Intraocular Pressure Changes While Reading Smartphone Digital Text Versus Printed Text in Healthy Individuals and those with Glaucoma

Abstract

Précis: Reading results in rise in intra-ocular pressure (IOP) which is greater while using smartphones compared to printed text among healthy and medically controlled POAG individuals. Purpose: To compare the effect of reading for 30 minutes using smart phone and printed text on intra-ocular pressure (IOP). Patients and Methods: 60 healthy volunteers and 22 medically controlled primary open angle glaucoma (POAG) patients were asked to perform reading tasks using printed text followed by digital (smartphone) text under standardised conditions. IOP assessment was done using rebound tonometer at baseline and subsequently at 10, 20 & 30 minutes of reading and 10 & 20 minutes post completion of reading tasks. IOP variations from baseline were measured and compared. Paired and Independent ‘T’ test analysis was performed to study IOP variations and a P-value <0.05 was considered statistically significant. Results: The mean baseline IOP among volunteers and POAG patients was 14.58 (± 2.91) and 15.02 (± 2.18) mmHg respectively. There was a rise in IOP in all participants with reading using either of the modalities which normalised after 20 minutes of cessation. There was a statistically significant difference in rise in IOP from baseline between the 2 modalities (printed text reading & smartphone reading) at 20 minutes {+0.78 & +2.01 (P=0.002)} & 30 minutes {+0.64 & +1.72 (P=0.004)} among healthy volunteers and at 20 minutes {+0.78 & +2.01 (P=0.002)} among POAG patients. Conclusion: Reading is associated with rise in IOP in both healthy volunteers and POAG individuals. The IOP rise is more marked with smartphone compared to printed text reading.