Iris seeding following iridocyclectomy for localised iris melanoma

Proton Beam Therapy for Iris Melanomas in 107 Patients

PURPOSE

To report on the clinical characteristics and outcomes for patients with iris melanoma using proton therapy.

DESIGN

Retrospective study.

PARTICIPANTS

One hundred seven patients with iris melanoma from 3 regional ophthalmologic centers.

METHODS

A retrospective study was conducted for iris melanoma patients from 3 regional ophthalmologic centers referred to and treated at a single proton therapy facility between 1996 and 2015.

MAIN OUTCOME MEASURES

At each follow-up visit, examinations included measurement of best-corrected VA, slit-lamp, examination, indirect ophthalmoscopy, and ultrasound biomicroscopy.

RESULTS

With a median follow-up of 49.5 months, 5 of 107 patients experienced a local relapse within a median of 36.3 months. The cumulative incidence of relapse was 7.5% at 5 years. All 5 patients showed involvement of the iridocorneal angle (P = 0.056). Diffuse iris melanoma showed a higher risk of relapse (P = 0.044). Four patients showed out-of-field relapse and 1 showed angular relapse. Three patients were retreated with proton therapy, whereas 2 other patients, one with T1b disease and another with diffuse T3 disease, underwent secondary enucleation. None of the patients experienced metastases nor died of iris melanoma. Vision improved in 59.4% of patients (n = 60/101). However, cataracts occurred in 57.4% of the 54 patients (n = 31) without cataract or implant at diagnosis. Secondary glaucoma was reported in 7.6% of the patients (n = 8), uveitis in 4.7% (n = 5), and hyphema in 3.7% (n = 4). All but 5 cases of complications were mild, transient, and not sight limiting after treatment. Five cases of glaucoma, including 1 with uveitis, were severe and associated with visual deterioration.

CONCLUSIONS

Proton therapy showed efficacy and limited morbidity in iris melanomas.

Proton beam therapy for iris melanomas

AIMS

To describe the results in terms of local control, eye preservation and systemic evolution of iris melanomas treated by proton beam irradiation.

METHODS

Retrospective review of the charts of patients with iris melanoma treated by proton beam therapy between April 1998 and September 2002. Ciliary body melanomas with iris involvement or tumours with extrascleral invasion were excluded. Treatment consisted of 60 Gy of proton beam irradiation delivered in four fractions to the tumour volume.

RESULTS

A total of 21 patients were treated, median follow-up of 33 months (8-72 months). 15 patients presented a lesion with documented growth. The median clinical diameter was 5 mm (2-8 mm), the median ultrasound diameter 4.8 mm (2-7.7 mm) The patients were 6% T1, 57.1% T2, and 14.3% T3 all N0M0. The iridocorneal angle was invaded by the tumour in 71.4% of patients. At the end of follow-up, all patients were alive with no proven metastatic disease except one patient with suspicious liver lesions. None of the patients showed tumour progression or ocular relapse. The tumour response at 2 years was a flat lesion for 6.3% of cases, partial regression in 75% and stable in 18.8%. None of the patients required secondary enucleation. The main complication was cataract (45% within 24 months of treatment). Raised intraocular pressure was observed in 15% of patients but no neovascular glaucoma.

CONCLUSIONS

Proton beam therapy shows potential utility for selected cases of localised iris melanomas allowing excellent local tumour control and eye preservation. Further follow-up on larger series is needed to confirm these results.

Iris melanoma: a case report and review

Iris melanoma is a rare ocular tumour, which can be detected early in its development. This tumour is almost always unilateral and arises usually from a pre-existing naevus. Failure to detect it may be associated with morbid ocular and systemic complications, yet there are successful therapies to treat this condition, if detected early. The patient presented to the eye clinic with symptoms of occasional, brief loss of vision in his left eye for a few weeks prior to his visit. Slit-lamp examination revealed a mass on the inferior part of the iris of the left eye. Intra-ocular pressure measurements were RE 15 mmHg and LE 38 mmHg. It was found that a tumour had spread throughout the iris stroma and invaded the anterior chamber angle. Although enucleation would have been the treatment of choice in the past, the trend today in the treatment of a growing, large circumscribed iris tumour is to excise it. It was successfully excised by irido-cyclo-trabeculectomy.