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Purpose: To determine the prevalence, incidence, and progression of myopia of Chinese children in Hong Kong., Methods: A cross-sectional survey was initially conducted. A longitudinal follow-up study was then conducted 12 months later., Results: A total of 7560 children of mean age 9.33 (95% confidence interval [CI] = 9.11-9.45; range, 5-16) participated in the study. Mean spherical equivalent refraction (SER) was -0.33 D (SD = 11.56; range, -13.13 to +14.25 D). Myopia (SER

Purpose: To investigate the ocular manifestations of patients with severe acute respiratory syndrome (SARS) and to monitor the possible ocular complications arising from the treatment regimen with high-dose systemic corticosteroid drugs., Design: Prospective, observational cohort case series., Methods: Ninety eyes from 45 patients with the diagnosis of SARS during an epidemic outbreak in Hong Kong were analyzed. Relevant medical and ophthalmic histories were taken. Ophthalmic examinations, including best-corrected visual acuity, intraocular pressure, slit-lamp, and indirect ophthalmoscopy examination, were performed at baseline and at 2-month and 3-month follow-up., Setting: Faculty practice in university hospital., Results: Only two patients had mild elevated intraocular pressure at baseline and at subsequent follow-up. There was no loss of visual acuity, cataract progression, or increased cup-disk ratio. Fundus examinations were unremarkable in all patients., Conclusions: Our study did not demonstrate any ocular manifestations in patients with SARS. The treatment regimen of high-dose corticosteroid also did not show any significant ocular complications. Routine ocular screening of patients with SARS for diagnosis or for complications might not be indicated.

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.

Objective: 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., Methods: 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., Main Outcome Measures: Intraocular pressures and anti-inflammatory responses were the main outcome measures and were serially measured postoperatively for 8 weeks., Results: 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)., Conclusions: 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.

Purpose: To assess the efficacy and tolerance of mydriatic and cycloplegic spray versus drops for Chinese children., Methods: The effects of the spray (cyclopentolate 0.25%, phenylephrine 0.625%, and tropicamide 0.5%) and the drops (cyclopentolate 1%, phenylephrine 0.5%, and tropicamide 0.5%) were evaluated in 29 children (58 eyes) in two separate sessions. There was a 1-week period between the applications of the spray and the drops. Dilated pupil size and refraction after cycloplegia were the primary outcome variables used to assess the efficacy. A subjective discomfort score was used to assess acceptance of the spray and the drops., Results: The mean age of the study population was 4.33 +/- 1.39 years (range, 3 to 8 years). The mean pupil size was 6.9 mm for the spray and 6.6 mm for the drops. The spray appeared to be slightly more effective than the drops, with a mean difference of 0.3 mm that was statistically significant (P = .001, two-tailed t test). No statistically significant difference in cycloplegic response was found between the spray and the drops (P = .535, two-tailed t test). Administration of the spray caused less discomfort than did administration of the drops (P < .001, Wilcoxon signed-rank test)., Conclusions: The spray system appears to be clinically equivalent to the drops for achieving effective pupil dilation and cycloplegia, even in a population with dark irides such as ours. Tolerability and acceptance improved because the spray was applied to the closed eyelids.

Purpose: The optineurin gene (OPTN) is the second gene besides MYOC in which mutations have been identified to be associated with primary open-angle glaucoma (POAG). In this study, sequence alterations in the OPTN gene associated with POAG in Chinese subjects were investigated., Methods: All the coding exons of OPTN were screened, including the intron-exon boundaries, for sequence alterations in a Chinese sample of 119 sporadic patients with POAG and 126 unrelated control subjects by polymerase chain reaction-conformation-sensitive gel electrophoresis and DNA sequencing., Results: Sixteen sequence changes were identified: 3 had been reported (T34T, M98K, and R545Q) and 13 were novel (T49T, E103D, V148V, P199P, T202T, H486R, IVS6-5T-->C, IVS6-10G-->A, IVS7+24G-->A, IVS8+20G-->A, IVS13+21C-->G, IVS15+10G-->A, and IVS15-48C-->A). Among them, only E103D, H486R, V148V, and IVS13+21C-->G were found exclusively in patients with POAG, whereas P199P, T202T, and IVS8+20G-->A were present only in control subjects. The genotype of IVS7+24G-->A showed a significant association with POAG (P = 0.02, Fisher two-tailed exact test) and with and increased cup-to-disc ratio in these patients (P = 0.005, Mann-Whitney test)., Conclusions: The findings in the current study enrich the evidence on the OPTN gene as a causative gene for POAG and suggest a different mutation pattern of OPTN in Chinese than in whites. The wide spectrum of putative mutations detected in this study suggests that both structural and functional disruptions in OPTN may contribute to the pathogenesis of glaucoma.

