What Is Congenital Ectropion Uveae?
Congenital ectropion uveae (CEU), also known as congenital iris ectropion syndrome or primary iris pigment epithelial hyperplasia, is a rare condition with unilateral anterior chamber dysgenesis (abnormal organ growth during the embryonic stage) that frequently causes unilateral secondary glaucoma by the middle of adolescence and is accompanied by morbidity and the potential for blindness. Ectropion uveae, which has been present since birth, and glaucoma as a result of Schlemm's canal dysgenesis and trabecular meshwork are its defining features.
What Causes Congenital Ectropion Uveae?
Ectropion uveae can be isolated into two fundamental classifications: acquired and congenital. The distinctions depend fundamentally on the etiology of ectropion. Congenital ectropion is less frequent than acquired ectropion, which is linked to tractional forces brought on by a fibrovascular membrane that has spread across the anterior portion of the iris. The posterior pigmented iris epithelium is pulled toward the anterior eye surface as this membrane contracts. The most common causes of this fibrovascular membrane (also known as neovascularization of the iris) are proliferative diabetic retinopathy and central retinal vein blockage. Less frequently occurring causes include inflammatory, neoplastic, or ischemic processes involving the iris. Congenital ectropion, on the other hand, is believed to be the result of the anterior chamber's primordial endothelium failing to regress. Acquired ectropion typically progresses unless the underlying cause is properly treated, whereas congenital ectropion frequently does not.
What Are the Risk Factors of Congenital Ectropion Uveae?
CEU does not have a particular genetic inheritance and is most often unrelated to a systemic condition. Nonetheless, NF-1(Neurofibromatosis-1) and other more uncommon disorders (facial hemihypertrophy, Prader-Willi condition) have been accounted to have a relationship with CEU.
What Is the Role of Family History in Congenital Ectropion Uveae?
A detailed family history should be taken to rule out any potential related systemic syndromes such as NF-1 (neurofibromatosis-1). It may be possible to clarify a history of anisocoria, which is frequently observed in infancy or early childhood. A close examination of old photos can show how subtle anisocoria has existed for a very long time. The classic triad of epiphora (excessive tearing), photophobia (eye irritation with light), and blepharospasm (uncontrolled eye movement) linked with congenital glaucoma are frequently absent due to the later onset of glaucoma. Some people may show late signs of elevated intraocular pressure or secondary glaucoma, including headaches, blurred vision, or eye pain.
How to Clinically Diagnose Congenital Ectropion Uveae?
Although bilateral cases have been reported, unilateral CEU presentations are the most common. A glassy, smooth, cryptless iris surface, iris stromal atrophy, an overgrowth of iris pigment epithelium on the anterior surface of the iris, and glaucoma are typical clinical observations. Although the pupil is usually round and responsive to light, the abnormal iris pigment epithelium can cause it to superficially look irregular. Additionally, with regular levator function, a mild case of ptosis may be seen in the affected eye. This is probably connected to Müller's muscle's neural crest genesis. An anterior iris insertion that can almost reach Schwalbe's line (but there should be no PAS or peripheral anterior synechia or other pathology that extends past) is one of the gonioscopic observations of CEU that is most frequently observed. Although it typically happens later in life and is frequently identified in late childhood or early adolescence, secondary glaucoma is a very common complication of CEU. Clinical results typically show a significantly asymmetric cup-to-disc ratio in the affected eye when compared to the unaffected eye. The most frequent cause of this is a marked rise in intraocular pressure (IOP) in the afflicted eye. An elevated or anterior iris insertion can be seen during gonioscopy and has been described as almost reaching Schwalbe's line.
What Is the Treatment for Congenital Ectropion Uveae?
Beta-blockers, carbonic anhydrase inhibitors (CAIs), and prostaglandin analogs are examples of topical IOP-lowering drugs that are suitable for toddlers. Although Brimonidine is not recommended for use in children under the age of two due to potential respiratory and central nervous system side effects, alpha-2 agonists help lower IOP. Therefore, until the child is about eight years old, these substances should be avoided. Apraclonidine has a high incidence of tachyphylaxis and allergy in young infants, but it can be helpful for short-term IOP reduction. In babies and young children, Apraclonidine can also cause somnolence and respiratory depression, though this is less common.
What Is the Surgical Treatment for Congenital Ectropion Uveae?
Similar to PCG, surgical management is mainly necessary for glaucoma in children with CEU. Due to severe angle dysgenesis in CEU, the surgical option is distinct from PCG. Goniotomy in CEU, therefore, has a significantly reduced success rate than in PCG. The most common method of controlling IOP is glaucoma filtration surgery, either with or without antimetabolites.
Three patients received six goniotomies in a case series of goniotomies in CEU by Dowling et al., and even with adjunctive medication, the IOP was insufficiently controlled. Seven out of nine patients in the same case report needed trabeculectomy.
There are no follow-up data on treatment success rates in CEU-associated glaucoma due to the rarity of this condition. The outcomes for other juvenile secondary glaucomas should, however, be comparable to these. In those circumstances, trabeculectomy alone has a long-term efficacy rate of 30 to 35 %. The procedural success rate rises to 52 to 95 % when supplemental Mitomycin C (MMC) is used, with a success rate of 60 % after two years.
Glaucoma drainage systems have a success rate of 44 to 95 percent, with 60 to 65 percent success at two years, which is comparable to trabeculectomy with MMC. To keep IOP under control, however, adjunctive medical treatment is frequently required. Cyclodestructive treatments may be required in refractory cases, but they can be risky and have a low chance of success.
Conclusion:
Congenital ectropian uvea is a condition in rare congenital disorder. This condition causes glaucoma in adolescents and teenagers. If left unattended, this condition could lead to blindness also. Early care and diagnosis can help in managing this condition better. Hence periodic eye check-ups can help in diagnosing early and managing better.
