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BILATERAL IRREVERSIBLE BLINDNESS

Objective: To find out the causes of bilateral irreversible blindness in patients of different age groups in District Swabi. Design: It is a prospective observational study of one hundred and eighty nine consecutive blind cases. Place and Duration of Study: The study was conducted from July 2010 to June, 2012 at the Ophthalmology Department of District Headquarter Hospital, Swabi. Subjects and Methods: Informed consent was taken from the patient or guardian of the patient. Patients fulfilling inclusion and exclusion criteria were included in the study. A standard proforma was designed and entries were made regarding present, past and family history, thorough ocular examination of every patient was performed on slit-lamp with relevant biomicroscopic aids and posterior segment examination was conducted with direct as well as indirect ophthalmoscope. Biomicroscopy was performed as and when required. lntraocular pressure using schiotz tonometer, corneal diameters, retinoscopy and ocular mobility were noted and relevant investigations were performed when needed. Children and mentally retarded patients were examined using short general anaesthesia. Results: Of 189 patients 61.4% were males and 38.6% were females. Congenital Causes were present in 49.7% and acquired causes in 50.3%. Diseases accounted for 88.9%, trauma in 10.1% and unknown causes in 1.1% cases. Congenital diseases included congenital glaucoma in 35.1%, retinitis pigmentosa in 29.7% and albinism in 19.1% cases. Acquired diseases included primary glaucoma in 33.8%, diabetic retinopathy 23 %, secondary glaucoma in 17.5% and childhood infection in 10.8% cases. Corneal findings included corneal opacity in 31.2%, corneal edema in 4.8% and absent cornea in 7.4%. Optic nerve findings included optic atrophy in 16.4%, glaucomatous optic atrophy in 16.9%, new vessels in 9.5%. Retina findings included retinal dystrophy in 14.3%, maculopathy in 5.3%, chorioretinopathy in 0.5%, vascular retinopathy and hypopigmentation in 9.5% each respectively. Conclusions: Irreversible blindness is more common in children and young adults and mostly males are affected. Glaucoma is the commonest cause followed by retinitis pigmentosa and albinism in this study.