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.

We describe a case of isolated bilateral microspherophakia with optic disc colobomata. A satisfactory outcome was achieved following uneventful lensectomy and scleral fixation of an intraocular lens.

Purpose: To investigate the coding exons of transforming growth factor (TGF)-beta-induced factor (TGIF) for mutations in Chinese patients with high myopia., Methods: Seventy-one individuals with high myopia of -6.00 D or less and 105 control subjects were screened by DNA sequencing for sequence alterations. Univariate analysis and logistic regression were performed to identify single-nucleotide polymorphisms (SNPs) and their interactions in TGIF that may be associated with myopia., Results: Six SNPs showed a significant difference (P < 0.05) between patient and control subject in univariate analysis. Four of them cause codon changes: G223R, G231S, P241T, and A262G. Among all the SNPs that entered multivariate analysis, only 657(T-->G) showed statistical significance in the logistic regression model (odds ratio 0.133; 95% confidence interval 0.037-0.488; P = 0.002)., Conclusions: TGIF is a probable candidate gene for high myopia. Further studies are needed to identify the underlying mechanism.

A locus for autosomal dominant high myopia was reported on chromosome 18p. We sought to confirm this finding and narrow the reported interval by analyzing high myopia among families of Hong Kong Chinese, in whom myopia is common. In 15 families with a possibly autosomal dominant inheritance of high myopia (>or=-6 dpt) in at least 2 generations, 10 chromosome 18p markers were analyzed for linkage with high myopia. Two-point linkage analysis showed trends toward linkage of markers D18S476 and D18S62 with high myopia, with maximum logarithm of odds (LOD) scores of at least 1.1 and 1.7, respectively. Multipoint analysis of those 2 markers gave a maximum LOD score of at least 2.1. To attempt to account for likely genetic heterogeneity, 5 families showing evidence of linkage of the 2 markers with high myopia were selected for further multipoint linkage analysis, resulting in a maximum LOD score of 2.4 at D18S476. While multiple genetic and environmental factors likely contribute to myopia, these data are consistent with the possibility of a locus on chromosome 18p., (Copyright 2003 S. Karger AG, Basel)

Objective: To investigate the features and application of phrenic radix conduction time (PRCT) in inflammatory demyelinating polyneuropathy (IDP) patients., Methods: Distal motor latency (DML) was recorded by stimulating phrenic nerve electrically and phrenic nerve root magnetically in 20 IDP patients with surface electrodes at intercostal space. The difference of the two DML was calculated and compared with those recorded previously from 61 sides in 31 healthy control subjects., Results: PRCT of the IDP patients was longer than that of the controls, and it correlated with the severity of clinical dyspnea. The abnormal rate of PRCT was higher than the incidence of clinical dyspnea., Conclusions: PRCT could reflect the functional status of the spinal roots related to respiration in IDP patients at an electrophysiological level. It correlates well with the degree of clinical dyspnea. Its detection is helpful to find out the subclinical dyspnea in IDP patients.

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., (Copyright 2002 Wiley-Liss, Inc.)

