Wilson W. K. Yip

Comparison of lidocaine 2% gel versus amethocaine as the sole anesthetic agent for strabismus surgery

PURPOSE To compare the efficacy of lidocaine 2% gel with amethocaine 1% eyedrops as the sole anesthetic agent for one-stage adjustable suture strabismus surgery. DESIGN Prospective, double-masked randomized trial. PARTICIPANTS Fourteen consecutive patients scheduled to undergo bilateral and symmetrical strabismus surgery under topical anesthesia in one institution. METHODS Each patient was randomized to receive lidocaine 2% gel in one eye and amethocaine 1% eyedrops in the other eye as the sole anesthetic agent for surgery. Masking of the patient and surgeon was ensured by administration of a placebo gel and eyedrop as part of the regimen. Pain and discomfort were assessed via a 10-cm visual analog scale. MAIN OUTCOME MEASURES Subjective pain and discomfort perceived during surgery were assessed separately by the patient and the surgeon, and the need for any additional anesthesia was recorded. RESULTS A total of 14 subjects indicated mean pain and discomfort scores of 2.6 and 3.2 respectively, for lidocaine gel, and 5.3 and 6.2, respectively, for amethocaine drops (P = 0.01). The mean number of additional drops required by eyes randomized to lidocaine gel was 0.3, compared with 1.6 for amethocaine drops (P = 0.02). CONCLUSIONS In terms of pain control, lidocaine 2% gel alone is a superior topical anesthetic for one-stage adjustable suture strabismus surgery when compared with amethocaine 1% eyedrops.

Two cases of X-linked juvenile retinoschisis with different optical coherence tomography findings and RS1 gene mutations.

The optical coherence tomography (OCT) findings, clinical features, and mutations in the RS1 gene of two unrelated patients with X‐linked retinoschisis (XLRS) are reported herein. Two Chinese patients with early onset XLRS were given a comprehensive ophthalmologic examination and OCT investigation. The RS1 gene was screened for sequence alterations in all exons and splice regions. The two patients presented with different phenotypic features and OCT findings. One patient with more severe clinical presentation had a RS1 exon 1 deletion and a P193S mutation was found in the other patient with mild macular involvement. OCT demonstrates the markedly different features of XLRS patients with different RS1 mutations. This study strengthens the role of OCT in the diagnosis and monitoring of XLRS.

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.

Refractive Errors and Concomitant Strabismus: A Systematic Review and Meta-analysis.

This systematic review and meta-analysis is to evaluate the risk of development of concomitant strabismus due to refractive errors. Eligible studies published from 1946 to April 1, 2016 were identified from MEDLINE and EMBASE that evaluated any kinds of refractive errors (myopia, hyperopia, astigmatism and anisometropia) as an independent factor for concomitant exotropia and concomitant esotropia. Totally 5065 published records were retrieved for screening, 157 of them eligible for detailed evaluation. Finally 7 population-based studies involving 23,541 study subjects met our criteria for meta-analysis. The combined OR showed that myopia was a risk factor for exotropia (OR: 5.23, P = 0.0001). We found hyperopia had a dose-related effect for esotropia (OR for a spherical equivalent [SE] of 2–3 diopters [D]: 10.16, P = 0.01; OR for an SE of 3-4D: 17.83, P < 0.0001; OR for an SE of 4-5D: 41.01, P < 0.0001; OR for an SE of ≥5D: 162.68, P < 0.0001). Sensitivity analysis indicated our results were robust. Results of this study confirmed myopia as a risk for concomitant exotropia and identified a dose-related effect for hyperopia as a risk of concomitant esotropia.

Retinopathy of prematurity: applicability and compliance of guidelines in Hong Kong.

Objective To analyse the incidence, application and compliance to Royal College of Ophthalmologists retinopathy of prematurity (ROP) screening recommendations and subsequent treatment of ROP in a neonatal intensive care unit of a large tertiary referral centre in Hong Kong. Design A retrospective review was performed for all eligible premature neonates screened for ROP over a 7-year period from June 2008 to December 2015 in our local tertiary neonatal intensive care unit in Prince of Wales Hospital, Hong Kong, using the Royal College of Ophthalmologists ROP screening guideline (2008). Comparison between established UK and American screening guidelines were analysed for their applicability in our locality. Results A total of 602 infants were screened, with the incidence of ROP in 28.2% and type 1 ROP in 3.8%, and indirect diode laser performed in all type 1 ROP cases. Overall, adherence for screening criteria was 99.7%, with the average time to commence first screening at 4 weeks postnatal age. Of the 602 cases, 94 (15.6%) were early and 35 (5.8%) were later than the guidelines, of which only 5 (0.8%) of late-screened cases developed ROP requiring treatment. Subsequent treatment of ROP for all the late-screened cases was not delayed. Conclusions Current ROP screening using the UK guidelines (2008) is applicable, effective and safe to our predominantly Asian population in Hong Kong, with a low rate of delayed screening.

