Comparison of Intraocular Pressure(IOP) estimation by Perkins Tonometer done by Ophthalmic Assistant and Goldmann Applanation Tonometer done by Ophthalmologist

INTRODUCTION: Glaucoma refers to a group of disorders that have in common a characteristic optic neuropathy associated with visual field loss with elevated intraocular pressure (IOP) as one of the primary modifiable risk factor. Glaucoma is one of the second most common cause of blindness worldwide. WHO has reported that due to glaucoma around4.5 million people are blind. Glaucoma is the leading cause of irreversible blindness in India with 12 million people affected and nearly 1.2 million people blind from the disease. Majority of Glaucoma cases approximately 90 % of remains undiagnosed in the community. Jacob A. et al, in their study conducted in Vellore, found that the prevalence of POAG in South India were 4.1 per 1000. The Andhra Pradesh eye disease survey (APEDS) reported a prevalence of 1.62% for POAG, 0.32% for OHT, and 0.71% for manifest PACG in those 30 years of age or older. Aravind comprehensive eye survey (ACES) reported a prevalence of 1.7% for POAG and 0.5% for primary angle closure glaucoma (PACG). AIMS AND OBJECTIVES: To assess the agreement of intraocular pressure (IOP) measured with Goldmann applanation tonometer (GAT) by glaucoma consultant and Perkins Tonometer by Ophthalmic Assistant METHODS: 500 patients in the age group of 20 to 70 years underwent both Perkins and Goldmann applanation tonometry in both eyes in an interval of 15 to 30 minutes, cyclically permuted in the order. Both the readings are masked for the examiner. Goldmann Applanation Tonometer is measured by an experienced Glaucoma consultant. Perkins tonometer is measured by an experienced paramedical person. The comparability of results given by the two instruments is evaluated using the Bland–Altman method. RESULTS: The Intraocular Pressure under study ranged from 5 to 60 mm of Hg. The mean GAT IOP in right eye and left eye was 17.74 mm of Hg (+/-7.20 ), 17.21mm of Hg(+/-6.18) respectively. The mean Perkin’s IOP in right eye and left eye was 15.91 mm of Hg (+/- 5.70), 15.93mm of Hg(+/-4.98) respectively. The interclass ...