LENS COMPLICATIONS
Managing Contact Lens Complications
Case histories help illustrate how to diagnose and treat soft contact lens complications.
By Carla Mack, OD, FAAO, and Jeff Schafer, OD, MS

Soft contact lens-related complications beyond nonclinically significant corneal staining include a plethora of corneal conditions such as edema, microcysts, endothelial polymegethism and neovascularization. High-Dk/t lenses such as silicone hydrogels can help prevent most of these complications.

However, even with high-Dk/t lens wear, other mechanical complications persist such as contact lens-induced papillary conjunctivitis (or giant papillary conjunctivitis [GPC]) and inflammatory complications including contact lens-induced acute red eye (CLARE), contact lens peripheral ulcer (CLPU), asymptomatic infiltrative keratitis (AIK) and asymptomatic infiltrates (Sweeney et al, 2003). Of course, we can't overlook the most significant and feared complication: Microbial keratitis (MK), aka infectious corneal ulcer.

We'll discuss these complications and present cases that illustrate how to diagnose and treat them.

CLPU, IK or MK?

Contact Lens Spectrum Editor, Joe Barr, OD, MS, FAAO, recently cited Bobby Christensen, OD, MBA, FAAO, who said in a lecture that he didn't like to use the term "ulcer" for typical limbal infiltrates associated with contact lens wear. "Ulcer" sounds far worse and looks far worse in a medical record than it should in most of these cases. They both prefer to call them contact lens peripheral infiltrates (CLPI).

Dr. Barr offers a more fundamental approach to differential diagnosis of contact lens-related infiltrative keratitis (IK), adapted from studies designed to monitor the long-term results of continuous wear (Bullimore personal communication). This approach is as follows:

• High probability of MK = 1+ infiltrates >2mm in diameter and either an anterior chamber reaction, or pain, or mucopurulent discharge or positive culture. A scar is required when adequate follow up is possible.
• High probability of IK with etiology indeterminate (aka CLARE) = 1+ infiltrates with signs/symptoms not clearly meeting MK or CLPU (below).
• High probability sterile keratitis (aka CLPU or CLPI) = 1+ infiltrates, ¾1mm in diameter, outside the 6mm central zone and minimal anterior chamber reaction and no mucopurulent discharge and mild pain.

	Figure 1. Contact lens-induced peripheral infiltrate

Robboy (2003) referred to contact lens-associated corneal infiltrates (CLACI). He pointed out that cytokines, chemokines, adhesion molecules and other molecular stimuli mediate these conditions. In these cases, differential diagnosis list should also include: chlamydial disease (including trachoma, adneovirus and epidemic keratoconjunctivitis), Staphylococcal marginal keratitis, Thygeson's superficial punctuate keratitis and herpes simplex keratitis.

The earliest stages of CLPI (or sterile CLPU) and MK are often difficult to differentiate. However, the signs and symptoms associated with CLPI aren't severe and can be self-limiting whereas the pain, photophobia, tearing and corneal excavation associated with MK rapidly progress to moderate or severe status without appropriate antimicrobial treatment.

A Case of CLPI

A 22-year-old Caucasian female presented to our office with mild pain, 2+ limbal injection worse superiorly, tearing and minimal photophobia of her left eye for one day. She reported wearing a two-week disposable contact lens on a daily wear basis for one to two months before discarding. She soaked her contact lenses nightly in fresh multipurpose solution, but didn't rub or rinse. She claimed to never wear her contact lenses overnight, but she did so one week prior for 48 hours. Her current lenses were one-and-a-half months old.

Figure 2. Central ulcer

Slit lamp examination revealed two infiltrates, both with central fluorescein stain, straddling the two o'clock position. No anterior chamber reaction was present. We diagnosed her with two sterile (CLPI) (Figure 1). We presumed that both infiltrates were sterile because their individual sizes were less than 1mm, pain was minimal and we found no anterior chamber reaction or mucopurulent discharge.

We initiated standard corneal ulcer treatment: fluoroquinolone solution, one drop every 15 minutes for six hours, then one drop every 30 minutes for six hours, followed by one drop every waking hour until re-evaluated. Evaluation at one day showed significant improvement in symptoms and minimal staining over the corneal infiltrates. We tapered the fluoroquinolone to one drop q2h. No corneal staining was present after 48 hours of treatment, allowing us to taper the fluoroquinolone to qid. One week following the initiation of treatment, all symptoms had resolved and two faint corneal scars remained.

A Case of MK

Although MK is rare, you must diagnose it correctly and initiate management promptly to avoid visually devastating outcomes. Educate your contact lens patients to seek medical care immediately if they experience eye pain or loss of vision.

We recently managed a contact lens wearer who delayed seeking care for his red eye. The 23-year-old male patient presented to the clinic with a painful, red left eye of three days duration. He was a two-week disposable contact lens wearer, but he reported that he habitually replaced his lenses every month. He cleaned his lenses with a generic multipurpose disinfection solution.

He had slept overnight wearing his contact lenses and had worn them continuously until midnight of the following evening when he began to notice pain and blurred vision. He didn't wear his contact lenses the following day, but his symptoms didn't improve. He sought medical care on the morning of day three because the pain had worsened and his vision had deteriorated.

