Tsing-Hong Wang

Changes of the ocular refraction among freshmen in National Taiwan University between 1988 and 2005

PurposeThe prevalence of myopia in Taiwan has been reported to be increasing in the sequential nationwide survey. The purpose of this study is to compare the change of ocular refraction among freshmen in 1988 and 2005 in National Taiwan University.MethodsThe refractive status of freshmen in National Taiwan University in 2005 was examined. The refractive status and corneal radius of each student were measured with autorefractometer. The data was compared with the data obtained in 1988. All the refractions of the right eye were chosen and myopia was defined as a mean spherical equivalent of −0.25 D or more.ResultsThe mean refractive status of total 4686 freshmen was −4.25±2.74 D in 1988 (−4.12±2.72 D for males and −4.41±2.75 D for females). The prevalence of myopia was 91.3% (90.1% for males and 92.8% for females). The prevalence of high myopia (over −6.0 D) was 23.5% (22.2% for males and 25.1% for females). In 2005, the mean refractive status of total 3709 freshmen was −4.93±2.82 D (−4.93±2.83 D for males and −4.93±2.80 D for females). The prevalence of myopia was 95.9% (95.9% for males and 95.9% for females). The prevalence of high myopia was 38.4% (38.1% for males and 38.8% for females).ConclusionsThe prevalence and severity of myopia in freshmen of National Taiwan University increased significantly in 2005 compared to 1988. The distribution of refractive status in different college changed also. These findings may be explained by the early onset of myopia.

Association Between High Myopia and Progression of Visual Field Loss in Primary Open-angle Glaucoma

BACKGROUND/PURPOSE Taiwan has a very high prevalence rate of myopia. We retrospectively studied the influence of myopia on the progression of visual field (VF) loss in primary open-angle glaucoma (POAG) patients. METHODS We studied 515 POAG patients for a minimum follow-up period of 5 years. VF examination was performed with Humphrey perimeter, 30-2 SITA standard program, every 6 months. A point-wise numerical comparison was applied to judge the VF changes. Test points showing more than 1.0 dB of sensitivity loss in mean defect were identified. A location was considered to have progression if it was detected on two consecutive visits. Progression of VF loss was confirmed if three or more test points deteriorated. Multivariate logistic regression was used to evaluate the association between progression of VF loss and various risk factors. RESULTS There were 262 cases. Progression of VF loss occurred in 57 eyes (21.8%) during the 5-year follow-up period. Logistic regression revealed that the deterioration was associated with older age, higher mean intraocular pressure, larger vertical cup-to-disc ratio, and greater myopic refraction status. The incidence of VF loss progression was 15.1% in the group of eyes with myopia less than -3 D, 10.5% in the group with -3 D to -6 D, 34.4% in the group with -6 D to -9 D, and 38.9% in the group with myopia greater than -9 D. CONCLUSION POAG patients with myopia greater than -6 D had a greater progression of VF loss.

Clinical Outcomes in Cytomegalovirus-Positive Posner-Schlossman Syndrome Patients Treated With Topical Ganciclovir Therapy

PURPOSE To evaluate the clinical characteristics and therapeutic outcomes of cytomegalovirus (CMV)-positive Posner-Schlossman syndrome patients undergoing topical ganciclovir treatment. DESIGN Retrospective, comparative, and interventional case series. METHODS One eye of each of 126 consecutive Posner-Schlossman syndrome patients was investigated using aqueous polymerase chain reaction (PCR) between January 2006 and June 2013. The initial presentations and follow-up data of the CMV-positive patients (68 eyes) and CMV-negative patients (58 eyes) were compared. RESULTS Severe endothelial cell loss (P < .001) and a higher number of eyes requiring glaucoma filtering surgery (P = .017) were observed in CMV-positive Posner-Schlossman syndrome patients. All CMV-infected eyes treated with continual topical 2% ganciclovir exhibited an undetectable CMV level at the following taps. During follow-up, the average number of antiglaucomatous agents decreased, and a similar frequency of intraocular pressure (IOP) spikes was observed in both groups (P = .358). Patients with CMV-positive eyes with a disease duration over 5 years were likely to require glaucoma surgery (P = .024, log-rank test). All patients receiving surgery exhibited CMV-negative PCR during the IOP attack, but experienced severe peripheral anterior synechiae and pigment clogging. Both groups exhibited a similar endothelial cell decrease (P = .243) and probability of progressive endothelial cell loss (P = .219, log-rank test). CONCLUSION Ganciclovir treatment was effective for clearing the viral load, assisting the IOP control, and preserving the corneal endothelium of CMV-positive Posner-Schlossman syndrome patients. Early diagnosis and proper treatment could decrease the risk of advanced glaucoma and avoid glaucoma surgery in long-lasting cases.