Purpose: To discover sequence alterations in the TIGR/MYOC gene associated with primary open-angle glaucoma (POAG) in Chinese subjects., Methods: Two hundred one unrelated Chinese patients with POAG and 291 unrelated individuals without glaucoma, aged 50 years or more, were screened for sequence alterations in the TIGR/MYOC gene by polymerase chain reaction, conformation sensitive gel electrophoresis, and DNA sequencing. Up to 111 more control subjects were screened for some of the alterations., Results: Fourteen sequence variants that lead to amino acid changes were identified. Seven were novel: Pro16Leu, Ala17Ser, Leu95Pro, Leu215Pro, Glu300Lys, Glu414Lys, and Tyr471Cys. Of these, Glu300Lys and Tyr471Cys were found only in POAG. Arg46Stop was found in 4 patients with POAG (2.0%) and 9 of 402 control subjects (2.2%); one control subject was homozygous. IOP showed a trend (P = 0.11) toward a decrease of 1.5 mm Hg among the control subjects, with Arg46Stop compared with matched control subjects without Arg46Stop. Gly12Arg occurred four times as frequently in control subjects as in patients, but the difference was not statistically significant., Conclusions: Gly12Arg might be negatively associated with POAG, suggesting a protective effect. Three patients with POAG had a sequence change not found in control subjects, for a frequency of possible disease-causing TIGR/MYOC mutations of 1.5% (95% confidence interval [CI] = 0.3%-4.3%). Arg46Stop occurred with similar frequency in patients with POAG and control subjects, suggesting that the reduced amount of TIGR/MYOC predicted to result from this truncation does not dramatically increase or decrease risk of glaucoma.

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.

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.

Purpose: Human limbal epithelial cells cultured on human amniotic membrane have been used for transplantation to treat corneal surface injuries. We determined whether the amniotic basement membrane affects the growth of human limbal epithelial cells through the production of growth factors., Methods: The epithelial cells grown out from limbal basal epithelium were placed on conventional culture plastic or on the epithelial side of denuded amniotic membrane under serum-free conditions. Culture supernatant was assayed for growth factor release at 24, 48, and 96 hours., Results: The cells grown on both substrata produced similar levels of epidermal growth factor (EGF). Cells grown on amniotic membrane showed enhanced secretion of tissue inhibitor of metalloproteinase type 1 (TIMP1) and reduced production of transforming growth factor beta1 and beta2. Depletion of EGF and TIMPI in cell culture slowed down cell growth and reduced EGF receptor expression, respectively., Conclusion: Increased TIMPI influences the proteolytic system in the cell and extracellular matrix interaction, and decreased transforming growth factor beta1 and beta2 may stimulate corneal cell proliferation. We show that the amniotic membrane leads to differential expression of cytokines of limbal epithelial cells cultured on its surface. Such effects may be favorable to the growth and differentiation of the cells when used for ocular surface reconstruction.

Purpose: To establish if the hygiene practice of contact lens wearers (CLWs) can be influenced by "health belief.", Methods: A nested case-control study based on questionnaires was conducted in Hong Kong over a 17-month period between 45 CLW patients with microbial keratitis and 135 matched asymptomatic CLW volunteer controls., Results: There was no significant difference between keratitis patients and controls (volunteers) in the perceived benefits of optometrists' instructions generally. When asked specifically, however, keratitis patients scored significantly higher than controls in the perceived benefit of checking initially with the optometrist for the correct method of lens cleaning. Contact lens wearing patients with keratitis were confident that their care of lenses would prevent complications, but this probably represented over confidence in themselves. Patients also scored significantly more neutrally in self-efficacy. Surprisingly, patients were significantly less likely to perceive the cost of lens care as a barrier but did not use their disinfecting regimes properly., Conclusion: We have found that CLWs still regard their eye care professional as being the most important for giving them advice on hygiene. There is considerable opportunity to educate and influence CLWs in ways to prevent infection, but the advice given must be correct. Continuing education of optometrists is also required.

