Surgical outcome of single-staged three horizontal muscles squint surgery for extra-large angle exotropia.

PURPOSE: To report the surgical outcomes of 24 patients undergoing single-staged three horizontal muscles squint surgery for extra-large angle exotropia. PATIENTS AND METHODS: Prospective case series of 24 consecutive patients with primary exotropia>60 prism diopters (PD) at distant and underwent single-staged three horizontal muscles squint surgery from 2003 to 2006. Surgery consisted of bilateral lateral rectus recession of 9.0 mm for 50 PD exotropic correction. For every 5 PD remaining angle exceeding 50 PD, we additionally performed 1.0 mm of unilateral medial rectus resection. The mean follow-up period was 15.8 months (range 6.0-38.0 months; SD 9.5 months). RESULTS: The mean age at surgery was 31.2 years old (range 7-78 years old, SD 18.2 years old). The mean distant preoperative deviation was 71.3 PD (range 60-85 PD, SD 7.7 PD). No limitation of eye movement or diplopia was found. The success rate was higher in the intermittent group (88.2%) than the constant group (42.9%) (P=0.02) and in cases with preoperative deviation of <80 PD (84.2%) compared with those with deviation>or=80 PD (40.0%) (P=0.042). CONCLUSION: Measurement of preoperative deviation and the surgery for extra-large angle exotropia made management of this condition difficult. Single-staged three horizontal muscles squint surgery can be one of the options. Further researches on management of exotropia of >80 PD are warranted.

Unilateral ptosis correction with mersilene mesh frontalis sling in infants: thirteen-year follow-up report.

PURPOSE: To assess surgical, visual, refractive, and aesthetic outcomes 13 years after mersilene mesh frontalis sling (MMFS) operation for severe unilateral congenital ptosis performed in 10 infants before 1 year of age. METHODS: Longitudinal follow-up of an interventional case series by structured ocular examinations, external photographs, and questionnaire-based interviews. RESULTS: Mean age at surgery was 6.9+/-2.7 months. After a mean follow-up of 13.0+/-0.6 years, one patient (10%) had recurrent ptosis with the upper lid 2 mm below the superior limbus at 3 months postoperatively. Best-corrected visual acuities were within two Snellen lines between the two eyes in all patients. Astigmatic errors were 1.20+/-1.00 D and 1.10+/-1.70 D between operated and unoperated eyes. Four patients had 2 mm lid lag on down-gaze and one of them had 2 mm lagophthalmos. Mean satisfaction scores (scale of 1 to 100) for lid position, cosmesis, function, and to the procedure were 83.3+/-11.8, 77.0+/-22.9, 89.4+/-5.5, and 86.8+/-6.3, respectively. No case of overcorrection, sling extrusion, stitch granuloma, or exposure keratopathy was noted. CONCLUSIONS: In view of the low recurrence rate (10%) and absence of serious complication or need for revision after 13 years, the use of MMFS seems effective and feasible in infants less than 1 year old. Achieving compatible long-term stability, satisfactory aesthetic, and visual outcomes, MMFS may offer an alternative to delaying operations for autogenous fascia lata harvesting in infants requiring early ptosis correction.

Residual torticollis in patients after strabismus surgery for congenital superior oblique palsy.

AIM: To study postoperative residual vertical deviation and abnormal head posture (AHP) after surgical treatment for congenital superior oblique palsy (SOP). METHOD: Children with both SOP and AHP who underwent extraocular muscle surgery for correction of AHP were recruited. The patients received complete ophthalmic and orthopaedic examinations. Residual AHP was classified according to severity of face turn, head tilt and chin elevation. RESULTS: Thirty-two children with mean age at operation of 82.6 months were recruited, with mean follow-up of 37.9 months. Of these children, 65.6% had a postoperative vertical deviation of less than three prism dioptres. In addition, 34.4% patients had resolved (0 degrees ), 34.4% had mild (1 degrees -10 degrees ), and 31.3% had significant residual torticollis (>10 degrees ). Of the patients with significant residual torticollis, 33.3% had ocular causes. The mean age at operation for the patients with residual torticollis (95.9 months) was older than those without torticollis (79.9 months) (p = 0.018). Residual torticollis was found to be related to sternocleidomastoid muscle tightness (p = 0.013). CONCLUSION: The success rate for eliminating significant AHP after strabismus surgery for patients with congenital SOP was 68.8%. Early surgery was associated with a better outcome. Association was also found between sternocleidomastoid tightness and AHP. A multidisciplinary approach is recommended in the management of torticollis as ophthalmic and orthopaedic comorbidities can coexist.

