Peripapillary Sclera Thickness in Non-Highly Myopic Glaucomatous Human Eyes

Jost Jonas

Purpose: To measure the thickness of the peripapillary sclera in non-highly myopic Caucasians with absolute secondary angle-closure glaucoma.

Methods: The histomorphometrical study included 8 eyes of 8 patients with absolute secondary angle-closure glaucoma and 25 eyes of 25 patients with malignant choroidal melanoma (control group). Histological sections were histomorphometrically examined. Eyes with an axial length of more than 26 mm were excluded.

Results: Between the glaucoma and the control group, respectively, the scleral thickness measurements did not vary significantly, neither inside of the optic nerve meninges (356±56 µm versus 367±64 µm;P=0.66), nor just outside of the optic nerve meninges (696±93 µm versus 740±117 µm;P=0.29), nor at a distance of 0.2 mm (445±65 µm versus 418±100 µm;P=0.38), at a distance of 0.4 mm (529±62 µm versus 543±142 µm;P=0.71) and at a distance of 0.6 mm from the optic disc border (601±65 µm versus 598±121 µm;P=0.92).

Conclusions: In non-highly myopic Caucasians, advanced secondary angle-closure glaucoma is not associated with a marked thinning of the peripapillary sclera. It is in contrast to a glaucoma related thinning of the lamina cribrosa, and it is in contrast to monkeys, in which a peripapillary scleral thinning occurs. Peripapillary scleral thinning may not markedly contribute to glaucomatous optic neuropathy in non-highly myopic Caucasians. The differences between humans and monkeys with respect to the peripapillary sclera in glaucoma may be taken into account if results of experimental glaucoma studies in monkeys are transferred to patients.