Posterior staphyloma is related to optic disc morphology and the location of visual field defect in normal tension glaucoma patients with myopia

Abstract

Purpose To determine the morphologic features of the optic disc and the location of visual field (VF) defect in relation to posterior staphyloma in normal tension glaucoma (NTG) eyes with myopia. Methods One hundred and thirty-four NTG patients with myopia were enrolled. B-scan ultrasonography was performed in enrolled patients. Disc tilt ratio, disc torsion, and area of peripapillary atrophy were measured from disc photographs. Patients were classified according to the presence of posterior staphyloma and its location: staphyloma involving the optic disc, staphyloma involving either the supero-temporal side of the optic disc or the infero-temporal side of the optic disc. The relationship between the location of the posterior staphyloma and that of the VF defect was analyzed. Results Among 134 eyes, 74 eyes (55.2%) had posterior staphyloma on B-scan ultrasonography. Mean torsion degree was significantly greater in eyes with staphyloma involving the temporal side of the optic disc (19.78±18.001) compared with eyes with staphyloma involving the optic disc (4.65±4.921, P ¼ 0.001). The frequency of the location of VF damage differed significantly between eyes with staphyloma involving the supero-temporal side and those involving the infero-temporal side of the optic disc (P ¼ 0.008), which was not significant in eyes with staphyloma involving the optic disc (P ¼ 0.813).Conclusions Optic disc torsion was a prominent finding in myopic NTG eyes when posterior staphyloma was located temporal to the optic disc. The location of posterior staphyloma was related to the direction of disc torsion and the location of VF defect.

Racial Differences in the Extracellular Matrix and Histone Acetylation of the Lamina Cribrosa and Peripapillary Sclera

“…Our previous clinical investigations showed that glaucoma with myopia or NTG had greater changes in the optic disc morphology, which was related to the glaucomatous damage location, and this seems to be related to the features of the LC and the posterior sclera. 19,[41][42][43][44][45][46] Further investigations are needed to reveal the exact association and clinical meanings of the present findings.…”

Implications of Optic Disc Tilt in the Progression of Primary Open-Angle Glaucoma

“…22,24,25 When we compared our tilted and nontilted optic disc groups, the degree of torsion was significantly different between them.…”

“…According to the location of scleral thinning, the optic disc and macula reportedly have different configurations. 25,26 Eyes with scleral thinning (including the macula) tend to have a titled optic disc, and eyes with scleral thinning (including the optic disc) tend to have a megalodisc. 25,26 It may be reasonable to think that the weakest point of the whole posterior segment in each eye undergoes thinning more easily during axial elongation.…”

The height of the posterior staphyloma and corneal hysteresis is associated with the scleral thickness at the staphyloma region in highly myopic normal-tension glaucoma eyes

“…In practice, because the type I staphyloma involving the optic disc is the most prominent type and the pattern inclining toward the optic disc is more prevalent, the nasal posterior staphyloma height may be deeper than any other directions. In the recent study by Park et al ,37 the location of the posterior staphyloma was related to the direction of disc torsion and optic disc torsion was a prominent finding in myopic NTG eyes when posterior staphyloma was located temporal to the optic disc. Thus this study has a potential for unintentional omission of compound staphylomas and a risk of selection bias.…”