INS and diabetes mellitus: Evidence has suggested that the development and survival of the photoreceptor cell outer segments is directly affected by hyperglycemia and hypoinsulinemia, with perturbations of insulin signaling playing a diminutive role.[31,32] Park et al showed that photoreceptors begin to undergo apoptotic cell loss about four weeks after the induction of experimental diabetes and continue to progressively degenerate from week 12 onward.[5] Our histological observations of apoptotic death of photoreceptors at week 16 of diabetes are in agreement with these findings.