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Tridimensional studies on the adult rat optic nerve head
Author(s) -
Pazos M.,
Yang H.,
Gardiner S.,
Cepurna W.,
Elaine J.,
Morrison J.,
Burgoyne C.
Publication year - 2016
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2016.0067
Subject(s) - optic nerve , neurovascular bundle , anatomy , medicine , glaucoma , sclera , ophthalmology , bruch's membrane , retinal , retinal pigment epithelium
Summary Purpose To reconstruct rat optic nerve heads (ONHs) with unilateral experimental glaucoma (EG), so as to 3D characterize the normal and early EG ONH anatomy in the rat. Methods Hypertonic saline was unilaterally injected into the episcleral veins of 8 Brown rats that were sacrificed 4 weeks later. Orbital optic nerve (ON) sections were graded. ONH's were 3D reconstructed, delineated, and parameterized. Overall and individual EG versus control eye differences were studied by linear mixed effect models adjusted for multiple comparisons. Results The rat ONH has 2 scleral openings (superior neurovascular and inferior arterial) separated by a sling. In the superior one, the nerve abuts a prominent extension of Bruch's Membrane (BM) superiorly and is surrounded by a plexus. ON and anterior scleral canal opening (ASCO) expansions were significant overall and in 7 EG eyes. In at least 5 EG eyes, significant expansions in BM Opening (BMO) (3–10%), ASCO and Posterior Scleral Canal Openings (PSCO) (8–21 and 8–41%, respectively) were found. ON expansion was correlated to ON damage. Conclusions The 3D complexity of the rat ONH has been undervalued in previous 2D studies. ON, BMO and neurovascular canal expand early in response to IOP elevation.