Three different ophthalmic presentations of juvenile xanthogranuloma.

Three cases of juvenile xanthogranuloma from two ophthalmology departments were reviewed. Clinical histories, ophthalmic examination, physical examination, investigations, and treatment of these cases are described. A 4-month-old boy presented with spontaneous hyphema and secondary glaucoma. He was treated with intensive topical steroid and anti-glaucomatous eye drops. The hyphema gradually resolved and the intra-ocular pressure reverted to 11 mm Hg without any other medication. Biopsy of his scalp mass confirmed the diagnosis of juvenile xanthogranuloma. A 31-month-old boy presented with a limbal mass. Excisional biopsy of the mass was performed and confirmed it was a juvenile xanthogranuloma. A 20-month-old boy was regularly followed up for epiblepharon and astigmatism. He presented to a paediatrician with a skin nodule over his back. Skin biopsy confirmed juvenile xanthogranuloma. He had no other ocular signs. Presentation of juvenile xanthogranuloma can be very different, about which ophthalmologists should be aware of. Biopsy of the suspected lesion is essential to confirm the diagnosis.

Allelic imbalance at 13q31 is associated with reduced GPC6 in Chinese with sporadic retinoblastoma.

BACKGROUND/AIMS: Loss of heterozygosity (LOH) has been discovered in retinoblastoma (RB) in previous studies. In this study, we aimed to discover potential tumour suppressor genes through investigation of the incidence of allelic loss in chromosome 1, 6, 9, 13, 19, 20, 21, 22 and X in Chinese sporadic retinoblastoma patients and to study the expression of genes flanking LOH region 13q31. METHODS: Twenty-five microdissected RB samples were analysed to investigate the LOH in 140 microsatellite markers. Expression of genes flanking D13S265 was investigated by real-time quantitative-PCR on available frozen samples. The promoter and entire coding region of GPC6 were examined for sequence changes in an extended batch of 29 RB samples. RESULTS: Allele losses were found in 92% (23/25) of the tumours. We identified a new LOH locus at 13q31 (D13S265) with a high occurrence rate (67%, 14/21) apart from the RB1 locus (68%, 17/25). Expression study detected the reduced expression of Glypican 6 (GPC6) transcript significantly associated with the LOH at 13q31 (p=0.024). Furthermore, mutation screening revealed no remarkable sequence alteration in GPC6 that could affect its expression. CONCLUSION: Results suggest that a reduction in GPC6 mRNA in retinoblastoma is associated with the non-random allelic loss at 13q31 that could contribute to RB development.

An unusual complication after strabismus surgery.

Orbital cellulitis is rarely reported after strabismus surgery; fewer than 10 cases have been reported. Nonetheless, orbital cellulitis is a potentially sight- and life-threatening condition. A high index of suspicion, use of a multidisciplinary approach, early diagnosis, aggressive treatment, and close monitoring are all important means of avoiding potentially irreversible visual loss and systemic complications. We report a case where early use of aggressive treatment to manage a post-strabismus surgery infection led to a good outcome.

Use of Anterior Segment OCT in the Evaluation and Management of Congenital Aphakia.

Anterior segment optical coherence tomography (AS-OCT) is a noninvasive technology capable of capturing high-resolution images of the anterior segment. With AS-OCT, a 7-year-old boy with nystagmus was diagnosed as having secondary congenital aphakia. The presence of lens capsules on the AS-OCT was of significant prognostic and management value and the child later benefited from bilateral sulcus-fixated intraocular lens implantation surgery. AS-OCT also required less cooperation from the patient compared to ultrasound biomicroscopy. To the authors' knowledge, this is the first reported case of congenital aphakia diagnosed by AS-OCT.

Prenatal screening for retinoblastoma in Hong Kong.

We report the first use in Hong Kong of molecular techniques to screen prenatally for retinoblastoma and review 17 cases of retinoblastoma seen at the Hong Kong Eye Hospital from 2001 to 2006. A pregnant couple whose first child had retinoblastoma requested prenatal screening for retinoblastoma during their second pregnancy in 2000. Whole RB1 coding gene sequencing was performed on peripheral blood cells taken from family members and cultured amniocytes collected from the foetus during the 14th week of gestation. No RB1 gene mutations were found in the amniocyte samples and at birth the baby had no evidence of ocular tumours. During 5 years of follow-up the child remained healthy with intact visual function. Prenatal diagnosis of retinoblastoma alleviates parental stress and improves the perinatal care of affected family members.

