Girl examined for retinal changes in her right eye

Retinal pigment epithelium changes, exudates and a peripapillary subretinal neovascular membrane were seen in the right macula.

Issue: March 25, 2008

ByDan S. Landmann, MD

ByMitchell B. Strominger, MD

ByJeffrey S. Heier, MD

Grand Rounds at the New England Eye Center

Isabel M. Balderas

Tom Hsu

An 8-year-old girl was referred for evaluation of retinal changes. The patient complained of a black dot in the center of her vision in the right eye for the past 3 to 4 months. She denied flashes, floaters, pain or diplopia. According to her parents, she had a normal eye exam 1 year ago. On review of systems, she reported a history of trauma to the right forehead 4 months prior without sequelae. Ocular history was unremarkable. The patient had environmental allergies for which she took Claritin (loratadine, Schering-Plough) as needed. Her birth history and family history were unremarkable. She had no medication allergies.

Examination

On initial workup, visual acuity without correction at distance was count fingers at 3 feet in the right eye and 20/30⁺² in the left eye. Visual acuity at near was 20/400 in the right eye and 20/20 in the left eye. Pupillary exam revealed a 1+ afferent pupillary defect in the right eye. The patient was unable to see the Ishihara plates with the right eye. On cover testing, she was orthotropic at distance and near. Cycloplegic autorefraction was +2.00 – 0.75 × 070 in the right eye and + 2.00 spherical in the left eye. Her anterior segment examination was unremarkable.


Color fundus photos show blurred disc margins in both eyes. The vessels are not obscured, and there is no hyperemia of the disc. Images: Landmann DS, Heier JS, Strominger M

Color fundus photographs show blurred disc margins in both eyes (Figures 1a and 1b). Nodules on the disc corresponded to areas of autofluorescence on the red free photos. In the right macula, retinal pigment epithelium changes, exudates and a peripapillary subretinal neovascular membrane were seen. In the left eye, optic disc drusen was seen, but no subretinal neovascular membrane was present (Figures 2a to 2e).


		Nodules on the disc correspond to areas of autofluorescence on the red free photos. In the right macula, retinal pigment epithelium changes, exudates and a peripapillary subretinal neovascular membrane are seen. In the left eye, optic disc drusen can be seen, but no subretinal neovascular membrane is present.
One year after submacular surgery, there are retinal pigment epithelium defects in the macula, but no recurrence of the subretinal neovascular membrane.	OCT through the fovea and retinotomy site shows that the foveal contour has improved, but there is disruption of the photoreceptor layer.

What is your diagnosis?

Retinal changes

The differential diagnosis for a pediatric patient with decreased vision, blurred disc margins and a peripapillary subretinal neovascular membrane includes papilledema, optic disc drusen, angioid streaks with trauma, and infectious or inflammatory etiologies. Serpiginous choroidopathy can also be considered.

It is important to note that the blood vessels are not obscured coming out of the optic disc, there is no hyperemia, and there are no papillary or peripapillary retinal hemorrhages visible in the left eye. Red free photos show autofluorescence at the optic discs representative of optic disc drusen.

In the pediatric population, the most common infectious etiologies of peripapillary subretinal neovascular membranes are Toxocara canis, rubella retinopathy, toxoplasmosis and ocular histoplasmosis syndrome.

The patient was diagnosed with peripapillary subretinal neovascular membrane associated with optic disc drusen based on her presentation, clinical and angiographic findings.

Peripapillary subretinal neovascular membranes in the pediatric population are an uncommon finding, and as such, the optimal treatment modalities are not well delineated.

Our patient underwent a pars plana vitrectomy, and a retinotomy was created in the superior macula. The subretinal space was inflated, and 40-gauge subretinal forceps were used to extract the membrane. An air-fluid exchange was performed with SF6 gas, and the patient was instructed to stay in a facedown position. One year after the surgery, visual acuity in the right eye improved from count fingers at 3 feet to 20/200 and 20/100 with the potential acuity meter. (Figures 3 and 4).

Discussion

Optic nerve head drusen are congenital, developmental anomalies of the optic nerve head. The prevalence is less than 5% in the general population but higher in family members with optic nerve head drusen owing to an autosomal dominant inheritance pattern. On exam, optic nerve head drusen are seen as elevated, lumpy irregularities on the anterior disc.

