Ophthalmic anaesthesia: Overview

We report the anesthetic management of a child diagnosed with Marinesco-Sjogren syndrome (MSS) scheduled for bilateral lens aspiration. MSS is an autosomal recessive multisystem disorder clinically characterized by cerebellar ataxia, cataract, myopathy, global developmental delay, and variable intellect first described by Marinesco et al in 1931.The neuro-radiologic hallmarks include cerebellar hypoplasia and a small posterior fossa.1 Sixty percent of patients have been found to have SIL1 gene mutation linked to chromosome 5q31.

Key points:
• Ophthalmic conditions requiring surgery in children are common.
• Anaesthetic techniques should minimise increases in intraocular pressure, particularly in glaucoma surgery and traumatic eye injuries.
• Ophthalmic surgery can elicit the oculocardiac reflex and is associated with a high incidence of postoperative nausea and vomiting.
• With improved neonatal care, there are increasing numbers of premature and ex-premature infants that require ophthalmic surgery.

Abstract
Purpose: Congenital corneal anesthesia (CCA) is a rare clinical entity that poses a diagnostic dilemma, particularly in the pediatric age group with very little literature on this. Accurate initial diagnosis, evaluation, early identification of risk factors, aggressive systemic workup, and appropriate therapy are paramount to prevent visual loss due to long-term complications of corneal anesthesia. The purpose of the study was to estimate and compare the corneal neural architecture using real time, in vivo confocal microscopy (IVCM) in patients with CCA as against a control population.

Methods: This was a retrospective nonconsecutive, comparative clinical case series in a tertiary hospital in South India from June 2015 to December 2018.

Methods: IVCM was accomplished in cooperative children in whom central cornea was relatively clear. The clearest three to five images from each eye were selected, and the nerves were analyzed for length, thickness, density, dichotomous pattern, and beading. Statistical analysis was done using Origin v7.0 (Origin Lab Corporation, Northampton, MA, USA).

Results: In total, 15 eyes of 11 cases and 20 eyes of 10 controls were imaged. Measurements on corneal nerve density showed a significant difference (P = 0.0005), cases having a lower mean (3.85 ± 1.38 mm per mm2) compared to the controls (6.74 ± 1.75 mm per mm2). Measurements on corneal nerve length (P = 0.28), thickness (P = 0.45), and presence of beading (P = 0.97) and dichotomous pattern (P = 0.07) did not reveal a significant difference between cases and controls.

Conclusion: There is a strong relationship between the functional loss (absent corneal sensation) and anatomical decrease (reduced subbasal nerve density) of corneal nerves in congenital corneal anaesthesia.