Biomedical subjects

Tin Aung

Publications and source records attributed to Tin Aung.

At least 37 records · Page 2Linked to original sources

PubMed2005

Cataract progression after prophylactic laser peripheral iridotomy: potential implications for the prevention of glaucoma blindness.

PURPOSE: To evaluate changes in lens opacity in the first year after prophylactic laser peripheral iridotomy (LPI) performed in fellow eyes of subjects with acute primary angle closure (APAC). DESIGN: Prospective observational case series. PARTICIPANTS: Sixty Asian subjects with unilateral APAC. METHODS: All fellow eyes underwent prophylactic LPI within the first week of presentation, followed by 1 week of topical steroids. The degree of lens opacity was graded at the slit-lamp examination using the Lens Opacity Classification System III (LOCS III) with standard color photographs as the reference for grading of lens opacity. This was performed 2 weeks, 4 months, and 12 months after LPI. Progression in lens opacity was defined as an increase in LOCS III grade by 2 or more units in any lens region. MAIN OUTCOME MEASURES: Lens Opacity Classification Sytem III grades in nuclear, cortical, and posterior subcapsular (PSC) regions. RESULTS: Most patients were Chinese (85%) and female (63.3%), with an average age of 61.5 +/- 10.6 years. The mean baseline LOCS grades in the nuclear, cortical, and PSC regions were 3.58 +/- 0.74, 0.57 +/- 1.08, and 0.23 +/- 0.72, respectively. With 12 months of follow-up, 14 of the 60 eyes (23.3%; 95% confidence interval, 16.9-29.7%) showed significant progression in any lens region. Progression in the nuclear, cortical, and PSC regions was documented in 5%, 6.7%, and 16.7% of cases, respectively. By use of logistic regression, the following factors were not found to be significant for cataract progression in any lens region: age, race, gender, history of hypertension or diabetes, presence of peripheral anterior synechiae or angle width at baseline, and total laser energy delivered. CONCLUSIONS: In fellow eyes of APAC, prophylactic LPI is complicated by significant cataract progression, mainly in the posterior subcapsular region. These findings may have implications for the role of prophylactic LPI in the prevention of angle-closure blindness.

Acute Disease↗

PubMed2005

Iris ischaemic changes and visual outcome after acute primary angle closure.

BACKGROUND: Ischaemic changes in the iris occur frequently after an episode of acute primary angle closure (APAC). The aim of this study was to investigate the significance of such changes with regards to visual outcome. METHODS: Acute primary angle closure cases were treated with medical therapy followed by laser peripheral iridotomy after resolution of the acute episode. Subjects were examined at 1, 4, 8, 12 and 16 weeks post laser peripheral iridotomy. Eyes were examined for signs of iris ischaemic changes (IIC), defined as the presence of iris whorling or stromal atrophy. Iris photographs were also taken at weeks 1, 8 and 16. Subjects requiring glaucoma medication or filtering surgery during the follow-up period were excluded. The visual acuity and visual field (using automated white-on-white threshold perimetry) at week 16 were used in the assessment of visual outcome. RESULTS: Sixty-one subjects with APAC completed the study. The majority of subjects were female (82%) and Chinese (92%), and the mean age was 59 +/- 8.8 years. More than half the subjects (52.5%) were found to have developed IIC during the study, 65% of whom already had signs of IIC by the first week. Only 13 subjects (41%) with IIC and 6 subjects (21%) without IIC had an abnormal visual field defect at week 16 (P = 0.09). There was also no difference in visual acuity at week 16, the majority of subjects in both groups having visual acuity of 6/12 or better. CONCLUSIONS: The development of iris ischaemic changes after a single episode of APAC may not be associated with an adverse visual outcome.

Acute Disease↗

PubMed2005

Use of optical coherence tomography to assess variations in macular retinal thickness in myopia.