Purpose: To report the unusual association of bilateral corneal keloids and anterior segment mesenchymal dysgenesis in a child with Rubinstein-Taybi syndrome., Methods: Case report of a 2-year-old boy., Results: Excision of the epicorneal mass in the right eye was followed by recurrence of the lesion. Multiple penetrating keratoplasties were unsuccessful in reconstructing the anterior segment because of recurrent corneal epithelial breakdown, suggesting limbal stem cell insufficiency. Histopathology and electron microscopy of the excised mass lesion showed features typical of a corneal keloid: thickened keratinized epithelium, absent Bowman's layer, and fibrovascular hyperplasia, with haphazard orientation of the collagen lamellae. Ultrasound biomicroscopy and intraoperative findings suggested a diagnosis of Peter anomaly, but genetic analysis did not show a PAX6 mutation., Conclusion: The findings in our patient add to the spectrum of ocular changes described in Rubinstein-Taybi syndrome and confirm earlier reports of poor ocular prognosis in corneal keloids and Rubinstein-Taybi syndrome.

Mutations in the adenomatous polyposis coli gene (APC) often cause both congenital hypertrophy of the retinal pigment epithelium (CHRPE) and familial adenomatous polyposis (FAP). To investigate the relationship between APC mutations, CHRPE and FAP, all FAP patients at the Prince of Wales Hospital, Hong Kong, were asked to participate in a study. Ten Chinese patients from 6 kindreds and their family members volunteered, along with 12 healthy control subjects selected among hospital visitors and staff. All were examined for dilated fundus by indirect ophthalmoscopy. Mutations in APC coding exons were detected by sequencing. In one FAP patient, a novel A insertion at codon 1023 was detected. Three previously reported mutations were detected in 6 FAP patients: a deletion of ACAAA at codon 1061, and 2 truncating point substitutions at codons 216 and 283. In 3 FAP patients, no APC mutation was found, suggesting that mutations in APC coding regions are not the sole cause of FAP or CHRPE. A total of 64 CHRPE lesions were found in FAP patients and some relatives with and without APC mutations. Contrary to most reports, APC mutations before exon 9 did cause CHRPE lesions, albeit relatively few., (Copyright 2001 S. Karger AG, Basel)

Objective: To investigate the ocular hypertensive and antiinflammatory response to different dosages of fluorometholone (FML)., Design: Prospective clinical trial with randomization of fellow eyes to different postoperative treatment., Participants: Thirty-one consecutive children undergoing bilateral symmetrical strabismus operation., Intervention: Among 31 children who received bilateral squint operations, one eye was randomized to receive topical FML six times daily (group 1), whereas the other eye received topical FML three times daily (group 2), both for 4 weeks. Intraocular pressure (IOP) and antiinflammatory response were measured serially in the postoperative period for 8 weeks., Main Outcome Measures: Intraocular pressure was measured on the day before surgery and on postoperative days 1, 3, 6, 13, 20, 27, 41, and 55. The antiinflammatory response was also assessed subjectively and objectively at days 6, 13, 20, and 27 after the operations. Peak IOP, net increase in IOP, and antiinflammatory responses in the two study groups were analyzed., Results: Thirty-one children, age 3 to 9 years, (mean +/- standard deviation [SD], 5.52 +/- 1.81) participated in the study. Intraocular pressure increased significantly in both groups compared with the preoperative values (P < 0.001). The peak IOP ranged from 12.00 to 31.00 mmHg and 12.30 to 25.00 mmHg in groups 1 and 2, respectively. The mean peak IOP (19.00 +/- 5.06 mmHg vs. 17.13 +/- 3.32 mmHg) was significantly higher in group 1 (P < 0.001). The net increase in IOP was similar (mean +/- SD, 4.37 +/- 4.79 vs. 2.57 +/- 3.32 mmHg; P = 0.005). Ranges of the net IOP increase were -1.00 to 16.00 mmHg and -2.50 to 10.30 mmHg in groups 1 and 2, respectively. Children in group 1 reached the peak IOP earlier than those in group 2 (median, 6 vs. 13 days; P = 0.033). However, there was no significant difference in antiinflammatory response between the two groups., Conclusions: Ocular hypertension occurs in a dose-dependent manner in children treated with FML. Children in group 1 had a quicker onset and more severe ocular hypertensive response than those in group 2. It would be desirable to monitor the IOP regularly when FML is used with a high frequency and for a long duration in children.

