Abstract
Purpose: :
In the literature, there is a deficit concerning structural changes of the optic nerve head after intravitreous triamcinolone acetonide (Volon A) injection. We wanted to analyze not only intraocular pressure (IOP) changes, but the morphology of the optic nerve head.
Methods: :
A subgroup with neovascular age–related macula degeneration planned for intravitreal triamcinolone acetonide injection combined with photodynamic therapy was recruited after informed consent. Confocal scanning laser tomography using Heidelberg Retina Tomograph II (HRT II) was performed to asses the following parameters at baseline and follow up control: Cup–area, rim area, cup to disc area ratio, horizontal cup to disc ratio, vertical cup to disc ratio, FSM discriminant function, RB discriminant function, rim volume, hight variation contour, cup shape measurement, mean retinal nerve fibre layer thickness.
Results: :
27% of the patients (3 of 11; age range 67–81 years) in the interventional case series showed IOP elevation above 21mmHg in the applanation tonometry. At baseline mean IOP was 15mmHg, at six month follow–up mean IOP was 17mmHg.
Median values of the measured parameters at baseline (BL) and follow up (FU):
Cup–area [mm²] (BL 0.42; FU 0.45); rim area [mm²] (BL 1.33; FU 1.28); rim volume [mm³] (BL 0.28; FU 0.24); hight variation contour [mm] (BL 0.31; FU 0.37); cup shape measurement (BL –0.19; FU –0.19); mean retinal nerve fibre layer thickness [mm] (BL 0.20; FU 0.19); cup to disc area ratio (BL 0.21; FU 0.20); horizontal cup to disc ratio (BL 0.46; FU 0.45); vertical cup to disc ratio (BL 0.47; FU 0.46); FSM discriminant function (BL 1.12; FU 1.56); RB discriminant function (BL 0.63; FU 0.71).
Using non parametric Wilcoxon (Signed Rank) test there is no significant difference (p<0,05) between baseline and follow up measurements.
Conclusions: :
In the presented cases, optic nerve head morphologies were stable six month after intravitreous triamcinolone injection. This applied accordingly to patients with IOP elevation avove 21mmHg. Further follow–up visits are planned to measure potential long–term changes after intravitreous triamcinolone.
Keywords: age-related macular degeneration • optic disc • intraocular pressure