Peters anomaly is a dysgenesis of the anterior segment characterized by congenital corneal opacity and iridocorneal (type I) or lenticulocorneal (type II) adhesion.1 Glaucoma may be present at birth or may develop, often as a complication of surgery undertaken to establish a clear visual axis. Patients with central corneal opacity and no lenticular involvement can usually achieve an adequate visual axis through an optical iridectomy.2 They thus avoid penetrating keratoplasty, which has poor results in infants with Peters anomaly.3 We describe a single operation for type 1 Peters anomaly with glaucoma that establishes a visual axis, releases iridocorneal adhesions to foster corneal clearing, and achieves a circumferential trabeculotomy. We refer to this procedure as the “3 in 1 approach.”
Video 1 (available in the online version of this article) demonstrates our technique. The procedure is performed under general anesthesia, and the eye is prepared and draped in the usual sterile manner. A 5-0 polyglactin 910 traction suture is placed at the temporal limbus to secure the eye in an adducted position. A temporal 3-clock-hour conjunctival peritomy is created (Figure 1A). Cautery is used for hemostasis as needed. Next, a thick scleral flap is created such that the brown/gray coloration of the choroid is visible in the scleral bed (Figure 1B). At the flap/corneal junction, the roof of the Schlemm's canal is identified as the slightly blue-appearing region just anterior to the white band of scleral spur. Schlemm's canal is incised radially under high magnification and the incision is slowly deepened (Figure 1C). Successful entry into the canal is often accompanied by reflux of aqueous or less frequently blood from the cut end of the canal. A blunted suture (eg, 6-0 polypropylene) or an illuminated microcatheter (iTrackTM fiberoptic microcatheter; Ellex Medical Lasers Ltd, Mawson Lakes, Australia) is threaded into one of the cut ends of the canal and advanced circumferentially until the tip emerges from the other end of the ostium.
Intraoperative view of ab externo trabeculotomy combined with lysis of iridocorneal adhesions and optical sector iridectomy. (A) A temporal 3-clock-hour conjunctival peritomy is created. (B) A thick temporal scleral flap is created, approximately one-third corneal diameter in width. (C) Schlemm's canal is incised radially. (D) After the catheter is threaded into the canal and the tip emerges from the sclerostomy, the two ends of the catheter are grasped with forceps and pulled to achieve lysis of iridocorneal adhesions. (E) Temporal iris tissue is grasped with a small-caliber toothed forceps and excised with iris scissors to create a broad, temporal optical iridectomy. (F) Conjunctiva is closed with two interrupted 8-0 polyglactin 910 sutures.
Once the cannulation is completed, the two ends of the catheter are grasped with forceps, the eye is rotated into primary position, and the catheter/suture is gently pulled until it is observed to be in the anterior chamber (Figure 1D). When the catheter approaches the center of the pupil, it is slowly and gently advanced to lyse the adhesion between the iris and the cornea until all of the adhesions are broken. After the trabeculotomy is complete, temporal iris tissue at the level of the sclerostomy is grasped with a small-caliber toothed forceps and excised with iris scissors to create a broad, temporal optical iridectomy (Figure 1E). Balanced salt solution is used to irrigate the anterior chamber. A small amount of ophthalmic viscoelastic device is injected through a paracentesis to reform the anterior chamber as needed. The scleral flap is closed meticulously to prevent bleb formation. Conjunctiva is then closed with two interrupted 8-0 polyglactin 910 sutures at each end of the peritomy (Figure 1F).
Subconjunctival anesthetic block is given for postoperative control of pain. Topical atropine drops and antibiotic/steroid ointment are applied and the eye is patched.
