Optic disc of the myopic eye: relationship between refractive errors and morphometric characteristics

Abstract

Because the optic disc in myopic eyes is different from a normal optic disc, there are many difficulties in examining the optic discs of myopic eyes. To study optic disc change due to myopia, we performed a morphometrical study of stereophotographs of 61 men, 109 eyes, who had no glaucoma history. The range of refractive error was from +0.75 diopter to -12.75 diopter, and all subjects had intraocular pressure below or equal to 21 mmHg. According to the increase in the myopic degree, the temporal slope of the disc cup was significantly decreased, but the ratio of the vertical disc diameter (VDD) to the horizontal disc diameter and the ratio of the width of peripapillary atrophy (PPA) to the VDD were significantly increased. The above results suggests that in high myopia the optic disc was tilted and the rim-cup border was indistinct and there are some problems in the estimation of the morphometric parameters. Also in evaluation of the PPA of myopic glaucoma patients, there may be some difficulty in deciding whether it is due to myopic change or glaucomatous damage.

Associations between Optic Nerve Head–Related Anatomical Parameters and Refractive Error over the Full Range of Glaucoma Severity

“…39 Although the OI is a gold standard for identifying ONH insertion obliqueness in myopic eyes, 23,40 its 2D characteristic does not take original optic disc shape into consideration. 40,41 We did not find evidence for an association between OI and SE (BF: 0.91) in our study and our result was in agreement with Takasaki et al 40 and Asai et al 23 who did not find a significant correlation between SE and OI as well. Although OI alone does not result in a satisfying model of SE, it has a strong modulatory effect in combination with other parameters, which is discussed in details further in this section.…”

Optic Nerve Head and Peripapillary Morphometrics in Myopic Glaucoma

“…Optic disc area and area of the peripapillary region with chorioretinal atrophy were correlated with degree of myopia along with disc elongation, 64,[76][77][78][79][80] and the LC was shown to be thinner in highly myopic eyes than in nonhighly myopic eyes. 81 In highly myopic glaucomatous eyes, compared to nonhighly myopic glaucomatous eyes, optic disc area, elongation, cup length, and peripapillary atrophy were significantly larger, 32,33 LC was thinner, 81 and rim loss was greater.…”

The relationship between retinal nerve fibre layer thickness profiles and CorvisST tonometry measured biomechanical properties in young healthy subjects

“…Curiously, in a different study no relationship was observed between ORA-measured corneal hysteresis and β -zone parapapillary atrophy 25 . Research also suggests that maximum deformation amplitude is associated to optic disc tilt, which, in turn, is closely related to myopia 26, 27 .…”