A 10-year-old white female presented with decreased vision in her right eye that was discovered on a routine examination. Her eye doctor noted suspicious findings in that eye and referred her for an evaluation. The patient was uncertain how long her vision had been reduced. She reported no problems in her left eye. Her medical and ocular history was unremarkable.
On examination, her best-corrected visual acuity was 20/200 O.D. and 20/20 O.S. Extraocular motility testing was normal, and she was orthophoric on cover testing. Her confrontation visual fields were full to careful finger counting O.U., and her pupils were equally round and reactive, with no afferent pupillary defect. The anterior segment exam was unremarkable O.U. Intraocular pressure measured 14mm Hg O.U.
On dilated fundus exam, the vitreous was clear O.U. She had moderate-sized cups with good rim coloration and perfusion in both eyes; however, the optic nerve O.D. appeared slightly unusual. Also, there were visible changes in the macula of the right eye (figure 1). The peripheral retinas of both eyes were normal. We obtained an optical coherence tomography (OCT) of the right eye (figures 2 and 3).
1. The posterior pole of the right eye shows interesting changes in the macula and optic nerve
2,3. OCT images of the macula O.D. Figure 2 is a horizontal slice, and figure three is an oblique slice that runs superior-temporal to inferior-nasal of the macula.
Take the Retina Quiz
1. What do the changes in the macula of the right eye illustrate?
a. A beaten metal appearance.
b. Macular schisis.
c. Serous fluid.
d. A localized area of inflammation of the retinal pigment epithelium (RPE).
2. What does the OCT of the macula in figure 2 show?
a. Serous retinal detachment.
b. Pigment epithelial detachment.
c. Cystoid macular edema (CME).
d. Inflammation of the RPE.
3. Besides the finding in figure 2, what else can be seen on the OCT in figure 3?
a. Retinal tear.
b. A dehiscence between the inner and outer retinal layers.
c. Retinal neovascularization.
d. Retinal schisis.
4. What is the correct diagnosis?
a. Central serous retinopathy (CSR).
b. Acute multifocal pigment placoid epitheliopathy (AMPPE).
c. Retinal angiomatosis proliferation (RAP).
d. Optic nerve pit with a serous macular detachment.
5. How should this patient be managed?
a. Observation.
b. Laser photocoagulation.
c. Intravitreal Avastin (bevacizumab, Genentech).
d. Vitrectomy.
For answers, see below.
Discussion
Figure 2 demonstrates that our patient has a neurosensory retinal detachment involving the macula O.D. Had our patient been in her mid-30s, we might have considered a diagnosis of central serous retinopathy. Given her age, however, our diagnosis is more complicated to explain. In this case, the correct answer concerns the optic nerve.
If we follow the extent of the serous detachment, it almost has a tear drop configuration, with the nasal edge leading up to the inferotemporal side of the optic nerve. Clearly, the optic nerve in the right eye appears unusual, especially when compared to the fellow eye. There is a colobomatous depression found temporally; this represents an optic nerve pit. On clinical examination with 3-D viewing, the pit could clearly be distinguished.
Optic nerve pits represent congenital abnormalities of the optic nerve. They may appear as a small, localized, dark gray or black (or, in rare instances, yellow) depression within the optic nerve. Over the years, optic nerve pits have been described as craters, holes, cavities and finally, congenital pits of the optic nerve.1
Most pits occur on the inferotemporal side of the optic nerve; about 20% are centrally located.1 There is usually loss of the retinal nerve fiber layer in the area of the pit, and there may be a corresponding visual field defect.1
Optic nerve pits generally do not affect visual function. However, some 40% to 50% of patients with optic nerve pits develop serous detachment, which adversely affects the macula.1 This is precisely what occurred in our patient.
There has been much speculation about the pathophysiology of these serous detachments. One theory: Fluid enters the optic disc at the site of the pit and travels between the inner and outer layers of the retina, resulting in a retinal schisis.1-2 OCT widely confirmed this theory.3 The inner retinal schisis develops first, followed by a large, outer-layer retinal detachment. The inner and outer retinal layers are likely connected by a hole in the outer layer of the retina, near the macula.
There has also been much speculation about the nature of serous fluid. In more traditional neurosensory retinal detachments, the fluid leaks from the choroid through the RPE. But, this is not the case with serous detachments associated with optic nerve pits.
One theory is that cerebrospinal fluid leaks from the subarachnoid space within the optic nerve and settles in the retina.4 Another possibility is that the fluid comes from retinal vessels that leak into the subretinal space.1 The most widely accepted theory, however, suggests that the fluid represents liquefied vitreous that enters through the optic nerve pit.5
Interestingly, about 75% of patients with serous macular detachments associated with an optic nerve pit also have a posterior vitreous detachment (PVD).1 Our patient, however, did not appear to have a PVD.
As for treatment, no option has demonstrated great success in preserving visual function. In some instances, the serous detachment may spontaneously flatten on its own without treatment. In those instances, the visual outcome generally depends on the duration of the serous detachment.
If the fluid does not spontaneously resolve, laser photocoagulation may be used to wall off the area between the area of the retinal detachment and optic nerve. Vitrectomy has also been tried, including removal of any traction that could contribute to the disease state. After treatment, even with successful macular reattachment, the mean outcome for visual acuity is approximately 20/80.1
1. Sanborn GE. Optic disc pits and associated serous macular detachments. In: Schachat AJ (ed). Retina: 4th Edition. Vol. 2: Medical Retina.
2. Lincoff H, Lopez R, Kreissig I, et al. Retinoschisis associated with optic nerve pits. Arch Ophthalmol 1988 Jan;106(1):61-7.
3. Lincoff H, Kreissig I. Optical coherence tomography of pneumatic displacement of the optic disc pit maculopathy. Br J Ophthalmol 1998 Apr;82(4):367-72.
4. Gass JDM. Serous detachments of the macula secondary to congenital pits of the optic nerve head. Am J Ophthalmol 1969 Jun;67(6):821-41.
5. Sugar HS. Congenital pits in the optic disc with acquired macular pathology. Am J Ophthalmol 1962 Feb;53:307-11.
