Yu-Hung Lai

The visual status of children ages 3 to 6 years in the vision screening program in Taiwan.

PURPOSE To investigate the current status of myopia, amblyopia, and strabismus of preschoolers in Taiwan. METHODS The records of a vision screening performed in 2005 at 4 preschools by a tertiary referral medical center in Kaohsiung, Taiwan were reviewed. Cycloplegic refraction, visual acuity by E chart, stereopsis by Titmus and National Taiwan University tests, and ocular alignment were analyzed. RESULTS Most (97.7%) of the children (n = 618) were able to perform visual acuity testing. There was good correlation between the results of cycloplegic spherical equivalent obtained by autorefraction and by retinoscopy (r = 0.934, p < 0.001). The prevalence of amblyopia was about 5%. A trend was found between amblyopia morbidity and the 4 age groups when a single criterion (best-corrected visual acuity <0.7) was used for all ages (decreased amblyopia incidence with increased age; p = 0.028, chi(2) test for trend). The prevalence of myopia was 3.0%, 4.2%, 4.7%, and 12.2% at ages 3, 4, 5, and 6 years, respectively. There was a trend of increased myopia with increased age (p = 0.021, chi(2) test for trend). CONCLUSIONS The prevalence of myopia in children ages 3 to 6 years in Taiwan was high compared with the prevalence in other countries. Criteria for amblyopia based on age difference and on the types of visual acuity test are recommended.

Astigmatism in preschool children in Taiwan.

PURPOSE To elucidate the prevalence of astigmatism and its corneal component, the association between the amount of astigmatism and its axis, and the association between the axis of astigmatism and body mass index (BMI) in Taiwanese preschool children. METHODS In this population-based study we analyzed 2 data sets, one obtained by retrospective review of vision-screening data and another obtained in a prospective observational study. Each study collected data for age, sex, and refraction status. Autokeratometry, height, and weight measurements were obtained only in the observational study. Astigmatism was classified as with-the-rule, against-the-rule, or oblique. RESULTS The prevalence of astigmatism was unassociated with age or sex in both data sets. The retrospective study (1,094 subjects; mean age, 5 years; range, 2.19-7.32 years) revealed that 13.3% of the subjects had astigmatism > or = 1.00 D, and most of them had with-the-rule astigmatism; 4.0% had high astigmatism (>1.50 D). Children with with-the-rule astigmatism had greater mean cylinder power than those with against-the-rule or oblique astigmatism. In the prospective study (190 subjects; mean age, 5.65 years; range, 3.79-6.68 years) astigmatism correlated with its corneal component. Preschoolers with with-the-rule astigmatism and with-the-rule corneal astigmatism had greater BMI and heavier weight than those with against-the-rule or oblique type. CONCLUSIONS Astigmatism is common in Taiwanese preschool children. The predominant types are with-the-rule and oblique astigmatism. Most patients with high astigmatism and high corneal astigmatism have with-the-rule type. High BMI or weight is associated with with-the-rule astigmatism and with with-the-rule corneal astigmatism.

Uncorrected Visual Acuity and Noncycloplegic Autorefraction Predict Significant Refractive Errors in Taiwanese Preschool Children

