Contact Lens Wear 'Bugged' by Endothelial Blebs

By Robert Campbell, M.D., & Patrick Caroline, C.O.T., F.A.A.O.

We often hear of strange things occurring to our patients while wearing contact lenses, but this story may take the cake. Patient J.C., a 44-year-old soft contact lens wearer, was descending a steep hill on his bicycle at a speed of 35mph when a bug struck his left eye. At the time, he was wearing his contact lenses without additional protective eye wear. His lenses were: OD a daily wear toric, 8.3mm base curve, +0.25 -1.75 x 70 power, 14.0mm diameter; OS a daily wear spherical, 8.3mm base curve, -0.75D power, 13.8mm diameter.

FIG. 1: CORNEAL MAPPING OU.

When J.C. returned home, he examined the left lens and found it to be intact. Within six hours after the incident, the left eye had become completely comfortable again. The day after the injury, J.C. began experiencing cloudy vision after five hours of contact lens wear. He didn't report to our office until four weeks later, by which time he had discontinued lens wear OS due to the cloudy vision.

BLEBS BELOW THE SURFACE

At the time of his visit, J.C. was wearing his spectacle prescription with a visual acuity of 20/15 OU and no symptoms of cloudy vision throughout the day. Videokeratoscopy showed that the corneal surface OS was regular and free of any traumatic irregular astigmatism (Fig. 1 ). However, at the level of the endothelium were five posterior polymorphous dystrophy-like blebs surrounded by small patches of stromal haze (Fig. 2). The remainder of the cornea was unremarkable. Specular microscopy OS revealed a normal cell count of 2400 cells/mm² over the central cornea (Fig. 3). However, the cell count was significantly less over the pathology 0.5 mm temporally, numbering 1500 cells/mm² (Fig. 4). The right eye showed no endothelial changes.

It was clear that the patient's symptoms were most likely related to corneal edema in and around the bleb sites after five hours of lens wear in a low Dk/L material.

TREATMENT OPTIONS

We presented the following three options to the patient: continue with his spectacles and wait for the blebs to resolve before attempting RGP or soft contact lens wear; continue to wear his right contact lens only and again postpone lens wear OS until the blebs resolve; or attempt a trial with a high Dk/L soft contact lens OS to evaluate the threshold of the edema response. The patient elected to continue wearing his right lens only, allowing him over the past few weeks to experience the monovision effect of the uncorrected left eye.

In this situation, as in the case of many traumatic corneal injuries, the presence of the contact lens may have played a protective role in limiting the amount of corneal damage. However, this case does illustrate our need to reinforce to patients the benefits of protective eye wear. CLS

FIG. 2: POST-TRAUMATIC PARACENTRAL ENDOTHELIAL BLEBS.

FIG. 3: CENTRAL SPECULAR MICROSCOPY WITH NORMAL ENDOTHELIAL SHAPE & COUNT.

FIG. 4: PARACENTRAL SPECULAR MICROSCOPY OVER THE BLEB SITE.