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Abstract Background Ring melanoma of the ciliary body and iris is extremely rare and often has adverse histology. This tumour may cause raised intraocular pressure. Methods A review of four cases of ring melanomas with insidious presentations seen in the ocular oncology service over a 12 month period. Results All four patients presented with unilateral anterior segment abnormalities and refractory glaucoma. The misdiagnoses of the causes of the glaucoma included angle recession from previous blunt trauma (patient 1); iridocorneal endothelial (ICE) syndrome supported by endothelial specular microscopy (patients 2 and 3); and melanocytoma on ciliary body biopsy (patient 4). Two patients were treated by several cyclodiode ciliary body ablation treatments and the other two underwent trabeculectomies and Molteno tubes. Two of the four patients have since died from their disease. Conclusion The ophthalmologist should re-evaluate the diagnosis in patients with anterior segment abnormalities and refractory ipsilateral glaucoma. Endothelial specular microscopy and biopsy of the suspicious lesion may give misleading reassurance. The potential presence of an anterior uveal melanoma must always be considered.

The accurate diagnosis of eyelid tumors such as basal cell carcinoma (BCC) requires histological confirmation, usually obtained by biopsy. Cytology provides a rapid alternative that can yield a diagnosis during the initial outpatient appointment. The accuracy of this technique has been reported to be very good but its sensitivity in the diagnosis of periocular lesions is unknown. In order to assess the accuracy of cytology in eyelid lesions suspected clinically to be BCCs, the cytological and histopathological diagnoses were compared retrospectively in 20 lesions from 17 consecutive patients who underwent cytology followed by excision biopsy. The sensitivity of cytology for the diagnosis of BCC was 92 compared with 88 for the diagnosis of malignant tumor. The predictive accuracy was 75 for either diagnosis. This was compared with a second group of 26 clinical BCCs from 22 consecutive patients who had incisional biopsy and histological examination followed by excision with histological confirmation, in which case the sensitivity was 100 and accuracy 96. It was concluded that cytology was sufficiently accurate to plan excision and reconstructive surgery, when a confirmatory tissue diagnosis can be made, but not sufficiently sensitive for conservative regimens such as radiotherapy because of the small risk of false negative diagnoses.

An applicator attached to a 6 MV linear accelerator has been adapted to produce a well defined beam for the treatment of retinoblastoma. By using a contact lens as the reference point on the patient's cornea, the beam edge is aligned to just behind the posterior margin of the crystalline lens, thus sparing the anterior chamber and lens from the radiation field. In addition to basic dosimetric measurements made using an ionisation chamber and film densitometry to quantify the output and dose distribution from the applicator, extensive use was made of thermoluminescent dosemeters and a tissue-equivalent anthropomorphic head phantom. This was designed for detailed dosimetry on the eye and was used to confirm the correct positioning and reproducibility of the clinical set-up. We present data that corroborate and extend the dosimetric analyses documented in an earlier Dutch publication. In addition to the improved dosimetric analysis, other advantages include patient immobilisation, anaesthetic procedure and finer couch control as well as a recommendation on the dose prescription.