PURPOSE To investigate the accuracy of uncorrected visual acuity (UCVA), stereopsis, and noncycloplegic autorefraction (NCAR) tests performed by vision-screening technicians and to determine the best referral criteria when using these methods to screen for significant refractive errors in preschool children. DESIGN Retrospective, case-control, and cross-sectional study. PARTICIPANTS We reviewed 1000 records for a population-based preschool vision-screening program. The target conditions were defined as myopia ≤-3.0 diopters (D), hyperopia ≥ 4.5 D, astigmatism ≥ 2.0 D, and anisometropia ≥ 2.0 D. METHODS Receiver operating characteristic (ROC) curve was used to calculate optimal referral cutoff values. The examination results obtained by the vision-screening technicians were compared with those obtained by a pediatric ophthalmologist, which were considered the gold standard. MAIN OUTCOME MEASURES The efficacies (sensitivity, specificity, positive predictive value, and negative predictive value) of different tests were evaluated. RESULTS In 7.0% (95% confidence interval [CI], 5.3-8.7) of the children, at least 1 eye showed 1 of the target conditions. If only the right eyes were considered, the prevalence of target conditions was 4.2% (95% CI, 2.9-5.5). The ROC curve analysis indicated that the NCAR cylinder test (cutoff value ≥ 0.875 D) was the best test for screening target conditions. With regard to age groups, UCVA ≤ 0.75 (Snellen equivalent) and ≤ 0.85 were the best referral criteria for ages ≤ 4 years and ≥ 5 years, respectively. Combining the UCVA test with the NCAR test (the child was referred after failing both tests) increased specificity without significantly decreasing sensitivity. CONCLUSIONS The UCVA and NCAR tests performed by vision-screening technicians are adequately sensitive and specific for preschool vision screening. The ROC curve analysis was used for determining the appropriate screening criteria for these tests, and combining the tests increased their accuracy. The screening criteria should be age dependent. When analyzing the test accuracy in ophthalmic problems, if the disease of interest does not symmetrically (in terms of disease severity and prevalence) involve both eyes, the prevalence based on only 1 eye should be interpreted with caution.

Geldanamycin and its analog induce cytotoxicity in cultured human retinal pigment epithelial cells

Geldanamycin (GA), a benzoquinone ansamycin, was originally isolated as a natural product with anti-fungal activity. GA and its analogs, including 17-allylamino-demethoxy geldanamycin (17-AAG), are also known to block the function of a molecular chaperone, heat shock protein 90 (Hsp90). In light of their anti-tumor properties through direct cytotoxicity and anti-angiogenicity, GA has been previously demonstrated to suppress hypoxia-induced VEGF production in retinal pigment epithelium (RPE) cells, implicating its applicability in treating intraocular neovascularization. This study aimed at investigating the effectiveness of Hsp90 inhibitor treatment in suppressing proliferation of cultured human RPE cells and elucidating its underlying mechanism. Cultured RPE cells were treated with GA or 17-AAG and subjected for cell proliferation assay and cell cycle analysis. Expression of apoptotic regulators and survival signaling activity were monitored by Western blotting. The results showed that both GA and 17-AAG significantly inhibited RPE cell proliferation at micromolar levels. Treatment with GA and 17-AAG led to growth arrests in G1 and S phases, increased sub-G1 hypodipoid cell population, induced apoptotic cell death, and upregulated P53 and P21 expression, although the drug-induced Bcl-2 upregulation cannot prevent cell death. Additionally, GA and 17-AAG significantly suppressed constitutive contents of phosphorylated ERK1/2 and total Akt proteins, and completely abrogated wortmannin-sensitized Akt phosphorylation. In conclusion, GA and 17-AAG inhibit RPE cell proliferation and induce cytotoxicity, possibly through downregulating Akt- and ERK1/2-mediated signaling activities. They might potentially constitute a therapeutic agent for ocular disorders with RPE over proliferation, such as proliferative vitreoretinopathy.

Toxic Effects of Mitomycin-C on Cultured Ciliary Process Cells and Trabecular Meshwork Cells