Anterior segment ischemia after two-muscle surgery in a patient with radiation-treated nasopharyngeal carcinoma.

Anterior segment ischemia after strabismus surgery is a rare occurrence. Risk factors include single-stage surgery of three or more muscles in one eye, dysthyroid eye disease, and advanced age. The authors report a case of anterior segment ischemia after single-stage surgery of two horizontal muscles without previous reported risk factors. However, the patient had received radiotherapy for nasopharyngeal carcinoma more than 20 years ago. The case was successfully treated with systemic steroids but with reduced best-corrected visual acuity. Previous radiotherapy in the related orbital field may be a new risk factor for this condition.

Randomized trial of early phacoemulsification versus peripheral iridotomy to prevent intraocular pressure rise after acute primary angle closure.

PURPOSE: To compare the efficacy of early phacoemulsification versus laser peripheral iridotomy (LPI) in the prevention of intraocular pressure (IOP) rise in patients after acute primary angle closure (APAC). DESIGN: Prospective randomized controlled trial. PARTICIPANTS: Sixty-two eyes of 62 Chinese subjects, with 31 eyes in each arm. METHODS: Subjects were randomized to receive either early phacoemulsification or LPI after aborting APAC by medications. Patients were followed up on day 1; week 1; and months 1, 3, 6, 12, and 18. Predictors for IOP rise were studied. MAIN OUTCOME MEASURES: Prevalence of IOP rise above 21 mmHg (primary) and number of glaucoma medications, IOP, and Shaffer gonioscopy grading (secondary). RESULTS: Prevalences of IOP rise for the LPI group were 16.1%, 32.3%, 41.9%, and 46.7% for the follow-ups at 3, 6, 12, and 18 months, respectively. There was only one eye (3.2%) in the phacoemulsification group that had IOP rise at all follow-up time points (P<0.0001). Treatment by LPI was associated with significantly increased hazard of IOP rise (hazard ratio [HR], 14.9; 95% confidence interval [CI], 1.9-114.2; P = 0.009). In addition, a maximum IOP at presentation > 55 mmHg was associated with IOP rise (HR, 4.1; 95% CI, 1.3-13.0; P = 0.017). At 18 months, the mean number of medications required to maintain IOP 55 mmHg is an added risk factor for subsequent IOP rise. For patients with coexisting cataract and presenting IOP of >55 mmHg, early phacoemulsification can be considered as a definitive treatment to prevent IOP rise.

Changes in refraction and ocular dimensions after cataract surgery and primary intraocular lens implantation in infants.

PURPOSE: To study refraction and axial length changes after cataract extraction and primary intraocular lens (IOL) implantation in children younger than 1 year of age. SETTING: Two regional hospitals. METHODS: After determining the IOL power for emmetropia, 80% of the value was used to choose the IOL for implantation to counter anticipated myopic shift with age. The main outcome measures were changes in refraction and axial length 3 years after surgery. RESULTS: Thirty-four eyes of 20 children (mean age 6.7 months +/- 3.9 [SD]) were studied. Refraction in the immediate postoperative period was +4.53 +/- 1.45 diopters (D). Three years after surgery, the mean refraction was -2.49 +/- 3.08 D (P<.001). Twenty-two eyes (64.7%) had surgery during the first 6 months of life (group 1) and had a shorter axial length at surgery (mean 18.92 +/- 1.32 mm) compared with 12 eyes (35.3%) that received surgery between 7 and 12 months (group 2, mean 20.29 +/- 1.00 mm) (P = .007). However, the final axial length was greater in group 1 (mean 22.67 +/- 1.04 mm) than in group 2 (mean 21.23 +/- 0.26 mm) (P = .019). CONCLUSIONS: Primary IOL implantation is an option for children having cataract surgery in the first year of life. Significant myopic shifts occurred, and this seemed to be more pronounced in younger children. It appears that rethinking current strategies for IOL power calculation may be required to achieve more optimal refractive outcomes.

The use of peribulbar anaesthesia in paediatric cataract surgery (age 7-15 years) in a mobile eye camp in China.

