The cornea's layers
The cornea has five layers, and disease tends to affect one of them. The epithelium is the surface skin, renewed every week, where erosions, abrasions and most infections start. Bowman's layer and the stroma make up the bulk of the cornea and give it strength and clarity; keratoconus, scarring and stromal dystrophies live here. Descemet's membrane and the endothelium form the inner lining, a single layer of cells that pumps fluid out of the cornea to keep it clear; Fuchs dystrophy and endothelial damage cause swelling and haze.
The main groups of corneal disease
- Infections: bacterial, viral (herpes simplex and zoster), fungal and amoebic keratitis, often in contact lens wearers. Urgent, treated with intensive drops
- Ectasia: keratoconus and related thinning disorders that steepen the cornea. Treated with cross-linking and specialty lenses
- Dystrophies: inherited conditions such as Fuchs endothelial dystrophy and map-dot-fingerprint dystrophy. Managed medically, with surgery for advanced cases
- Scarring: from injury, infection or inflammation. Managed with lenses, surface treatments or, rarely, transplantation
- Surface disorders: recurrent erosion, neurotrophic keratitis, severe dry eye and exposure. Treated with drops, plugs, bandage lenses, serum tears and scleral lenses
- Growths: pterygium and pinguecula, from sun and wind exposure. Removed surgically when they threaten vision
Symptoms that should be seen promptly
A painful red eye with light sensitivity, particularly in a contact lens wearer, can be an infection that damages the cornea within days, so call us right away at (855) 456-2253 and say it is urgent. Sudden blurring with a white spot on the cornea, a foreign body sensation after injury, or a sharp pain on waking that recurs are all reasons to be examined sooner rather than later.
How corneal disease is diagnosed
The slit lamp shows the cornea layer by layer under magnification, with dyes to highlight surface defects. Corneal topography and tomography map its shape and thickness, which is how keratoconus is detected before it is visible. Anterior segment optical coherence tomography images the layers in cross section. Specular microscopy counts the endothelial cells. Cultures identify the organism in an infection. Together these tell the specialist which layer is affected and why, which decides the treatment.
Treatment
Most corneal disease is treated medically: antibiotics, antivirals or antifungals for infection; lubricants, anti-inflammatories and serum tears for surface disease; hypertonic drops for early Fuchs. Specialty contact lenses restore vision over an irregular or scarred cornea. Cross-linking halts keratoconus. Surgery, from superficial keratectomy to pterygium excision to the various forms of corneal transplantation, is reserved for cases that medicine and lenses cannot manage; our cornea specialist evaluates each case and discusses whether surgery is appropriate. Dr. Youssefzadeh personally performs corneal transplant surgery.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is what is affecting your vision is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
