An Ocular Endoscope Enables a Goniotomy Despite a Cloudy Cornea

Infantile glaucoma is often initially treated with a surgical goniotomy or trabeculotomy. A goniotomy is not possible if the cornea is too cloudy, despite preoperative glaucoma medications and removal of the corneal epithelium. Bimanual endoscopic goniotomy has been reported in 1 child, but this technique requires great dexterity to maintain the endoscopic image on the needle tip.¹ In the following case, we used a new technique, coaxial endoscopic goniotomy,² that allowed a goniotomy to be performed when the anterior chamber angle could not be distinguished through the surgical gonioprism.

A 19-month-old girl was referred with a several-month history of film covering both eyes. The child was photophobic, tearing, and had bilateral buphthalmos with extremely cloudy corneas. She was prescribed timolol maleate, latanoprost, and acetazolamide sodium syrup while undergoing treatment for otitis media. She had no other health problems. An examination under anesthesia 9 days later revealed intraocular pressures of 31 mm Hg OD and 33 mm Hg OS, corneal diameters of 14.5 mm OD and 15 mm OS, circumferential and horizontal Haab striae in both eyes, a cup-disc ratio of 0.8 OU, axial eye lengths of 25.4 mm OD and 27.0 mm OS, and attached retinas by B-scan ultrasound. A high-iris insertion was present in the right eye by gonioscopy, but the view was too hazy in the left eye (Figure 1A).

The child underwent bilateral goniotomies with the aid of a coaxial ocular endoscope in the left eye. Permission for this procedure had been obtained from the child's mother and approved by the institutional review board of Vanderbilt University, Nashville, Tenn. A thin blood lancet (Microlance; Becton-Dickinson Co, Rutherford, NJ) had been formed to wrap tightly around a 20-gauge ocular endoscope (Endoptiks, Little Silver, NJ) and was sterilized separately. The lancet was placed on the endoscope with the needle tip observable in the endoscopic image. The coaxial endoscopic goniotomy needle was then inserted through a paracentesis after viscoelastic material was placed into the anterior chamber; the needle was directed to the anterior chamber angle (Figure 2). The image of the anterior chamber angle was viewed on a videoscreen as the lancet tip cut the high-iris insertion for 130° (Figure 3). The corneal incision was closed, and a routine goniotomy was performed on the right eye.

At the child's next examination under anesthesia, her intraocular pressures were still uncontrolled at 35 mm Hg OD and 34 mm Hg OS with poor medication compliance, but her left cornea had substantially cleared so that regular bilateral goniotomies could be performed. Corneal diameters were 14.5 mm OD and 14.5 mm OS, and axial eye lengths were 25.4 mm OD and 26.8 mm OS. The previously treated angle in the left eye was observed by gonioscopy (Figure 1B).

A goniotomy is a relatively simple procedure to treat congenital glaucoma. However, visualization of the anterior chamber angle structures is required. Coaxial endoscopic goniotomy permits visualization, as previously demonstrated in cadaver eyes² and in the successful treatment of rabbits with congenital glaucoma.³ The coaxial alignment requires only 1 corneal incision and permits the lancet tip to be continuously viewed on the videoscreen as it incises the angle structures. The operating time is similar to that of a routine goniotomy.

This project was supported by a grant from Research to Prevent Blindness Inc, New York, NY.

The authors have no commercial, financial, or proprietary interest in the product or company, nor do they receive payment as consultants, reviewers, or evaluators.

Reprints: Karen M. Joos, MD, PhD, Department of Ophthalmology and Visual Sciences, Vanderbilt University, 1215 21st Ave S, 8017 MCE, Nashville, TN 37232-8808. (e-mail: karen.joos@mcmail.vanderbilt.edu).