Contents

Cornea plana 1

Medical condition

Cornea plana 1
Other names	Autosomal Dominant Cornea Plana, CNA1.
Cornea plana 1 is inherited in an autosomal dominant manner.
Specialty	Ophthalmology

Cornea plana 1 (CNA1) is a congenital disorder that causes the cornea to flatten and the angle between the sclera and cornea to shrink.^[1] This could result in the early development of arcus lipoides, hazy corneal limbus, and hyperopia.^[2] Cornea plana 1 is an autosomal dominant disorder.^[3]

Signs and symptoms[edit]

Cornea plana commonly presents as a flat cornea, early-onset arcus lipoides, low anterior chamber depth, and an indistinct border between the sclera and cornea due to a decreased angle between the two.^[2] Although a small corneal diameter is anticipated, measuring it can be challenging because the scleral tissue overlaps the cornea by a few millimeters. In the patients who have been described, the anterior chamber depth has been found to vary from 0.8 to 2.1 mm.^[3]

Moreover, high hyperopia, strabismus, microcornea, posterior embryotoxon, iridocorneal adhesions, iris lumps, iris wasting, and pupillary abnormalities can all be present.^[4] Instead of hyperopia, myopia has been identified in a few cases.^[5] As many as 90 percent of cases have a bilateral presentation, which is linked to sclerocornea.^[1] Finally, congenital ptosis has also been reported, and the absence of corneal protrusion is most likely the cause.^[3]

Diagnosis[edit]

Clinical presentation, keratometry,^[5] pachymetry, and endothelial imaging are used to make the diagnosis.^[6]

Since the decreased refraction in the autosomal recessive form is more severe than in the autosomal dominant form, corneal refraction measurements can be used to differentiate between CNA1 and CNA2.^[3]

Histology is distinguished by acanthosis, keratinization of the corneal epithelium, Bowman's membrane defects, and stromal vascularization and scar formation.^[7]

See also[edit]

• Cornea plana 2
• Keratoglobus

References[edit]

Further reading[edit]

• Khan, Arif O. (2012). "Cornea Plana". Genetic Diseases of the Eye. Oxford University Press. pp. 85–91. doi:10.1093/med/9780195326147.003.0006. ISBN 978-0-19-532614-7.
• Coleman, Michael (2018). "Cornea Plana". Encyclopedia of Ophthalmology. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 513–514. doi:10.1007/978-3-540-69000-9_779. ISBN 978-3-540-68292-9.

External links[edit]

• The University of Arizona
• EyeWiki