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Primary orbital Ewing's sarcoma is a very rare condition. Since the first case was reported in 1950, only 7 other cases have been reported in the English literature. Herein we describe the ninth, the only bilateral and the youngest case of primary orbital Ewing's sarcoma occurring in a 2-year-old boy, who presented to us with bilateral painless proptosis. Tissue biopsy of the tumour was obtained through the nasal sinus. Immunohistological studies of the biopsy tissue confirmed the diagnosis of Ewing's sarcoma. No distant site of the tumour was found so this was considered a primary orbital tumour. Combined chemotherapy and radiotherapy without surgical resection achieved an encouraging result in that the patient has remained in remission for 30 months after completion of treatment. The successful use of combined chemotherapy and radiotherapy, without surgery, adds further support to evidence that surgical excision may be avoided in selected cases of primary orbital Ewing's sarcoma.

Ten consecutive cases of severe unilateral congenital ptosis were surgically corrected before 1 year of age (range 3-11 months) in an attempt to achieve early functional and cosmetic improvement. In all cases, a frontalis suspension using Mersilene mesh was performed. With a mean follow-up of 40.3 months (range 33-54 months), all patients achieved normal or near normal eyelid position and all had their chin-up head posture resolved. One patient developed a mild exposure keratitis that was treated successfully with topical antibiotics and lubricants. Our findings suggest that the Mersilene mesh sling has good potential for ptosis management in infants who are too young for fascial harvesting. However, a larger series with a longer follow-up period is required before the eventual safety and efficacy of the Mersilene mesh sling can be properly ascertained.

Cystic schwannoma of the orbit is unreported in the world literature. A 54-year-old Caucasian man presented to our clinic with a 5 year history of progressive right-sided proptosis and diplopia. A large paramedian cystic mass displacing the right globe downwards and laterally was demonstrated. From the clinical and radiological features, the presumptive diagnosis of right frontal sinus mucocoele was made. However, the excisional biopsy of the lesion revealed the rare diagnosis of cystic schwannoma, arising from a branch of the first division of the trigeminal nerve. Post-operatively, the patient had a smooth recovery with visual acuity of 20/20 in each eye; full binocular single vision was also re-established. The differential diagnoses of cystic orbital mass, and the radiological and histological findings of the lesion, are described and discussed.

To compare the ocular-hypertensive and anti-inflammatory response to rimexolone (116-hydroxy-16alphafluoro-6alphamethylpresdnisolone) and fluorometholone (21-deoxy-9alphafluoro-6alphamethylprednisolone) therapy in children's eyes.With parental consent, children who underwent surgical procedures for bilateral symmetric strabismus from January 18, 2000, through November 16, 2001, were recruited. One eye was randomized to receive topical 1% rimexolone while the contralateral eye received topical 0.1% fluorometholone, 4 times daily for 4 weeks.Intraocular pressures and anti-inflammatory responses were the main outcome measures and were serially measured postoperatively for 8 weeks.Fifty-four children, aged from 4 to 8 years (mean [SD] age, 5.33 [1.26] years), participated in the study. Intraocular pressure increased significantly in both treatment groups compared with the preoperative values (P.001). The mean (SD) peak intraocular pressure was significantly higher in the rimexolone-treated group, 19.7 (6.1) vs 17.6 (4.6) mm Hg (P.001). Similarly, the mean (SD) net increase in intraocular pressure (P.001), was also higher in the rimexolone-treated eyes, 5.9 (4.4) vs 3.9 (4.1) mm Hg (P.001). In addition, a greater percentage of the rimexolone-treated patients had no conjunctival erythema on days 13 (11.1% vs 0.0%) and 20 (88.9% vs 55.6%) (P =.03).Rimexolone seems to be a more effective anti-inflammatory agent than fluorometholone. However, unlike adults, the ocular-hypertensive effect in children treated with rimexolone was higher. It would be desirable to monitor the intraocular pressure regularly when rimexolone therapy is used in children.

We investigated sequence alternation, promoter methylation, and loss of heterozygosity (LOH) of the RB1 gene as possible mechanisms of its inactivation in retinoblastoma. In 42 Chinese patients with sporadic retinoblastoma, the promoter and entire coding region of RB1 were examined for sequence changes. Status of methylation of the CpG-rich island at the 5'end was determined by methylation specific PCR assay. We detected 15 RB1 mutations in 38% (16/42) of the retinoblastoma patients, among them 19% (8/42) were germ-line mutations. A total of nine novel mutations were identified: E54X, S114X, I126S, g73779insG, D718N, IVS2+1G>C, IVS14+1G>C, IVS21+1G>C, and a complex alteration g78177G>T/g78176insTT leading to 543X. Most of them are likely to affect the RB1large pocket domain through the production of truncated gene products. None of the DNA samples showed methylation at the RB1promoter. In 15 cases where both normal and cancerous retinoblastoma tissue specimens were available, allelic loss according to microsatellite markers within or distal to the RB1 locus was analyzed and immunohistological staining for RB1 expression performed. Among them, frequency of LOH at 13q14 was found to be high at 60% (9/15) with no segregation with unilateral tumors. All these nine tumors did not express RB1 protein, showing an association of LOH at the RB1 locus with its loss of expression in retinoblastoma. Our results indicate that the RB1 gene in sporadic retinoblastoma is commonly inactivated because of loss-of-function mutations and loss of heterozygosity but not by the epigenetic phenomenon of promoter hypermethylation.