the contact lens exam
Mechanical Complications of Soft Contact Lens Wear
BY LORETTA B. SZCZOTKA-FLYNN, OD, MS, FAAO
Contact lens-related mechanical complications are usually related to GP lens use. But when a soft lens patient complains of foreign body sensation, lens awareness or pain, don't forget that soft lenses can induce mechanical complications as well. Higher-modulus silicone hydrogel lenses typically create more mechanical complications than softer-modulus lenses do, but mechanical complications can occur with almost any lens type.
When a patient complains of a foreign body or other uncomfortable sensation, don't just examine the lens/eye combination. Always remove the lens and use fluorescein. Following are two examples of patients in my practice who had soft lens-induced mechanical complications. They highlight the range of signs and symptoms that may occur in such scenarios.
Case 1: SEAL
This 18-year-old patient was sleeping in lotrafilcon A (Night & Day, CIBA Vision) lenses on a monthly replacement schedule for four months. She presented for a routine follow-up visit with no complaints. Lens removal and fluorescein instillation revealed a prominent superior epithelial arcuate lesion (SEAL) in the superior temporal quadrant of her right cornea (Figure 1). A SEAL usually presents as an arcuate punctate pattern or as a full-thickness corneal epithelial break usually in the area covered by the upper eyelid within the 10 o'clock to 2 o'clock region close to or just within the limbus.
Figure 1. A classic presentation of a soft lens-induced SEAL.
SEALs are produced by mechanical chafing of the peripheral cornea. This chafing results from inward pressure of the upper lid in an area where the peripheral corneal topography and lens design, rigidity and surface characteristics combine to create excessive frictional pressure and abrasive shear force on the epithelial surface. It's managed by discontinuation of lens wear, lubrication and by refitting either the lens material (to a softer modulus) or the lens design.
Case 2: Acute Corneal Abrasion
This 34-year-old patient presented with acute pain and photophobia since he awakened. He was a continuous wear user of lotrafilcon A lenses, with no complaints for the last four months.
Upon examination we found a 3mm-by-1mm epithelial defect in his central-to-superior cornea. No infiltrates were present. The patient was still wearing the lens after awakening that morning with symptoms.
We diagnosed a mechanically induced corneal abrasion, presumably from debris from his pillow that lodged beneath the lens during sleep (Figure 2). We treated him for symptomatic pain relief and prescribed Vigamox (Alcon) six times per day as prophylaxis against infection. Within 24 hours the abrasion was 95 percent resolved with no epithelial defect and only faint stippling of the epithelium in the site of the previous abrasion.
Figure 2. Debris trapped under the soft lens caused this corneal abrasion.
Fortunately, most mechanical soft lens-induced complications are easily managed and resolve completely in a matter of days. CLS
Dr. Szczotka-Flynn is an associate professor at Case Western Reserve University Dept. of Ophthalmology and is director of the Contact Lens Service at University Hospitals of Cleveland.