AN ASSOCIATION BETWEEN STELLATE NONHEREDITARY IDIOPATHIC FOVEOMACULAR RETINOSCHISIS, PERIPHERAL RETINOSCHISIS, AND POSTERIOR HYALOID ATTACHMENT

Stellate nonheritable idiopathic foveomacular retinoschisis in juveniles: case report

BACKGROUND

Stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) is a rare type of retinoschisis with a spoke-like splitting that occurs in the outer plexus layer. We present a case of stellate nonhereditary idiopathic foveomacular retinoschisis in a juvenile, in which two eyes show different development trends and macular retinoschisis could be associated with mechanical force in the Henle fibre layer. The removal of mechanical force can partially restore vision.

CASE PRESENTATION

A 14-year-old girl with bilateral SNIFR was diagnosed and followed up with spectral-domain optical coherence tomography (SD-OCT). During the two follow-up visits, vitreous adhesion was released in the left eye, and visual acuity improved. Neuroepithelial detachment was aggravated in the right eye, and visual acuity decreased. Therefore, vitrectomy was performed on the right eye. After surgery, the patient's retina was reattached, and her vision was partially restored.

CONCLUSIONS

We reported a juvenile with bilateral SNIFR. Each of her eyes showed different development trends, so we adopted different treatment methods for each eye. Vitrectomy was performed on the patient to address progressive vision loss, which improved the patient's vision. It was further confirmed that the Henle layer of SNIFR patients was susceptible to posterior vitreous membrane adhesion.

Bilateral Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis (SNIFR) Incidentally Identified in a Non-Myopic Female

Stellate foveomacular retinoschisis is commonly associated with congenital X-linked retinoschisis, which is almost exclusively seen bilaterally in males. In the absence of a family history of retinoschisis and other related conditions, the term stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) is used. SNIFR constitutes a rather rare diagnosis and is usually observed unilaterally in myopic females. Within this context, we report a case of a non-myopic female patient with bilateral SNIFR detected with optical coherence tomography (OCT).

Non-vasogenic cystoid maculopathies

Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.

Stellate nonhereditary idiopathic foveomacular retinoschisis and an approach to the differential diagnosis of macular star

PURPOSE OF REVIEW

This review aims to introduce stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) and its differential diagnosis. We summarize findings from case reports and series published in the last few years on the clinical and imaging findings in SNIFR.

RECENT FINDINGS

SNIFR presents as either a unilateral or bilateral macular star on fundus examination without clinical or imaging evidence of exudation or frank vitreomacular traction. optical coherence tomography (OCT) imaging shows schisis cavities in the Henle fibre and outer plexiform layers that correspond to the stellate en face findings. Visual acuity is usually minimally affected, and the presence of significant vision loss should prompt high clinical suspicion for alternate diagnoses.

SUMMARY

SNIFR is a recently characterized clinical entity that serves as an important addition to the differential diagnosis of a macular star. It is a diagnosis of exclusion and should be distinguished from other causes of macular star such as neuroretinitis, vitreomacular traction, ocular manifestations of malignant hypertension, congenital juvenile X-linked macular schisis, myopic maculopathy, optic pit maculopathy, nicotinic acid maculopathy or taxane maculopathy among others.