Peripheral and posterior pole retinal lesions in association with high myopia: a cross-sectional community-based study in Hong Kong.

PURPOSE: To evaluate the prevalence and factors associated with posterior pole and peripheral retinal lesions in Chinese subjects with high myopia. METHODS: Three hundred and thirty-seven asymptomatic adults with high myopia of refractive error

Causes of childhood blindness in a school for the visually impaired in Hong Kong.

OBJECTIVE: To identify the causes of blindness in children attending a school for the blind in Hong Kong. DESIGN: Cross-sectional observational study. SETTING: School for blind children in Hong Kong. PARTICIPANTS: Eighty-two blind students at the Ebenezer School and Home for the Visually Impaired were examined between December 1998 and August 1999. MAIN OUTCOME MEASURES: Demographic data were obtained from students and a questionnaire assessment made of their medical and ocular history. Visual acuity was assessed and visual loss classified according to the World Health Organization classification of visual impairment. Complete ophthalmic assessments were performed in all students including slit-lamp examination and dilated binocular indirect ophthalmoscopy. RESULTS: The mean age of the students was 12.2 years. Ten (12.2%) had a family history of eye disease. Major past medical illnesses were reported in 50% with prematurity and diseases of the central nervous system found in 26.8% and 11.0% of students, respectively. The most common anatomical site for visual impairment was the retina (47.6%), followed by diseases of the optic nerve (14.6%), and diseases of the anterior segment and the lens (14.6%). CONCLUSIONS: The pattern of childhood blindness in Hong Kong is similar to that seen in other developed countries. Preventable causes of childhood blindness, such as prematurity and birth asphyxia, were responsible for a large proportion of cases. Early diagnosis and treatment of such conditions may reduce the incidence of childhood blindness in Hong Kong.

Phacoemulsification with intravitreal triamcinolone in patients with cataract and coexisting diabetic macular oedema: a 6-month prospective pilot study.

AIMS: To assess the safety and efficacy of phacoemulsification with intravitreal triamcinolone (ivTA) injection in diabetics with cataract and clinically significant macular oedema (CSMO). METHODS: A total of 19 eyes of 15 consecutive diabetic patients with cataract and CSMO were prospectively recruited. Patients underwent phacoemulsification and intraocular lens implantation with 4 mg ivTA injection at completion of surgery. Patients were followed up on day 1, then weekly for 1 month, and thereafter monthly until 6 months postoperatively. Best corrected visual acuity (BCVA), central macular thickness (CMT) measured by optical coherence tomography, and adverse events were recorded. RESULTS: In total, 17 eyes completed 6 months of follow-up. In all, 58.8% showed improvement in BCVA of >or=2 lines, with statistically significant improvement in mean Snellen BCVA of 2.4 lines at 6 months. The peak BCVA was achieved at 4 months. The mean CMT decreased from a baseline of 449 microm to a minimum of 321+/-148 microm (28.5% reduction) achieved at 2 months, with statistically significant reduction at all postoperative time intervals until 6 months. Of 17 eyes, 4 (23.5%) developed transiently elevated intraocular pressure that normalised by 6 months in all but one patient. No injection- or surgery-related complications were encountered. CONCLUSIONS: Phacoemulsification with concurrent 4 mg ivTA injection appears to be a safe option for managing diabetics with cataract and CSMO. However, large-scaled randomised controlled trials are necessary for delineating the relative contributions of cataract removal and CMT reduction to visual improvement. Moreover, the transient effect on CMT may warrant further studies to determine optimal timing and dosage of further ivTA injections.

Ocular-hypertensive response and corneal endothelial changes after intravitreal triamcinolone injections in Chinese subjects: a 6-month follow-up study.