He had no history of any ocular disease or injury and was in good overall health. Upon presentation, his left eye was painful and exhibited redness, photophobia and mucopurulent discharge. He reported the pain as a seven on a scale from one to 10. He presented without visual correction with entrance acuities of count fingers at one foot OS. His acuity OS failed to improve with a pinhole. Gross examination revealed a large, white opacity on the left cornea (Figure 2). Biomicroscopy OS showed mucous debris throughout the eyelashes and inferior cul-de-sac. We noted grade 4 circumlimbal and grade 3+ diffuse injection of the bulbar conjunctiva. There was a 5mm epithelial defect with an underlying ring-shaped stromal infiltrate on the cornea OS. We also found grade 2 anterior chamber reaction OS.

	Figure 3. Contact lens-induced papillary conjunctivitis

We obtained scrapings of the affected corneal tissue for culturing. We then initiated treatment with a topical fourth-generation fluoroquinolone solution, one drop every 15 minutes for six hours, one drop every 30 minutes for six hours, then one drop every waking hour until re-evaluation. Although the U.S. Food and Drug Administration (FDA) has not yet approved the use of fourth-generation fluoroquinolones for treating MK, the off-label use of these drops has quickly become the drug of choice for many eyecare professionals because of their increased potency against both Gram-positive and Gram-negative pathogens.

We prescribed a second-generation fluoroquinolone ointment for use during sleep. A few days later, the culture had grown Pseudomonas aeruginosa as we expected. We monitored the patient closely over the next several days. At the two-week follow up, his visual acuity had improved to 20/80 OS. The corneal opacity had cleared substantially. We believe his vision will continue to improve and that he won't need to undergo a corneal transplant.

Managing Mechanically Induced GPC

Before the advent of frequent replacement, disposable and daily disposable contact lens modalities, GPC was a common condition that often forced patients to go without contact lens wear for months. Frequent replacement schedules and simplified cleaning regimens have since resulted in a dramatic decrease in the incidence of GPC.

But as of late, several cases of papillary conjunctivitis associated with silicone hydrogel continuous wear have presented to our practice. In both cases, the patients were male and had worn 30-night continuous wear silicone hydrogel contact lenses for just over two years. In the first case, mild irritation and slight itching of the left eye prompted the office visit. The cornea and bulbar conjunctiva were clear and quiet; however, the superior palpebral conjunctiva had a cluster of five giant papillae. The silicone hydrogel lens was five days old, and because the patient had no other allergic or traumatic history, we presumed that the lens was the causative agent.

We promptly discontinued contact lens wear and prescribed a mast cell stabilizer/antihistamine for use bid. Re-examination one week later showed resolution of all signs and symptoms. This patient has resumed successful 30-night continuous wear for the last six months.

In the second case, excessive lens movement and mild irritation of the right eye over a one-month period prompted the office visit. The continuous wear silicone hydrogel contact lenses were 22 days old, and the patient hadn't removed or disinfected them since the initial application. Visual acuity wasn't reduced and the cornea was intact without fluorescein stain. The right tarsal plate had a cluster of 17 large papillae (Figure 3) with mild to moderate palpebral conjunctival injection.

Once again, we discontinued contact lens wear and prescribed a mast cell stabilizer/antihistamine for use bid. The signs and symptoms persisted at both the one- and three-week follow-up visits, so we added a steroid (loteprednol etabonate 0.5%) qid over the next month. We tapered the steroid over another four weeks.

The patient resumed silicone hydrogel lens wear on a daily wear basis with nightly disinfection for several weeks before resuming continuous wear. This patient has remained symptom-free for about one month. If symptoms return, then we'll advise him to continue with silicone hydrogels on a daily wear basis indefinitely or to change his wearing modality and material all together for more frequent and possibly even daily replacement. Given that GPC is both a mechanical and an immunologic event, we expect that decreased exposure to the lens material in switching from continuous wear to daily wear would make GPC less likely to occur or recur.

Figure 4. CLARE

Taking Care of CLARE

Contact lens wearers present to our practice with acute red eyes of varying etiologies. CLARE is an inflammatory condition associated with many possible causes: hypoxia, toxic effects from post-lens tear debris, mechanical irritation from a poor-fitting lens, dehydration of the tear lens while wearing lenses during sleep, solution hypersensitivity or toxicity or a reaction to bacterial toxins. Under hypoxic conditions, glucose converts to lactate. Lactate diffuses into the stroma and increases the osmolarity and metabolic acidosis that results in corneal edema. A decrease in normal corneal metabolism causes tissue compromise that can lead to CLARE. White blood cells migrate from the limbal vasculature and form infiltrates in the peripheral cornea. These sterile infiltrates are often small (<2mm) and cause little to no epithelial staining.

A 19-year-old female who was new to our office presented with circumlimbal redness, mild photophobia and tearing in her left eye upon awakening. She reported wearing soft contact lenses that she replaced only when they felt uncomfortable. She didn't know what brand of lenses she wore or the prescribed replacement schedule. She also reported that she habitually sleeps overnight in her lenses, typically removing them once or twice per week.

Slit lamp examination OS revealed grade 2 circumlimbal injection and multiple, small peripheral infiltrates that didn't stain with fluorescein. No anterior chamber reaction was evident. We diagnosed CLARE OS (Figure 4) and initiated treatment with an antibiotic/steroid combination drop qid OS for one week. We advised her to discontinue contact lens wear until follow up. Examination one week later revealed that all signs and symptoms had resolved. The conjunctiva was white and quiet, and all the infiltrates had cleared without scarring.

Be Prepared

Although higher Dk/t lenses and improved care regimens have made lens wear and care safer and simpler, complications still occur. Make sure you can effectively diagnose and treat these complications so that you can best serve your patients.

To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #110.