The optic nerve head in myocilin glaucoma.

Area of Science:

• Ophthalmology
• Genetics
• Glaucoma Research

Background:

• Approximately 1 in 30 patients with open-angle glaucoma (OAG) carry a mutation in the myocilin gene.
• Myocilin gene mutations are associated with certain glaucoma phenotypes.

Purpose of the Study:

• To investigate and describe the morphologic features of the optic nerve head (ONH) in patients with myocilin glaucoma.
• To compare the ONH morphology in myocilin glaucoma with non-myocilin OAG.

Main Methods:

• A case-control study matched 66 myocilin mutation carriers (cases) with 105 OAG patients without mutations (controls) by disease severity.
• Quantitative and subjective analysis of optic nerve head stereoscopic photographs, including cup depth, lamina cribrosa, and neuroretinal rim.
• Mutation screening via direct sequencing or single-stranded conformation polymorphism analysis.

Main Results:

• Myocilin mutation carriers were diagnosed earlier and had higher maximum intraocular pressures than controls.
• No significant differences were observed in global disc area, rim area, parapapillary atrophy, rim slope, or lamina cribrosa morphology.
• Disc hemorrhages were less frequent in mutation carriers, but this finding was not statistically significant after correction.

Conclusions:

• No major structural or morphologic differences in the optic nerve head were detected between myocilin glaucoma and non-myocilin glaucoma when analyzing pooled data.
• The study did not identify distinct ONH structural characteristics attributable to myocilin mutations.