Clinical features predictive of orbital exenteration for conjunctival melanoma

Conjunctival malignant melanoma can sometimes be difficult to control locally, and orbital exenteration may be necessary. To our knowledge, the risk factors that portend exenteration have not been previously identified. The purpose of this study was to review patients who underwent orbital exenteration for advanced disease and to identify retrospectively the clinical factors predictive of ultimate exenteration.

The records of patients with conjunctival melanoma who were managed on the Oncology Service at Wills Eye Hospital from 1974 to 1997 were reviewed. Factors predictive of orbital exenteration were analyzed using Cox proportional hazards regression models.

Of 151 consecutive patients with conjunctival melanoma, 20 (13%) required orbital exenteration for advanced disease. The number of melanoma excisions performed before referral ranged from 0 to 11, with a mean of 2. The clinical factors predictive of orbital exenteration on multivariable analysis were visual acuity of 20/200 or worse, lack of tumor pigmentation, and extralimbal tumor location. All exenterations were performed using an eyelid-sparing technique. At mean follow-up of 51 months after exenteration, 4 patients (20%) had died of metastasis, 3 (15%) were alive with metastasis, and 13 (65%) had not developed metastasis.

Conjunctival melanoma can show aggressive local behavior, and orbital exenteration is necessary in up to 13% of cases at a tertiary referral center. Patients with risk factors such as poor visual acuity, amelanotic tumor, and extralimbal tumor location may require wider excision and radiation therapy to control the tumor and avoid orbital exenteration. It is hoped that modern surgical approaches will decrease the need for orbital exenteration.