This article is more than 5 years old. Information may no longer be current.
Staining shows nerve morphology in keratoconic corneas
Am J Ophthalmol. 2011;152(3):364-376
Click Here to Manage Email Alerts
Biomicroscopic imaging and staining showed that corneal nerve morphology may play a key role in the pathogenesis and progression of keratoconus, a study found.
"Recent advances in corneal in vivo confocal imaging have provided new and interesting data on the microstructural alterations of the corneal tissue in keratoconus," the study authors said.
The prospective study included 14 corneal buttons from 14 patients with keratoconus (mean age: 34.3 years). A control group comprised six buttons from three deceased patients with normal corneas (mean age: 57.3 years).
All corneal buttons underwent acetylcholinesterase staining and digital biomicroscopy. An oil staining technique was used to examine the basal epithelial layer-Bowman zone interface. Additional image processing was performed with Adobe Photoshop CS4.
Nerve changes were seen in 10 of 14 keratoconic corneas (71%). Mean central stromal nerve thickness was 18.9 µm in keratoconic corneas and 8.11 µm in controls; the between-group difference was statistically significant (P < .001).
Eight patients with abnormal stromal nerves had clinical evidence of central scarring. Two of four patients with normal stromal nerves had central scarring.
Peripheral stromal nerve thickness was 12.6 µm in keratoconic corneas and 14.86 µm in controls. The difference was statistically insignificant. Mean diameter of subbasal nerves was 4.11 µm in keratoconic corneas and 4 µm in controls. The difference was statistically insignificant, the authors said.
Keratoconus is a hot topic currently. The options for treatment have dramatically changed over the past 5 years. We have increased use of deep anterior lamellar keratoplasty, with lesser risk of endothelial rejection, yet with much higher demand for technical excellence during the surgical procedure. We have increased use of intrastromal ring segments to try to change the corneal shape and prevent transplants in patients with contact lens intolerant keratoconus. This article provides a better understanding of the abnormalities in corneal nerves in keratoconus. Information about the changes that occur in the structural and biochemical nature of the cornea will be helpful in optimizing preventative therapies as we move more from corrective to preventative therapies over the next several years. It will be interesting to see what happens in the structural and biochemical nature of the tissue with therapies such as collagen cross-linking, or collagen shrinkage procedures.
– David R. Hardten, MD
OSN
Cornea/External Disease Section Editor
Disclosure: Dr. Hardten has no
relevant financial disclosures.