Epithelial basement membrane degeneration (EBMD) previously was classified as a type of corneal dystrophy. It historically was referred to as epithelial basement membrane dystrophy and also is known as map-dot-fingerprint dystrophy.[1] This name comes from the distinctive appearance observed in its characteristic slit-lamp findings. Other past names include Cogan microcystic epithelial dystrophy and anterior basement membrane dystrophy.[2, 3, 4, 5, 6]
Epithelial basement membrane degeneration is much more common than any corneal dystrophy. Unlike corneal dystrophies, epithelial basement membrane degeneration is sporadic, not hereditary, and is variable and fluctuating in its course rather than progressive.[7] It usually is bilateral, but can be unilateral or very asymmetric in presentation.[8]
Corneal dystrophies usually are described as hereditary, progressive, bilateral, and not associated with systemic or local disease.[9] The International Committee for Classification of Corneal Diseases (IC3D) classifies corneal dystrophies partly by anatomic layer of corneal involvement, but increasingly on a genetic basis. In the updated 2024 IC3D 3rd edition, the historical nomenclature epithelial basement membrane dystrophy is retained but noted to be "most likely degenerative and not hereditary."[9] It remains included as a class 3 dystrophy based on one report of two families with a presumed autosomal-dominant pattern attributed to the TGFBI gene, locus 5q31.[10, 11, 12, 13] ("Class 3: a well-defined corneal dystrophy in which the disorder has not yet been mapped to a chromosomal locus.")[9]
The corneal epithelium produces and adheres to its underlying basement membrane. Corneal abnormalities associated with epithelial basement membrane degeneration are the result of a faulty basement membrane, which is thickened, multilaminar, and misdirected into the epithelium.[3, 8, 14] Deeper epithelial cells that normally migrate to the surface can become trapped. Epithelial cells anterior to aberrant basement membrane may have difficulty forming viable hemidesmosomes and basement membrane complexes, which attach to the underlying stroma, resulting in recurrent erosions. Irregular epithelium centrally can cause decreased vision.
Misdirected and reduplicated basement membrane into the epithelium in parallel or concentric rows may on slit lamp view appear as fingerprints. Sheetlike arrangements of intraepithelial multilamellar basement membrane may appear as maps or map outlines. Trapped epithelial cells may degenerate into microcysts containing cellular debris and apppear as dots or irregular grey-white patches. Small mounds of abnormal fibrillogranular material or thickened basement membrane located between the epithelium and Bowman layer may appear as blebs best seen in retroillumination.[15]
Estimates of the prevalence of EBMD from 2% to 43% of the general population.[16] Of patients with EBMD, 10% to 33% have recurrent corneal erosions. As many as 50% of patients with recurrent corneal erosions have EBMD.[17, 18, 19, 20]
Mortality/Morbidity
Patients with EBMD may be asymptomatic. Others experience painful recurrent erosions, decreased vision, or both.[20]
Sex
This condition is slightly more common in females than in males.
Epithelial basement membrane degeneration findings may fluctuate but tend not to progress over time. Most patients are able to maintain sufficient vision and comfort for reading, driving, and other visual tasks, except during episodes of corneal erosions.[20] Most patients with visually disabling symptoms can be successfully treated with mechanical or laser keratectomy, or rigid contact lenses including scleral lenses.
Patients with EBMD should be informed that refractions and best spectacle corrected vision may vary from visit to visit and even day to day, due to fluctuations in epithelilal and basement membrane involvement.
Most patients with epithelial basement membrane degeneration (EBMD) are asymptomatic.
The past eye history may be positive for recurrent corneal erosions.[20]
Visual symptoms usually are mild and occasionally debilitating. Vision is variable and fluctuating due to migratory and intermittent corneal involvement. Refractions often are unstable and are not the fault of the doctor or the patient. Visual complaints include the following:
Visual acuity among patients with EBMD ranges from 20/15 to 20/200.
Refraction may have an uncertain endpoint due to irregular astigmatism.
On slit lamp examination, pathology is at the epithelial and basement membrane levels. Areas of pathology often are identified best by broad-beam illumination, fluorescein with cobalt blue light (to identify areas of negative staining), or retroillumination following dilation. Slit lamp findings include the following:
The corneal maps in EBMD are irregular geographic shaped, faint gray-white patches that may contain clear oval areas. They vary greatly in size (usually 1 mm to several mm) and are seen best with broad oblique illumination.
The corneal dots in EBMD are gray-white, puttylike opacities, which can be round, comma-shaped, or irregular. They usually are 0.05-1 mm in size.
The corneal fingerprints in EBMD are clusters of contoured concentric lines, 0.25-4 mm in length. They are seen best with retroillumination.
Corneal blebs are clear, round, bubblelike defects, 0.05-0.2 mm in diameter. They are seen best with retroillumination. See the images below.
View Image
Corneal maps. Best seen with broad illumination beam.
View Image
Corneal dots. Cluster of corneal dots.
View Image
Corneal fingerprints and maps.