Mitomycin-C has recently become an adjunct medication for inhibition of fibroblast proliferation in glaucoma filtering procedures. Prolonged postoperative ocular hypotony has been a frequent complication of trabeculectomy with mitomycin-C. In order to characterize the hypotony mechanism, we compared the toxic effects of mitomycin-C on cultured rabbit ciliary process cells and trabecular meshwork cells. The results indicate that mitomycin-C has a more marked effect on ciliary process cells on 3H-thymidine uptake than on trabecular meshwork cells at concentrations ranging from 10(-1) to 10(-5) mg/ml after 3-, 5- and 60-min treatment, respectively. The living cells after mitomycin-C treatment were estimated with MTT assay that was converted tetrazolium dye of living cells only into insoluble purple formazan crystals within mitochondria. In the presence of mitomycin-C for 3, 5, and 60 min, the cellular MTT values in ciliary process cells were more decreased than in trabecular meshwork cells. Depolarization of the trabecular meshwork cells with 50 mM KCl led to an increase in intracellular calcium concentration, whereas application of mitomycin-C at 10(-3) mg/ml resulted in decrease of KCl-induced intracellular calcium increase. Mitomycin-C (10(-3) mg/ml) decreased cAMP concentration in ciliary process cells following 3- and 5-min treatment; however, it did not significantly affect the cellular cAMP concentration after only a 1-min exposure. Mitomycin-induced marked ladder pattern of DNA fragmentation was observed in ciliary process tissues after treatment with 10(-1) mg/ml of mitomycin-C for 3 and 5 min. However, the DNA pattern in trabecular meshwork tissues was not obviously affected by mitomycin-C. These findings from our results indicate that mitomycin-induced ocular hypotony may result from damage to both ciliary process and trabecular meshwork tissues.

The oculocardiac reflex during strabismus surgery: its relationship to preoperative clinical eye findings and subsequent postoperative emesis.

PURPOSE To compare the occurrence of significant bradycardia due to the oculocardiac reflex (OCR) during strabismus surgery and its relationship to preoperative clinical eye findings and subsequent development of postoperative emesis. METHODS The medical records of consecutive patients who underwent strabismus surgery August 2006 to June 2009 were retrospectively reviewed. OCR was defined as presence of dysrhythmia or a sudden heart rate decrease ≥ 20% after traction on the extraocular muscle. OCR incidence was compared between the first, second, and third (if any) extraocular muscles in patients who had multiple-muscle strabismus surgery and also between specific muscles (eg, medial rectus vs lateral rectus muscle). Associations with OCR were compared for different strabismus types. Vomiting was considered postoperative if it occurred before discharge of the patient at noon on the day following surgery. Risk factors for OCR and postoperative vomiting were evaluated by logistic regression analysis. RESULTS A total of 111 records were reviewed; 41 patients (37%) experienced OCR. Incidence of OCR and absence of OCR during traction of the first muscle were significantly associated with events during traction of the second (χ(2) = 36.681, P < 0.001) and third muscles (Fisher exact test, P = 0.030). The best predictors of OCR were the absence of fine stereopsis and a larger number of surgically treated muscles. Of the 111 patients, 30 (27%) who had postoperative vomiting, the best predictors were female sex and young age. CONCLUSIONS In our cohort, patients experiencing intraoperative OCR when the first extraocular muscle was manipulated during multiple-muscle strabismus surgery were likely to experience it again during traction of additional muscles. More severe postoperative vomiting was common in these patients. OCR was associated with the preoperative absence of fine stereopsis.

Pleiotropic role of atorvastatin in regulation of human retinal pigment epithelial cell behaviors in vitro

Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, possess pleiotropic effects that have been extended to modulation of various cellular behaviors. This study aimed at examining whether atorvastatin (AVN) modulates cell growth, adhesion, migration, and contraction of cultured human retinal pigment epithelium (RPE) cells. The in vitro effects of AVN on human RPE cells was analyzed in terms of cell proliferation, cell cycle, cell adhesion, migration, and contraction assays. The modulatory effect of AVN on TGF-β2-triggered signaling was determined by Western blotting detection. AVN at submicromolar dose exhibited no prominent morphological alteration and cytotoxicity, whereas it elicited cytostatic effect at concentrations higher than 1 μM. Cell cycle analysis showed that AVN induced growth arrest in both G1 and G2/M phases. AVN at 1 μM or higher concentrations significantly suppressed RPE cell adhesion. Cell migration and 3D collagen contraction assays showed that AVN significantly suppressed RPE cell migration and contractility, respectively. Mechanistically, AVN treatment transiently up-regulated phosphorylation of Akt, ERK1/2, and p38 MAPK, whereas down-regulated that of JNK1. Intriguingly, AVN pretreatment prominently attenuated the TGF-β(2)-mediated non-Smad signaling, including Akt, ERK1/2, p38 MAPK, and JNK1 phosphorylation. Besides, it directly reduced constitutive level of myosin regulatory light chain peptide MYL9 and mitigated the TGF-β(2)-induced phosphorylation of myosin phosphatase-targeting subunit 1, MYPT1. These in vitro findings strongly suggest that AVN possesses pleiotropic function on RPE cells, including anti-proliferation, anti-adhesion, anti-migration as well as anti-contraction. In conclusion, AVN treatment may be considered a useful therapy for proliferative vitreoretinal diseases.