Ocular hypotensive effect and safety of brinzolamide ophthalmic solution in open angle glaucoma patients.

BACKGROUND AND PURPOSE Brinzolamide is a new topical carbonic anhydrase inhibitor for intraocular pressure (IOP) control. It has high inhibitory activity against human carbonic anhydrase II, which is the key isoenzyme regulating aqueous humor production. We conducted this study to compare the ocular hypotensive effect and safety of 1% brinzolamide versus that of 0.5% timolol twice daily. METHODS In a double-masked design, 50 open angle glaucoma patients who had a baseline IOP between 20 to 30 mm Hg were randomized to receive either 1% brinzolamide ophthalmic solution or 0.5% timolol twice daily. After completing a 2-week pre-study screening period, patients were scheduled to receive 6 weeks of treatment. Visual acuity, IOP, slit-lamp biomicroscopy, corneal thickness, refraction status, blood pressure, heart rate, and treatment-related signs and symptoms were evaluated at follow-up visits. The eye selected for treatment was the one with the higher baseline IOP, or the right eye if the IOPs were the same in both eyes. The fellow eye served as control. RESULTS 48 patients completed the study, and there were 24 patients in each group. A significant decrease in mean IOP was found after 6 weeks of treatment in both the brinzolamide group (-17.0%) and the timolol group (-19.7%), with no significant between-group difference in the control of IOP. The central corneal thickness of treatment eyes, measured by ultrasound pachometry, had not changed after 6 weeks of brinzolamide treatment. The study medications were generally well tolerated and no serious adverse reactions occurred during the 6-week study period. CONCLUSION When used twice a day, topical brinzolamide is as effective as 0.5% timolol in lowering IOP in patients with open angle glaucoma.

Characteristics of Optic Disc Changes in Taiwanese Patients with Primary Angle-Closure Glaucoma

BACKGROUND AND PURPOSE Primary angle-closure glaucoma (PACG) is the predominant form of glaucoma among Asians. Although numerous studies have been done to describe the characteristic optic disc changes in patients with primary open angle glaucoma (POAG) which is the predominant form of glaucoma among Western populations, few studies have evaluated the optic disc changes in patients with PACG. The aim of this study was to elucidate the characteristic intrapapillary and parapapillary disc changes in PACG in a cross-sectional study and to develop a practical approach to the detection of glaucomatous optic disc changes in PACG by ophthalmoscopic examination. METHODS A total of 103 eyes in 103 PACG patients were studied. Forty one eyes of 41 age- and sex-matched healthy subjects served as controls. Three glaucoma-trained subspecialists examined stereophotographs of optic discs to evaluate the intrapapillary and parapapillary changes. The differences in PACG and control group eyes were compared. RESULTS Concentric steep enlargement of the optic disc was found in 99 PACG eyes (96%). Local notching was noted in only 3 eyes, and vertically oval-shaped cupping of the optic disc in only 1 eye. Disc hemorrhage was not detected in any eye. Parapapillary atrophy of the alpha zone involving both temporal and nasal side of the optic disc and parapapillary atrophy of beta zone were significantly more frequent in the PACG group. The presence of an alpha zone or a beta zone simultaneously involving both the temporal and nasal side of the optic disc was associated with more severe optic nerve head damage. CONCLUSIONS The intrapapillary change in the PACG group eyes reflected the development of cupping in PACG patients with small and compact optic discs. The parapapillary atrophy paralleled the intrapapillary optic disc cupping in eyes of the PACG group.

The Refractive Status of Middle-Aged and Elderly Population in Chin-Shan Xiang, Taipei County

Introduction: To investigate the distribution of visual acuity and refractive status on middle-aged (40 to 65 years old) and elderly (＞65 years old) people in Taiwan. Methods: A total of 3901 residents (middle-age 2634, elderly 1267) in 1992 and 2817 residents (middle-age 1866, elderly 951) in 1994 received visual acuity and autorefractor exam. If visual acuity less than 20/25, further ocular exams were performed. Totally, 1267 cases (middle-age 976, elderly 291) in 1992 and 1814 cases (middle-age 1406, elderly 408) in 1994 received a complete ophthalmologic exam, including slit-lamp exam, cycloplegic refraction, funduscopy, intraocular pressure, and biometric axial length. Results: Around half of middle-aged participants had their corrected visual acuity better than 20/25. However, only 10% were found in elderly participants. About 40% of elderly populations had their corrected visual acuity between 20/200 and 20/50. Besides, 15% of elderly populations were less than 20/200, but for the middle-aged populations, the figure was only 5%. The refractive status showed hyperopic shift after cycloplegia. The percentage of mild hyperopia decreased and mild myopia increased in elderly population. Conclusion: The corrected visual acuity declined with age. The myopic shift after 65 years old might be due to cataract formation.

Long-term follow-up of retinal nerve fiber layer cleavages in glaucoma patients and suspects

PurposeTo investigate the structural and functional characteristics and change of the retinal nerve fiber layer cleavages (RNFLCs) in glaucoma patients and suspects in long-term follow-up.MethodsThis is a retrospective longitudinal study. Within 43 eyes of 30 subjects, 62 RNFLC locations were detected on color fundus photography. Basic ophthalmic examinations, color fundus photography, optical coherence tomography (OCT), and visual field (VF) test were performed in 6-month intervals. Clinical characteristics and the structural and functional changes of the cleaved areas were analyzed.ResultsRNFLC and localized vitreoretinal traction occurred most commonly along the superotemporal retinal vessel arcade. Nine locations had corresponding defects on OCT deviation map, while 31 locations were associated with defects on OCT deviation map. Three locations had corresponding VF defects. More of the non-highly myopic eyes had lamellar hole than the highly myopes (p = 0.038). The RNFLC lesions in glaucomatous eyes were more frequently associated with OCT defects on deviation map (p = 0.021). There was no difference in the presence of lamellar hole or the number of RNFLCs between the glaucomatous and non-glaucomatous eyes. During a 66.8 ± 37.8-month follow-up, there was no structural or functional progression of the RNFLCs as determined by color fundus photography, VF test, and GPA of OCT interpreted by three ophthalmologists. There was no statistically significant change of RNFLC area (p = 0.268).ConclusionsRNFLC did not show detectable functional or structural change in early glaucoma patients and suspects after long-term follow-up.

Comparing the Effect of Central Corneal Thickness (CCT) on Intraocular Pressure as Measured by Dynamic Contour Tonometry (DCT) and Non-Contact (Air-Puff) Tonometry (NCT)

