Abstract
Purpose: :
To compare the tiling value around optic disc in highly-myopic glaucoma patients with highly-myopic healthy subjects.
Methods: :
This is a retrospective investigation. Fourteen eyes diagnosed as open angle glaucoma in treatment over 30 years old (y.o.), axial length (AL) longer than 26.0mm without any other ophthalmic diseases and surgical history (glaucoma group) and 23 eyes of healthy subjects under same conditions (controls) were enrolled.The prototype high penetration OCT (HP-OCT, Swept-source, Topcon, Japan) was used for imaging optic disc. Image taken by 3.4mm diameter circle scan around optic disc was divided to the 12 clock hour sectors and numbered 1 to 12 starting from nasal tip in horizontal line to superior, temporal, and inferior in order. Retinal pigment epithelium (RPE) height in each sector which is the mean distance from the bottom of the image to RPE line was calculated by using a custom-designed software program. To quantify the disc tilting, peripapillary index (PPI; pixel) which was the deference in RPE height between one sector and the opposite sector was evaluated. PPI was calculated by subtraction of RPE height in temporal sector from that in nasal sector. PPI in 6 pairs of sector (A:1-7, B:2-8, C:3-9, D:10-4, E:11-5, F:12-6) was compared in both group.
Results: :
Mean age (51.6±2.3y.o., 54.0±3.0y.o., p=0.54), AL (28.42±0.34mm, 28.23±0.44mm, p=0.74) and intraocular pressure (15.9±0.8mmHg, 15.7±1.0mmHg, p=0.90) were no significant differences between controls and glaucoma group. PPI (controls vs. glaucoma group) in 6 pairs of sector was shown as follows; A (314±32 vs. 200±41, p=0.038), B (352±30 vs. 210±39, p=0.007), C (292±25 vs.165±32, p=0.003), D (-167±20 vs.-79±26, p=0.013), E (6±23 vs. 29±30, p=0.55) and F (183±29 vs.134±38, p=0.31). The absolute value of PPI in A, B, C and D in glaucoma group was significantly smaller than that in controls. Furthermore, B was the largest absolute value of PPI in both groups.
Conclusions: :
Peripapillary tilting in highly-myopic glaucoma patients is smaller than healthy highly-myopic subjects.
Keywords: myopia • optic disc • imaging/image analysis: clinical