healthmedicinet

Case 1

A 70-year-old woman was referred to our institution in July 2012 for treatment of
left ocular pain. She complained of ocular discomfort and decreased visual acuity
(12/20) at the first visit. She underwent nasal pterygium excision with topical MMC
in the left eye six years previously at another facility. A few years after surgery,
symptoms of intermittent ocular discomfort and mild ocular pain developed, so she
went for treatment to a local medical center. She had neither medical history or family
history of ophthalmic disease.

On slit-lamp examination, the underlying sclera at the site of the prior pterygium
excision was necrotic and avascular, and showed marked thinning in the nasal portion
of the left eye (Fig. 1a). The scleral bed appeared conjunctivalization over the exposed ciliary body with
no evidence of scleral perforation sign by Seidel test. The adjacent corneal epithelium
was intact and there was no anterior chamber inflammatory reaction. We thought that
the scleral thinning was a possible MMC-associated thinning. Microbial smears and
cultures of the scleral bed were obtained at the first visit, but were negative.

Fig. 1. Preoperative and postoperative slit-lamp photographs of Case 1, the left eye. a Preoperative photography showing large severe scleral thinning and excavation with
impending uveal exposure. b First week after surgery. c One month after surgery. d Two years after surgery

The patient was started on topical 0.1 % fluorometholone and 0.5 % levofloxacin eye
drops. Two weeks later, the patient’s ocular pain and discomfort was gone. After informed
consent, the patient underwent an OCM graft with CAU at the scleral thinning area.
The surgical technique is described in Fig. 2. Proparacaine hydrochloride eye drop (0.5 %, Alcaine; Alcon, Fort Worth, TX) was
used as topical anesthesia before surgery. First, the necrotic soft tissues and devitalized
sclera were surgically debrided with a diamond burr, taking care not to damage the
exposed ciliary body and the unaffected adjacent conjunctiva. Gentle polishing with
a diamond burr instead of a knife can produce a flat, regular surface without damaging
the already much thinned scleral bed. All necrotic scleral tissue was dissected away
until the scleral surface was clean, smooth, and even. Conjunctival hemorrhage during
debridement was controlled by ocular bovie and cotton swab compression. To determine
the boundary for the conjunctivectomy, the size of the scleral defect was measured
and its margin was marked with a 3-mm diameter biopsy punch (Fig. 2a, b). The margin of scleral thinning area was trimmed by Vannas scissors and the OCM
was cut with a circular-shaped biopsy punch of the same size (3-mm diameter). The
OCM was trimmed and fitted to cover the scleral defect (Fig. 2c). The OCM was sutured with a recipient scleral wall using six stitches of 10–0 nylon
interrupted sutures. The color of the OCM changed from white to red due to blood accumulation
(Fig. 2d). Once the scleral defect was repaired, a 4-mm diameter, circular, free CAU was harvested
from the superonasal bulbar conjunctiva with a punch biopsy 1 mm larger in diameter
than that of the piece of OCM. A conjunctival graft that is larger than the scleral
defect can achieve a stable, tension-free graft to avoid a wound dehiscence (Fig. 2e, f). The CAU was carefully positioned over the previously sutured OCM bed and anchored
to the scleral wall and the healthy conjunctival margin through the OCM bed with 11
stitches of interrupted sutures of 10–0 nylon (Fig. 2g, h).

Fig. 2. The surgical procedure for Ologenâ„¢ collagen matrix (OCM) graft and conjunctival autograft
surgery. a,b The size of the scleral defect was measured and its margin was marked with a 3-mm
diameter biopsy punch to determine the boundary of conjunctivectomy, c The margin of scleral thinning area was trimmed by Vannas scissors and the OCM was
cut with a circular-shaped biopsy punch of the same size (3-mm diameter). The OCM
was trimmed and fitted to cover the scleral defect. d The OCM was sutured with a recipient scleral wall using six stitches of 10–0 nylon
interrupted sutures. The color of the OCM changed from white to red due to blood accumulation.
e A 4-mm diameter, circular, free CAU was harvested from the superonasal bulbar conjunctiva
with a punch biopsy 1 mm larger in diameter than that of the piece of OCM. f The CAU was carefully positioned over the previously sutured OCM bed. g The CAU was anchored to the scleral wall and the healthy conjunctival margin through
the OCM bed with 11 stitches of interrupted sutures of the 10–0 nylon. h Immediate final postoperative appearance

After surgery, the patient was given a patch dressing with a topical antibiotic ointment
(Erythromycin, Ecolicin
^®
, Taejoon Pharm., Seoul, Korea) and a steroid ointment (Dexamethasone, Maxitrol
^®
, Alcon Laboratories Inc., Fort Worth, TX, USA) to be taken four times daily. The
patient was examined daily for the first five postoperative days. After five days,
the ointment patch dressing was replaced by topical antibiotics (0.5 % levofloxacin,
Cravit
^®
, Taejoon Pharm, Seoul, Korea) and steroid eye drops (0.1 % fluorometholone, Flarex
^®
, Alcon Laboratories Inc., Fort Worth, TX, USA) to be taken four times a day. Inflammation
of the scleral bed subsided and the patient was comfortable. The ocular surface was
re-epithelialized six days after surgery. The conjunctival sutures were removed at
intervals of one week to one month over the postoperative course. Starting about one
month after surgery, the topical 0.1 % fluorometholone and 0.5 % levofloxacin eye
drops were tapered off over three months. Artificial tear substitutes were used continuously
after surgery. The patient was examined weekly for the first two months and at three,
four, six, nine, 12, 16, 20, and 24 months postoperative.

Over the first postoperative month, the graft site vascularized and was taken up well
(Fig. 1c). The conjunctival surface was stable at six months and 12 months postoperative.
When reviewed 24 months later, the conjunctival surface was still stable with no recurrence
of scleral thinning and scleromalacia (Fig. 1d).

Case 2

A 76-year-old man visited our institution complaining of long standing ocular discomfort
and decreased visual acuity (16/20). He underwent nasal pterygium excision with topical
MMC in his left eye 10 years prior at another facility. He had neither medical history
or family history of ophthalmic disease.

On slit-lamp examination, a focal epithelial defect at the site of the prior pterygium
excision and an approximately 3 mm scleral excavation with impending uveal exposure
were observed (Fig. 3a). At presentation, there was no sign of infectious scleromalacia. We thought that
the scleral excavation was possibly an MMC-associated lesion. Microbial staining and
cultures were negative.

Fig. 3. Preoperative and postoperative slit-lamp photographs of Case 2, the left eye. a Preoperative photography showing irregular scleral thinning and excavation with impending
uveal exposure. b First week after surgery. c One month after surgery. d Two years after surgery

In the same manner as described in Case 1, steroid and antibiotic eye drops were used
before surgery. We performed an OCM graft with CAU. Postoperatively, the patient was
treated with topical eye drops and examined daily for the first postoperative week.
Three days after surgery, the OCM graft vascularized and was taken up well. The surrounding
conjunctival and scleral inflammation subsided and the patient was comfortable. The
reconstructed ocular surface was stable with no complications during the two-year
follow-up period (Fig. 3b,c,d).