Contact Lens Management of Peters Anomaly
By Melanie Frogozo, OD
Peters anomaly is a sporadic congenital condition involving the anterior ocular segment. There are three categories of Peters anomaly: Type I is characterized by central corneal opacity with iridocorneal adhesions; Type II is characterized by a central corneal opacity with cataracts or corneolenticular adhesions; and Peters plus syndrome is characterized by Peters anomaly in association with cleft lip/palate, short stature, abnormal ears, and mental retardation (Zaidman et al, 2007). Causes include mutations in homeobox genes that control development of the eye such as the PAX6 gene (Bhandari et al, 2011). Visual deprivation secondary to Peters anomaly can result in sensory deprivation amblyopia. To avoid vision loss from amblyopia, Peters anomaly must be addressed within the first year of life and properly managed thereafter.
Children who have Peters anomaly type I may be candidates for penetrating keratoplasty (PK) (Bhandari et al, 2011); however, in the pediatric age group, this procedure is still considered high-risk because of the technical difficulties of the surgery, the risks associated with general anesthesia in infants, and the complex postoperative management. Due mainly to glaucoma, almost 50% of eyes lose all light perception despite aggressive surgical and postoperative care (Yang et al, 2009). Other treatments include peripheral iridectomy (Zaidman et al, 1998) and pupil dilation in cases in which the corneal opacity is not large (Bhandari et al, 2011). Another option is GP lenses. They can correct the irregular astigmatism caused by corneal changes in Peters anomaly and are a good option for visual rehabilitation in cases in which the corneal opacity is not too dense or after PK.
Consider a 12-year-old female who had a case of bilateral Peters anomaly with an additional history of short stature and bilateral hearing loss. The patient’s right eye had dense deprivation amblyopia from central corneal opacity and corneolenticular adhesions. At 8 months old, her left eye underwent PK. When she was 2 years old, her left eye was complicated by glaucoma that was surgically treated with trabeculectomy. She had uncorrected vision of 20/70 in her left eye until six months before presenting to clinic. At that time, her corneal transplant showed signs of corneal edema, thus degrading her vision to 20/200. The referring surgeon deferred PK treatment due to the high risk of failure. Fitting her into a corneal GP lens improved her vision to 20/60 OS.
Another example is a 13-year-old male who had unilateral Peters anomaly and a history of branchio-oculo-facial syndrome. He had glaucoma OS, but his pressure was controlled with topical ocular antihypertensive medication. The right eye had no ocular abnormalities and was corrected to 20/20, with a manifest refraction of –8.00 –2.00 x 180. The left eye had a central corneal opacity and an iris abnormality (Figure 1A); before GP optics, it was correctable only to 20/200, with a manifest refraction of –11.00 –1.50 x 180. With hybrid lenses in both eyes, he was corrected to 20/20 and 20/60 OD and OS, respectively (Figure 1B).
Figure 1. A patient who has Peters anomaly before (A) and after (B) correction with hybrid lenses.
While rare, Peters anomaly diminishes visual potential by affecting development of the anterior segment. Whether or not surgical intervention is required, GP lenses are a good option for correcting irregular astigmatism in cases of Peters anomaly. Best results occur when the corneal opacity is not dense and after PK.
Contact Lens Spectrum, Volume: 35, Issue: February 2020, page(s): 44
For references, please visit www.clspectrum.com/references and click on document #291.