Purpose: To report the rate of ultrasonically visible vitreous incarceration and longitudinal changes of incarcerated vitreous in pars plana sclerotomies after conventional suturing or sutureless technique using ultrasound biomicroscopy., Methods: Twenty-five consecutive eyes (25 patients) undergoing primary three-port pars plana vitrectomy participated. The first 16 pars plana vitrectomies were performed with standard conventional sutured sclerotomies, and the following nine pars plana vitrectomies were performed with modified sutureless sclerotomies. Patient demographics, diagnoses, procedures, and complications were recorded. Each patient had ultrasound biomicroscopy performed 1 week before surgery, and also after surgery at 1 week, 2 weeks, 3 weeks, 4 weeks, 2 months, 3 months, and 6 months. Visible vitreous incarceration was graded as 0 to 3., Results: Vitreous incarceration was seen in 41 of 48 sclerotomies (85.4%) in the conventionally sutured group, and in 23 of 27 sclerotomies (85.2%) in the sutureless group, with no significant difference in severity among sclerotomies within each group and between the two groups. There was a significant difference in the rate of vitreous incarceration between diabetic patients with proliferative retinopathy and others (P =.002). No progressive change of visible vitreous incarceration was noted in any eye during the 6-month postoperative period. No sclerotomy-related complications occurred during the study period., Conclusions: Ultrasound biomicroscopy showed no difference in the amount of visible vitreous incarceration in conventionally sutured or sutureless sclerotomies. There was no visible longitudinal change in the incarcerated vitreous during the 6 months of follow-up in uncomplicated cases.

Purpose: To evaluate the effect of preoperative keratometry on the refractive outcome after laser in situ keratomileusis (LASIK) for myopia., Setting: University Eye Clinic, Prince of Wales Hospital, Hong Kong, China., Methods: In this retrospective study, the records of patients who had LASIK for myopia greater than -6.0 diopters (D) using the Chiron Automated Corneal Shaper and the Schwind Keratome-F excimer laser were reviewed., Results: Laser in situ keratomileusis was performed in 167 eyes of 103 patients (mean age 34.7 years +/- 7.5 [SD]). Preoperative myopic spherical equivalent (SE) refraction was -9.0 +/- 2.0 D (range -6.0 to -13.9 D). Three months after surgery, SE refraction was -0.04 +/- 1.1 D (range +2.3 to -3.3 D); uncorrected visual acuity > or = 20/40 was present in 91.8% of 110 eyes in which emmetropia was the postoperative goal. Mean preoperative keratometry was 43.9 +/- 1.5 D (range 40.3 to 48.1 D). When eyes were stratified by the degree of preoperative myopia in 1.0 D steps, a trend toward greater undercorrection was noted in eyes with preoperative keratometry < 43.5 D than in those with steeper keratometry (> 44.5 D) in all myopia groups except the -7.0 to -7.9 D group. This difference was statistically significant in eyes with a preoperative SE of -10.0 to -10.9 D and -11.0 to -11.9 D., Conclusions: Preoperative keratometry appeared to influence the refractive outcome after myopic LASIK. Eyes with flatter corneas tended to have greater undercorrection than eyes with similar myopia and steeper corneas. Validation of these findings in larger data sets using the methodology described may improve the predictability of current LASIK nomograms, particularly in eyes with high myopia.

