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Introduction
Traditionally, trabeculotomy is the preferred initial surgical intervention for congenital glaucoma when corneal haze precludes the performance of a goniotomy. 1 It was first described by Burian in 1960. 2 In the classical trabeculotomy ab externo, an external approach is used to cannulate the Schlemm's canal (SC) and connect it to the anterior chamber through incision of the trabecular meshwork using the trabeculotome. Recent modifications of trabeculotomy include circumferential suture techniques with or without the use of flexible illuminated microcatheter and viscotrabeculotomy. 3-5 The most critical step in all these procedures is to identify the SC to prevent the complications such as collapse of the anterior chamber, iridodialysis and misdirection into the suprachoroidal space. The reported incidence of non-localisation of SC during trabeculotomy is 4-15%. Non-localisation may be due to congenital absence or dysgenesis of SC. 6 7 It is challenging in children due to less pigmented trabecular meshwork, malposition or absence of the canal in children with anterior segment developmental anomalies and most importantly in buphthalmic eyes with congenital glaucoma in which the limbal anatomy is disturbed because of stretching of the eyeball. 6 8 In this report, we describe a technique to identify SC to simplify the procedure of trabeculotomy. This method was developed since the senior author had had difficulty identifying SC prior to the compression of external jugular vein (EJV).
Anatomy
The surgeon should be familiar with the surgical anatomy of limbus, drainage of the aqueous humour and venous drainage of the eye. Surgical limbus is 1-1.5 mm wide zone, which can be divided into two equal bands. An anterior bluish grey band overlying cornea and posterior...