Pupilloplasty for congenital pupillary‐iris‐lens membrane with 25‐gauge vitreous cutter (2009)

Editor, In 1986, Cibis and coworkers reported congenital pupillary-iris-lens membrane with goniodysgenesis (CPILMG) as a new clinical entity characterized by anomalies of the chamber angle and iris-lens membrane (Cibis et al. 1986). CPILMG is a rare, congenital, unilateral and sporadic disease with distinctive features of a white pupillary membrane that can be progressive and adheres to the anterior iris surface. Because the membrane often causes an ectopic pupil or pupillary block glaucoma, surgical intervention is sometimes required (Cibis et al. 1994; Robb 2001; Cibis & Walton 2004; Demidenko et al. 2009). We present a case of CPILMG in which a white membrane on the iris of the right eye triggered pupillary displacement and caused pupillary block. A 2-month-old full-term boy delivered uneventfully was noted by his paediatrician to have a white opacity in the right pupil. The patient was referred to our department for evaluation. White membranes on the surface of the lens and iris were observed biomicroscopically. Virtually no pupil dilation was observed after application of mydriatic eyedrops, most likely because of strong adhesion of the membrane to the iris and lens surface. The anterior segment of the left eye was normal. Because the centre of the pupil was open, the patient was followed bimonthly. At 4 months of age, although the centre of the pupil remained open, the pupil diameter was smaller than it had been 2 months previously. At 6 months of age, he was examined because the mother noticed a corneal opacity accompanied by conjunctival redness in the right eye. Slit-lamp examination showed severe corneal oedema, ciliary injection and a shallow peripheral anterior chamber. The pupil was a pinpoint and had shifted to the inferior-nasal quadrant (Fig. 1A). The intraocular pressure (IOP) of the right eye was 60 mmHg. Although the fundus could not be visualized, B-scan ultrasonography showed a grossly normal eye. (A) The right eye at 6 months of age before pupilloplasty. The pupil has become smaller and displaced inferonasally. The pupillary membrane obstructs the visual axis. (B) Ultrasound biomicroscopy performed with the patient under general anaesthesia shows pupillary block glaucoma and iris bombe and that the iris is attached to the posterior corneal surface, resulting in an obstructed angle. Ultrasound biomicroscopy under general anaesthesia showed that the pupillary margin adhered completely to the lens surface because of the white membrane, resulting in iris bombe (Fig. 1B). Surgical excision of the iris at the visual axis was performed to normalize the IOP by releasing the pupillary block and create a new pupil centrally. An excision was performed using a 25-gauge vitreous cutter inserted from the limbus under BSS plus® irrigation into the anterior chamber. Caution was exercised to avoid damaging the anterior lens surface (Fig. 2A); thus, the white membrane that adhered to the lens surface was not removed. (A) The appearance of the right eye after pupilloplasty. The opening of the iris (new pupil) was created in the centre of the visual axis. (B) The right eye 30 months after surgery. The newly created pupil remains open and in the centre of the visual axis. After surgery, the depth of the anterior chamber and the IOP became normal. The left eye was patched part-time. The newly created pupil has remained open and at the central position during the 30-month postoperative follow-up (Fig. 2B). Although the patient could fixate and follow with patching of his left eye, visual acuity measurement was impossible because of delayed mental development. In previous reports, a relatively large percentage of patients with CPILMG developed pupillary closure with iris bombe and angle-closure glaucoma (Cibis & Walton 2004). This patient required surgery for pupillary block glaucoma with closure of the visual axis. Forceps and scissors may be used to perform the surgery (Robb 2001), but a 25-gauge vitreous cutter that can be inserted into the anterior chamber with smaller wounds allows easier and more controlled surgical manoeuvres, resulting in safer and less invasive surgery. Especially in the small eyes of infants who have a thin and soft eye wall, smaller wounds are critical for good wound sealing and protection of the underlying lens. We believe that pupilloplasty with a 25-gauge vitreous cutter can be a good treatment for pupillary block glaucoma.