remained constant over last two decades with an increasing manifestation of intravitreal cysticercosis in the recent years. This could imply either improved diagnostic modalities, available expertise in vitreo-retinal surgery or ineffective medical treatment for intraocular parasitic infection. The relative decrease in extraocular cysticercosis is probably due to the increased preference and success with medical management.

Keywords
Subconjunctival, Inrtavitreal cysticercosis, T. solium, ocular cysticercosis