Optic Disc Pit
Dr. Shreya Jaiswal, Dr. Sarang Lambat, Dr. Vinay Nangia
Suraj Eye Institute, Nagpur
Introduction
Optic disc pit (ODP) is a rare congenital anomaly of optic nerve head. It is seen in 1 in 11,000 population with no gender predilection. ODPs are usually asymptomatic, but if it has associated maculopathy there may be nonreversible central vision defects leading to decreased central visual acuity. The macular changes include serous detachment, schisis, cystic degeneration and degenerative pigmentary changes.1
Case Report
A male, 41 years of age, presented with the complaints of blurring of vision in left eye noted since 6 months. Ocular examination revealed a best corrected visual acuity of 6/6, N6 in right eye and 6/24, N18 in left eye. Anterior segment examination was within normal limits (WNL). Intraocular pressure by Goldmann applanation tonometer was 14 mmHg in both eyes. Fundus examination of the left eye showed two oval pits at temporal and infero-temporal margin of the optic disc, with abnormal vascular loops superiorly and serous retinal detachment of the macula associated with yellow refractile deposits on the margin (Fig.1a,b).
The right eye was WNL. Spectral domain optical coherence tomography (SD-OCT) of left eye showed schitic changes in the outer nuclear and inner nuclear layer nasal to the fovea that extended till the disc. A possible communication channel with the pit was noted, along with thinning of the outer nuclear layer at fovea, serous retinal detachment with photoreceptor layer distortion (Fig. 2).
SDOCT of the right eye was WNL. Patient underwent pars plana vitrectomy (PPV) with Internal limiting membrane (ILM) peeling with sulphur hexafluoride gas injection in left eye. Post surgery there was gradual reduction in the sub sensory fluid over several months with improvement in the visual acuity to 6/9 at 1 year and 6/6p at 3 years (Fig.3)
Discussion
The pathophysiology of Optic disc pit associated maculopathy is yet to be elucidated and thus there is no definitive treatment for the same. There are studies demonstrating spontaneous resolution in the optic disc pit associated with serous macular detachment over a variable period of time.2,3 Other management options include laser photocoagulation, gas injection, macular buckling surgery4, and vitrectomy surgery. A variety of surgical approaches have been advocated for vitrectomy, including the variable use of laser, induction of posterior vitreous detachment5, internal limiting membrane peeling6,7, inner retinal fenestration8, and/or gas tamponade. A long standing macular detachment leads to irreversible changes at the macula leading to poor visual prognosis.9,10 Thus it is advisable to plan early intervention for the best chances of visual improvement. In this case we have done a pars plana vitrectomy with Internal limiting membrane peeling with Sulphur hexafluoride gas injection, and were able to achieve satisfactory anatomical and functional outcomes over a period of time. Immediate improvement in the vision may be seen in some cases, although majority require a long term follow-up.
References
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2. Vedantham V, Ramasamy K. Spontaneous improvement of serous maculopathy associated with congenital optic disc pit: an OCT study. Eye. 2005 May;19(5):596-9 https://doi.org/10.1038/sj.eye.6701540
3. Sugar HS. Congenital pits in the optic disc: and their equivalents (congenital colobomas and colobomalike excavations) associated by submacular fluid. American journal of ophthalmology. 1967 Feb 1;63(2):298-307. DOI:https://doi.org/10.1016/0002-9394(67)91553-X
4. Theodossiadis GP. Treatment of maculopathy associated with optic disk pit by sponge explant. American journal of ophthalmology. 1996 Jun 1;121(6):630-7. https://doi.org/10.1016/S0002-9394(14)70628-2
5. Hirakata A, Inoue M, Hiraoka T, McCuen II BW. Vitrectomy without laser treatment or gas tamponade for macular detachment associated with an optic disc pit. Ophthalmology. 2012 Apr 1;119(4):810-8. https://doi.org/10.1016/j.ophtha.2011.09.026
6. Georgalas I, Petrou P, Koutsandrea C, Papaconstadinou D, Ladas I, Gotzaridis E. Optic disc pit maculopathy treated with vitrectomy, internal limiting membrane peeling, and gas tamponade: a report of two cases. https://doi.org/10.1177/112067210901900230
7. Snead MP, James N, Jacobs PM. Vitrectomy, argon laser, and gas tamponade for serous retinal detachment associated with an optic disc pit: a case report. British journal of ophthalmology. 1991 Jun 1;75(6):381-2. http://dx.doi.org/10.1136/bjo.75.6.381
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9. Sobol WM, Blodi CF, Folk JC, Weingeist TA. Long-term visual outcome in patients with optic nerve pit and serous retinal detachment of the macula. Ophthalmology. 1990 Nov 1;97(11):1539-42. https://doi.org/10.1016/S0161-6420(90)32380-1
10. Patton N, Aslam SA, Aylward GW. Visual improvement after long-standing central serous macular detachment associated with an optic disc pit. Graefe’s Archive for Clinical and Experimental Ophthalmology. 2008 Aug 1;246(8):1083. https://doi.org/10.1007/s00417-008-0824-5