RESUMEN
AIM: To determine the sensitivity and specificity of the Reichert™ Tono-Pen AVIA® when used by novice medical students in an ethnically diverse population in Trinidad. SUBJECTS AND METHOD: Participants were residents of Trinidad between the ages of 20 and 90 years attending the Ophthalmology Clinic at the Eric Williams Medical Sciences Complex (EWMSC). Intraocular pressure (IOP) was measured using the Goldmann applanation tonometer (the gold standard) for ophthalmology clinic patients as part of their routine care. Intraocular pressure measurements were then taken using the Tono-Pen. RESULTS: One hundred persons participated, consisting of Indo-Trinidadians (55%), Afro-Trinidadians (36%), Mixed (8%) and 1% of Caucasian descent. Fourteen per cent reported a diagnosis of glaucoma, with 70.6% of these being of African descent. One hundred and ninety-eight readings of IOP were taken. At a cut-off point of 21 mmHg, there were nine true positives, four false positives, seven false negatives and 178 true negatives. The sensitivity and specificity were found to be 56.3% (95% CI 33.2, 76.9) and 97.8% (95% CI 94.5, 99.1), respectively. The positive predictive value was calculated as 69.2% (95% CI 42.4, 87.3) while the negative predictive value was 96.2% (95% CI 92.4, 98.2). The prevalence of elevated IOP in this population was 8.1% (95% CI 4.8, 13.0). The likelihood ratio of a positive result was calculated to be 25.6 (95% CI 8.6, 73.9). CONCLUSION: The high specificity and negative predictive value suggests that the Tono-Pen can be used with minimal training, and can prove beneficial at the primary care level in the exclusion of increased IOP in an ethnically diverse high-risk Caribbean population.
RESUMEN
Five case histories are presented. Waldenstrom's macroglobulinaemia caused bilateral central retinal vein occlusion, proptosis was the presenting feature of retro-orbital plasmacytoma in relapsed multiple myeloma, a red painful eye was due to neovascular glaucoma in primary polycythaemia, bilateral VIth nerve palsy caused convergent squint and diplopia in meningeal relapse of acute lymphoblastic leukaemia and lymphoma of the eyelid caused complete ptosis. Interdisciplinary management is described. Ophthalmological lesions in haematological disease should be promptly recognized and managed. Collaboration between ophthalmology and haematology departments may be effective for palliative management.