A pterygium is a common degenerative corneal disorder. Adjunctive treatments,
including radiation, antimetabolites, and conjunctival and limbal grafts,
are used to decrease the rate of recurrence after simple excision.1,2 Mitomycin C (MMC) is an alkylating
agent that is commonly used in glaucoma filtration surgery to treat conjunctival
neoplasia and also to prevent recurrence of pterygia.3
A 55-year-old man was referred for a nonhealing conjunctival epithelial
defect and scleral necrosis. The patient had dry eyes and pterygia in both
eyes. He had punctal cautery of both lower puncta. He received a 0.15-mL subconjunctival
injection of 0.1 mg/mL of MMC in the pterygium head in his left eye. One month
after the MMC injection, he underwent pterygium excision combined with a free
conjunctival autograft taken from the inferior bulbar conjunctiva. Postoperatively
the patient was prescribed topical 0.3% ciprofloxacin for 3 days, followed
by a combination of 0.3% tobramycin and 0.1% dexamethasone drops 4 times per
day and 0.1% diclofenac twice per day. Eleven weeks after surgery, the patient
noticed that the conjunctival graft was sloughing off and then disappeared,
exposing bare sclera. One week later, a dark area consistent with scleral
melting was noted at the 9-o'clock position. Diclofenac was discontinued and
a lubricating gel was prescribed to be applied every 2 hours. The patient
was then referred to the cornea service at Wills Eye Hospital (Philadelphia,
On initial examination, the patient reported photophobia, pain, and
tearing in his left eye. His best-corrected visual acuity was 20/25 OD and
20/50 OS. Slitlamp examination of the right eye revealed a nasal pterygium
measuring 1.5 mm onto the cornea and 5 mm vertically at the limbus. The left
eye had a large area of porcelain white sclera extending 7 to 8 mm posterior
from the limbus between the 5- and 9-o'clock positions. The whitened sclera
was thinned and stained with fluorescein but there was no uveal show (Figure 1). The conjunctiva was injected superiorly,
and a papillary reaction was noted in the inferior tarsus. The anterior chamber
was deep and quiet and the lens was clear. Examination of the lower puncta
revealed that the right side was closed and the left was open. The intraocular
pressure was 14 mm Hg OU. The patient was treated conservatively, with bacitracin-polymyxin
B ointment every 2 hours, a lubricating ointment twice per day, and 25 mg/d
of oral rofecoxib.
Slitlamp photograph of the left eye. Bare necrotic sclera is observed
between the 5- and 9-o'clock positions. The sclera was mildly thinned and
stained with fluorescein.
At 8 weeks, the examination results were consistent with advancing conjunctival
epithelium from the limbal area. The epithelial defect was also noted to be
smaller. The patient was still symptomatic and showed a slow healing process.
An amniotic membrane graft was offered, but the patient refused further surgery.
He was followed up closely every few weeks. Eight months after the pterygium
surgery, he still complained of light sensitivity. Ocular examination revealed
a best-corrected visual acuity of 20/30; the sclera was still mildly thinned.
The large conjunctival epithelial defect had improved, although 2 epithelial
defects measuring 4.5 × 2.5 mm and 1.0 × 0.5 mm remained. There
was no evidence of recurrent pterygium.
Mitomycin C has been used to treat primary and recurrent pterygia. Different
routes of administration, including instillation of drops after surgery and
intraoperative application of a sponge soaked with MMC on the scleral bed
of excision, have been used.1 A single 0.1-mL
injection of 0.1 mg/mL of MMC into the pterygium head in 6 patients, followed
by pterygium excision 4 weeks later, was described by Donnenfeld et al.4 This is the only report, to our knowledge, to support
the use of subconjunctival MMC before surgery to prevent recurrence of pterygia.
In this case, a higher volume of the same concentration was injected, with
serious adverse effects.
The use of topical MMC eye drops after pterygium excision has been associated
with severe discomfort and vision-threatening complications, including glaucoma,
cataract, corneal edema, corneal perforation, and scleral calcification.5,6 Rubinfeld et al5 recommended
avoiding MMC in patients who had other conditions associated with poor wound
healing, such as keratoconjunctivitis sicca and Sjögren syndrome.
In our patient, multiple factors may have predisposed to poor wound
healing. We suspect that the MMC accumulated inferiorly, causing damage to
the inferior sclera and inferior conjunctival tissue used for the conjunctival
graft. Dry eye syndrome and long-term postoperative treatment with topical
nonsteroidal anti-inflammatory drugs and steroids are additional factors that
could have interfered with the healing process. Although MMC has been demonstrated
to decrease the rate of recurrences after pterygium excision, a conventional
route of administration, careful dosing, and patient selection are recommended.
This research was supported in part by XV Congreso Argentino de Oftalmología,
The authors have no proprietary interest in any of the products or techniques
discussed in this article.
Corresponding author and reprints: Christopher J. Rapuano, MD, Cornea
Service, Wills Eye Hospital, 900 Walnut St, Philadelphia, PA 19107 (e-mail: firstname.lastname@example.org).
Carrasco MA, Rapuano CJ, Cohen EJ, Laibson PR. Scleral Ulceration After Preoperative Injection of Mitomycin C in the Pterygium Head. Arch Ophthalmol. 2002;120(11):1585–1586. doi: