A 30 y/o male presented to the clinics with a chief complaint of blurry vision at distance and near in the left eye for the last 2 weeks. BCVA was 20/20 OD and 20/30 OS. Anterior segment evaluation was unremarkable whereas fundus evaluation showed a round elevated area at the level of the macula in the left eye with subretinal fluid seen on OCT (see photos below). Notice how the fluid is decentered nasally towards the optic nerve.
Based on this unilateral presentation one could think that this patient is suffering from Central Serous Retinopathy but upon careful examination of his optic nerve, one could also note a small round grayish area located temporally that is pathognomonic for a condition called “Optic Nerve Pit”.
Discussion
An optic nerve pit is a congenital anomaly that results from imperfect closure of the superior edge of the embryonic fissure. It appears as a gray-white round or oval-shaped depression on the inferotemporal aspect of the optic nerve, often found with adjacent peripapillary atrophy(1).
25-75% of patients experience visual symptoms that are caused by either a serous retinal detachment, retinal schisis or cystoid macular edema(2). Patients usually become symptomatic in the 3rd or 4th decade of life.
The exact source of the fluid found in optic nerve pit maculopathy is yet unclear and is thought to be coming from either the vitreous cavity, cerebrospinal fluid (CSF) or dural leaking vessels at the base of the pit.
Management
Without macular involvement, observation is recommended.
Should the macula be affected, treatment options include:
1- Laser photocoagulation temporally to the disc to create a barrier for the fluid not to enter the macula. Unfortunately, this therapy has not had much success and treated patients did not notice improvement, in fact, some reported more visual disturbance after the treatment(3).
2- Pars plana vitrectomy (PPV) with or without gas tamponade with promising long-term results in both retinal re-attachments (50-95% of patients) and visual improvement(>50% of patients)(3).
Prognosis
Isolated optic pits have an excellent prognosis as long as no maculopathy is present. Should a patient develop optic disc maculopathy, 80% will progress to a visual acuity of 20/200 or worse. Favorable anatomic and functional results have been reported after surgery with an 87% success rate reported recently in the literature.
Finally, I just want you to enjoy this beautiful OCT captured across the pit of one of my patients without maculopathy. I hope you enjoyed this case!
Case shared by Karla Delgado, OD
References:
- K.Bailey Freund, David Sarraf, William F. Mieler, Lawrence A. Yannuzzi. Optic nerve pit. The Retinal Atlas. Second Edition. Elsevier: 2017: p1123
- Wang Y, Xu L, Jonas JB. Prevalence of congenital optic disc pits in adult Chinese: The Beijing Eye Study.
- Chatziralli I, Theodossiadis P, Theodossiadis GP. Optic disk pit maculopathy: Current management strategies. Vol. 12, Clinical Ophthalmology. Dove Medical Press Ltd; 2018. p. 1417–22.
