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Dive into the research topics where Thomas Y. H. Chiu is active.

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Featured researches published by Thomas Y. H. Chiu.


Ophthalmology | 2008

Phacoemulsification versus combined phacotrabeculectomy in medically uncontrolled chronic angle closure glaucoma with cataracts.

Clement C.Y. Tham; Yolanda Y.Y. Kwong; Dexter Y.L. Leung; Sze-Wing Lam; Felix C.H. Li; Thomas Y. H. Chiu; Jonathan Cheuk Hung Chan; Dennis S.C. Lam; Jimmy S. M. Lai

OBJECTIVE To compare phacoemulsification alone versus combined phacotrabeculectomy in medically uncontrolled chronic angle closure glaucoma (CACG) with coexisting cataract. DESIGN Prospective randomized clinical trial. PARTICIPANTS Fifty-one medically uncontrolled CACG eyes with coexisting cataract of 51 patients. INTERVENTION Recruited patients were randomized into group 1 (phacoemulsification alone) or group 2 (combined phacotrabeculectomy with adjunctive mitomycin C). Postoperatively, patients were reviewed every 3 months for 2 years. MAIN OUTCOME MEASURES Intraocular pressure (IOP) and requirement for topical glaucoma drugs. RESULTS Twenty-seven CACG eyes were randomized into group 1, and 24 CACG eyes were randomized into group 2. Combined phacotrabeculectomy resulted in lower mean postoperative IOP than phacoemulsification alone at 3 months (14.0 vs. 17.0 mmHg, P = 0.01), 15 months (13.2 vs. 15.4 mmHg, P = 0.02), and 18 months (13.6 vs. 15.9 mmHg, P = 0.01). Combined phacotrabeculectomy resulted in 1.25 fewer topical glaucoma drugs (P<0.001) in the 24-month postoperative period, compared with phacoemulsification alone. Combined surgery was associated with more postoperative complications (P<0.001) and more progression of optic neuropathy (P = 0.03), compared with phacoemulsification alone. CONCLUSIONS Combined phacotrabeculectomy with adjunctive mitomycin C is more effective than phacoemulsification alone in controlling IOP in medically uncontrolled CACG eyes with coexisting cataract. Combined phacotrabeculectomy is associated with more postoperative complications.


Ophthalmology | 2008

Randomized Trial of Early Phacoemulsification versus Peripheral Iridotomy to Prevent Intraocular Pressure Rise after Acute Primary Angle Closure

Dennis S.C. Lam; Dexter Y.L. Leung; Clement C.Y. Tham; Felix C.H. Li; Yolanda Y.Y. Kwong; Thomas Y. H. Chiu

PURPOSE To compare the efficacy of early phacoemulsification versus laser peripheral iridotomy (LPI) in the prevention of intraocular pressure (IOP) rise in patients after acute primary angle closure (APAC). DESIGN Prospective randomized controlled trial. PARTICIPANTS Sixty-two eyes of 62 Chinese subjects, with 31 eyes in each arm. METHODS Subjects were randomized to receive either early phacoemulsification or LPI after aborting APAC by medications. Patients were followed up on day 1; week 1; and months 1, 3, 6, 12, and 18. Predictors for IOP rise were studied. MAIN OUTCOME MEASURES Prevalence of IOP rise above 21 mmHg (primary) and number of glaucoma medications, IOP, and Shaffer gonioscopy grading (secondary). RESULTS Prevalences of IOP rise for the LPI group were 16.1%, 32.3%, 41.9%, and 46.7% for the follow-ups at 3, 6, 12, and 18 months, respectively. There was only one eye (3.2%) in the phacoemulsification group that had IOP rise at all follow-up time points (P<0.0001). Treatment by LPI was associated with significantly increased hazard of IOP rise (hazard ratio [HR], 14.9; 95% confidence interval [CI], 1.9-114.2; P = 0.009). In addition, a maximum IOP at presentation > 55 mmHg was associated with IOP rise (HR, 4.1; 95% CI, 1.3-13.0; P = 0.017). At 18 months, the mean number of medications required to maintain IOP <or= 21 mmHg was significantly higher in the LPI group (0.90+/-1.14) than in the phacoemulsification group (0.03+/-0.18, P<0.0001). Mean IOP for phacoemulsification group (12.6+/-1.9 mmHg) was consistently lower than that of the LPI group (15.0+/-3.4 mmHg, P = 0.009). Mean Shaffer grading for the phacoemulsification group (2.10+/-0.76) was consistently greater than that of the LPI group (0.73+/-0.64, P<0.0001). CONCLUSION Early phacoemulsification appeared to be more effective in preventing IOP rise than LPI in patients after abortion of APAC. High presenting IOP of >55 mmHg is an added risk factor for subsequent IOP rise. For patients with coexisting cataract and presenting IOP of >55 mmHg, early phacoemulsification can be considered as a definitive treatment to prevent IOP rise.


