A study pointing to the possible role of corneal nerves in diseases processes affecting the cornea has been published in the American Journal of Ophthalmology this month. The research paper was led by Professor Harminder S Dua, Head of the Division of Ophthalmology at the School of Clinical Sciences.
Keratoconus is a condition where the cornea, the transparent window of the front of the eye, becomes conical in shape instead of being nice and round (spherical). The cornea is the main focusing lens of the eye. When its shape changes, light rays are focused irregularly and vision drops. The condition usually affects young individuals but the exact mechanism by which it occurs is unknown. Most individuals can be managed with special contact lenses. A proportion (10-15%) need corneal transplant surgery.
Different previous studies have looked at the structure of the cornea to understand the condition. The corneal nerves were not looked at. In specimen obtained after corneal transplantation, the authors were able to examine in detail the nerves using a special staining technique and a special microscope called the nanozoomer digital pathology microscope. They found that the corneal nerves are very disorganised, showing thickening, coiling, looping, loss of normal alignment, irregularity and aberrant re-generation, which vary according to the stage of the disease.
The findings are novel and build on the authors' recently published work, 'Normal micro-architecture of human corneal nerves' in the British Journal of Ophthalmology, and 'Other abnormalities of nerves in chronic corneal edema' in the American Journal of Ophthalmology. The latest results indicate that the nerves are not passive bystanders but participate dynamically in diseases processes affecting the cornea. This is a novel concept and a direct result of the research in our laboratory.
Reference:
"The Morphologic Characteristics of Corneal Nerves in Advanced Keratoconus as Evaluated by Acetylcholinesterase Technique", American Journal of Ophthalmology; Volume 152, Issue 3, September 2011, Pages 364-376.e1 (doi:10.1016/j.ajo.2011.03.006)
Posted on Monday 12th September 2011