Objective: To investigate the ocular-hypertensive response to different dosages of topical dexamethasone eye drops in Chinese children., Design: Prospective, randomized clinical trial., Participants: Thirty-one consecutive children undergoing bilateral strabismus surgery., Intervention: Topical dexamethasone (0.1%) was administered to children undergoing bilateral strabismus surgery. They were all less than 10 years of age. One eye was randomized to receive a regimen of four times daily, and another received a twice daily regimen. Intraocular pressure (IOP) was serially measured in the postoperative period for 4 weeks or more. Topical steroids were discontinued if IOP was 30 mmHg or more., Main Outcome Measures: Intraocular pressure was measured on the day before the surgery, on postoperative days 1, 3, 5, 8, 12, 15, 22, 29, and 2 weeks thereafter until the IOP reached preoperative levels. Peak IOP, IOP net increase, and time to reach an IOP more than 20 mmHg in the two study groups were analyzed., Results: A total of 31 patients (20 male, 11 female) were examined. The mean age was 5.8 +/- 2.0 years (range, 2-10 years). Preoperative IOP in groups treated twice daily and four times daily were similar. After topical dexamethasone treatment, both groups showed a significant rise in peak IOP compared with preoperative values (twice daily, 25.2 +/- 6.8 mmHg vs. 14.3 +/- 2.4 mmHg, P < 0.001; four times daily, 28.7 +/- 6.9 mmHg vs. 14.3 +/- 2.9 mmHg, P < 0.001). The peak IOP was significantly higher in the four times daily group (P < 0.001), as was the net increase in IOP (twice daily, 10.9 +/- 5.8 mmHg vs. four times daily, 14.5 +/- 6.4 mmHg; P < 0.001). There was no difference in time for both groups to achieve the peak IOP, but the time to exceed its upper normal value (20 mmHg) was shorter in the four times daily group (twice daily, 12.3 +/- 9.1 days vs. four times daily, 10.0 +/- 7.4 days; P < 0.05)., Conclusions: In children treated with topical dexamethasone, ocular hypertension occurs in a dose-dependent manner. Children in the four times daily group had a quicker onset and more severe ocular hypertensive response than the twice daily group. Nevertheless, even the twice daily regimen produced significant IOP rise, suggesting that dexamethasone use in children should be avoided if possible, and it would be desirable to monitor the IOP twice weekly when it is administered to children.

We investigated the coding exon and promoter sequence in the trabecular meshwork-inducible stretch response (TISR)/oculomedin gene for mutations in Chinese primary open angle glaucoma (POAG) subjects. The entire TISR/oculomedin coding sequence, together with 138 bp of promoter sequence 5' to the start codon and 170 bp of the 3' untranslated region in 110 Chinese POAG patients and 108 unrelated control subjects without glaucoma, aged 50 years or above, were screened for alterations by DNA sequencing. One heterozygous sequence alteration, K28E, was identified in one control subject, and two homozygous sequence alterations, K28K and 135+36delC, were universally found in every sample. As a result, no common TISR/ oculomedin coding sequence nor any proximal promoter mutation that causes POAG was found. The effect of TISR/ oculomedin in glaucoma has yet to be established.

Parkinson's disease (PD), a neurological disease suited to gene therapy, is biochemically characterized by a severe decrease in the dopamine content of the striatum. One current strategy for gene therapy of PD involves local production of dopamine in the striatum achieved by inducing the expression of enzymes involved in the biosynthetic pathway for dopamine. We previously showed that the coexpression of tyrosine hydroxylase (TH) and aromatic-L-amino-acid decarboxylase (AADC), using two separate adeno-associated virus (AAV) vectors, resulted in more effective dopamine production and more remarkable behavioral recovery in 6-hydroxydopamine-lesioned parkinsonian rats, compared with the expression of TH alone. Not only levels of TH and AADC but also levels of tetrahydrobiopterin (BH4), a cofactor of TH, and GTP cyclohydrolase I (GCH), a rate-limiting enzymes for BH4 biosynthesis, are reduced in parkinsonian striatum. In the present study, we investigated whether transduction with separate AAV vectors expressing TH, AADC, and GCH was effective for gene therapy of PD. In vitro experiments showed that triple transduction with AAV-TH, AAV-AADC, and AAV-GCH resulted in greater dopamine production than double transduction with AAV-TH and AAV-AADC in 293 cells. Furthermore, triple transduction enhanced BH4 and dopamine production in denervated striatum of parkinsonian rats and improved the rotational behavior of the rats more efficiently than did double transduction. Behavioral recovery persisted for at least 12 months after stereotaxic intrastriatal injection. These results suggest that GCH, in addition to TH and AADC, is important for effective gene therapy of PD.

