Corneal map-dot-fingerprint dystrophy is by far the most common corneal dystrophy and is named for the appearance of its characteristic slit-lamp findings. Map-dot-fingerprint dystrophy is also known as epithelial basement membrane dystrophy, anterior basement membrane dystrophy, and Cogan microcystic epithelial dystrophy.[1, 2, 3, 4, 5]
Historically, corneal dystrophies are usually described as hereditary, bilateral, progressive, and not associated with systemic or local disease. However, in most cases, map-dot-fingerprint dystrophy is sporadic and may be a degenerative rather than familial condition.[6] Map-dot-fingerprint dystrophy is also not progressive but rather variable and fluctuating in its course. Map-dot-fingerprint dystrophy is usually bilateral, but it can be unilateral or very asymmetric in presentation.[7]
According to the International Committee for Classification of Corneal Diseases (IC3D), corneal dystrophies are still classified by the anatomic layer of corneal involvement, but they are increasingly defined on a genetic basis. Map-dot-fingerprint dystrophy was reclassified in 2015 as a degenerative condition in the majority of cases, with rare cases considered hereditary and class 1 ("a well-defined corneal dystrophy in which the gene has been mapped and identified and the specific mutations are known").[8] Map-dot-fingerprint dystrophy has been associated in several families with a presumed autosomal-dominant pattern attributed to the TGFBI gene, locus 5q31.[9, 10, 11]
The corneal epithelium produces and adheres to its underlying basement membrane. Corneal abnormalities associated with map-dot-fingerprint dystrophy are the result of a faulty basement membrane, which is thickened, multilaminar, and misdirected into the epithelium.[12] 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.
Estimates of the prevalence of map-dot-fingerprint dystrophy range from 2-43% of the general population.[13] Of patients with map-dot-fingerprint dystrophy, 10-33% have recurrent corneal erosions. As many as 50% of patients with recurrent corneal erosions have map-dot-fingerprint dystrophy.[14, 15]
Mortality/Morbidity
Patients with map-dot-fingerprint dystrophy may be asymptomatic. Others experience painful recurrent erosions, decreased vision, or both.
Sex
This condition is slightly more common in females than in males.
Map-dot-fingerprint dystrophy 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.
Most patients with map-dot-fingerprint dystrophy are asymptomatic.
The past eye history may be positive for recurrent corneal erosions.
Visual symptoms are usually 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 map-dot-fingerprint dystrophy 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 map-dot-fingerprint dystrophy 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 map-dot-fingerprint dystrophy are gray-white, puttylike opacities, which can be round, comma-shaped, or irregular. They are usually 0.05-1 mm in size.
The corneal fingerprints in map-dot-fingerprint dystrophy 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. Best seen in retroillumination.
Keratometry or computerized topography can be used to check for irregular astigmatism. A Placido disk or keratometer often demonstrates irregularity better than computerized topography.
The corneal maps in map-dot-fingerprint dystrophy histologically represent areas of multilaminar basement membrane, which extend into the epithelium. The corneal dots in map-dot-fingerprint dystrophy are intraepithelial microcysts that contain nuclear, cytoplasmic, and lipid debris. The corneal fingerprints in map-dot-fingerprint dystrophy are curvilinear clusters of reduplicated and thickened basement membrane and fibrillogranular material.[17, 12]
Blebs, a less common manifestation of map-dot-fingerprint dystrophy, are localized areas of fibrillogranular material or thickened basement membrane.
Numerous treatment options are available, and like map-dot-fingerprint dystrophy itself, results are variable and differ from patient to patient.[18]
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 dinner, and ointment at bedtime are recommended.
Nonhypertonic lubricating drops or ointment may be used; the only prospective study to date detected no difference in the results of bland versus hypertonic lubricating treatment.[19]
Consider patching for acute episodes of associated corneal erosions.
Bandage extended-wear soft contact lenses may be useful, but the risk of infectious keratitis makes this a secondary choice.
Hard or gas-permeable contact lenses, including scleral lenses, may improve vision by masking corneal irregular astigmatism, but they are often poorly tolerated because of increased corneal fragility/erosion problems.
Indications for surgical treatment of corneal map-dot-fingerprint dystrophy 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.
Debridement/superficial keratectomy is preferred by this author, for both significant visual loss from associated irregular astigmatism and recurrent corneal erosions, if treatment with hypertonic drops and ointment fails. 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. 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.[20, 21]
Diamond burr superficial keratectomy is very useful for recurrent erosions associated with map-dot-fingerprint dystrophy that does not respond to keratectomy with a Kimura spatula. 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.[22, 23]
Excimer laser phototherapeutic keratectomy is an alternative treatment for recurrent corneal erosions associated with map-dot-fingerprint dystrophy, with results similar to the above-described superficial keratectomy procedures (but much more expensive in most settings). Ablation should not extend more than 10 micrometers beyond the debrided epithelium, as an undesired hyperopic shift can occur.[24, 25, 26, 27]
Corneal anterior stromal needle puncture is useful for recurrent corneal erosions from trauma that recur in the same location.[28] This procedure is not as successful for recurrent erosions associated with map-dot-fingerprint dystrophy, which is usually more diffuse and often migratory.
Map-dot-fingerprint dystrophy 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 of flap keratolysis and corneal scarring.[29, 30, 31] 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, Co-Director of Refractive Surgery Department, Wills Eye Hospital
Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Cornea Society, AAO, OMIC, Avedro; Bio-Tissue; GSK, Kala, Novartis; Shire; Sun Ophthalmics; TearLab<br/>Serve(d) as a speaker or a member of a speakers bureau for: Avedro; Bio-Tissue; Shire<br/>Received income in an amount equal to or greater than $250 from: AAO, OMIC, Avedro; Bio-Tissue; GSK, Kala, Novartis; Shire; Sun Ophthalmics; TearLab.
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;
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