A female infant presented at 2 weeks of age with type I Peters anomaly consisting of bilateral dense central corneal opacities and iridocorneal adhesions seen on external examination (Figures 2A–2B) and high-resolution ultrasound biomicroscopy (Zeiss-Humphrey Instruments Inc., San Leandro, CA) (Figures 2C–2F). On presentation, the patient had elevated intraocular pressure in both eyes (38 mm Hg in the right eye and 40 mm Hg in the left eye) measured by Tono-Pen (Tono-Pen XL, Reichert Inc., Depew, NY), with no other signs of glaucoma. Bilateral ab externo trabeculotomy, synechiolysis, and sector iridectomies were performed in both eyes as described in the technique section.
(A and B) Preoperative external photography showing bilateral dense central corneal opacities. Preoperative ultrasound biomicroscopy images showing iridocorneal adhesions and central corneal thickening in the (C and D) right and (E and F) left eyes.
Postoperative ultrasound biomicroscopy images showed resolution of iridocorneal adhesions and decrease in central corneal thickness suggesting improvement in corneal edema (Figures 3A–3D). She underwent alternate side patching (3 hours daily) and was prescribed a mydriatic agent for visual rehabilitation. Eight months after surgery, red reflex was present temporally in both eyes by streak retinoscopy without the use of a mydriatic agent. At the 16-month follow-up visit, the central corneal opacity continued to improve in both eyes (Figures 3E–3F) and intraocular pressure was stable (17 mm Hg in the right eye and 19 mm Hg in the left eye) measured by Icare rebound tonometry (Icare, Helsinki, Finland) with no glaucoma medications. The patient remains a glaucoma suspect according to the Childhood Glaucoma Research Network criteria.4
Postoperative ultrasound biomicroscopy images showing resolution of iridocorneal adhesions and decrease in central corneal thickness in the (A and B) right and (C and D) left eyes. Postoperative external photography showing clearing of central corneal opacities in the (E) right and (F) left eyes.
Glaucoma in Peters anomaly is a difficult condition to manage given the intrinsic complexity of the disease. According to the Consensus Report of the World Glaucoma Association,4 glaucoma drainage implant surgery is usually attempted as the first-line surgical option for patients with moderate to severe disease.4 Many patients require multiple procedures to achieve intraocular pressure control.5
Although reducing intraocular pressure is paramount in patients with Peters anomaly who have increased intraocular pressure, it is similarly critical to establish a clear visual axis. Treatment of central corneal opacities in Peters anomaly has long been a subject of discussion. Despite the advances in corneal transplant surgery, penetrating keratoplasty within the first year of life remains a challenging procedure and has high rates of failure, ranging from 10% to 77%.6–10 Postoperative care is complicated by lack of patient cooperation and depends greatly on family support and access to care. Each repeat graft is more likely to fail than the previous graft.6
Optical sector iridectomy has been proposed as a safer procedure compared to penetrating keratoplasty in the effort to establish a clear visual axis in patients with a dense central corneal opacity and a clear lens.2,11,12 Broad optical iridectomy at the site of maximum corneal clarity may create an adequate visual axis without the complications associated with penetrating keratoplasty. In a retrospective case series of patients diagnosed as having Peters anomaly who underwent optical iridectomy, a red reflex was observed in 96.6% (28 of 29) of eyes, providing a clear visual axis for visual rehabilitation.2 Their mean follow-up time was 41.6 ± 43.8 months, with results showing improved vision in 72.4% (21 of 29) of eyes.2
With this background, we suggest there are several benefits from this novel “3 in 1” approach for patients with type 1 Peters anomaly who have glaucoma or suspected glaucoma. First, it strips the trabecular meshwork, which is likely the main cause of restricted outflow in this anterior segment dysgenesis. Second, it breaks the iridocorneal adhesions, allowing endothelial cells adjacent to the area of endothelial defect to enlarge and migrate to restore anatomic and functional integrity to the endothelial layer and hence improve corneal edema.13,14 Stripping of iridocorneal adhesions has been avoided in the past due to the concern of damaging surrounding endothelial cells. Recently, however, reports of cornea clearing with scraping of unhealthy endothelium to allow repopulation of the healthy cells without a graft replacement have been documented.15 Third, performing an optical iridectomy at the end of the procedure establishes a clear visual axis to promote visual pathway development. Finally, an advantage of this novel single combined approach is avoiding additional anesthesia events and therefore decreasing the overall risk to the patient.