Objective: To review the effect of smoking on common ocular disorders., Data Sources: Medline literature search, 1966 to 1999., Study Selection: The following key words were used: smoking; Graves' disease, age-related macular degeneration; glaucoma; cataract., Data Extraction: Epidemiological and experimental studies were reviewed., Data Synthesis: Cigarette smoking is an important risk factor for cardiovascular, respiratory, and malignant diseases. There is also a strong association between smoking and a number of common eye diseases, which include Graves' ophthalmopathy, age-related macular degeneration, glaucoma, and cataract. Despite the multifactorial aetiology of these ocular syndromes, smoking is an independent risk factor that has dose-response effects. It causes morphological and functional changes to the lens and retina due to its atherosclerotic and thrombotic effects on the ocular capillaries. Smoking also enhances the generation of free radicals and decreases the levels of antioxidants in the blood circulation, aqueous humour, and ocular tissue. Thus, the eyes are more at risk of having free-radical and oxidation attacks in smokers., Conclusion: Smoking, if continued, may perpetuate further ocular damage and lead to permanent blindness. Cessation of smoking and avoidance of passive smoking is advised to minimise the harmful effects of smoking on the eyes.

Purpose: To investigate the coding exons in the trabecular meshwork-induced glucocorticoid response protein (TIGR) gene for mutations in primary open-angle glaucoma (POAG) in Chinese subjects., Methods: Ninety-one Chinese patients with POAG and 113 of their family members without glaucoma were screened for sequence alterations in the TIGR gene by polymerase chain reaction, conformation-sensitive gel electrophoresis, and DNA sequencing. One hundred thirty-two unrelated individuals without glaucoma, aged 50 years or more, were studied as control subjects., Results: Five sequence variants that lead to amino acid changes were identified. One was novel: Arg91Stop in one patient with POAG. Four had been reported: Arg46Stop in subjects with and without POAG, including an unaffected 77-year-old woman homozygous for Arg46Stop; Gly12Arg in subjects without glaucoma; and Asp208Glu and Thr353Ile in subjects with and without POAG. The previously reported 1-83(G-->A) and Arg76Lys polymorphisms were detected in both patients and controls and always occurred together., Conclusions: A different pattern of TIGR sequence variants exists in the Chinese than in non-Chinese populations. No common TIGR mutation that causes POAG was found. The occurrence of subjects without glaucoma who are heterozygous or homozygous for Arg46Stop suggests that reduction in the amount of TIGR protein does not cause glaucoma. Thus, the TIGR missense mutations known to cause POAG probably do not cause glaucoma by inactivating a normal TIGR function, but rather through the gain of a pathologic function.

A 4-year-old boy with bilateral idiopathic and progressive ectopia lentis had phacoaspiration of the lens and capsular tension ring (CTR) insertion in his left eye. Postoperatively, lens capsule centration remained poor. Single-point scleral fixation of the CTR was performed and centration of the lens capsule achieved. In-the-capsule intraocular lens (IOL) implantation was tried, but excessive IOL manipulation sliced open the capsule at the equator. Anterior vitrectomy and scleral IOL fixation were required. A similar approach was adopted in the right eye with meticulous attention given to gentle maneuvers. The operation was uneventful, with good IOL centration. Three and 11 months after surgery in the right and left eye, respectively, best corrected visual acuity was 20/50 in both eyes. Scleral fixation of the CTR, accompanied by gentle IOL manipulation, is an option to improve IOL centration in patients with severe zonular deficiency.

Purpose: To describe the clinical features and outcomes in patients who had a flap buttonhole during laser in situ keratomileusis (LASIK) and propose an etiopathogenic mechanism for this complication., Setting: University Eye Center, Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China., Methods: Retrospective review of case records of 6 patients (6 eyes) who had a flap buttonhole during LASIK., Results: The mean patient age was 38.2 years +/- 4.1 (SD) and the mean preoperative spherical equivalent (SE) refraction, -8.13 +/- 4.04 diopters (D). Mean keratometry was 44.20 +/- 1.30 D. Retreatment was performed after a mean interval of 9.2 +/- 3.2 months. Final postoperative SE refraction was -0.44 +/- 0.58 D after a mean follow-up of 59.0 +/- 5.3 weeks. No patient experienced loss of best spectacle-corrected visual acuity., Conclusions: Retreatment of eyes that have a flap buttonhole during LASIK is associated with good visual outcomes. Flap buttonholes can produce alterations in refraction, so retreatment is best performed after the refractive error has stabilized. Microkeratome malfunction may be responsible for the occurrence of a flap buttonhole during LASIK in eyes that do not have significant corneal steepening.

