Anterior Segment Developmental Anomalies

Anterior Segment Developmental Anomalies



Microcornea is an uncommon congenital unilateral or bilateral condition. Inheritance is autosomal dominant or recessive.


• Infant horizontal corneal diameter less than 10 mm; adult horizontal corneal diameter less than 11 mm (Fig. 3-1)

• Shallow anterior chamber, angle-closure or open-angle glaucoma, corneal flattening, and hyperopia

• May have associated nanophthalmos (Table 3-1).

• Other ocular dimensions are normal.


• Varies depending on associated ocular and systemic abnormalities

FIGURE 3-1. Microcornea. This cornea measured 8.5 to 9.0 mm in diameter. Otherwise, the eye was essentially normal.

TABLE 3-1. Association of Microcornea


Systemic Syndromes

  • Anterior segment dysgeneses

  • Congenital cataract

  • Congenital glaucoma

  • Corneal leukoma

  • Cornea plana

  • Hyperopia

  • Microphakia

  • Uveal coloboma

  • Cornelia de Lange

  • Ehlers-Danlos

  • Nance-Horan

  • Trisomies 13, 18, 21

  • Turner

  • Waardenburg

  • Weill-Marchesani


Megalocornea is an uncommon congenital bilateral condition that is usually inherited in an X-linked recessive manner and is therefore found mostly in males.


• Clear cornea with a horizontal diameter of greater than 12 mm in the neonate and 13 mm in adults (Fig. 3-2, eFig. 3-2)

• Very deep anterior chamber

• Normal intraocular pressure

• Corneal steepening, high myopia, and astigmatism, but good visual acuity

• Lens subluxation may occur as a result of zonular stretching.

• May develop glaucoma secondary to angle abnormalities


• Generally good, but depends on associated ocular and systemic abnormalities (Table 3-2)

FIGURE 3-2. Megalocornea. This cornea measured 14 mm in diameter. The cornea is clear except for some calcific degeneration nasally and temporally.

TABLE 3-2. Associations of Megalocornea


Systemic Syndromes

  • Astigmatism

  • Axenfeld-Rieger

  • Cataract

  • Congenital glaucoma

  • Ectopia lentis

  • Myopia

  • Albinism

  • Alport

  • Apert

  • Craniosynostosis

  • Down

  • Ehlers-Danlos

  • Marfan

  • Osteogenesis imperfecta

  • Progressive facial hemiatrophy


Nanophthalmos is an uncommon congenital bilateral condition in which the globe has reduced volume but is otherwise grossly normal.


• Very high hyperopia (e.g., + 12D to + 15D)

• Adult corneal diameter is reduced, but the lens has a normal volume.

• Short axial length (e.g., 16 to 18 mm)

• Shallow anterior chamber

• Thick sclera

• Fundus may show a crowded disc, vascular tortuosity, and macular hypoplasia.

Associated Problems

• Angle-closure glaucoma

• Uveal effusion

• Retinal detachment

• Poorly tolerated intraocular surgery


Microphthalmos is an uncommon unilateral or bilateral condition in which the axial length of the eye is reduced and the eye is malformed (Fig. 3-3). The effects on vision depend on its severity and the presence of associated anomalies. There are two types of microphthalmos: noncolobomatous and colobomatous (Table 3-3).

FIGURE 3-3. Microphthalmos. This microphthalmic eye has a small cornea, abnormal iris, and overall small size. (Courtesy of Peter Laibson, MD.)

TABLE 3-3. Types of Microphthalmos





  • Sporadic

  • Inherited (dominant, recessive, X-linked recessive)

  • Sporadic

  • Inherited (dominant)

With anterior persistent hyperplastic primary vitreous

With systemic syndromes:

  • Patau (trisomy 13)

  • Edward (trisomy 18)

  • Cat-eye (partial trisomy 22)

Intrauterine infections (rubella, toxoplasmosis, cytomegalovirus, varicella)


  • Meckel

  • Lenz microphthalmia

CHARGE syndrome is coloboma, heart anomaly, choanal atresia, retardation, and genital or ear anomalies.


Buphthalmos is an uncommon, usually bilateral condition in which the globe is enlarged as a result of stretching of the cornea and sclera because of increased intraocular pressure before birth or during the first few years of life.


• Large cornea with variable scarring; may develop corneal edema later in life

• Horizontal or curvilinear ruptures in Descemet membrane (Haab striae) (Fig. 3-4, eFig. 3-4A and B)

• Very deep anterior chamber

• Angle anomalies

• Myopia

• Optic disc cupping

Associations of Infantile Glaucoma

• Ocular

▪ Aniridia

▪ Anterior segment dysgeneses

▪ Congenital ectropion uveae

• Systemic

▪ Down syndrome

▪ Lowe syndrome

▪ Mucopolysaccharidoses

▪ Neurofibromatosis type I

▪ Nevus of Ota

▪ Patau syndrome (trisomy 13)

▪ Pierre Robin syndrome

▪ Rieger syndrome

▪ Sturge-Weber syndrome


• Guarded, depending on amount of optic nerve damage prior to diagnosis, efficacy of treatment, and associated ocular and systemic disorders. Haab striae of the cornea do not prevent good vision.

FIGURE 3-4. Haab striae. A. These breaks in Descemet membrane occurred secondary to congenital glaucoma. Note the multiple parallel swirling lines, which are rolled-up edges of Descemet membrane. B. Multiple parallel swirling lines are evident in this eye with congenital glaucoma.

Oct 13, 2019 | Posted by in OPHTHALMOLOGY | Comments Off on Anterior Segment Developmental Anomalies

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