Purpose
Optic disc tilting is reportedly associated with glaucoma in highly myopic eyes. We attempted to evaluate the peripapillary tilting in highly myopic eyes using customized software and swept-source optical coherence tomography (SS-OCT).
Methods
We retrospectively analyzed SS-OCT images of a total of 105 eyes of 105 subjects (32 male and 73 female, mean age of 54.6 years) with high myopia (axial length > 26mm or refractive error < -6 diopter) who visited the Department of Ophthalmology, Osaka University Hospital. Glaucoma patients were excluded. SS-OCT images were acquired using 3.4mm diameter peripapillary circle scan mode. The scan was divided into 24 segments. The segments were alphabetically named as A to L from temporal 0 degree and then, superior, and nasal. The opposite segments were named as A’ to L’ similarly. Retinal pigment epitherium (RPE) were automatically traced and the height was calculated by customized software. The vertical distance (pixels) between mean RPE height in each sector and mean RPE height of overall sectors were defined as perpipapillary tilting index (PTI). Correlation between PTI and peripapillary choroidal thickness (ChT), size of peripapillary atrophy area from color fundus photograph, and demographic data were investigated.
Results
Mean refractive error (RE) was -10.0±5.4D, and mean axial length (AL) was 28.7±1.8mm. PTI was lowest at K’ (infero-temporal) of -713 pixel. There was significant negative correlation between PTI and age (P<0.05). PTI did not correlate RE or AL. Age positively correlated with RE (P<0.01), but did not correlated with AL (P=0.07). In female, minimum PTI was significantly lower than male at sector G, H, I, J, K(P=0.05, 0.02, 0.01, 0.01, 0.03). Gender did not correlate with age, RE or AL (P=0.42, 0.34, 0.23). Minimum PTI negatively correlated with PPA(P<0.05), and tended to be coefficient with minimum ChT (P=0.06).
Conclusions
In highly myopic eyes, peripapillary tilting was remarkable in female, high age and low RE. The more tilt was remarkably the more choroidal thinning and peripapillary atrophy were extent.
Keywords: 605 myopia •
627 optic disc •
712 shape and contour