PURPOSE: To assess the intraocular pressure (IOP) and corneal endothelial changes, over a 6-month period, after a single injection of intravitreal triamcinolone (ivTA) in Chinese patients. METHODS: A total of 43 eyes of 43 consecutive Chinese patients with various macular diseases received a single bolus injection of 4 mg ivTA, of which, 14 eyes with significant cataracts underwent simultaneous phacoemulsification and primary intraocular lens implantation. IOP was measured preoperatively and weekly in the first month, and then monthly until 6 months postinjection. Specular microscopy was performed on 24 of the 29 eyes without simultaneous cataract surgery, preoperatively and at months 1, 3, and 6. RESULTS: All patients completed 6 months of follow-up. Nine out of 43 (20.9%) eyes had IOP >21 mmHg. Their mean maximum IOP was 29.2 mmHg (range 23.0-37.0), necessitating the use of 2.0 types of topical antiglaucomatous medications on average. The IOP elevation occurred at a mean of 5.2 weeks (range 1-17) postinjection. All IOPs returned to normal, without additional antiglaucomatous medications, by 6 months. There was no statistically significant difference (paired t-test, P<0.05) in the corneal endothelial cell count and other specular microscopy parameters up to 6 months after the injections. CONCLUSION: A single 4 mg bolus injection of ivTA appeared to have no harmful effects on the corneal endothelium. IvTA caused transient IOP elevations in 20.9% of Chinese patients, similar to that observed in Caucasians. As the IOP rise can occur as early as 1 week after the injection, early monitoring will help its early detection and prevent optic nerve damage.

Long-term results of autogenous palmaris longus frontalis sling in children with congenital ptosis.

PURPOSE: To investigate the long-term outcome of using autogenous palmaris longus tendon (PLT) sling for correcting congenital ptosis in children. METHODS: This is an observational case series involving 15 eyelids of 14 consecutive children with congenital ptosis who underwent frontalis suspension surgery using PLT in a university teaching hospital. RESULTS: One child had bilateral ptosis and the other children had unilateral ptosis. The age of patients at the time of surgery ranged from 2 to 7 years, with an average of 4.7 years. At a mean follow-up of 92 months (range, 80-104 months), all eyelids were successfully corrected with good lid height. No recurrence or other postoperative complications were encountered except one patient who developed a small skin fold over the PLT harvest site. CONCLUSION: Long-term lid position is remarkably stable after surgical correction using PLT. PLT sling appears to be a safe and effective treatment for children with congenital ptosis requiring frontalis sling operation. It could be a good alternative to autogenous fascia lata, and further studies, to compare these two sling materials seem warranted.

Photodynamic therapy with verteporfin for juxtafoveal choroidal neovascularization secondary to pathologic myopia-1-year results of a prospective series.

PURPOSE: To study the efficacy of photodynamic therapy (PDT) with verteporfin in the treatment of juxtafoveal choroidal neovascularization (CNV) secondary to pathologic myopia. METHODS: Prospective, open label, two-centre, noncomparative, interventional case series. Consecutive patients with juxtafoveal CNV associated with pathologic myopia were recruited and treated with a standard regimen of PDT with verteporfin. Patients were being followed up every 3-monthly and retreatment was considered when there was evidence of angiographic leakage. Outcome measures included changes in the mean best-corrected visual acuity (BCVA) at the 1-year follow-up when compared with the baseline, the proportion of patients who had stable (within 1 line) and improved visions. RESULTS: A total of 11 eyes from 11 patients with juxtafoveal CNV secondary to pathologic myopia were recruited and all completed the 1-year follow-up. The mean age at presentation was 44.8 years. The refractive error ranged from -6.0 to -15.0 D (+/-SD was -9.55+/-3.04 D). The logMAR BCVA improved from 0.57 to 0.39 at the 1-year follow-up (Wilcoxon signed-ranks test, P=0.027). The mean improvement was 1.8 lines. Five eyes (45.4%) had BCVA improved by >or=3 lines. None of the treated patients had visual loss of >or=1 line. The mean number of treatments over the 12-month study period was 2.3 sessions. CONCLUSIONS: The results are encouraging, especially on considering the low retreatment rate, stable or improved BCVA in all treated eyes, and consistently good safety profile. Juxtafoveal myopic CNV may be an expanded indication for PDT with verteporfin.

Photodynamic therapy with verteporfin for subfoveal choroidal neovascularisation of pathologic myopia in Chinese eyes: a prospective series of 1 and 2 year follow up.

