Medical Care
Treatment of congenital corneal clouding or opacity is primarily surgical. After surgery, treatment of amblyopia and optical therapy are helpful.
The future holds new treatments for clouding of the cornea. An interesting mouse study found a cure for corneal defects in mice with mucopolysaccharidosis type VII with transplantation of umbilical stem cells of the mesenchymal type from humans. [28]
Surgical Care
For patients with bilateral and visually disabling corneal opacity, corneal transplantation or keratoplasty is recommended. To prevent amblyopia, the earlier the surgery is performed (generally prior to age 3-6 months), the better the results.
In patients with a dense unilateral opacity and a normal fellow eye, the decision to operate may be more difficult because, although the treatment is still surgical, the visual prognosis is guarded.
In children, keratoplasty is a high-risk transplantation. Indications for keratoplasty have increased with the improvement of surgical techniques and therapies. In children, keratoplasty allows for satisfying anatomical success but moderate visual improvement. Amblyopia is the major obstacle to success in children undergoing corneal grafting.
Surgical techniques for children differ from those used in adults because of the reduced ocular rigidity encountered in infants and young children. Use of a multispecialty team approach is important to improve the patient's visual outcome. Poor prognostic indicators include bilateral disease, concomitant infantile glaucoma, lensectomy and vitrectomy at the time of surgery, previous graft failure, extensive goniosynechiae, and extensive corneal vascularization. Prompt postoperative optical rehabilitation, combined with occlusion therapy when appropriate, is an important determinant of success. [29]
In 1 study, the overall success rate of graft clarity was 78% for children undergoing corneal transplantation for congenitally opaque corneas. [30] Best results were achieved in patients with posterior polymorphous dystrophy, followed by patients with Peters anomaly. Sclerocornea and congenital glaucoma were associated with a 50% likelihood of success, with repeated transplants needed in many of the eyes.
Al-Torbak performed simultaneous Ahmed glaucoma valve implantation and penetrating keratoplasty (PK) to manage refractory congenital glaucoma with corneal opacity. [31] Twenty eyes of 17 patients were studied.
The most common cause of glaucoma failure that required subsequent surgery was subconjunctival scarring, which resulted in loss of long-term IOP control. Main graft-related complications included failure (13 of 20 eyes) and graft ulceration (6 of 20 eyes). In 4 of 6 ulcerated grafts, Streptococcus pneumoniae was cultured.
Subsequent surgery was the only significant clinical factor associated with poor outcome of glaucoma. However, a low graft survival rate was significantly associated with delinquency of follow-ups, corneal ulcers, subsequent surgeries, and postoperative complications.
The long-term success of simultaneous Ahmed glaucoma valve implantation and PK in refractory congenital glaucoma associated with corneal opacity is low, and the complication rate is high.
Miller described an infant born with bilateral corneal clouding that was clinically diagnosed as congenital anterior staphyloma. [32] Peters anomaly was confirmed histopathologically and reflected one entity on the clinical spectrum of Peters anomaly. Miller detailed the patient's clinical course and histopathologic findings, as well as the unique surgical approach to corneoscleral grafting that was used to preserve the right globe. [32]
Primary combined trabeculotomy-trabeculectomy is a feasible surgical option in infants who have cloudy corneas at birth as a result of congenital glaucoma. The procedure was associated with a favorable visual outcome and a low rate of anesthetic complications in an Indian population. [33]
Frueh and Brown retrospectively assessed the prognosis and complications of corneal grafting in 58 infants and young children with congenital corneal opacities. [34] Preoperative diagnoses included sclerocornea (27 eyes), Peters anomaly (17 eyes), partial sclerocornea (12 eyes), and congenital glaucoma (2 eyes). PK was performed between age 5 days and 65 months with a mean follow-up of 40 months (standard deviation, 29). The overall success (including repeat grafts) was 70% for eyes with sclerocornea, 83% for those with partial sclerocornea, and 100% for those with Peters anomaly. However, 23 eyes had to be regrafted 2 weeks to 110 months after the first surgery.
The probability of maintaining a clear graft, calculated in survival analysis, was 75% (standard error, 6%) at 1 year and 58% (7%) at 2 years for the entire group. Complications included cataract development (12 eyes), secondary glaucoma (14 eyes), epithelial defects (6 eyes), band keratopathy (5 eyes), retinal detachment (3 eyes), wound leakage (2 eyes), retrocorneal membrane (1 eye), and microbial keratitis (2 eyes).
In patients with MPS, corneal transplantation does not permanently resolve the problem.
A 15-year-old male adolescent had Sly disease, a rare MPS caused by a deficiency of beta-glucuronidase and progressive bilateral corneal opacification. He received complete medical, genetic, and ophthalmic evaluation followed by PK. The cornea has remained clear for 2 years after surgery. Histopathology of the corneal button demonstrated vacuoles and granular inclusions consistent with this lysosomal storage disease.
For patients with a clear peripheral cornea, peripheral optical iridectomy may be performed.
Consultations
Consultations may include the following:
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Pediatrician - Thorough examination to rule out other systemic abnormalities
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Geneticist - Genetic counseling
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Vitreoretinal surgeon - Lensectomy and/or vitrectomy
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Cornea specialist - Keratoplasty
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Pediatric ophthalmologist – Amblyopia therapy
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Low-vision specialist - Management of poor vision, provision of optical aids
Complications
Complications of corneal transplantation vary (eg, failure, rejection, infection, secondary glaucoma).
Long-Term Monitoring
An ophthalmologist should provide regular follow-up eye care.
In addition, a pediatrician should monitor patients for other systemic anomalies.
Patients should receive visual rehabilitation as needed.
A pediatric contact lens specialist should fit patients with aphakic contact lenses.
Inpatient & Outpatient Medications
Medications may be indicated for treatment after corneal transplantation.
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Congenital stromal dystrophy. The cornea is particularly opaque in the anterior stroma by slit-lamp biomicroscopy. Courtesy of Wikipedia (© 2009 Klintworth; licensee BioMed Central Ltd).
