Hereditary anomaly in which scleralization involves either the peripheral cornea or entire cornea.
Non progressive, bilateral, asymmetric.
The opacification of cornea is smooth, white and vascularised.
It is an extension of sclera without limbal landmarks and is greater peripherally than centrally.
Vessels are fine continuations of conjunctival vessels.
Waring & Rodrigues classification:
1) Isolated peripheral Sclerocornea
Abrupt change from sclera tissue to clear corneal tissue with no other ocular abnormality
2) Sclerocornea plana
Flat corneas having K reading <38 D causing high hyperopia
AC is shallow
Pseudoptosis present due to flat cornea supporting the upper eyelid poorly
3) Sclerocornea associated with anterior chamber cleavage anomalies:
Has paracentral corneal adhesions. Eg. Peter’s anomaly
4) Total sclerocornea
Corneas are totally opaque and vascularised.
Central cornea is not as densely opaque as peripheral cornea. The opacification affects the full thickness of the stroma
Histopathologically, corneal stroma resembles sclera. Stromal vascularisation present.
Precisely arranged stromal lamellar absent.
Histopathology
Vascularised stroma consists of irregularly arranged collagen lamellae.
Collagen lamellae have variable diameter- increased anteriorly and decreased posteriorly (the reverse is true for normal cornea).
Diagnosis
UBM: for diagnosis of sclerocornea, associated structural abnormalities, to help in surgical planning.
Differential Diagnosis
Arcus juvenilis. Interstitial keratitis. Peter’s anomaly. Microcornea.
Management:
Neutralise refractive errors if any.
If disorder is unilateral and other eye has good visual acuity: Surgery performed only if other ocular structures are relatively normal.
If central corneas are affected bilaterally: Penetrating Keratoplasty.
Art by @mahuness
#cornea #ocularsurface #sclerocornea