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.

SUCCESSFUL TREATMENT OF REFRACTORY PROLIFERATIVE RETINOPATHY OF INCONTINENTIA PIGMENTI BY INTRAVITREAL RANIBIZUMAB AS ADJUNCT THERAPY IN A 4-YEAR-OLD CHILD.

Purpose: To describe a case of incontinentia pigmenti with proliferative retinopathy successfully treated by combination of repeated retinal laser photocoagulation and intravitreal ranibizumab injection. Methods: Single interventional case report of a 4-year-old girl, known case of incontientia pigmenti, first screened at the age of two, presented with proliferative retinopathy. Sole treatment by panretinal laser photocoagulation failed to control the progression of retinal neovascularization. Intravitreal ranibizumab injections were used as an adjunct therapy. Results: The proliferative retinopathy was brought under control and halted till this date with repeated intravitreal ranibizumab and panretinal photocoagulation. No systemic side effect was noted. Conclusion: Intravitreal ranibizumab can be considered as an adjunct therapy in proliferative retinopathy secondary to incontinentia pigmenti when monotherapy with panretinal photocoagulation fails. Intravitreal ranibizumab may quickly inhibit the intraocular vascular endothelial growth factor and may prevent devastating complications like tractional retinal detachment. Extra caution has to be taken in adopting different dosages and injection regimes especially in pediatric cases.

Serous retinal detachment in Joubert syndrome.

This report describes a 3-year-old Chinese-Italian boy with Joubert syndrome. Fundus examination showed bilateral optic disc coloboma. Left serous retinal detachment was also found. This ocular finding was not reported in the previous literature. Although Joubert syndrome has many variable phenotypes and the molecular basis is still unknown, the newly reported ocular features suggest that a different genetic form may be present.

Association of antenatal steroid and risk of retinopathy of prematurity: a systematic review and meta-analysis

Background Retinopathy of prematurity (ROP) is one of the leading causes of childhood blindness. Use of antenatal steroid can reduce neonatal morbidity and mortality in preterm births, but its effect on ROP remained controversial. We aim to determine the association between antenatal steroid and risk of ROP by a systematic review and meta-analysis. Methods Reported studies on the association between antenatal steroid and risk of ROP or severe ROP were identified from MEDLINE and Embase databases from their inception to November 2016. Outcome measures were ORs with 95% CIs. Extracted data were pooled using a random-effect model or fixed-effect model where appropriate. Heterogeneity was assessed, and sensitivity analysis was performed. Results A total of 434 relevant studies were identified, and 28 studies were eligible for the meta-analysis, involving 20 731 neonates with 4202 cases of ROP. Among the 28 studies included, 13 studies provided data evaluating the association between antenatal steroid use and severe ROP, involving 4999 neonates with 792 cases of severe ROP. Antenatal steroid administration was associated with a reduced risk of ROP development (ORunadjusted=0.82, 95% CI 0.68 to 0.98; ORadjusted=0.67, 95% CI 0.47 to 0.94) and progression to severe ROP (ORunadjusted=0.58, 95% CI 0.40 to 0.86). Conclusion Antenatal steroid administration is associated with a reduced risk of ROP development and progression to severe ROP. Our results strengthened the indications of antenatal steroid therapy to high-risk mothers giving preterm births, especially in low-income and middle-income countries where antenatal steroid are not yet widely used.

Re: Screening for retinopathy of prematurity and treatment outcome in a tertiary hospital in Hong Kong

To the Editor—We read with interest the elegant study by Iu et al1 on the prevalence and severity of retinopathy of prematurity (ROP) in a tertiary hospital in Hong Kong. Compared with their data in which the incidence of ROP was 16.9% in 89 premature infants screened over 1 year,1 our analysis of 602 infants screened over 7 years2 and another local study of 513 infants over 5 years3 revealed a ROP prevalence of 28.2 and 18.5%, respectively. We would like to highlight the point that the prevalence rates could be related to the case-mix. We had a larger proportion of high-risk infants. Our youngest mean gestational age was 29+3 weeks compared with 30+2 weeks in Iu et al’s study1 and 30 weeks in Yau et al’s study.3 We also had a higher proportion of extremely low birth weight (ELBW) infants (<1000 g; 24.1%2 vs 19.1%1). This may reflect socio-economic differences and the complexity of cases. Among ELBW infants, however, a comparable percentage (70.6%1 vs 71.7%2) developed ROP and treatment rates among the studies were also very similar (3.4%1, 3.8%2, and 3.7%3). While all three studies adopted the Royal College of Ophthalmologists ROP guidelines,1-3 Iu et al1 identified 11 infants who would not have been screened had the American Academy of Pediatrics’ criteria been applied, and none of whom developed Hong Kong Med J 2017;23:316 DOI: 10.12809/hkmj176306