Increased reflectivity of the tapetum is associated with which condition?

Increased reflectivity of the tapetum is indeed associated with retinal thinning. The tapetum lucidum is a layer of tissue in the retina that reflects light, enhancing vision in low-light conditions. When retinal thinning occurs, the overall structure and density of the retinal tissue are altered, leading to increased reflectivity due to a reduction in the accompanying retinal pigments that normally diffuse light. This results in a more pronounced shine or reflective quality of the tapetum.

In contrast, conditions such as retinal inflammation, retinal detachment, and vitreous hemorrhage typically do not cause increased reflectivity of the tapetum. Retinal inflammation can lead to changes that may affect overall reflectivity but usually result in a decrease in visual acuity rather than an obvious increase in tapetal reflectivity. Likewise, retinal detachment disrupts the normal anatomy and function of the retina, often resulting in a loss of the typical reflective properties. Vitreous hemorrhage introduces blood into the vitreous chamber, which obstructs light transmission and can likewise reduce reflectivity rather than increase it.

Thus, observing increased tapetal reflectivity is a significant clinical indicator of retinal thinning, helping veterinary ophthalmologists assess the health and integrity of the retina.