There are several conditions associated with optic nerve head drusen. Optociliary shunts occur as the retinal venous system forms collaterals with the choroidal network. Anterior ischemic optic neuropathy is the most common cause of vision loss in patients with optic disc drusen and is presumed to occur because of an anatomic predisposition and disc crowding. This may occur in younger patients without the common risk factors. Both central retinal artery and vein occlusions are also associated with optic disc drusen. Finally, peripapillary subretinal neovascular membranes, while uncommon, are a well-documented complication of optic disc drusen.

The management for this patient took into consideration a multitude of treatment modalities.

Not all subretinal neovascular membranes involve the macula and visual acuity so drastically. The membrane may be nasal to the optic disc, and in the pediatric population, subretinal neovascular membranes have been observed to spontaneously involute. In a study by Harris, wherein seven patients had choroidal neovascular membranes, six patients had a final visual acuity of 20/40 or better when followed with observation alone.

Using the Macular Photocoagulation Study as a guideline, one could consider laser photocoagulation, with the understanding that this study looked at an adult population with different pathologies. Nevertheless, laser photocoagulation has been reportedly used with mixed results for peripapillary subretinal neovascular membranes in pediatric patients. Complications associated with laser photocoagulation include severe vision loss, multiple recurrences and the need to fully treat the edges of the lesion.

No large studies on the use of photodynamic therapy in pediatric patients with peripapillary subretinal neovascular membranes associated with optic disc drusen could be found using an extensive Medline search. Similarly, anti-VEGF therapies have only recently been used in select pediatric patients. The package insert for Lucentis (ranibizumab, Genentech) states that it has not been studied in pediatric patients; systemic use of Avastin (bevacizumab, Genentech) has been associated with dysplasia of the growth plate in monkeys. Certainly, the risks, benefits and alternatives to anti-VEGF therapies would have to be thoroughly explained to patients and their parents for this off-label use. Sullu et al reported a case of submacular surgery for choroidal neovascular membrane secondary to optic nerve head drusen with dramatic improvement in visual acuity.

At 1 year after submacular surgery, our patient had a moderate improvement in visual acuity. She is currently being prescribed hyperopic corrective lenses and patching to see if any amblyopic component can be corrected.

For more information:

Dan S. Landmann, MD, and Mitchell Strominger, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com.

Jeffrey S. Heier, MD, can be reached at Ophthalmic Consultants of Boston, 50 Staniford St., Suite 600, Boston, MA 02114; 617-367-4800; Web site: www.eyeboston.com.

Edited by Isabel M. Balderas, MD, and Tom Hsu, MD. Drs. Balderas and Hsu can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com. Drs. Balderas and Hsu have no direct financial interest in the products mentioned in this article, nor are they paid consultants for any companies mentioned.

References:

Davis PL, Jay WM. Optic nerve head drusen. Semin Ophthalmol. 2003;18(4):222-242.

Goshorn EB, Hoover DL, et al. Subretinal neovascularization in children and adolescents. J Pediatr Ophthalmol Strabismus. 1995;32(3):178-182.

Harris MJ, Fine SL, Owens SL. Hemorrhagic complications of optic nerve drusen. Am J Ophthalmol. 1981;92(1):70-76.

Hoover DL, Robb RM, Petersen RA. Optic disc drusen in children. J Pediatr Ophthalmol Strabismus. 1988;25(4):191-195.

Lopez PF, Green WR. Peripapillary subretinal neovascularization. A review. Retina. 1992;12(2):147-171.

Rubinstein K, Ali M. Retinal complications of optic disc drusen. Br J Ophthalmol. 1982;66(2):83-95.

Sullu Y, Yildiz L, Erkan D. Submacular surgery for choroidal neovascularization secondary to optic nerve drusen. Am J Ophthalmol. 2003;136(2):367-370.

Wilson GA, Lloyd C, Moore AT. Optic disc drusen and peripapillary subretinal neovascular membranes in children. J Pediatr Ophthalmol Strabismus. 2002;39(6):351-354.