Ab external trabeculotomy combined with optical sector iridectomy can achieve trabecular cleavage to improve aqueous outflow, release iridocorneal adhesions to improve corneal clarity, and establish a visual axis when central corneal opacity is present. Further studies are needed to compare this combined approach with the traditional, step-wise approach to assess long-term efficacy and safety.
- Ozeki H, Shirai S, Nozaki M, et al. Ocular and systemic features of Peters' anomaly. Graefes Arch Clin Exp Ophthalmol. 2000;238(10):833–839. doi:10.1007/s004170000177 [CrossRef]
- Suwannaraj S, Spierer O, Cavuoto KM, Chang T, Chang P, McKeown C. Outcome of optical iridectomy in Peters anomaly. J AAPOS. 2015;19(4):e64. doi:10.1016/j.jaapos.2015.07.206 [CrossRef]
- Rao KV, Fernandes M, Gangopadhyay N, Vemuganti GK, Krishnaiah S, Sangwan VS. Outcome of penetrating keratoplasty for Peters anomaly. Cornea. 2008;27(7):749–753. doi:10.1097/ICO.0b013e31816fe9a7 [CrossRef]
- Weinreb RN, Grajewski Al, Papadopoulos M, Grigg J, Freedman S, eds. Childhood Glaucoma, vol 9. Amsterdam: Kugler Publications; 2013.
- Yang LL, Lambert SR, Lynn MJ, Stulting RD. Surgical management of glaucoma in infants and children with Peters' anomaly: long-term structural and functional outcome. Ophthalmology. 2004;111(1):112–117. doi:10.1016/j.ophtha.2003.02.002 [CrossRef]
- Yang LL, Lambert SR, Lynn MJ, Stulting RD. Long-term results of corneal graft survival in infants and children with Peters anomaly. Ophthalmology. 1999;106(4):833–848. doi:10.1016/S0161-6420(99)90175-6 [CrossRef]
- Dana MR, Schaumberg DA, Moyes AL, et al. Corneal transplantation in children with Peters anomaly and mesenchymal dysgeneses. Ophthalmology. 1997;104(10):1580–1586. doi:10.1016/S0161-6420(97)30093-1 [CrossRef]
- Zaidman GW, Flanagan JK, Furey CC. Long-term visual prognosis in children after corneal transplant surgery for Peters anomaly type I. Am J Ophthalmol. 2007;144(1):104–108. doi:10.1016/j.ajo.2007.03.0581. [CrossRef]
- Limaiem R, Chebil A, Baba A, Youssef NB, Mghaieth F, El Matri L. Pediatric penetrating keratoplasty: indications and outcomes. Transplant Proc. 2011;43:649–651.
- Chang JW, Kim MK, Kim JH, Kim SJ, Wee WR, Yu YS. Long-term visual outcomes of penetrating keratoplasty for Peters anomaly. Graefes Arch Clin Exp Ophthalmol. 2013;251:953–958.
- Zaidman GW, Rabinowitz Y, Forstot SL. Optical iridectomy for corneal opacities in Peter's anomaly. J Cataract Refract Surg. 1998;24:719–722.
- Sundaresh K, Jethani J, Vijayalakshmi P. Optical iridectomy in children with corneal opacities. J AAPOS. 2008;12:163–165.
- Osigian CJ, Sayed MS, Kontadakis G, et al. Correlation between age and corneal edema in pediatric patients with Peters anomaly. Int Ophthalmol. 2019;39:2083–2088.
- Joyce NC. Cell cycle status in human corneal endothelium. Exp Eye Res. 2005;81:629–638.
- Soh YQ, Mehta JS. Selective endothelial removal for Peters anomaly. Cornea. 2018;37:382–385.