PURPOSE: To investigate the variation in macular retinal thickness in otherwise normal young Asian myopic subjects by using optical coherence tomography (OCT). METHODS: One hundred thirty ophthalmically normal men 19 to 24 years of age with myopia (spherical equivalent, -0.25 to -14.25 D) underwent examination of one randomly selected eye. Visual acuity, refraction, slit lamp examination, applanation tonometry, gonioscopy, A-scan ultrasound, fundus examination, visual field testing, and optic disc photography were performed. Exclusion criteria were visual acuity worse than 20/30, previous intraocular surgery, intraocular pressure >21 mm Hg, or other ocular diseases. Three horizontal transfixation and three vertical transfixation OCT scans (ver.4.1; Carl Zeiss Meditec, Dublin, CA) of 6 mm each were conducted on each eye by a single operator. Neurosensory retinal thicknesses at 100 points along each scan were measured, and the overall average, maximum, and minimum retinal thicknesses were analyzed by simple linear regression and analysis of variance. RESULTS: The average macular retinal thickness (overall) was 230.9 +/- 10.5 microm and was not significantly related to the degree of myopia. The mean maximum retinal thickness (at the parafovea) was 278.4 +/- 13.0 microm, and correlated negatively with axial length (P = 0.03). The mean minimum retinal thickness (at the foveola) was 141.1 +/- 19.1 microm, and this was positively correlated with axial length (P = 0.015) and spherical equivalent (P = 0.0002). The retina was thicker at the superior and nasal parafovea compared to the inferior or temporal parafovea. CONCLUSIONS: Average retinal thickness of the macula does not vary with myopia. However, the parafovea was thinner and the fovea thicker with myopia.

Adult↗

PubMed2005

Clinical features and course of patients with glaucoma with the E50K mutation in the optineurin gene.

PURPOSE: To investigate the clinical features of subjects with glaucoma with the E50K mutation in the optineurin (OPTN) gene and to compare the onset, severity, and clinical course of these patients with a control group of subjects with glaucoma without this mutation. METHODS: The phenotype of well-characterized subjects from Moorfields Eye Hospital, London, who had been identified as carrying the OPTN E50K mutation was examined. A wide range of structural, psychophysical, and demographic factors were then compared with those in a control group of subjects with glaucoma without this mutation. RESULTS: Eleven subjects with glaucoma with the E50K mutation (nine in two families and two sporadic cases) were studied. All 11 subjects had normal tension glaucoma (NTG), with presenting and highest IOP of 15.3 +/- 3.0 and 16.5 +/- 2.5 mm Hg (+/-SD) on diurnal testing. Compared with 87 NTG control subjects who did not have this mutation, subjects with E50K presented at a younger age (40.8 +/- 15 years, P = 0.0001) and had more advanced optic disc cupping (mean cup-disc ratio +/- SD 0.86 +/- 0.1, P = 0.001) and smaller neuroretinal rim area (+/-SD; 0.5 +/- 0.28 mm2, P = 0.001) at diagnosis. The rate of filtration surgery performed for progressive visual field loss in those with and without the E50K mutation was 72.7% and 25.3%, respectively (P = 0.003), and all subjects with E50K were found to have progressing visual fields. In addition, seven E50K mutation-carrying individuals in two families (age range, 23-58 years) presented with normal optic discs and visual fields and, as yet, no signs of glaucoma. CONCLUSIONS: In this study, subjects with glaucoma who had the OPTN E50K mutation were found to have NTG that appeared to be more severe than that in a control group of subjects with NTG without this mutation. The findings emphasize the importance of early detection and treatment of glaucoma in such individuals, to minimize visual loss.

Adult↗

PubMed2005

Molecular analysis of the myocilin gene in Chinese subjects with chronic primary-angle closure glaucoma.

PURPOSE: Mutations in the myocilin (MYOC) gene have been implicated in juvenile as well as late-onset primary open-angle glaucoma (POAG). Overall, MYOC mutations account for 3% to 5% of cases of POAG worldwide, making it the most significant gene identified so far in glaucoma. Although there are some similarities in the phenotype of POAG and in particular chronic primary angle-closure glaucoma (PACG), little is known about the role of MYOC in the causation of PACG. To address this, the MYOC gene was screened in a cohort of 106 patients with chronic PACG. METHODS: Genomic DNA was extracted from leukocytes of the peripheral blood and exons 1 to 3 of the MYOC gene were PCR amplified and subjected to bidirectional sequencing and analysis. RESULTS: One hundred six patients with chronic PACG of Chinese ethnicity were studied. Sequencing of the MYOC gene in these patients revealed eight sequence variants. Of these, one was a nonsense change, three were missense changes, two were synonymous codon changes, and two were changes in noncoding sequences. These included the Arg46Stop and Thr353Ile mutations, which have been reported in individuals with POAG. However, all the sequence alterations identified have been found in normal Chinese subjects. CONCLUSIONS: The results of this study do not support a role for MYOC mutations in the pathogenesis of chronic PACG in the Chinese.

