###Rationale: The nerve fibers forming the optic nerve exit the eye posteriorly through a hole in the sclera that is occupied by a mesh-like structure called the lamina cribrosa. It is formed by a multilayered network of collagen fibers that inse into the scleral canal wall. It is absent in morning glory syndrome. Ref khurana 6/e

###Answer: OPTION A IS CORRECT.
###Question: Lamina cribrosa is absent in -
###Options:
A. Morning glory syndrome
B. Nanophthalmia
C. Colobama of retina
D. Optic nerve agenesis
