Pupillary block is a known complication of cataract surgery leading to peripheral anterior synechiae and angle closure glaucoma. It was first noted by Ridley and has been reported with nearly every known design of pseudophakos. The authors describe a case of pupillary block glaucoma with a posterior chamber intraocular lens (PCIOL) implanted in the anterior chamber following complicated extracapsular cataract extraction (ECCE). We are unaware of any earlier report of pupillary block glaucoma following implantation of PCIOL in the anterior chamber.
A 50-year-old female was referred to us six days after cataract surgery complaining of pain in the left eye. She was using ciprofloxacin 0.3% eye drops four times daily, betamethasone 0.1% eye drops four times daily and tablet ciprofloxacin 750 mg twice daily. On examination, her best corrected visual acuity was 6/9 in the right eye and counting fingers at 2 metres in the left eye. Intraocular pressure (IOP) by applanation tonometry was 21 mmHg in the right eye and 57 mmHg in the left eye. Examination of the right eye was essentially within normal limits. Examination of the left eye showed lid oedema, conjunctival congestion, corneal epithelial and stromal oedema. The anterior chamber of the left eye showed 2+ flare and cells. The anterior chamber was deep axially and flat in the periphery. A PCIOL was present in the anterior chamber with pupillary capture temporally [Figure:1]. There was vitreous in the anterior chamber. Gonioscopy could not be done due to marked corneal oedema. Disc and fundus appeared normal.
A diagnosis of pseudophakic pupillary block glaucoma was made and Nd : YAG laser iridotomy was done the same day. She was started on tablet acetazolamide 250 mg four times daily, betaxolol 0.5% eye drops twice daily, cyclopentolate 1% eye drops three times daily and betamethasone 0.1% eye drops every three hours. Following treatment, her vision improved to 6/15 and the IOP reduced to 19 mmHg on the second day following Nd: YAG laser iridotomy. Explantation of the pseudophakos through the scleral tunnel of the previous surgery with anterior vitrectomy and peripheral iridectomy was done as a definitive management strategy on the fifth day after laser iridotomy. A Kelman multiflex ACIOL was implanted and dialled anticlockwise to horizontal position to keep the haptics away from the wound [Figure:2]. The postoperative course was uneventful except for intraocular inflammation which was treated with topical corticosteroids and cycloplegics. On the last follow-up 2 years postoperatively, her best corrected visual acuity was 6/12 and the IOP was under control with timolol maleate 0.5% eye drops twice daily. The anterior chamber was quiet, AC IOL was in situ and fundus examination was within normal limits.
Pupillary block glaucoma is relatively more common after AC IOL implantation. Stark and associates reported a 0.3% incidence of pupillary block within one year of PCIOL implantation in 2,703 eyes and 0.8% incidence after ACIOL implantation in 3,587 eyes. This is probably because PCIOLs afford the most physiologic substitute for the natural lens without adversely affecting the aqueous flow dynamics. With ACIOL, the round optical portion just anterior to the pupil acts like a “flap valve” which is readily sealed by the transient anterior displacement of the iris. If cataract surgery is complicated in any way (vitreous loss, shallow chamber, positive vitreous pressure, etc.), the chances of pupillary block are further enhanced. Since these patients may be asymptomatic and may have normal IOP, a thorough clinical examination is very important. Even in presence of minimal iris bombe configuration, one should assess the integrity of the cataract incision, record the IOP, note the presence and patency of the iridectomy, the location of the haptics of the lens in relation to the site of iridectomy, and assess the vitreous face position.
This patient was successfully managed by explantation of the PCIOL, anterior vitrectomy, peripheral iridectomy and secondary Kelman multiflex open loop ACIOL implantation. She completed 2 years of follow-up and her IOP was controlled with 0.5% timolol maleate twice daily and her best corrected visual acuity was 6/12. In the present case, the pupillary block was probably precipitated by occlusion of the pupillary aperture with the PCIOL optic and the vitreous, and by the lack of a patent peripheral iridectomy to provide an alternate channel for aqueous flow. Thorough anterior vitrectomy and peripheral iridectomy are essential in cataract surgery complicated by posterior capsular rupture and vitreous loss.
In this case as the capsular rim was insufficient for PCIOL implantation, an ACIOL was implanted. However, it is very essential to dial the ACIOL in anticlockwise direction because the inherent design of the haptics could damage the angle structures if dialled otherwise. Along with meticulous anterior vitrectomy, a peripheral surgical iridectomy is a necessity as it ensures relief from pupillary block. The temptation of implanting a PCIOL in the anterior chamber should be avoided at all costs as these lenses are not designed for anterior chamber implantation.
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