Aged↗

PubMed2005

Characterization of Bietti crystalline dystrophy patients with CYP4V2 mutations.

PURPOSE: Mutations of the CYP4V2 gene, a novel family member of the cytochrome P450 genes on chromosome 4q35, have recently been identified in patients with Bietti crystalline dystrophy (BCD). The aim of this study was to investigate the spectrum of mutations in this gene in BCD patients from Singapore, and to characterize their phenotype. METHODS: Nine patients with BCD from six families were recruited into the study. The 11 exons of the CYP4V2 gene were amplified from genomic DNA of patients by polymerase chain reaction and then sequenced. Detailed characterization of the patients' phenotype was performed with fundal photography, visual field testing, fundal fluorescein angiography, and electroretinography (ERG). RESULTS: Three pathogenic mutations were identified; two mutations, S482X and K386T, were novel and found in three patients. The third mutation, a previously identified 15-bp deletion that included the 3' splice site for exon 7, was found in all nine patients, with six patients carrying the deletion in the homozygous state. Haplotype analysis in patients and controls indicated a founder effect for this deletion mutation in exon 7. Clinical heterogeneity was present in the patients. Compound heterozygotes for the deletion in exon 7 seemed to have more severe disease compared to patients homozygous for the deletion. There was good correlation between clinical stage of disease and ERG changes, but age did not correlate with disease severity. CONCLUSIONS: This study identified novel mutations in the CYP4V2 gene as a cause of BCD. A high carrier frequency for the 15-bp deletion in exon 7 may exist in the Singapore population. Phenotype characterization showed clinical heterogeneity, and age did not correlate with disease severity.

Adult↗

PubMed2004

Surgical outcomes of combined phacoemulsification and glaucoma drainage implant surgery for Asian patients with refractory glaucoma with cataract.

PURPOSE: To examine the safety and efficacy of combined phacoemulsification and glaucoma drainage implant surgery in providing reduction of intraocular pressure (IOP) and visual rehabilitation in eyes with refractory glaucoma and cataract. DESIGN: Interventional case series. METHODS: A retrospective chart review was performed on all subjects who underwent combined phacoemulsification with intraocular lens implantation and glaucoma drainage implant surgery by a single surgeon at the National University Hospital, Singapore. The implants used were the 185 mm2 Ahmed glaucoma valve and the 350 mm2 Baerveldt glaucoma implant. In terms of IOP, a complete success was defined as IOP of between 6 to 21 mm Hg without medication, qualified success as IOP between 6 to 21 mm Hg with one or more medication, and failure as a sustained IOP of >21 mm Hg or <6 mm Hg with or without one or more medication on two or more visits. RESULTS: A total of 32 combined phacoemulsification and glaucoma implant surgeries in 32 patients was performed. All patients were of Asian origin, and the mean age was 58 +/- 16 years (range, 20-78 years). The Baerveldt glaucoma implant and Ahmed glaucoma valve implant were inserted in 16 eyes each. With a mean follow-up of 13 +/- 5 months (range 6 to 22 months), IOP was reduced from a mean of 28.0 +/- 11.5 mm Hg to 15.2 +/- 6.0 mm Hg postoperatively (P <.0001), whereas the number of antiglaucoma medications decreased from a mean of 2.4 +/- 1.4 to.3 +/-.7 (P <.0001) at last follow-up. Overall, there were 24 eyes (75%) that were classified as complete successes, 4 eyes (12.5%) that were qualified successes, and 4 eyes that failed (12.5%). Twenty-three eyes (72%) had improvement of visual acuity, while only one eye had a loss of more than 1 line of Snellen acuity. There was no case that encountered an intraoperative complication, and postoperative complications occurred in 12 eyes (38%), the most common of which was hypotony (in six eyes, 19%). CONCLUSION: For subjects with refractory glaucoma and cataract, combined phacoemulsification and glaucoma drainage implant surgery provide good visual rehabilitation and control of IOP, with low incidence of complications.

Adult↗

PubMed2004

Intraocular pressure-reducing effects and safety of latanoprost versus timolol in patients with chronic angle-closure glaucoma.