AIMS: To evaluate the visual and fluorescein angiographic outcomes of photodynamic therapy (PDT) with verteporfin in patients with subfoveal choroidal neovascularisation (CNV) caused by pathologic myopia in the Chinese. METHODS: Prospective, non-comparative, two centre interventional study. Patients with CNV secondary to pathologic myopia of Chinese ethnicity were recruited and treated with a standard regimen of PDT with verteporfin. Results of this study in Chinese eyes with pigmented retinal pigment epithelium were compared with those from the Verteporfin in Photodynamic Therapy (VIP) Study of predominantly white eyes. RESULTS: Thirty one and 22 eyes that completed the 12 month and 24 month follow up studies respectively were analysed. The mean and median best corrected visual acuities (BCVA) could be maintained at the baseline level at the 12 month and 24 month visits. Fourteen (63.6%) eyes had stable or improved BCVA at 24 months and six (27.3%) of them had a moderate gain in vision (improved by three or more lines). Visual results were comparable with that of the VIP study, but the average accumulative PDT treatments required in one and two years were 1.7 and 2.3 respectively, which were significantly less than 3.4 and 5.1 treatments in VIP study. Mean logMAR BCVA of the younger age group (<55 years) at 24 months was 0.41 (SD 0.29), which was significantly better than the older age group (>/= = 55 years) of 0.82 (SD 0.40) (Mann-Whitney U test, p = 0.029). CONCLUSIONS: PDT using the predetermined treatment protocol has achieved similar visual outcomes in the Chinese population as in white people with subfoveal myopic CNV over a 2 year study period. The complete cessation of CNV leakage can be accomplished, on average, with fewer PDT retreatments than reported in the VIP study. The disparity may be due to ethnic differences in these two populations.

Astigmatism in Chinese preschool children: prevalence, change, and effect on refractive development.

AIM: To study the prevalence, type, and progression of astigmatism in Chinese preschool children, and its effect on refractive development. METHODS: A cross sectional study of preschool children was carried out in two randomly selected kindergartens. A cohort study was performed on a subset of children, five years after initial examination. Refractive error (measured by cycloplegic autorefraction) and axial ocular dimensions (measured by ultrasonography) were the main study outcomes. RESULTS: 522 children participated in the study; the mean age was 55.7 months (SD 10.9; range 27 to 77). Mean cylinder reading was -0.65 D (SD 0.58; range 0.00 to -4.75), and with the rule astigmatism was predominant (53%). In the 108 children studied longitudinally, the mean cylinder reading reduced from -0.62 D to -0.50 D (p = 0.019). The presence of astigmatism in initial examination predisposed the eyes towards greater myopisation (p<0.001). In addition, children with increased astigmatism had greater myopic progression (p<0.001) and axial length growth (p = 0.002). CONCLUSIONS: This study reports a high prevalence of astigmatism in Chinese preschool children. The presence of astigmatism, and particularly with increasing astigmatism, appears to predispose the children to progressive myopia. Further studies are warranted.

Myopia progression among preschool Chinese children in Hong Kong.

INTRODUCTION: Myopia is the most common eye disorder especially in Asia. However, the information on myopic progression and ocular growth among preschool children, who undergo rapid changes, is limited. The aim of this study was to determine the prevalence, incidence of myopia and myopic progression among preschool children in Hong Kong. MATERIALS AND METHODS: A kindergarten was randomly chosen in Hong Kong, China. Preschool children aged 2 to 6 years attending the selected kindergarten were invited to participate. One hundred and eight children completed the 5-year cohort study. Refractive error and axial ocular dimensions were the main outcome measures. RESULTS: A total of 255 preschool children with a mean age of 4.96 (SD, 0.90) years were examined in the initial examination. Only 4.6% children had myopia of at least -0.50 D. The prevalence of myopia increased almost 10-fold to 43.5% after 5 years in the final examination. The annual incidence of myopia was 8.2%. The mean increase in axial length was 1.72 mm (SD, 0.80 mm) over the 5-year period (P < 0.001). The lens thickness decreased significantly from 3.80 mm (SD, 0.37 mm) to 3.74 mm (SD, 0.51 mm) whereas the vitreous chamber depth increased significantly from 15.01 mm (SD, 0.68 mm) to 16.42 mm (SD, 0.88 mm) (both P < 0.001). Children who were younger or were less hypermetropic at the initial examination was having greater myopic progression (P = 0.015, P < 0.001 respectively). CONCLUSION: This is the first prospective study to investigate the myopic progression and ocular growth among preschool children. Hong Kong has a high prevalence of myopia even in preschool children. They also experience a significant myopic shift and ocular growth. Further studies on the prevention of myopic development or progression should be targeted on this population.