Archives of Ophthalmology | 2010

Phacoemulsification vs phacotrabeculectomy in chronic angle-closure glaucoma with cataract complications

Clement C.Y. Tham; Yolanda Y.Y. Kwong; Dexter Y. L. Leung; Sze Wing Lam; Felix C.H. Li; Thomas Y. H. Chiu; Jonathan C.H. Chan; Dennis S.C. Lam; Jimmy S. M. Lai

OBJECTIVE To compare the complications of phacoemulsification alone vs combined phacotrabeculectomy in chronic angle-closure glaucoma (CACG) with coexisting cataract. METHODS Patients with CACG with coexisting cataract recruited into 2 randomized controlled trials comparing phacoemulsification alone vs combined phacotrabeculectomy were pooled for analysis. The first trial recruited patients with medically controlled intraocular pressure, while the second trial recruited patients with medically uncontrolled intraocular pressure. The 2 trials had otherwise identical study designs. All patients were reviewed every 3 months for 2 years after surgery. The main outcome measure was the surgical complications of phacoemulsification alone vs combined phacotrabeculectomy in CACG eyes with cataract. RESULTS One hundred twenty-three CACG eyes with cataract from 123 patients were included. Sixty-two CACG eyes were randomized to receive phacoemulsification alone, and 61 eyes had combined phacotrabeculectomy. In the phacoemulsification group, 5 of the 62 CACG eyes (8.1%) had a total of 5 surgical complications. In the combined phacotrabeculectomy group, 16 of the 61 CACG eyes (26.2%) had a total of 19 surgical complications. The difference in the proportion of eyes with 1 or more surgical complications between the 2 treatment groups was statistically significant (P = .007, Pearson chi(2) test). There was no statistically significant difference in final visual acuity or glaucomatous progression during the 24-month follow-up. CONCLUSIONS Combined phacotrabeculectomy resulted in significantly more surgical complications than phacoemulsification alone in CACG eyes with coexisting cataract. There was no difference in visual acuity or disease progression between the 2 treatment groups.


Clinical and Experimental Ophthalmology | 2005

Prevalence and mechanism of appositional angle closure in acute primary angle closure after iridotomy.

Barry Ym Yeung; Philip Wc Ng; Thomas Y. H. Chiu; Chi Wai Tsang; Felix C.H. Li; Chung Chai Chi; Jimmy S. M. Lai; Clement C.Y. Tham; Dennis S.C. Lam

Purpose:  A prospective observational case series to assess the prevalence of appositional angle closure in darkness among iridotomized Chinese eyes after acute primary angle closure (APAC) with the use of both clinical methods and ultrasound biomicroscopy.


Eye | 2009

Correlation of previous acute angle-closure attack with extent of synechial angle closure in chronic primary angle-closure glaucoma patients

C C Y Tham; Jimmy S. M. Lai; Yolanda Y.Y. Kwong; Sze-Wing Lam; Jonathan Cheuk Hung Chan; Thomas Y. H. Chiu; Dennis S.C. Lam

AimTo document any correlation between previous acute angle-closure attack and the extent of synechial angle closure in chronic primary angle-closure glaucoma (PACG) patients.MethodsConsecutive cases of chronic PACG with patent peripheral iridotomy had gonioscopy performed. The extents of synechial angle closure of those chronic PACG eyes with previous documented acute angle-closure attack were compared to those eyes without such a history.ResultsA total of 102 chronic PACG eyes of 102 patients were recruited. Twenty-seven eyes (26.5%) had a previous documented acute angle closure, while 75 eyes (73.5%) did not. The mean extent of synechial angle closure ±1 SD was 307±68 degrees (range, 150–360 degrees) in those chronic PACG eyes with a history of previous acute angle closure, compared to 266±89 degrees (range, 90–360 degrees) in those chronic PACG eyes without such a history (P=0.03, Students t-test). There were no statistically significant differences between the two groups in age, LogMAR visual acuity, intraocular pressure (IOP), number of glaucoma eye drops, vertical cup-to-disk ratio, mean deviation or pattern SD in Humphrey automated perimetry, and anterior chamber depth (P>0.05).ConclusionPrevious acute angle-closure attack correlated with more extensive synechial angle closure in chronic PACG patients in this study.