Keratometry or computerized topography can be used to check for irregular astigmatism. A Placido disk or keratometer often demonstrates irregularity better than computerized topography.
Computerized topography (CT) can identify irregular corneal astigmatism. Optical CT and confocal microscopy can document epithelial thickening and structural changes and assist in diagnosis of EBMD.[22]
Numerous treatment options are available, and like epithelial basement membrane degeneration (EBMD) itself, results are variable and differ from patient to patient.[23]
Hypertonic drops or ointment often are the first line of treatment. They may help both irregular astigmatism and recurrent corneal erosion problems. Sodium chloride (5%) drops at breakfast, lunch, and supper, and ointment at bedtime are recommended.
Nonhypertonic lubricating drops or ointment may be used; the only prospective study detected no difference in the results of bland versus hypertonic lubricating treatment.[24]
Consider patching for acute episodes of associated corneal erosions.[20] Bandage extended-wear soft contact lenses may be useful, especially for comfort, but with increased risk for infectious keratitis.
Rigid corneal contact lenses may improve vision by masking corneal irregular astigmatism, but they are often poorly tolerated because of increased corneal fragility/erosion problems. Scleral contact lenses may be a more attractive option as they are supported by the conjunctiva and vault over the fragile corneal epithelium.
Indications for surgical treatment of EBMD include decreased vision or discomfort (including recurrent corneal erosion syndrome) that does not respond to medical treatment as outlined above. Another common indication for surgical treatment is the need for a smooth and stable corneal surface prior to undergoing cataract surgery to maximize intraocular lens calculation accuracy.[25, 26]
Debridement/superficial keratectomy is preferred by this author, both for significant visual loss from associated irregular astigmatism and recurrent corneal erosions, if treatment with hypertonic drops and ointment fails.[20] Combined debridement and superficial keratectomy can be completed easily in the office setting, at the slit lamp, using topical proparacaine or a similar anesthetic drop or gel. Place a lid speculum, then debride (with a rather blunt Kimura spatula) the entire extent of any loosely adherent epithelium or basement membrane level opacities. With sweeping and pushing motions, using the trailing or leading edges of the instrument, keeping nearly parallel to the corneal plane, redundant basement membrane level material can be massaged away, while maintaining the integrity of the Bowman layer.[27, 28] Take care to avoid cutting into Bowman layer or stroma.
Diamond burr superficial keratectomy is very useful for recurrent erosions associated with epithelial basement membrane degeneration that does not respond to keratectomy with a Kimura spatula.[20] Following epithelial debridement, a 4- or 5-mm diameter diamond-dusted burr very gently is used to polish the basement membrane throughout the area of epithelial debridement.[29, 30]
Excimer laser phototherapeutic keratectomy is an alternative treatment for visual disturbances or recurrent corneal erosions associated with EBMD, with results similar to the above-described superficial keratectomy procedures (but much more expensive in most settings). Approximately 80% of eyes improve following PTK; the probability of being recurrance free 5 years following successful treatment for visual disturbances is 83%, and for recurrent erosions 88%.[17, 25, 26] Ablation should not extend more than 10 micrometers beyond the debrided epithelium, as an undesired hyperopic shift can occur.[31, 32, 33, 34]
Corneal anterior stromal needle puncture is useful for recurrent corneal erosions from trauma that recur in the same location.[35] This procedure is not as successful for recurrent erosions associated with epithelial basement membrane degeneraration, which is usually more diffuse and often migratory.
Epithelilal basement membrane degeneration is a significant contraindication to laser in situ keratomileusis (LASIK) surgery owing to poorly adherent epithelium predisposing to epithelial defects, interface epithelial ingrowth, and increased risk for flap keratolysis and corneal scarring.[36, 37, 38] For patients undergoing refractive surgery, photorefractive keratectomy (PRK) is a better choice than LASIK.
David D Verdier, MD, Clinical Professor, Department of Surgery, Division of Ophthalmology, Michigan State University College of Human Medicine
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Christopher J Rapuano, MD, Professor, Department of Ophthalmology, Sidney Kimmel Medical College of Thomas Jefferson University; Director of the Cornea Service, Wills Eye Hospital
Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: AAO; OMIC; American Society of Ophthalmic Trauma (ASOT)<br/>Received income in an amount equal to or greater than $250 from: AAO; OMIC.
Chief Editor
Hampton Roy, Sr, MD, † Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Disclosure: Nothing to disclose.
Additional Contributors
Fernando H Murillo-Lopez, MD, Senior Surgeon, Unidad Privada de Oftalmologia CEMES
McKusick, VA. Corneal dystrophy, epithelial basement membrane; EBMD. Online Mendelian Inheritance in Man. Available at https://www.omim.org/entry/121820. September 17, 2015; Accessed: January 6, 2025.
Guerry D III. Fingerprint-like lines in the cornea. Am J Ophthalmol. 1950. 33:724-726.
El Sanharawi M, Sandali O, Basli E, et al. Fourier-domain optical coherence tomography imaging in corneal epithelial basement membrane dystrophy: A structural analysis. Am J Ophthalmol. 2015. 159:755-763.
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