Meyahealth
HomeGeneticsConditionPeters anomaly
Back to Condition
Peters anomaly
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Condition

Peters anomaly

Peters anomaly is a rare eye condition characterized by abnormal development of the anterior segment, often resulting in corneal clouding and vision impairment.

Overview

Peters anomaly is characterized by eye problems that occur in an area at the front part of the eye known as the anterior segment. The anterior segment consists of structures including the lens, the colored part (iris) of the eye, and the clear covering of the eye (cornea). In Peters anomaly, development of the anterior segment is abnormal, leading to incomplete separation of the cornea from the iris or the lens. As a result, the cornea is cloudy (opaque), which causes blurred vision.

Nearly half of the individuals affected with Peters anomaly have low vision early in life and about a quarter are legally blind. Due to a lack of visual stimulation, some individuals develop "lazy eye" (amblyopia). Peters anomaly is often associated with other eye problems, such as increased pressure within the eye (glaucoma), clouding of the lens (cataract), and unusually small eyeballs (microphthalmia). In most cases, Peters anomaly is bilateral, affecting both eyes, though the level of vision impairment may differ. These individuals may have eyes that do not point in the same direction (strabismus).

Types

  • Type I: Characterized by an incomplete separation of the cornea and iris and mild to moderate corneal opacity.
  • Type II: Characterized by an incomplete separation of the cornea and lens and severe corneal opacity that may involve the entire cornea.

Frequency

The exact prevalence of Peters anomaly is unknown. This condition is one of a group of disorders known as congenital corneal opacities, which affect 3 to 6 individuals per 100,000.

Causes

Mutations in the FOXC1, PAX6, PITX2, or CYP1B1 gene can cause Peters anomaly. The FOXC1, PAX6, and PITX2 genes are members of a family called homeobox genes that direct the formation of many parts of the body and are involved in the development of the anterior segment of the eye. The CYP1B1 gene provides instructions for making an enzyme that is active in many tissues, including the eye.

Mutations in any of these four genes disrupt development of the anterior segment of the eye. In many cases of Peters anomaly, there is no mutation identified in any of these four genes, and the cause remains unknown.

Inheritance

Most cases of Peters anomaly are sporadic, occurring in people with no apparent history of the disorder in their family. When caused by mutations in the CYP1B1 gene, it follows an autosomal recessive pattern of inheritance. When caused by mutations in the FOXC1, PAX6, or PITX2 gene, the condition follows an autosomal dominant pattern of inheritance.

Frequently Asked Questions

Glaucoma develops in up to 30‑50 % of affected eyes due to angle maldevelopment. Monitor intra‑ocular pressure (IOP) at each clinic visit using handheld tonometry, assess optic nerve cupping with fundus photography or OCT, and watch for corneal enlargement. Early medical therapy (beta‑blockers, prostaglandin analogues) is started when IOP rises, and surgical intervention (goniotomy, trabeculectomy) is considered if pressure remains uncontrolled.
Initiate aggressive visual rehabilitation as soon as the cornea clears enough for light perception. This includes prescribing appropriate refractive correction, patching the better‑seeing eye for several hours daily to stimulate the affected eye, using low‑vision aids (magnifiers, high‑contrast toys), and enrolling in early‑intervention vision therapy. Regular follow‑up with a pediatric ophthalmologist ensures timely adjustments to the treatment plan.
Penetrating or lamellar keratoplasty is usually considered after the visual axis is cleared, often between 12 months and 3 years of age, once the eye is large enough to accept a graft. Graft survival rates vary (≈50‑70 % at 5 years) and are lower if glaucoma or persistent inflammation is present. Multiple surgeries may be needed, and visual rehabilitation remains essential after graft placement.
Diagnosis begins with a detailed eye examination showing a central corneal opacity. Confirmatory tests include slit‑lamp biomicroscopy, anterior‑segment optical coherence tomography (OCT) or B‑scan ultrasonography to assess cornea‑iris or cornea‑lens adhesions, and ocular ultrasound to evaluate lens position and globe size. Genetic testing (e.g., sequencing of PAX6, PITX2, or other associated genes) may be offered, especially if systemic anomalies are present.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