Which describes the normal reptile fundus?

Which describes the normal reptile fundus?

• A. Anangiotic
• B. Optic nerve head not visible due to ventrolateral conus papillaris
• C. Pecten is a vascular structure
• D. Retina has many blood vessels

Answer: (A)

The main idea here is that reptile retinas are avascular. In the normal reptile fundus there are no retinal blood vessels—this is described as anangiotic. The retina receives nutrients from the surrounding choroidal circulation rather than from vessels within the retinal layers, which is why you don’t see a network of retinal vessels like in mammals. The other statements don’t fit as well: a retina with many blood vessels would not be typical for reptiles; birds often have a prominent vascular pecten, which is not a standard feature of the reptile fundus; and while the optic nerve head and any papillary structures can have species-specific appearances, the defining and most accurate description of the normal reptile fundus is its lack of retinal vessels.

The main idea here is that reptile retinas are avascular. In the normal reptile fundus there are no retinal blood vessels—this is described as anangiotic. The retina receives nutrients from the surrounding choroidal circulation rather than from vessels within the retinal layers, which is why you don’t see a network of retinal vessels like in mammals.

The other statements don’t fit as well: a retina with many blood vessels would not be typical for reptiles; birds often have a prominent vascular pecten, which is not a standard feature of the reptile fundus; and while the optic nerve head and any papillary structures can have species-specific appearances, the defining and most accurate description of the normal reptile fundus is its lack of retinal vessels.