A historical perspective of registered cases of malignant ocular tumors in Zimbabwe (1990 to 1999). Is HIV infection a factor?

INTRODUCTION Anecdotal and published reports suggest that ocular tumours are on the increase in Zimbabwe. OBJECTIVES To determine the trends in incidence rates of common malignant ocular tumours registered with the Zimbabwe Cancer Registry during the last decade (1990 to 1999). DESIGN Retrospective study. SETTING Data were collected from the Zimbabwe National Cancer Registry, the Zimbabwe National Census 1992 and 2002 Reports, and patient records from hospitals. SUBJECTS All cases of malignant ocular tumours registered with the Zimbabwe National Cancer Registry between 1 January 1990 and 31 December 1999. MAIN OUTCOME MEASURES Age standardized annual incidence rates for registered cases of common ocular tumours. RESULTS The age-adjusted annual incidence rates of squamous cell carcinoma of the conjunctiva had a more than 10-fold increase from 0.17 to 1.8 per 100,000 people during periods 1990 and 1999 respectively. Retinoblastoma dropped by more than half from 0.8 to 0.34 per 100,000 during the same period. The annual age standardised incidence rates for all ocular tumours showed a significant upward linear trend (chi2: 362.78, df=9 and p < 0.001). There was no significant gender difference in the distribution of these tumours amongst the study population. CONCLUSION The increasing trend in the age-adjusted annual incidence rates of ocular surface squamous neoplasms could be attributed to the worsening HIV and AIDS pandemic in Zimbabwe or improved access/utilization of health services by the public.