OBJECTIVE: To demonstrate that the intraocular pressure (IOP)-reducing effect of latanoprost once daily is at least as good as that of timolol twice daily in patients with chronic angle-closure glaucoma (CACG). DESIGN: Randomized, double-masked, multicenter 12-week study. PARTICIPANTS: In all, 137 patients with unilateral or bilateral CACG were treated with latanoprost, and 138 were treated with timolol. METHODS: Patients received either latanoprost (9 pm) and a placebo (9 am) or timolol (both 9 am and 9 pm). Intraocular pressure was measured at 9 am and 5 pm at baseline and weeks 2, 6, and 12. MAIN OUTCOME MEASURES: The difference between groups in daily IOP (average of 9 am and 5 pm measures) reduction was the primary outcome. Secondary outcomes included differences between groups in IOP reductions at 9 am and 5 pm, and in proportions of patients reaching specified daily IOP levels. RESULTS: Using repeated measures (analysis of covariance: intent to treat), mean changes from baseline in daily IOP levels during 12 weeks were -8.2 mmHg and -5.2 mmHg for latanoprost- and timolol-treated patients, respectively (difference: -3.0 mmHg [95% confidence interval: -4.0, -2.1], P<0.001). Greater reductions in IOP levels at both 9 am and 5 pm were found in latanoprost-treated patients (P<0.001 for both), and greater proportions of patients receiving latanoprost reached prespecified target daily IOP levels (P<0.001 for all 3 target levels tested). Both drugs were well tolerated. CONCLUSION: Latanoprost administered once daily provides significantly greater IOP reduction in CACG patients than does timolol instilled twice daily.

Adult↗

PubMed2004

Changes in retinal nerve fiber layer thickness after acute primary angle closure.

PURPOSE: To evaluate the changes in retinal nerve fiber layer (RNFL) thickness in the first 16 weeks after acute primary angle closure (APAC) using scanning laser polarimetry (SLP). DESIGN: Prospective, observational case series. PARTICIPANTS: Thirty-seven Asian subjects with APAC. METHODS: For all cases, APAC had resolved after treatment, and the study was conducted during the follow-up period after the acute episode. Using the GDx Nerve Fiber Analyzer (Laser Diagnostic Technologies, San Diego, CA), the RNFL was assessed in both eyes 2 weeks after APAC, and again after 16 weeks. The SLP parameters were compared between week 2 and week 16 within affected and fellow eyes. A multiple logistic regression analysis was carried out to analyze factors likely to influence RNFL outcome. MAIN OUTCOME MEASURES: Superior and inferior average RNFL thickness. RESULTS: The mean age of study subjects was 60.1+/-10.3 years (range, 46-91 years), and most subjects were female (68%) and Chinese (86%). In APAC eyes, the superior average RNFL thickness decreased from 63.8+/-13.6 microm to 61.4+/-11.2 microm (P = 0.04) and the inferior average RNFL thickness decreased from 69.5+/-14.4 microm to 66.3+/-12.6 microm (P = 0.005). There was also a decrease in inferior ratio (P = 0.008) and ellipse modulation (P = 0.02). In the fellow eyes, there was no difference found between week 2 and week 16 for any of the SLP parameters studied. Logistic regression analysis showed no significant association between developing a 10% reduction in either superior or inferior RNFL thickness with age, gender, history of ischemic risk factors, duration of symptoms during APAC, the level of presenting intraocular pressure (IOP), or the development of a rise in IOP between study visits. CONCLUSIONS: After an episode of APAC, superior and inferior average RNFL thickness was found to decrease significantly from week 2 to week 16.

Acute Disease↗

PubMed2004

Long-term outcomes in asians after acute primary angle closure.

PURPOSE: To determine the long-term outcome of Asian eyes with an acute attack of primary angle closure (APAC) and to identify risk factors at presentation associated with the development of glaucomatous optic nerve damage. DESIGN: Cross-sectional observational case series. PARTICIPANTS: Ninety individuals who were initially seen with APAC 4 to 10 years previously at 2 Singapore hospitals. METHODS: All subjects underwent a complete eye examination, including visual acuity, visual field testing, dilated eye examination, and optic nerve head photography. The optic discs were judged clinically and photographically as to whether there was glaucomatous optic neuropathy present, and visual fields were assessed for corresponding visual field loss. All visual fields and optic nerve photographs underwent a second evaluation by an experienced, but masked, glaucoma specialist, who assessed whether the changes were compatible with glaucoma. MAIN OUTCOME MEASURES: The main outcome measures were blindness (defined as best-corrected visual acuity worse than 6/60 and/or central visual field of less than 20 degrees in the attack eye) and glaucomatous optic neuropathy (GON). RESULTS: A total of 90 of 170 eligible subjects (65.2%) were examined. All subjects were Asian and were predominantly Chinese (78 subjects [86.7%]). There were 61 females (67.8%), and the age of the subjects was 62.0+/-9.0 years (mean +/- standard deviation) at the time of APAC, with a mean duration of 6.3+/-1.5 years from the time of the APAC episode to the study examination. Sixteen (17.8%) subjects were blind in the attack eye; half of the cases of blindness were caused by glaucoma. Forty-three subjects (47.8%) had GON, with 13 eyes (15.5%) having markedly cupped optic discs (cup-to-disc ratio >0.9). Thirty-eight eyes (58%) had best-corrected vision worse than 6/9, with cataract responsible for close to half the cases of poor vision. There were no identifiable risk factors related to the APAC episode that were significantly associated with the presence of GON. CONCLUSIONS: Several years after being seen with APAC, 17.8% of subjects examined were blind in the attack eye, and almost half had glaucomatous optic nerve damage. Vision was also reduced in a large number of individuals, largely from unoperated cataract. Subjects with APAC would benefit from regular follow-up to monitor for visual field decline and glaucoma development.

