Epithelial Splits/Superior Epithelial Arcuate Lesions (SEALs)
- CLINICAL DESCRIPTION:
- Arcuate lesions related to the wear of soft contact lenses and occurring in the superior cornea that is covered by the upper lid, have been termed epithelial splits or superior epithelial arcuate lesions (SEAL's). These lesions can vary in location from being just inside the limbus, to several millimeters below the limbus superiorly, generally corresponding to the location of the upper lid margin. The area stains with fluorescein, and is an erosion like lesion or furrow in the epithelium, with irregular or jagged edges, and some heaped-up tissue at the margins. Deeper lesions may be accompanied by infiltrates, and increased haze in the arcuate area. (Figure 1)
- Epithelial splits are asymptomatic in many cases. If symptomatic it, it is generally a mild foreign body sensation or slight scratchiness. The majority of patients who develop these lesions are not bothered enough to discontinue lens wear.
- The incidence of epithelial splits is specific for each lens design and material, with the position and tightness of the upper lid being a factor as well. Lathe cut, stiffer modulus lenses are more often implicated. However, the incidence is very low, even in more susceptible lenses types. Some reports have suggested an increased incidence in higher Dk lenses. Therefore, it seems that lens design and other material characteristics are likely more responsible for this, not a lack of oxygen. Recently, epithelial splits have been seen more often in newer, highly permeable silicone / hydrogel lenses designed for extended wear. Estimates range from 2-4 % for this new lens type.
- There is no definitive, widely accepted etiology for epithelial splits. The best explanations suggest that lenses of high modulus (stiffer), especially those that are lathe-cut, are compressed against the cornea by perhaps tighter than average lid force. It may be more common on steeper corneas. The lens design may play a factor, with the area of the lesion sometimes corresponding exactly to where a back surface change occurs, or in some cases where a front optic zone junction occurs and the lid pushes the lens into the cornea in this exact spot.
- While a mechanical abrasion is believed to cause the lesion, some have hypothesized that the lid holds debris and stops tear flow in this area, leading to poorer wetting of the cornea. The debris itself may elicit a response that also contributes to the break down of the corneal integrity. Finally, some have implicated poor tear quality, and low level lid disease in epithelial splits lesions.
- The primary treatment is removal of the contact lens until the epithelium heals. In severe erosions, prophylactic broad-spectrum topical antibiotics may be used, but generally unpreserved ocular lubricants are sufficient. The epithelium usually heal with no evidence that the lesion had been present. However, lesions that are very pronounced, or more centrally located, seem to carry a slight risk of mild scarring.
- Once the lesion has healed, the patient should be refit. Generally this will be with a different material or different lens design. Occasionally the original lens type in new parameters can be successfully refit. In a small percentage of cases, epithelial splits have continued to recur with all different types of hydrogel materials and designs, in which case the patient must be refit into rigid gas permeable lenses.
- BEST REFERENCES:
- Holden BA, Stephenson A, Stretton S, Sankaridurg P, O’Hare N, Jalbert I, Sweeney D. Superior Epithelial Arcuate Lesions with Soft Contact Lens Wear. Optom Vis Sci 2001; 78:9-12. (excellent review article)
- Malinovsky V, Pole J, Pence N, Howard D. Epithelial splits of the superior cornea in hydrogel contact lens patients. ICLC 1989;16:252-5. (retrospective study of clinical cases)
- Hine H, Back A, Holden BA. Aetiology of arcuate epithelial lesions induced by hydrogels. Trans Br Cont Lens Assoc Conf 1987:48-50. (introduced the term SEAL's)
- OTHER REFERENCES:
- Jalbert I, Sweeney DF, Holden BA. The characteristics of corneal staining in successful daily and extended disposable contact lens wearers. Cddn Exp Optom 1999;82:4-10.
- O'Hare NA, Naduvilath TJ, Jalbert I, Sweeney DF, Holden BA. Superior epithelial arcuate lesions (SEALS): a case control study. Invest Ophthalmol Vis Sci 2000;41:S74.
- Young G, Mirejovsky D. A hypotheses for the aetiology of soft contact lens-induced superior arcuate keratopathy. ICLC 1993;20:177-80.
- Snakaridurt Pr, Sweeney DF, Sharma S, Gora R, Naduvilath R, Ramachandran L, Holdern BA, Rao GN. Adverse events with extended wear of disposable hydrogels: results for the first 13 months of lens wear. Ophthalmology 1999;106:1671-80.
- Liao K. Superior epithelial lesions. Aust J Optom 1998;32(/contact Lens Supplement):34.
- Gerry P. Bilateral superior epithelial arcuate lesions: a case report. Clin Exp Optom 1995;78:194-5.
Vinita Allee Henry, O.D., F.A.A.O.
University of Missouri-St. Louis College of Optometry