Incidence and risk factors for microbial keratitis in Hong Kong: comparison with Europe and North America.

PURPOSE: To establish the incidence, etiology and risk factors for microbial keratitis (MK) in Hong Kong. METHODS: Two hundred and twenty-three new cases of presumed MK were recruited over a period of 17 months and comprehensive microbiologic studies performed. A nested case-control study was pursued for patients wearing contact lenses (CLW) to determine risk factors for MK with regards to types of CLW and hygiene practice. RESULTS: Of the 223 patients recruited, 59 (26%) wore contact lenses. Corneal scrapes yielded positive cultures from 77 patients (35% overall, 56 non-CLW, 21 CLW). Two hundred and six CLW volunteers were recruited to participate in the case-control study, of whom 135 were matched with 45 CLW patients. The annual incidence of MK was 0.63 per 10,000 population and 3.4 per 10,000 CLW with rates for daily, extended and rigid lens wear of 3.09, 9.30 and 0.44 per 10,000 CLW respectively. Pseudomonas aeruginosa was the dominant bacterial pathogen. Six cases of Acanthamoeba keratitis occurred, five in CLW (incidence 0.33 per 10,000 CLW) and one following corneal abrasion. Non-CLW developed MK at a peak age of 73, which is 10 years younger than expected for Scotland and USA. CONCLUSIONS: Previous ocular surface disease and trauma were the main risk factors for MK in Hong Kong. CLW appears at least as safe as that found in Scotland and the USA. Acanthamoeba keratitis was detected but with an incidence rate five times lower than Scotland. Factors predisposing hydrogel CLWs to MK, that were statistically significant, included overnight wear, poor hygiene and smoking.

Changing patterns of strabismus: a decade of experience in Hong Kong.

BACKGROUND/AIMS: Racial variation in the pattern of strabismus is known, but few large scale studies on non-white populations are available. Furthermore, longitudinal change in this pattern within a local setting has not been well documented in the past. This study aims to support the clinical impression that exotropia is more common in Chinese patients, and that the proportion of patients with exotropia has been increasing in the past decade. METHODS: A total of 2704 consecutive patients with the diagnosis of primary horizontal strabismus, seen in the strabismus clinic of the Hong Kong Eye Hospital, were retrospectively analysed to determine the relative prevalence of esotropia and exotropia. Characteristics recorded include patient demographics, type of strabismus, and whether the nature of the squint was constant or intermittent. RESULTS: 742 (27.4%) patients were found to have esotropia, 548 (20.3%) had constant exotropia, 1213 (44.9%) had intermittent exotropia, and 201 (7.4%) had microtropia. The proportion of exotropic to esotropic patients was shown to increase steadily throughout the past decade (p<0.0001). This was mainly accounted for by an increase in the number of patients with intermittent exotropia, and a corresponding decrease in the number of patients with esotropia. CONCLUSION: Exotropia was shown to be more prevalent than esotropia in a Hong Kong Chinese population. Furthermore, the proportion of patients with intermittent exotropia appears to be increasing, in contrast with esotropic patients. The exact nature of this trend, and possible aetiological factors will require further study.

Ophthalmopathy in childhood Graves' disease.

AIMS: To study the ocular manifestations and their severity in children with Graves' disease. METHODS: All patients with Graves' disease having regular follow up in a paediatric endocrine clinic were recruited for the study. A comprehensive ophthalmic assessment including ocular motility, exophthalmometry, intraocular pressure (IOP), slit lamp, and fundus examinations was performed. RESULTS: 83 patients (72 female, 11 male) aged 16 years or below were examined. All are Chinese. Ocular symptoms occurred in 12 patients. Ocular signs of ophthalmopathy were documented in 52 patients (62.7%). Most of them presented with eyelid abnormalities such as lid oedema, lid lag, and lagophthalmos, whereas lower lid retraction was the commonest clinical sign noted (38.6%). Diffuse conjunctival injection was found in four patients (4.8%). 10 patients (12.0%) had mild proptosis of less than 3 mm. Only one patient (1.2%) had limited extraocular motility in extreme gaze. Punctate epithelial corneal erosions were reported in 11 patients (13.3%). CONCLUSIONS: This is the largest series on the ocular complications of childhood Graves' disease in the literature. Although 52 patients (62.7%) were identified with positive ocular changes, none of them had visual threatening complications or debilitating myopathy.