Acute Disease↗

PubMed2004

Visual field loss from primary angle-closure glaucoma: a comparative study of symptomatic and asymptomatic disease.

PURPOSE: To assess the degree of visual field (VF) loss in subjects diagnosed with primary angle-closure glaucoma (PACG), and to compare the severity of such loss between those with symptomatic and asymptomatic disease. DESIGN: Observational case series. PARTICIPANTS: Seventy-six consecutive subjects with PACG who presented at a Singapore hospital. METHODS: Primary angle-closure glaucoma was defined as the presence of glaucomatous optic neuropathy and compatible VF loss associated with closed angles. There were 2 groups of subjects studied: group A consisted of those who presented with acute symptomatic angle closure, and group B consisted of those who were asymptomatic. Subjects underwent static automated threshold perimetry, and the first reliable VF was analyzed using the Advanced Glaucoma Intervention Study (AGIS) scoring system. The field tests were graded according to severity as mild, moderate, severe, and end-stage VF defects, based on AGIS scores of 0 to 5, 6 to 11, 12 to 17, and 18 to 20 respectively. MAIN OUTCOME MEASURES: Advanced Glaucoma Intervention Study scores of the first reliable threshold VF test. RESULTS: The mean age of study subjects was 61.4+/-9.6 years (range: 33-84), and the majority of subjects were female (59%) and Chinese (91%). In group A (n = 40), most eyes had mild or moderate VF defects (23 eyes [57.5%]), whereas 7 eyes (17.5%) had end-stage defects. This was in contrast to group B (n = 36), in which the majority of eyes had end-stage VF loss (19 eyes [52.8%]), with only 5 eyes (13.7%) having mild VF defects. Mean AGIS scores were 9.1+/-7.6 for group A and 14.2+/-6.9 for group B (P = 0.004). Cup-to-disc ratio was a significant predictor for VF loss, but age, gender, and level of presenting intraocular pressure were not correlated with VF outcome. CONCLUSIONS: Eyes with asymptomatic PACG often present with severe to end-stage VF loss at the time of first presentation to hospital. In contrast, most PACG eyes with previous symptomatic angle closure present with mild or moderate VF defects. The visual morbidity of PACG may be related to the finding that the asymptomatic form of the disease is visually destructive.

Acute Disease↗

PubMed2004

Acute primary angle closure: configuration of the drainage angle in the first year after laser peripheral iridotomy.

