Bandage Contact Lenses for A 'Garden Variety' Wound

Nita had been pulling up a yucca plant, a cactus-like succulent with very sharp points on the tip of each leaf, when its roots gave way and a point struck her in the eye. She presented four days later complaining of intermittent foreign body sensation, but no decrease in vision.

Presenting visual acuities were 20/20^-1 in both eyes. Slit lamp examination of her right eye showed a three-millimeter area of corneal erosion with accompanying epithelial edema and a previously documented scar. The anterior chamber was free of cells or flare, and there was no evidence of infection.

When we instilled fluorescein, we noted the pattern seen in Figure 1. We suspected a wound leak, but simply refused to believe it was possible given the four-day history and uninflamed eye. Our initial diagnosis was corneal erosion secondary to trauma. We pressure-patched the eye after applying topical tobramycin ointment and instructed Nita to return in one day.

TRUST YOUR EYES FOR THE SAKE OF THEIRS

The following day, Nita continued to complain of foreign body sensation, and when we instilled fluorescein, we noted that the tears overlying the wound were devoid of dye and that surrounding the dark area was a ring of tears that glowed brightly under the cobalt light. We recognized this as Seidel's sign, diagnostic of a penetrating ocular injury and caused by a difference in pH between the tears and the aqueous.

FIG. 1: CORNEAL WOUND WITH SEIDEL'S SIGN.

Careful evaluation of the anterior chamber revealed no cells or flare, and more importantly, no evidence of endophthalmitis. Applanation tensions were: OD 12mmHg, and OS 19mmHg. Examination of the iris showed a small slit immediately behind the site of the entry wound, something obscured by edema in our initial evaluation.

We instilled two drops of Ocuflox in the cul de sac and placed a sterile bandage contact lens on the eye. We instructed Nita to instill two drops of Ocuflox every two hours and tobramycin ointment at bedtime. Small penetrating wounds can draw tears and pathogens into the eye, creating a risk for endophthalmitis that extends for weeks after the injury. We told Nita to report any worsening of redness or vision immediately.

The next day, visual acuities were 20/40 OD, 20/20^-1 OS. Biomicroscopy showed a well-centered contact lens that moved upon blinking. The edema had decreased, and there was no evidence of anterior chamber activity. We felt that the vision reduction was primarily due to the residual ointment on the lens surface. We told Nita to continue her present regimen.

Nita had no complaints at follow-up two days later, and visual acuities were OD 20/30^-1 and OS 20/20. When we removed the bandage contact lens, there was no evidence of wound leakage, anterior chamber activity or infection. We told Nita to decrease the Ocuflox to four times a day, continue the tobramycin ointment hs, and return in two weeks so we could dilate her pupils to determine if the tip of the yucca plant had penetrated the lens.

TREATMENT RATIONALE

We treated Nita with a bandage contact lens because they are readily available and can absorb and maintain antibiotic at a therapeutic level to prevent endophthalmitis. Pressure-patching wouldn't have allowed continuous application of fresh antibiotics nor would it have sealed the wound. We might have chosen a cyanoacrylate to seal the wound, but this is generally reserved for larger wounds.

We chose ofloxacin because it has a broad spectrum of activity, it is effective against gram negative organisms and it is relatively non-toxic, which is important when it is concentrated in bandage lenses.

This case illustrates two important lessons: use fluorescein in any case of corneal trauma, and believe that what you see is real. The case also emphasizes the need to advise patients whe have hobbies or vocations that pose a threat of penetrating injury to use safety glasses. Had Nita been wearing some form of eye protection, it's doubtful that we would have had occasion to report her case to you. CLS

Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center.