Association between Shape of Sclera and Myopic Retinochoroidal Lesions in Patients with Pathologic Myopia

Abstract

In vivo evaluations of the sclera in highly myopic eyes by swept-source OCT can provide important information on deformations of the sclera and how such deformities are related to myopic fundus lesions.

Advances of optical coherence tomography in myopia and pathologic myopia

“…OCT can be useful in studying the biometrics of the sclera, detecting more minute and subtle deformities within the staphyloma, and allows the analysis of the spatial relationship between morphology of the retinal and choroidal layers with the protruded sclera. 55 In OCT, the sclera appears as a relatively uniform, hyperreflective structure exterior to the choroid. Age, axial length, presence of staphyloma, central retinal thickness, and choroidal thickness were associated with the visibility of the scleral layer by OCT. 55,56 A head-tohead comparative study reported that the detection rates of posterior border of the sclera were 67% using EDI OCT and 78% using SS OCT, but in eyes with myopia the detection rates dropped to 31% with EDI OCT and 53% with SS OCT.…”

“…55 In OCT, the sclera appears as a relatively uniform, hyperreflective structure exterior to the choroid. Age, axial length, presence of staphyloma, central retinal thickness, and choroidal thickness were associated with the visibility of the scleral layer by OCT. 55,56 A head-tohead comparative study reported that the detection rates of posterior border of the sclera were 67% using EDI OCT and 78% using SS OCT, but in eyes with myopia the detection rates dropped to 31% with EDI OCT and 53% with SS OCT. Therefore, SS OCT is preferred over EDI OCT for imaging of the sclera.…”

“…55,57 Ohno-Matsui et al 55 studied 488 highly myopic eyes with both 3D MRI and SS OCT and they found that the most protruded part of the sclera existed along the visual axis in 78% and inferior to the central axis in 22%. The sclera in the lower half of the eye is the area where the embryonic ocular fissure closes, and it may be possible that this part of the sclera is structurally weaker and more susceptible to elongation.…”

Complicated mechanism for axial elongation in eyes with pathologic myopia accompanying scleral thinning and deformity

“…In such extremely myopic cases, the sclera becomes very thin and deformed [3,4]. Recently, we measured the scleral thickness of eyes with pathologic myopia (mean axial length; 29.9 mm) by using swept-source OCT, and found that the mean subfoveal scleral thickness of these patients was as thin as 227.9±82.0 μm, with a minimum value of 80 μm [3]. In 32.7 % of the patients, the curvature of the posterior eye segment was totally irregular and not spherical at all.…”

Sekundärerkrankungen bei hoher Myopie

“…Retinal Detachment · Glaucoma · Staphyloma · Choroidal neovascularization · Open angle glaucoma Irregularität der Sklerakurvatur ab, die mit Achslänge und Alter zunimmt [114].…”