Journal of Cataract and Refractive Surgery | 2003

Isolated microspherophakia with optic disc colobomata

Alvin L. Young; Christopher B O Yu; Thomas Y. H. Chiu; Nongnart R. Chan; Dennis S.C. Lam

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.


Journal of Pediatric Ophthalmology & Strabismus | 2011

Measurement of intraocular pressure with pressure phosphene tonometry in children.

Thomas Y. H. Chiu; Nathan Congdon; Jeffrey C W Chan; Eva Y. Y. Cheung; Dennis S.C. Lam

PURPOSE To study the accuracy and acceptability of intraocular pressure (IOP) measurement by the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer in children. METHODS Fifty children (5 to 14 years old) participated in this prospective comparative study. IOP was measured with the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer by three different examiners who were masked to the results. The children were also asked to grade the degree of discomfort from 0 to 5 (0 = no discomfort; 5 = most discomfort). RESULTS The mean IOPs measured by the Goldmann tonometer, pressure phosphene tonometer, and non-contact tonometer were 15.9 mm Hg (standard deviation [SD]: = 5.5 mm Hg; range: 10 to 36 mm Hg), 16.0 mm Hg (SD: 2.9 mm Hg; range: 12 to 25 mm Hg), and 15.7 mm Hg (SD = 5.1 mm Hg; range: 8 to 32 mm Hg), respectively (P = .722). The mean difference between pressure phosphene tonometer and Goldmann tonometer readings was 2.9 mm Hg and that between non-contact tonometer and Goldmann tonometer readings was 2.1 mm Hg. The 95% confidence interval of the mean difference between pressure phosphene tonometer and Goldmann tonometer readings was -1.07 and 1.19, and that between non-contact tonometer and Goldmann tonometer readings was -1.07 and 0.53. The mean discomfort ratings for the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer were 0.6, 2.0, and 2.3, respectively (P < .001). CONCLUSION Although the pressure phosphene tonometer was less accurate than the non-contact tonometer compared with Goldmann tonometer, it gave a reasonably close estimate and had a high specificity of raised IOP. In addition, measurement by the pressure phosphene tonometer is most acceptable to children. The pressure phosphene tonometer can be considered as an alternative method of IOP measurement in children.


Journal of Pediatric Ophthalmology & Strabismus | 2004

Ocular Manifestations and Surgical Management of Lid Coloboma in a Chinese Infant With Linear Nevus Sebaceous Syndrome

Thomas Y. H. Chiu; Winnie C.W. Chu; Nongnart R. Chan; Dennis S.C. Lam

An 8-month-old Chinese girl with linear nevus sebaceous syndrome had a right upper lid coloboma and right superior scleral ectasia. At 20 months old, successful surgical repair of the lid coloboma was performed with particular attention paid to the sclera ectasia.


Investigative Ophthalmology & Visual Science | 2004

Pressure Phosphene Self-Tonometry: A Comparison with Goldmann Tonometry in Glaucoma Patients

Dennis S.C. Lam; Dexter Y.L. Leung; Thomas Y. H. Chiu; Eva Y. Y. Cheung; Tien Yin Wong; Jimmy S. M. Lai; Clement C.Y. Tham


Archives of Ophthalmology | 2003

Ocular-Hypertensive and Anti-inflammatory Response to Rimexolone Therapy in Children

Christopher B O Yu; Thomas Y. H. Chiu; Chun yu Wong; Joan S.K. Ng; Chi Pui Pang; Dennis S.C. Lam

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Dennis S.C. Lam

The Chinese University of Hong Kong

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Clement C.Y. Tham

The Chinese University of Hong Kong

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Felix C.H. Li

The Chinese University of Hong Kong

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Yolanda Y.Y. Kwong

The Chinese University of Hong Kong

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Dexter Y.L. Leung

The Chinese University of Hong Kong

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Sze-Wing Lam

The Chinese University of Hong Kong

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Christopher B O Yu

The Chinese University of Hong Kong

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David T.L. Liu

The Chinese University of Hong Kong

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Eva Y. Y. Cheung

The Chinese University of Hong Kong

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