AIM: To evaluate the feasibility and acceptability of the use of peribulbar anaesthesia (PA) in paediatric cataract surgery in rural areas in China, where there are limitations in expertise and equipment for general anaesthesia (GA). METHODS: We prospectively evaluated the feasibility and acceptability of carrying out paediatric cataract surgery under PA in children aged 7-15 years. Informed consent was obtained from the subjects and their parents. Children were assessed for their suitability for PA. Peribulbar anaesthesia was given as a peribulbar block using a 2% lidocaine, 0.5% bupivacaine-hyaluronidase mixture administered before lens aspiration with intraocular lens implantation. The acceptability of the PA was evaluated by questionnaire. RESULTS: A total of 19 patients were recruited. Their mean age was 12 +/- 2 years (range 7-15 years). None required conversion to GA. All subjects regarded PA as either totally acceptable (63.2%) or acceptable (36.8%). The mean pain scores (from 0 to 100) during the injection and surgery were 28 +/- 26 and 6 +/- 8, respectively. Seventeen patients (89.5%) said they would prefer PA if choices in anaesthesia were offered again. CONCLUSIONS: Peribulbar anaesthesia can be considered as a viable option in selected children undergoing cataract surgery when facilities for safe and optimal general anaesthesia are unavailable.

25-gauge transconjunctival sutureless vitrectomy system in the surgical management of children with posterior capsular opacification.

PURPOSE: To evaluate the safety and efficacy of the 25-gauge transconjunctival sutureless vitrectomy (TSV) system in the surgical management of posterior capsular opacification (PCO) in pseudophakic children. METHODS: Pars plana membranectomy was performed for PCO in 10 pseudophakic eyes of six children (mean age 35.1 +/- 37.8 months; range 6-93 months) using the TSV system. Surgical technique, intraoperative problems and postoperative complications including wound leakage, hypotony and the need for suturing were recorded. RESULTS: Wound leakage and other intraoperative problems were not noted in any of the eyes. All eyes showed improvement of visual acuity from a mean of 6/67 before to 6/29 after surgery (P = 0.001). Mean postoperative intraocular pressure (IOP) was 7.8 +/- 3.1 mmHg (range: 3-10 mmHg). Four eyes (40%) had hypotony on the first postoperative day (IOP: 3-5 mmHg), which was transient in three eyes. One eye in a patient with uveitis had persistent hypotony, but hypotony was also present preoperatively, and the postoperative IOP returned to preoperative levels. This eye also developed recurrent PCO and a second capsulotomy was performed using the 25-gauge TSV system. CONCLUSIONS: Posterior capsulotomy using the 25-gauge TSV system appears to be a safe and effective approach in the management of PCO in pseudophakic children. Advantages include easier manipulation with the smaller instruments in these small eyes, and it can be considered in appropriate cases.

Ocular hypertensive and anti-inflammatory responses to different dosages of topical dexamethasone in children: a randomized trial.

BACKGROUND: The purpose of the present study was to investigate the ocular hypertensive and anti-inflammatory responses to two different dosage schedules of 0.1% topical dexamethasone in a population of Chinese children undergoing strabismus surgery. METHODS: Children undergoing bilateral strabismus surgeries were randomly assigned to receive topical 0.1% dexamethasone eye drops four times daily (group A) or twice daily (group B) for 4 weeks. Intraocular pressure (IOP) and anti-inflammatory responses were monitored for 8 weeks. RESULTS: A total of 137 children with mean age 6.5 years (SD, 1.9 years; range, 3-10 years) participated in the study. The IOP increased significantly after 4 weeks in both groups compared to the preoperative values (P < 0.001). Peak IOP ranged from 14.0 to 50.3 mmHg in group A and 11.0-41.3 mmHg in group B. Cases in group A (mean, 13.8 mmHg; SD, 8.4 mmHg) had a greater net increase in IOP than cases in group B (mean, 10.2 mmHg; SD, 6.2 mmHg; P = 0.004). Younger-aged children had higher peak IOP (r = -0.244, P = 0.048), and attained the peak IOP earlier (r = 0.252, P = 0.041) in group A. There was no significant difference in ocular inflammatory response between the two groups. CONCLUSION: Ocular hypertensive effect to topical 0.1% dexamethasone is dose and age dependent in children. Twice-daily 0.1% topical dexamethasone eye drops control inflammation after strabismus surgery as effectively as four-times-daily dosage, but induces less increase in IOP, and may be a better treatment schedule.

Clinical implications of promoter hypermethylation in RASSF1A and MGMT in retinoblastoma.

