Abstract
Purpose: :
To study the effect of intraocular pressure (IOP) lowering on the peripapillary retinal nerve fiber layer (PRNFL) thickness as determined by the newest generation of optical coherence tomography (OCT; Stratus OCT, Carl Zeiss, Inc.)
Methods: :
OCT was performed prior to intervention to lower IOP (0 to 38 days before; mean ± standard deviation [SD], 9.8 ± 9.3 days) and after the intervention (32 to 74 days; 46.8 ± 11.2 days) to measure PRNFL thickness. The intervention involved trabeculectomy with antimetabolite, Baerveldt aqueous shunt implantation, or medical treatment.
Results: :
IOP decreased from 31.5 ± 8.2 mm Hg to 18.8 ± 9.4 mm Hg (mean ± SD) with the intervention. There was no significant change in the overall mean PRNFL thickness associated with the lowering of IOP (p = 0.65). Quadrant analysis did not show a significant change in PRNFL thickness of any of the four quadrants (p ≥ 0.30). No significant correlation was found between extent of IOP reduction and any of the changes in OCT parameters or % changes in OCT parameters with or without adjusting for pre–operative OCT measurements (p–values ranged from 0.33 to 0.99).
Conclusions: :
No significant change in PRNFL thickness was associated with the lowering of IOP via medical or surgical therapy.
Keywords: imaging/image analysis: clinical • intraocular pressure • nerve fiber layer