FEVR combined with macular heterotopia in children presenting as pseudo-exotropia: a case report and literature review

Abstract

Familial exudative retinopathy (FEVR) is a hereditary disease involving abnormal retinal vascular development in which macular heterotopia (MH) caused by mechanical-like pulling of the vitreous may lead to pseudo-strabismus. We describe the case of a 12-year-old male patient from China who presented to our hospital with a request for surgical correction of exotropia. Examination revealed that the strabismic appearance was due to MH, and dilated pupil examination of the peripheral fundus revealed that the blood vessels of the left eye and the macula were displaced toward the temporal retina by pulling, and further FFA examination was performed to diagnose FEVR. With good binocular vision and stereoscopic distance vision, corrective surgery for strabismus in this patient would have resulted in a hard-to-resolve diplopia. Therefore, it is important to identify FEVR combined with MH in clinical practice to avoid wrong diagnostic and treatment options.

Keywords: binocular vision; familial exudative vitreoretinopathy; macular heterotopia; macular perfusion density evaluation; pseudo-strabismus.

Figure 1

Patient’s eye position. (A) Hirschberg method shows −15° in the left eye; (B) alternate masking: slight external shadow motion, motion inconsistent with corneal reflection point.

Figure 2

Nine direction eye situation. Normal movement of both eyes in all directions.

Figure 3

Patient’s fundus condition. (A,B) For fundus photography: no obvious abnormality in the right eye (A), the macula in the left eye is shifted to the temporal side, and the macula is 5 PD from the optic disc on the temporal side (B). (C,D) For Zeiss wide-angle fundus photography: no obvious abnormality in the right eye’s peripheral retina (C), the vascular arch of the left eye’s retina is straightened to the temporal side, and the black arrows show the pre-fibrofilarial membrane-like hyperplasia of the temporal side of the peripheral retina (D). (E,F) For the left eye’s posterior segment. OCT, macular morphology is fair, white arrow shows a little fibrous membranous proliferation, red arrow shows local separation between neuroepithelial layers.

Figure 4

Binocular OCTA macular perfusion density evaluation. (A,B) OCTA macular blood flow density imaging, (C) Comparison of macular perfusion density in each region of both eyes, the macular perfusion density of the left eye is lower than that of the right eye, and the decrease is more pronounced on the nasal side. C, center; T, temporal; N, nasal; S, superior; I, inferior.

Figure 5

Binocular FFA. (A–F) Right eye: early temporal peripheral retinal surface with tortuous vascular alignment; (a–f) Left eye: early mid-peripheral retinal vascular alignment is straight, peripheral retinal vascular alignment is tortuous, tube diameter is not uniform, capillary dilation, with the imaging process, the dilated capillaries and part of the vessel wall appear fluorescence leakage, and fluorescence staining in the late stage.

Figure 6

Wide-angle fundus photography of the patient’s parents. Panels (A,B) are fundus photographs of the patient’s mother, and Panels (C,D) are fundus photographs of the patient’s father, all of which show no significant abnormalities.