Ocular-Surface Squamous Neoplasia (OSSN) is the most common conjunctival malignancy in the tropics. An exponential rise in its incidence has been observed, common among young people and aggressive among HIV-patients. Clinical differentiation between OSSN and non-OSSN tumours is difficult, requiring histopathology for a definitive diagnosis. With limited availability of histopathology services in low- and middle-income countries, critical clinical judgement might be the only available tool for the clinician.
To determine the sensitivity and specificity of clinical diagnosis of Ocular-Surface Squamous Neoplasia and associated factors at Ruharo Eye Centre (REC) and Mbarara University and Referral Hospital Eye Centre (MURHEC).
This was an analytical, hospital-based, cross-sectional study were patients with an ocular-surface tumour in the eye scheduled for ocular-surgery, consented, were interviewed using structured-questionnaire, examined and had pre-counselling and voluntary HIV-testing done. During their surgeries the tumours were biopsied and transferred to the Universitys histopathology department for analysis. Final histopathology diagnoses were utilised as gold-standard for statistical analysis.
Consented patients (n=195) from both MURHEC (24.6%) and REC (75.4%) with ocular-surface tumours, contributed 212 biopsies taken from 203 eyes. Median age was 48 (32-65) years. The sensitivity and specificity of Clinical Diagnosis of OSSN were 45% and 93%, and those for SCC were 87% and 87% respectively. Interpalpebral tumour-location, six or more feeder-vessels, and rough tumour-surface were associated with OSSN and only the latter was associated with SCC. HIV prevalence among patients with OSSN and SCC were 18.3% (OR=1.66, CI: 0.66-4.45) and 42.9% (OR=5.53, CI: 1.78-16.38) respectively.
Clinical differentiation of ocular-surface tumours is difficult especially at early stages of their malignant transformations. However it can be improved by utilizing clinical features such as; rough tumour-surface, six or more feeder-vessels, and interpalpebral-location of the tumour.
HIV prevalence among patients with OSSN is higher than among those without OSSN.