We investigated the epigenetic silencing and genetic changes of the RAS-associated domain family 1A (RASSF1A) gene and the O6-methylguanine-DNA methyltransferase (MGMT) gene in retinoblastoma. We extracted DNA from microdissected tumor and normal retina tissues of the same patient in 68 retinoblastoma cases. Promoter methylation in RASSF1A and MGMT was analyzed by methylation-specific PCR, RASSF1A sequence alterations in all coding exons by direct DNA sequencing, and RASSF1A expression by RT-PCR. Cell cycle staging was analyzed by flow cytometry. We detected RASSF1A promoter hypermethylation in 82% of retinoblastoma, in tumor tissues only but not in adjacent normal retinal tissue cells. There was no expression of RASSF1A transcripts in all hypermethylated samples, but RASSF1A transcripts were restored after 5-aza-2'-deoxycytidine treatment with no changes in cell cycle or apoptosis. No mutation in the RASSF1A sequence was found. MGMT hypermethylation was present in 15% of the retinoblastoma samples, and the absence of MGMT hypermethylation was associated (P = .002) with retinoblastoma at advanced Reese-Ellsworth tumor stage. Our results revealed a high RASSF1A hypermethylation frequency in retinoblastoma. The correlation of MGMT inactivation by promoter hypermethylation with lower-stage diseases indicated that MGMT hypermethylation provides useful prognostic information. Epigenetic mechanism plays an important role in the progression of retinoblastoma.

Prevalence and characteristics of peripheral retinal degeneration in Chinese adults with high myopia: a cross-sectional prevalence survey.

PURPOSE: The purpose of this study was to study the prevalence of peripheral retinal findings in adult Chinese patients with high myopia (refraction < or = -6.00 D) and to investigate the correlation between the retinal lesions and the severity of myopia or axial length. METHODS: A cross-sectional prevalence survey screening was conducted in high ethnic Chinese myopes with refractions equal to or less than -6.00 D. The examinations included cycloplegic refraction, A and B scan ultrasonography, and retinal examinations by indirect ophthalmoscopy with scleral indentation and Goldmann three-mirror contact lens examination. RESULTS: Two hundred thirteen eyes in 213 patients with a mean refraction of -10.10 +/- 4.23 D (range = -6.00 to -27.00 D) were examined. The mean axial length was 26.69 +/- 1.68 mm (range = 25.18-33.62 mm) and the mean age was 33.5 +/- 10.6 years (range = 18-73 years). The most common peripheral retinal finding was pigmentary degeneration (51.2%), followed by lattice degeneration in 12.2% and retinal holes in 7.5% of eyes. A positive correlation was noted between axial length and the lesions of pigmentary degeneration and pavingstone degeneration. The prevalence of retinal holes was 6.4% and 30.0% in eyes with axial length of < 30 mm and > or = 30 mm, respectively (chi-squared test, p = 0.006). CONCLUSION: A high prevalence of peripheral retinal degenerations was found in adult Chinese high myopes. The presence of retinal holes was positively correlated with very high myopia of an axial length of > or = 30 mm.

Intraocular pressure measurement in patients with previous LASIK surgery using pressure phosphene tonometer.

PURPOSE: To compare intraocular pressure (IOP) assessment in post-LASIK patients using non-contact tonometry, pressure phosphene tonometry and applanation tonometry. METHODS: Sixty-two consecutive LASIK patients were analysed preoperatively and postoperatively with non-contact, pressure phosphene and applanation tonometry. Comparisons among these values were assessed with paired sample Student t-test, Pearson's correlation test and Bland-Altman plotting. RESULTS: There was no significant difference for preoperative IOP measurement between non-contact, pressure phosphene and applanation tonometry. The mean +/-SD difference between the preoperative non-contact tonometry and postoperative pressure phosphene tonometry IOP measurements was 0.80 +/- 2.77 mmHg (P < 0.01). Postoperative applanation tonometry significantly underestimated IOP measurement by 5.45 +/- 2.96 mmHg (P < 0.001) and postoperative non-contact tonometry significantly underestimated IOP measurement by 9.96 +/- 2.25 mmHg (P < 0.001). CONCLUSION: Pressure phosphene tonometry may provide an alternative method for the assessment of IOP in post-LASIK patients.

Failure of systemic antibiotic in preventing sequential endogenous endophthalmitis of a bronchiectasis patient.

