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Abstract #46429 Published in IGR 13-3
Posterior (Outward) Migration of the Lamina Cribrosa and Early Cupping in Monkey Experimental Glaucoma
Yang H; Williams G; Downs JC; Sigal IA; Roberts MD; Thompson H; Burgoyne CFInvestigative Ophthalmology and Visual Science 2011;
PURPOSE: To quantify the lamina cribrosa insertion into the peripapillary sclera and optic nerve pia in normal (N) and early experimental glaucoma (EEG) monkey eyes. METHODS: Perfusion-fixed optic nerve heads (ONHs) from 21 animals were digitally 3D reconstructed and delineated. Anterior Laminar Insertion Position (ALIP), Posterior Laminar Insertion Position (PLIP), Laminar Insertion Length (LIL - distance between the Anterior and Posterior Laminar Insertions) and Scleral Thickness were calculated for each ONH. Animals were pooled into 4 groups based on the sacrifice condition (N vs. EEG) and perfusion IOP (10, 30 or 45 mmHg) of each eye: N10-N10 (n=6); N30/45-N10 (n=6); EEG10-N10 (n=3) and EEG30/45-N10 (n=6). Glaucomatous EEG vs N eye differences in each group and each animal were required to not only achieve statistical significance (ANOVA p < 0.05) but also exceed physiologic inter-eye differences within the bilaterally normal groups. RESULTS: ALIP was significantly posterior (outward) in the EEG compared to N10 eyes of the EEG30/45-N10 group and 5 of 9 individual EEG eyes (difference range 12 - 49 ?m). PLIP was significantly posterior in the EEG eyes of both EEG groups and in 6 of 9 individual EEG eyes (range 25 - 83 ?m). LIL ranged from 90 to 190 ?m in normal eyes and was significantly increased within the EEG eyes of both EEG groups and 7 of 9 individual EEG eyes (difference range 30 - 47 ?m). CONCLUSIONS: Posterior migration of the lamina cribrosa is a component of early cupping in monkey EEG.
Devers Eye Institute, Optic Nerve Head Research Laboratory, Legacy Health System, Portland, OR, USA.
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
5.2 Primates (Part of: 5 Experimental glaucoma; animal models)
2.3 Sclera (Part of: 2 Anatomical structures in glaucoma)