A COMPARISON OF DIURNAL VARIATION AND SPLIT DIURNAL VARIATION IN INTRAOCULAR PRESSURE: A PROSPECTIVE STUDY

Dr. Abha Shukla, Dr. Shraddha P. Tatte, Dr. Adharsh Shukla, Dr. U. S. Tiwari, Dr. Rashmi Kujur, Dr. K. P. Ranjan*

ABSTRACT

Glaucoma is an important cause of blindness. Intraocular pressure (IOP) is easily measurable and identified modifiable risk factor for the prevention of progressive glaucomatous field defects. IOP measurements during different hours of the day have a well recognized clinical importance which can directly affect the diagnosis. This study was to compare the two methods of measuring the diurnal fluctuations in IOP. A total of 50 eyes of Primary open angle glaucoma (POAG) patients and 50 eyes of normal subjects had included in this study. The prevalence rate was higher in male patients compared with female. There was a strong correlation for the maximum and the minimum IOP as well as for all the individual measurements. The minimum and maximum IOP as well as fluctuation in IOP were recorded by either of the methods i.e. diurnal variation (DV) and split diurnal variation (SDV). It was observed that POAG subjects had higher peak IOP and larger diurnal fluctuations as compared to normal subjects and also POAG patients patients who were under treatment had low peak IOP and significantly less range of diurnal fluctuation in IOP. There is a strong correlation between the diurnal variation and split diurnal variation. Therefore diurnal IOP variation in POAG patients can be assessed by IOP measurements at different time points on different days. Measuring the split diurnal variation in IOP could be a valid choice and can be used as a surrogate measure to diurnal variation in IOP in a single day.

Keywords: Glaucoma, Intraocular pressure, Primary open angle glaucoma, diurnal variation, split diurnal variation