PURPOSE: To report a rare presentation of bilateral, sequential Pseudomonas aeruginosa endogenous endophthalmitis in a woman with bronchiectasis. DESIGN: Interventional case report. METHODS: A 69-year-old woman with bronchiectasis developed right and then left endogenous endophthalmitis with the microbial of P. aeruginosa, even though a course of 3-week intravenous ceftazidime antibiotic was prescribed. RESULTS: The presentation of endogenous endophthalmitis in the right eye was late, and final visual acuity was hand movements. The condition was recognized much earlier in the left eye, and the infection was treated early on with vitrectomy and intravitreal antibiotics. Visual acuity at 1 year was stable at 20/40. CONCLUSION: Systemic antibiotic failed to eradicate the primary source of Pseudomonas infection in the bronchiectasis patient. Unusual, painful red eye may be the presenting feature of endogenous endophthalmitis. Early vitrectomy may be considered in endogenous endophthalmitis caused by virulent pathogens such P. aeruginosa.

Intravitreal triamcinolone for diabetic macular oedema in Chinese patients: six-month prospective longitudinal pilot study.

AIM: To evaluate the safety and efficacy of intravitreal triamcinolone (IVTA) in Chinese patients with diabetic clinical significant macular oedema (CSMO). METHODS: Eighteen eyes of 17 consecutive patients with CSMO were prospectively recruited and treated with a 4 mg injection of IVTA. Best-corrected visual acuity (BCVA) on the ETDRS chart and central macular thickness (CMT) on optical coherence tomography were measured at baseline weeks 1, 2, 3, and months 1, 2, 3, 4, 5 and 6. Side-effects were monitored. RESULTS: All patients completed 6 months of follow up. The mean baseline BCVA and CMT were 1.20 +/- 0.31 logMAR units and 552 +/- 179 microm, respectively. Improvements in CMT and BCVA were observed as early as at 1 and 2 weeks, respectively (P < 0.05). Mean BCVA peaked at 2 months (0.97 +/- 0.38 logMAR units) while mean CMT was maximally reduced at 3 months (326 +/- 145 microm). Improvements in BCVA and CMT were less afterwards but still statistically significant at 6 months; the final mean BCVA and CMT were 0.99 +/- 0.36 logMAR units and 427 +/- 145 microm, respectively. A total of 5/18 (28%) eyes developed a transient increase in intraocular pressure. Cataract progression was noted in 2/12 (17%) of the phakic eyes. CONCLUSIONS: Intravitreal triamcinolone appeared generally safe and effective in Chinese patients with CSMO. Although the improvements in BCVA and CMT were transient, there were residual benefits at 6 months. Due to the transient nature of IVTA, re-treatment seems necessary but the optimal timing and dosage will require further investigations.

Ocular manifestations and surgical management of lid coloboma in a Chinese infant with linear nevus sebaceous syndrome.

An 8-month-old Chinese girl with linear nevus sebaceous syndrome had a right upper lid coloboma and right superior scleral ectasia. At 20 months old, successful surgical repair of the lid coloboma was performed with particular attention paid to the sclera ectasia.

Microsatellite instability and MLH1 promoter methylation in human retinoblastoma.

PURPOSE: To investigate the link between microsatellite instability and epigenetic silencing of the MLH1 gene in the human retinoblastoma genome. METHODS: Methylation at the 5' region of MLH1 was studied, along with its protein expression level by using immunohistochemical staining in 51 retinoblastoma tumors and 2 retinoblastoma cell lines. Also assessed was the genomic stability of 26 retinoblastoma DNAs from microdissected tumor tissue and matched normal retina tissue obtained from the same patient by microsatellite instability (MSI) analysis. The National Cancer Institute-designed reference panel, and 85 markers on chromosomes 1, 6, 9, and 13 were used. RESULTS: Hypermethylation of the MLH1 promoter was detected in the WERI-Rb1 cell line and in 34 (67%) of the 51 tumors, but not in cell line Y79 and the other 17 tumors. MLH1 hypermethylation was associated with null MLH1 protein expression (P < 0.0005) and with well-differentiated histology (P < 0.05). MSI at three markers (D2S123, D6S470, and D13S265) was frequently identified among 26 retinoblastoma specimens with matched normal DNA. Among these 26 retinoblastomas, high-frequency MSI (MSI-H) tumors were detected in 19% (5/26) and low-frequency MSI (MSI-L) in another 19% (5/26). The remaining 62% (15/26) were genetically stable (MSS). MSI status (MSS, MSI-L, and MSI-H) was not associated with MLH1 promoter hypermethylation (P = 0.088; Kruskal-Wallis test). CONCLUSIONS: Epigenetic silencing of the DNA repair gene MLH1 by promoter hypermethylation is a frequent event in retinoblastoma. The results showed that somatic genetic changes involving MSI occur in a subset of retinoblastoma and implicated the presence of a defective DNA mismatch repair pathway resulting in MSI in retinoblastoma.