Purpose: To compare the effect of corneal thickness on intraocular pressure (IOP) measured by dynamic contour tonometer (DCT) and non-contact tonometer (NCT).Method: A total of 112 participants without history of corneal disease or current ocular hypotensive agent use were enrolled. IOP was measured by NCT and DCT sequentially on their first visit to the clinic. Central corneal thickness (CCT) was determined by an ultrasonic pachymeter at the same time. The inter-method agreement on IOP measured by these two different tonometers was assessed by the Bland-Altman method and intra-class correlation coefficient (ICC). The relationship between CCT and IOP measurement by NCT, IOP measurement by DCT, and difference in IOP measurement between the two different tonometers was assessed by simple linear regression.Results: The mean difference in IOP measurement between NCT and DCT was -1.6 mmHg (95% limit of agreement: -7.9 ~ 4.7 mmHg). There was a fair to good agreement in IOP measurement between NCT and DCT (ICC = 0.623, p ＜ 0.001). The correlation coefficients between CCT and IOP measured by NCT and DCT were 0.647 and 0.374 respectively, indicating a strong correlation between CCT and IOP in the NCT group. When CCT was less than 612.2μm, the IOP measured by NCT tended to be lower than that measured by DCT. Conversely, NCT tended to yield a higher IOP reading than DCT when CCT exceeded 612.2μm.Conclusion: IOP measured with DCT is more independent of CCT than NCT. Higher agreement between these two tonometers was noted when the CCT value came closer to 612.2μm.

Acute Angle-Closure Attack Associated with Travoprost Induced Uveal Effusion in A Nanophthalmic Eye – A Case Report

Purpose: To report a case of acute angle-closure attack associated with travoprost-induced uveal effusion in a nanophthalmic eye even with a patent iridotomy.Methods: A case report.Results: A 70-year-old man with the history of nanophthalmos and acute angle-closure attack in the right eye (RE) received laser iridotomies in both eyes and received a fixed combination of timolol maleate 0.5% and dorzolamide HCl 2% twice per day in the RE after the episode. Intraocular pressure (IOP) was stable with the medication until bradycardia was noted. Travoprost 0.004% once daily in the RE was used. Four days later, foggy vision (20/400) and significant IOP elevation (69 mm Hg) were found in the RE. Oral acetazolamide 500 mg and intravenous mannitol 20% 300 mL were given emergently. The topical anti-glaucomatous agent was shifted from travoprost 0.004% to pilocarpine 2% four times per day, dorzolamide HCl 2% and brimonidine tartrate 0.15% three times per day. The ultrasound biomicroscopy (UBM) showed circumferential uveal effusion. Four weeks later, uveal effusion was completely resolved. The IOP was adequately controlled with dorzolamide 2% only in the RE.Conclusion: In a nanophthalmic eye, travoprost-enhanced uveoscleral outflow would result in uveal effusion. The forward shifting of the lens secondary to choroidal expansion might narrow the anterior chamber angle and lead to acute angle-closure attack. Travoprost should be used with caution in patients with nanophthalmos.

Visual Impairment among the Middle-Aged and Elderly Population in Chin-Shan Township, Taipei County

Objective: To investigate the status and causes of visual impairment in middle-aged (40 to 65 years old)and elderly(＞65 years old)people in Taiwan. Materials and Methods: A total of 3901 residents of Chin-Shan Township, Taipei County, in 1992 and 2817 residents in 1994 received visual acuity and autorefractor examinations. If visual acuity was less than 20/50, further ocular examinations were performed. A total of 1210 subjects in 1992 and 884 subjects in 1994 received a complete ophthalmological exam, including slit-lamp examination, intraocular pressure, cycloplegic refraction, funduscopy examination, and biometric exial length. Results: The most frequent cause of low vision (corrected visual acuity between 20/50 and 20/200) for the middle-aged and aged population was cataract (70%) and related diseases. The second most frequent cause was retinopathy (15%). Corneal diseases, glaucoma and other factors comprised the remaining 15% of cases. Cataract was also the main cause of blindness (corrected visual acuity less than 20/200) in the middle-aged and aged population (60%). Retinopathy (20%) was the second most frequent cause of blindness in both groups. Conclusions: Cataract was the most frequent cause of visual impairment and retinopathy was the second most frequent cause for the middle-aged and aged population of Chin-Shan Xiang, Taipei County, in 1992 and 1994.