Occult plastic intravitreal foreign body retained for 30 years: a case report.

A 41‐year‐old man had suffered trauma to the right eye 30 years ago. In March 1996, he underwent trabeculectomy and peripheral iridectomy under the diagnosis of open angle glaucoma in the right eye. Autoperimetry at that time revealed visual field constriction. In addition, ocular examination showed that the cup/disc ratio of his right eye was increased. Cataract was diagnosed in September 2002 and cataract extraction was performed on October 22, 2002. A plastic intravitreal foreign body was detected during the operation. However, preoperative B‐scan ultrasonography had failed to detect an intraocular foreign body (IOFB), and the previous fluorescein angiography had shown only retinal pigment epithelium changes. This case reminded us that we should be alert to an occult IOFB in the event of ocular trauma, even if none had been detected during prior imaging examinations.

Alteration of cyclic frequency by botulinum toxin injection in adult onset cyclic esotropia

Cyclic strabismus is an uncommon disorder in which strabismus comes and goes alternately, consistently, and repetitively over a period of time. In a 48 hour cycle, a 24 hour period of orthotropia would be followed by a 24 hour period of constant strabismus. Cycles of 24 hour1 to 96 hour2 patterns have been reported. Most cases have been described in children, and the aetiology of cyclic strabismus is still speculative. A 57 year old woman was referred to Kaohsiung Medical University Hospital with the complaint of a periodic visual fluctuation of a “good day“ and a “bad day” alternately for about 6 months. She had diplopia on bad days. She did not have diabetes or hypertension. There was no history of strabismus, amblyopia, patching therapy, ocular trauma, or oculomotor palsy. She had received …

Eyelid Tumors in Southern Taiwan: A 5-Year Survey from a Medical University

This retrospective case analysis investigated the epidemiology of eyelid tumors in a subtropical area. The study assessed the proportion of all eyelid tumors that were malignancies, the accuracy of diagnosis, and surgical results. We retrospectively collected all cases of eyelid tumors in the Department of Ophthalmology, Kaohsiung Medical University, Taiwan, between January 1994 and December 1998. Among the 144 cases collected, about half of the tumors were located in the upper eyelids and the other half in the lower eyelids. Nearly 50% of cases underwent tumor resection with eyelid reconstruction. When followed up to April 1999, 97% of patients were satisfied with the surgical results. There were 18 cases (12.5%) of malignant tumors, including 14 basal cell carcinomas, three sebaceous carcinomas, and one squamous cell carcinoma. Before surgery, two malignancies were presumed to be benign tumors while another two were thought to be different malignant tumors. The benign tumors included 38 nevi, 15 squamous papillomas, 13 cysts, 11 verrucae, 10 seborrheic keratoses, four hemangiomas, and others. All tumors that were thought to be malignancies were treated using complete resection with margin monitoring by frozen section. At the end of follow‐up, no recurrence was noted. More than 10% of cases of eyelid tumors in this subtropical teaching hospital were malignant. All surgeons should be alert to this phenomenon when they operate on an eyelid tumor. The best policy is to send all specimens for pathologic examination.