Woman complains of poor vision, foreign body sensation and tearing

A nasal pterygium was previously removed from the right eye, and one was found in the left eye on current exam.

Issue: September 1, 2006

ByHelen K. Wu, MD

ByShazia Ahmed, MD

An elderly Hispanic woman presented to the eye center with a complaint of poor vision, foreign body sensation and tearing in the left eye for the past 3 weeks. Her ocular history was significant for removal of a nasal pterygium from the right eye with placement of a conjunctival autograft. She also previously underwent cataract surgery in both eyes.

Examination

Shazia Ahmed

My Hanh T. Nguyen

On exam, the patient’s best corrected visual acuity was 20/50 in the right eye and 20/400 in the left eye. Pupils were equal and reactive to light, and IOP was within normal limits. Anterior slit-lamp exam of the right cornea was revealing for an epithelial haze nasally associated with a pannus (Figure 1a). The left cornea was remarkable for a nasal pterygium with an associated diffuse epithelial haze extending into the visual axis (Figure 1b). Both eyes had deep, quiet anterior chambers with well-positioned posterior chamber IOLs. Dilated fundus exam revealed a flat, attached retina with a healthy-appearing optic nerve.

With the patient’s consent, a decision was made to perform a pterygium excision with mitomycin C in the left eye. After the procedure, residual epithelial haze was noted nasally in the left eye (Figure 2). Four months later, the lesion transformed into a frosted epithelial plaque (Figure 3).

External photograph of right eye demonstrating slight epithelial haze nasally.	External photograph of left eye demonstrating a nasal pterygium with diffuse epithelial haze extending centrally.
External photograph of left eye demonstrating residual epithelial haze after pterygium removal.	External photograph of left eye revealing a frosted intraepithelial plaque with a fimbriated appearance 4 months after pterygium removal. Images: Ahmed S, Wu HK

What is your diagnosis?

Complaint of poor vision

While initially the patient’s presentation may seem consistent with a pterygium associated with a pannus, the differential diagnosis must include premalignant and malignant neoplasms, such as corneal/conjunctival intraepithelial neoplasia and squamous cell carcinoma. Causes of limbal stem cell deficiency, such as surgery, trauma, chemical burns or autoimmune diseases, may present in a similar fashion. Histology studies from the pterygium removal revealed a conjunctival epithelium with moderate to severe dysplasia (Figure 4). This confirmed the diagnosis of corneal/conjunctival intraepithelial neoplasia (CCIN).

Discussion

CCIN is a precancerous lesion of the ocular surface with low malignant potential, but it may be a precursor to squamous cell carcinoma. The clinical presentation is highly varied and ranges from the patient being completely asymptomatic to complaining of a foreign body sensation to experiencing blurry vision. On slit lamp exam, the cornea appears to have a gray, frosted, avascular intraepithelial plaque with a fimbriated edge. The conjunctival lesion may appear gelatinous, papilliform or leukoplakic.

Risk factors for the development of CCIN include HPV, HIV, ultraviolet light exposure, light-colored irises, a history of smoking and age greater than 70 years. The etiology is unknown but is thought to occur either as a result of de novo dysplasia or spread from the limbus. The diagnosis can be made either with exfoliative cytology, impression cytology or, more commonly, by biopsy. The biopsy should not be limited in nature because it may show intraepithelial neoplasia but miss invasive squamous cell carcinoma. Histopathology of these lesions typically reveals increased nuclear to cytoplasmic ratio, abnormal polarity and mitotic figures.

Histopathology slide of pterygium excision revealing moderate to severe dysplasia within conjunctival epithelium.

External photograph of left eye after treatment with topical mitomycin-C 0.02%.

Treatment

Multiple treatment modalities exist for CCIN. These include wide excision of the tumor with corneal debridement and cryotherapy, radiation treatment, topical 5-fluorouracil, topical mitomycin-C and topical interferon. Surgical excision of the tumor may not be ideal for multiple reasons. Fifty-three percent of lesions may recur when pathology shows involved margin. The histologic monitoring of tissue margins can be difficult given small size and tissue characteristics. This especially becomes cumbersome when there are multifocal areas of involvement. In addition, excision with cryotherapy may lead to limbal stem cell deficiency and ocular surface complications. Radiation treatment, while an option, carries with it a list of side effects, which includes conjunctivitis, dry eye, cataract, scleral ulceration and scarring of the conjunctiva and cornea.

Topical agents are the most favored method of treatment. Many small studies have been conducted to further delineate the strength and treatment cycle for each agent. Our patient was started on mitomycin drops, a non-cell-cycle-specific alkylating agent that crosslinks and reacts with DNA, thereby inhibiting synthesis and fibroblast proliferation. Her left eye was treated with 0.2 mg/mL of mitomycin four times a day for 2 weeks followed by two 1-week re-treatment sessions over 2 months leading to regression of the lesion (Figure 5). Another popular treatment option involves the use of interferon, a naturally occurring class of glycoproteins that binds to cell surface receptors and triggers a cascade of antiviral and antitumor properties. The effective dose of topical interferon is 1 million units per mL administered four to six times a day for a period ranging anywhere from 1 to 6 months. This has likewise demonstrated effective regression with minimal recurrence of the lesion.

For more information:

Shazia Ahmed, MD, and Helen K. Wu, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com.

Edited by Shazia Ahmed, MD, and My Hanh T. Nguyen, MD. Drs. Ahmed and Nguyen can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com. Drs. Ahmed and Nguyen have no direct financial interest in the products mentioned in this article, nor are they paid consultants for any companies mentioned.

References:

Barry SA, Schrier A, et al. Regression of presumed primary conjunctival and corneal intraepithelial neoplasia with topical interferon alpha-2b. Cornea. 2002;21(1):6-11.

Frucht-Pery J, Sugar J, et al. Mitomycin C treatment for conjunctival-corneal intraepithelial neoplasia: a multicenter experience. Ophthalmology. 1997;104:2085-2093.

Karp CL, Moore JK, Rosa RH. Treatment of conjunctival and corneal intraepithelial neoplasia with topical interferon alpha-2b. Ophthalmology. 2001;108(6):1093-1098.

Kaufman HE, McDonald MB, Barron BA, Waltman SR, eds. The Cornea. New York: Churchill Livingstone; 1988.

Rozenman Y, Frucht-Pery J. Treatment of conjunctival intraepithelial neoplasia with topical drops of mitomycin C. Cornea. 2000;19(1):1-6.