Purpose: Congenital hypertrophy of the retinal pigment epithelium (CHRPE) exists almost exclusively among familial adenomatous polyposis (FAP) patients with adenomatous polyposis coli (APC) mutations between codon 413 in exon 9 and codon 1387 in exon 15. We investigated the locality of APC mutations in relationship to the occurrence of CHRPE in two Chinese families with FAP., Methods: Genomic DNA of available members of two unrelated Chinese FAP families was investigated for sequence alteration in the APC gene by polymerase chain reaction and direct sequencing. All subjects were examined by binocular indirect ophthalmoscopy (BIO) for CHRPE., Results: A mutation in exon 6, Arg216Stop, was identified in one patient with FAP and CHRPE. An Arg283Stop mutation in exon 8 was found in 5 members in another family; 4 of them had FAP and all had small hypopigmented white lesions, probably a new type of CHRPE., Conclusions: We found two mutations, Arg216Stop and Arg283Stop, upstream of codon 413 in FAP patients presenting with CHRPE. Arg283Stop has not previously been reported in such patients. A large-scale study on CHRPE and APC mutations in Chinese FAP patients is required to affirm their inter-relationships and the significance of the hypopigmented white lesions.

Parkinson's disease (PD) is characterized by the progressive loss of the dopaminergic neurons in the substantia nigra and a severe decrease in dopamine in the striatum. A promising approach to the gene therapy of PD is intrastriatal expression of dopamine-synthesizing enzymes [tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC)]. The most appropriate gene-delivery vehicles for neurons are adeno-associated virus (AAV) vectors, which are derived from non-pathogenic virus. Therefore, TH and AADC genes were introduced into the striatum in the lesioned side using separate AAV vectors in parkinsonian rats, and the coexpression of TH and AADC resulted in better behavioral recovery compared with TH alone. Another strategy for gene therapy of PD is the protection of dopaminergic neurons in the substantia nigra using an AAV vector containing a glial cell line-derived neurotrophic factor (GDNF) gene. Combination of dopamine-supplement gene therapy and GDNF gene therapy would be a logical approach to the treatment of PD.

Purpose: To investigate a case of isolated pedunculated congenital corneal dermoid., Methods: Case report., Results: In a 14-day-old infant, the pedunculated portion of the dermoid was removed and confirmed by histopathologic examination. No surgical complication or recurrence was encountered, and the patient is waiting for a rotational autokeratoplasty., Conclusions: Prompt treatment of such an unusual tumor is important to allow for visual rehabilitation and development.

Purpose: To review the management and results of cases with severe flap wrinkling or dislodgment after laser in situ keratomileusis (LASIK)., Setting: University Eye Center, Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong., Methods: Four patients with severe flap wrinkling or dislodgment after LASIK are described. Surgical repositioning of the flap was performed in all cases. Flap status, refractive changes, and final uncorrected and best corrected visual acuities were used to evaluate the outcome of flap repositioning., Results: Flap repositioning required suturing in 2 patients, 1 of whom developed severe epithelial ingrowth with melting of the corneal flap and stromal bed and eventually required flap removal. The stromal inflammation resolved, and the corneal surface re-epithelialized after flap excision. In 2 other patients, wedge-shaped tissue excision (1.0 x 1.5 mm) from the superior portion of the corneal flap was necessary to allow better flap realignment. In 1 of these patients, the corneal flap was eventually converted to a free cap to correct residual wrinkling. At a mean follow-up of 15 months, the postoperative uncorrected visual acuity ranged from 20/20 to 20/60, and the best spectacle-corrected visual acuity (BSCVA) was 20/30 or better in all patients. In 1 patient, BSCVA decreased by 1 line., Conclusions: Flap dislodgment and wrinkling are serious postoperative complications of LASIK. Early recognition of these complications and prompt surgical management are crucial to achieve a successful surgical and visual outcome.