HYDERABAD, India — Small globe size, possibly in correlation with a thicker vitreous and a higher concentration of VEGF, may be a major risk factor for early age-related macular degeneration, according to a speaker here.
“In the Beijing Eye Study, hyperopia, short interscleral spur distance and small optic disc size, besides older age, were found to be the main risk factors associated with early AMD. This points to a small globe size, and we may speculate that the vitreous plays a role,” Jost B. Jonas, MD, said at the joint meeting of the Asia-Pacific Academy of Ophthalmology and All India Ophthalmological Society.
Jost B. Jonas
The vitreous differs in myopic and hyperopic eyes, Jonas said, with a thicker consistency and stronger attachment to the retina in hyperopic eyes. The concentration of VEGF in non-AMD eyes with cataract was found to decrease with higher ocular volume measured by axial length.
“We could think of changing the hyperopic vitreous into a myopic vitreous. Theoretically this could be obtained by injecting an enzyme leading to vitreolysis, such as ocriplasmin. But this is pure speculation,” Jonas said.
He added that 80% to 90% of the AMD patients presenting to his clinic are hyperopic, but nutritional factors and smoking do not seem to be associated with AMD.
“This was concluded by the Beijing Eye Study, and I also found that amongst my AMD patients, smoking is the same or even less than in the normal German population,” he said.
Disclosure: Jonas has no relevant financial disclosures.