CASE STUDY

Optic Pit Maculopathy: Where Is the Fluid?

RYAN C. YOUNG, MD • JONATHAN H. TZU, MD • HARRY W. FLYNN, JR., MD

First described by Wiethe in 1882,¹ optic disc pits are small, gray-white, oval depressions found at the optic nerve head. Macular involvement with optic nerve pits has been reported in 25% to 75% of patients.^2,3

Visual loss in patients with optic pits may be associated with retinoschisis or serous retinal detachment involving the macula, or both.³ Lincoff proposed that the fluid from optic pits forms a schisis-like cavity in the retina initially, which then progresses to an outer layer retinal hole and allows fluid to track into the subretinal space.⁴

However, subsequent OCT studies have shown that serous detachment can be associated with optic disc maculopathy without the schisis-like cavities.^5,6 In this report, we describe a patient with optic pit maculopathy and with subretinal fluid initially. After two years of follow-up, she had schisis only.

Figure 1. An 8-year-old girl with a colobomatous optic disc and optic pit maculopathy. VA fluctutated between 20/40 and 20/80 with variable fluid in the macula over two years.

CASE REPORT

An 8-year-old girl was referred for evaluation of subretinal fluid causing decreased vision in the right eye. Her past medical and ocular histories were unremarkable.

On examination, her best-corrected visual acuity in the right eye was 20/50, and the BCVA in the left eye was 20/20. Both eyes had anomalous optic nerves resembling coloboma.

In the right eye, she was noted to have subretinal fluid with yellow subretinal exudates (Figure 1). The fluid extended to the optic nerve head, which showed an optic pit. Optical coherence tomography confirmed the subretinal fluid (Figure 2). The patient was observed at that point.

Figure 2. An 8-year-old girl with optic pit maculopathy who initially presented with subretinal fluid and over two years of follow-up developed a schisis-like cavity on OCT. Upper left: February 28, 2011, BCVA 20/50; upper right: August 3, 2011, BCVA 20/60; lower left: January 27, 2012, BCVA 20/80; lower right: December 5, 2012, resolved subfoveal fluid and improved vision, BCVA 20/40.

At the six-month and one-year follow-ups, the subretinal fluid and her visual acuity remained stable. At the two-year follow up, her OCT showed resolution of the subretinal fluid but the formation of a new schisis-like cavity, extending from the nerve to the center of the macula. Visual acuity in the right eye remained stable at 20/40 (Figure 2).

DISCUSSION

Optic nerve pits are a rare entity, with an estimated prevalence of 1 in 11,000. Optic pit maculopathy can be associated with progressive visual loss and a poor visual prognosis in many patients.^2,3

The origin of the fluid and the pathophysiology of the maculopathy associated with optic pits is controversial. Various reports have suggested either vitreous or cerebrospinal fluid as the source of the intraretinal and subretinal fluid.³

Lincoff proposed a bilaminar structure, in which the fluid from the optic pit forms a schisis-like cavity initially, which then may progress to a neurosensory detachment via outer lamellar hole formation.⁴ A case series involving OCT by Rutledge et al.⁷ and Krivoy et al.⁸ supported this hypothesis.

A recent study reported two cases of optic pit maculopathy with serous macular detachment without schisis-like changes.⁵ The authors theorized that the layer of fluid accumulation within the retina depends upon the level at which the fluid enters from the optic pit.

In a larger series, serous detachment with overlying schisis-like changes occurred in the majority of cases, but rarely with outer retinal hole formation, indicating that outer-hole formation is not necessary for serous detachment. Similar to the report by Moon et al., the authors suggested that the level of fluid accumulation within the retina varies with the level of entry of fluid into the retina.⁵ They further noted that the fluid may directly enter under the retina from the optic pit, leading to serous detachment.

In this young patient, optic pit maculopathy was observed with good visual acuity over two years. Notably, the anomalous optic nerve head showed changes within the spectrum of a coloboma and a pit.

Initially, OCT demonstrated an apparent connection between the optic pit and the subretinal space, leading to serous macular detachment. The subretinal fluid resolved over the course of follow-up without treatment, but later a schisis-like cavity developed within the outer retina. Serial OCT did not detect an outer retinal hole.

As prior authors suggested,^5,6 fluid may enter the retina at any level, which may dictate the morphology of the resulting maculopathy. Observational management may be indicated for patients with stable vision, even though serial OCT imaging may show anatomical changes. RP

REFERENCES

1. Wiethe T. Ein Fall von angeborener Deformitat der Schnervenpapille. Arch Augenheilkd. 1882;11:14-19.

2. Gass JDM. Serous detachments of the macula secondary to congenital pit of the optic nerve head. Am J Ophthalmol. 1969;67:821-841.

3. Brown GC, Shields JA, Goldberg RE. Congenital pits of the optic nerve head. II. Clinical studies in humans. Ophthalmology. 1980;87:51-65.

4. Lincoff H, Lopez R, Kreissig I, Yannuzzi L, Cox M, Burton T. Retinoschisis associated with optic nerve pits. Arch Ophthalmol. 1988;106:66-67.

5. Moon S, Kim J, Spaide R. Optic pit maculopathy without inner retinal schisis cavity. Retina. 2006;26:113-116.

6. Imamura Y, Zweifel SA, Fujiwara T, Freund KB, Spaide RF. High-resolution optical coherence tomography findings in optic pit maculopathy. Retina. 2010;30:1104-1112.

7. Rutledge BK, Puliafito CA, Duker JS, Hee MR, Cox MS. Optical coherence tomography of macular lesions associated with optic nerve head pits. Ophthalmology. 1996;103:1047-1053.

8. Krivoy D, Gentile R, Liebmann J, Stegman Z, Walsh J, Ritch R. Imaging congenital optic disc pits and associated maculopathy using optical coherence tomography. Arch Ophthalmol. 1996;114:165-170.