Bilateral compressive optic neuropathy and outer retinopathy due to optic canal hyperostosis in a child with isolated vitamin a deficiency.

PURPOSE: Vitamin A plays a crucial role in rod phototransduction, with deficient levels manifesting as night blindness. Animal models have demonstrated bone dysplasia in the setting of hypovitaminosis A. We present a rare case of bony overgrowth leading to bilateral compressive optic neuropathy, combined with outer retinopathy, in a paediatric patient secondary to isolated vitamin A deficiency. METHODS: A single case report was conducted from Toronto, Canada. RESULTS: A 12-year-old boy with known autism spectrum disorder presented with a 9-month history of progressive painless vision loss. Vision was 20/300 and hand motion in the right and left eye, respectively. Fundus photography demonstrated bilateral optic atrophy and yellow lesions notably in the right eye far periphery. Optical coherence tomography (OCT) imaging demonstrated thinning of the retinal nerve fibre layer, alterations in the ellipsoid zone, as well as retinal pigment epithelium deposits. Computed tomography imaging demonstrated sphenoid bone thickening with narrow optic canals and moderate optic atrophy bilaterally. Full-field electroretinogram (ERG) demonstrated mildly reduced dark adapted (DA) 0.01 b-wave amplitudes and electronegative configuration of DA 3.0 and DA 10.0 ERG; the light adapted ERGs were normal. The patient was treated with pulse vitamin A therapy. Subsequently, the DA ERG normalized, outer retinal changes reversed and vision stabilised; no surgical intervention was conducted. CONCLUSION: This case represents a rare presentation of compressive optic neuropathy with concomitant outer retinopathy secondary to isolated vitamin A deficiency. Despite improvement in outer retinal integrity on OCT imaging and ERG testing results following vitamin A supplementation, no functional improvement was obtained due to severe optic atrophy.

Anesthesia for ophthalmic surgery: an educational review.

PURPOSE: Selecting an anesthetic agent for ophthalmic surgery has crucial implications for the surgeon, anesthesiologist, and patient. This educational review explores the common classes of anesthesia used in ophthalmology. Additionally, we discuss the considerations unique to cataract, glaucoma, strabismus, orbital, oculoplastic, and ocular trauma surgeries. METHODS: A comprehensive Embase search was performed using combinations of the subject headings "anesthesia", "eye surgery", "ophthalmology" and "cataract extraction", "glaucoma", "strabismus", "vitreoretinal surgery", "retina surgery", "eye injury", and "eyelid reconstruction". RESULTS: Topical anesthetics are the most commonly used form of ocular anesthesia, used in both an office and surgical setting, and carry a minimal side effect profile. Notably, topical anesthetics offer analgesia, but do not provide akinesia or amnesia. Regional blocks, such as are sub-Tenon's, peribulbar, and retrobulbar blocks, are used when akinesia is required in addition to analgesia. Recently, sub-Tenon's blocks have recently gained popularity due to their improved safety profile compared to other regional blocks. General anesthesia is considered for long, complex surgery, surgery in patients with multiple comorbidities, surgery in young pediatric patients, or surgery in patients intolerant to local or regional anesthetic. CONCLUSION: Anesthetizing the eye has rapidly evolved in recent years, supporting the safety, efficacy and comfort of ocular surgery. Since there are many viable options of anesthetics available for ophthalmic surgery, a robust understanding of the patients needs, the skill of the surgical team, and surgery-specific factors ought to be considered when creating an anesthetic plan for surgery.