Abstract
Purpose: :
To study the effect of decrease in IOP on retinal nerve fibre layer thickness (RNFL) on Optical Coherence Tomography (OCT) after treatment in Primary Open Angle Glaucoma (POAG) patients.
Methods: :
A retrospective observational case series including 115 eyes of 115 glaucoma patients out of which 80 eyes (69.5%) were managed with antiglaucoma medications and 35 eyes (30.5%) were managed with surgical treatment (trabeculectomy). All eyes were imaged with OCT pre- treatment at 3 and 6 months post treatment to measure peripapillary nerve fibre layer thickness. IOP readings were recorded with Goldman applanation tonometry at both the visits.
Results: :
Mean IOP decreased significantly post treatment from 25.74±4.23 mm Hg to 16.35±2.29 (36.4%) at 3 months follow up and to 16.01±3.37 mm Hg (37.76%) at 6 months in medically managed eyes. Mean IOP decreased post treatment from 28.42±4.55 mm Hg to 16.25±3.37 mm Hg (42.82%) at 3 months and to 16.31±3.39 mm Hg (42.61%) at 6 months in eyes which underwent trabeculectomy. There was increase in retinal nerve fibre layer thickness in all quadrants following decrease in IOP both in medically treated and surgically treated patients. While the increase in mean RNFL thickness in the inferior quadrant (Iavg) was correlated with IOP reduction in the medically managed eyes at 6 months (r=-0.252,p=0.022), the mean increase in RNFL thickness in the superior quadrant (Savg) in the eyes which underwent trabeculectomy was correlated with IOP reduction at 6 months (r=-0.415, p=0.039).
Conclusions: :
At 6 months after treatment the increase of mean RNFL thickness in superior and inferior quadrant was correlated to decrease in IOP. However no correlation was found between increase in average RNFL thickness and IOP reduction.
Keywords: nerve fiber layer • intraocular pressure