Reviewing an optic pit in a glaucoma suspect

A 24-year-old was referred to the Ocular Disease Service at UAB Eye Care for a glaucoma evaluation. Other than a history of spectacle correction for myopic refractive error, the personal ophthalmic history is negative. He reports that his maternal grandfather had glaucoma, but this is unconfirmed. He has never smoked and drinks alcohol socially. Visual acuity is correctable to 20/20 in each eye. Pupils are round and equally reactive without RAPD. Goldmann applanation tonometry was 16 mm Hg in each eye at 9:55 a.m. Pachymetry was 619 and 622 µm in the right and left eyes, respectively. The anterior segments of each eye were unremarkable in each eye. 

Dilated fundus evaluation of the optic nerves is shown in Figure 1. Note particularly the asymmetry between the disc appearances.

Laser injury requires second opinion

As a baseline, a visual field was performed, as was an OCT. These are depicted in Figures 2 and 3, respectively. 

The appearance of an optic pit can present clinical challenges. Careful stereoscopic observation may lead to the diagnosis but additional testing, such as the OCT images obtained in this case may be helpful. Looking at the appearance of the optic nerve head of the patient’s left eye, it may be difficult to appreciate the depth of the pitting. Stereoscopically, it becomes evident. What would not be clear at clinical examination is the extent of any communication between the pit and the sub-sensory retina space. The potential conduit can be seen in the cross-sectional images from the OCT(See figures). 

The images confirm the presence of the optic pit, which is felt to be congenital/developmental, and not the so-called acquired pit of the optic nerve (APON) that has been reported in glaucomatous optic atrophy.¹

The patient’s baseline data will serve as a starting point for follow-up. We are planning to monitor the patient, who appears to be as low risk for glaucomatous damage. However, the possibility of serous retinal detachment secondary to the optic pit remains.^2,3 The patient was asked to report if any visual changes occur in the left eye. 

References

1. Javitt JC, Spaeth GL, Katz LJ, et al. Acquired pits of the optic nerve. Increased prevalence in patients with low-tension glaucoma. Ophthalmology. 1990 Aug;97(8):1038-43; discussion 1043-4.

2. Skaat A, Moroz I, Moisseiev J. Macular detachment associated with an optic pit: optical coherence tomography patterns and surgical outcomes. Eur J Ophthalmol. 2013 May-Jun;23(3):385-93.

3. Michalewski J, Michalewska Z, Nawrocki J. Spectral domain optical coherence tomography morphology in optic disc pit associated maculopathy. Indian J Ophthalmol. 2014 Jul;62(7):777-81.