Surgery for congenital glaucoma requires precise visualization of angle structures of Schlemm canal. Transverse goniotomy requires a relatively clear cornea for controlled incision of angle structures. When an opaque cornea precludes this, ab externo trabeculotomy is a logical alternative. In severely buphthalmic eyes, finding Schlemm canal may be difficult because of distorted limbal anatomy. When trabeculotomy fails or Schlemm canal cannot be positively identified, direct goniotomy offers another surgical possibility.
The technique of performing a goniotomy through a 60° limbal incision is described in detail. Angle structures are directly viewed and operated on through an open anterior chamber. Strict adherence to surgical technique and meticulous wound closure are essential to prevent postoperative complications.
The approximately 50% cure rate justifies the potential risks inherent in opening a severely buphthalmic eye.
Fernández JL, Galin MA. Technique of Direct Goniotomy. Arch Ophthalmol. 1973;90(4):305-306. doi:10.1001/archopht.1973.01000050307013