PURPOSE: To evaluate the changes in the configuration of the drainage angle in the first year after acute primary angle closure (APAC). DESIGN: Prospective observational case series. PARTICIPANTS: Forty-four Asian subjects with APAC. METHODS: Acute primary angle closure cases were treated with medical therapy followed by laser peripheral iridotomy (LPI). Static and dynamic gonioscopies were performed in APAC-affected and fellow eyes before LPI (baseline) and then at 2 weeks, 4 months, and 12 months after presentation. The angles were graded in each quadrant according to the Shaffer scheme, and the number of clock hours of peripheral anterior synechiae (PAS) was recorded. Patients who underwent intraocular surgery at any point during follow-up were excluded from the study. Intraocular pressure (IOP) and medical treatment were documented at each visit, and gonioscopic changes were correlated with the development of elevation in IOP requiring medical treatment. MAIN OUTCOME MEASURES: Average Shaffer grade and the number of clock hours of PAS. RESULTS: The majority of subjects were Chinese (84%) and female (64%), and the mean age was 60.2+/-10.7 years. At presentation, 73% of both affected and fellow eyes had very narrow angles (average Shaffer grade < or = 1), with affected eyes having more extensive PAS (P<0.001), a third of whom had > or =8 clock hours of PAS. In APAC eyes, there was a significant increase in angle width from baseline to 2 weeks after LPI (P = 0.045), but no change in angle width subsequently. Fellow eyes showed a widening of the angle between baseline and week 2 (P = 0.01) and from week 2 to month 4 (P = 0.001). There was no significant change in PAS in either affected or fellow eyes over the 12 months of follow-up. Of the 44 subjects, 19 (41.3%) subsequently developed IOP elevation during follow-up that required treatment. However, there was no difference in angle width or amount of PAS between eyes with and without a subsequent rise in IOP, and the angle configuration did not change significantly in either group over 1 year. CONCLUSION: In Asian eyes with APAC, the angle widened in the first 2 weeks after LPI, but did not change thereafter over 1 year, and the amount of PAS remained stable throughout. The results indicate the effectiveness of LPI in preventing progressive closure of the angle in the first year after APAC.

Acute Disease↗

PubMed2004

Systemic autonomic function in subjects with primary angle-closure glaucoma: a comparative study of symptomatic and asymptomatic disease presentation.

BACKGROUND: Autonomic dysfunction is thought to be a contributory factor in primary angle-closure glaucoma (PACG) by precipitating pupil block in anatomically predisposed eyes. This study aimed to compare systemic autonomic function between subjects who had suffered a previous episode of acute angle closure (symptomatic PACG), those who had asymptomatic PACG, and age and sex-matched controls. METHODS: Tests for systemic parasympathetic function included the heart-rate response to standing (30:15 ratio), heart-rate variation during deep breathing, and the ratio of the heart rate at phases IV and II of the Valsalva manoeuvre (Valsalva ratio). For assessment of the sympathetic nervous system, blood pressure was recorded supine and then after 2 and 5 min of standing. A modified sweat test, the sympathetic skin response, was recorded on the palm and sole. RESULTS: A total of 30 subjects were examined: eight previous symptomatic PACG, eight asymptomatic PACG and 14 control subjects. The mean ages were similar, and all except one subject were Chinese. None of the subjects had evidence of systemic dysautonomia. There was no significant difference found between the groups for the 30:15 ratio, heart-rate variation during deep respiration and the Valsalva ratio. No significant orthostatic hypotension was detected in subjects with PACG. Abnormal sympathetic skin response was not more common in PACG subjects compared to control subjects. CONCLUSIONS: This study identified no systemic autonomic dysfunction in people with PACG.

Autonomic Nervous System↗

PubMed2003

Intermediate-term outcome of Baerveldt glaucoma implants in Asian eyes.

PURPOSE: To determine the intermediate-term efficacy and safety of Baerveldt glaucoma implants in Asian eyes with complicated glaucoma. DESIGN: Retrospective, nonrandomized, comparative trial. PARTICIPANTS: One hundred twenty-four Asian patients (124 eyes) with complicated glaucoma. INTERVENTION: Implantation of 54 250-mm(2) and 70 350-mm(2) Baerveldt glaucoma drainage implants at Singapore National Eye Center from 1994 through 1999. MAIN OUTCOME MEASURES: Intraocular pressure, number of glaucoma medications, and complications. RESULTS: The mean follow-up period was 33.4 +/- 14.4 months (mean +/- SD; range, 12-72 months). Intraocular pressure (IOP) was reduced from a mean preoperative IOP of 36.5 +/- 10.7 mmHg (range, 21-80 mmHg) to 15.3 +/- 6.0 mmHg (range, 1-34 mmHg), and the number of glaucoma medications decreased from 2.6 +/- 0.6 (range, 1-5) before the time of surgery to 0.5 +/- 0.9 (range, 0-4) medications at last follow-up. Overall, there were 67 eyes (54%) that were classified as complete successes, 27 eyes (22%) that were qualified successes, and 30 eyes that failed (24%). Postoperative complications occurred in 43 eyes (34.7%), and 21 eyes (17%) required further surgical intervention and revision. There was no statistically significant difference between the 250-mm(2) and 350-mm(2) type of implants in terms of success rates, final IOP, number of medications, and rates of complications. After adjusting for gender, preoperative IOP, and length of follow-up, increasing age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.09; P = 0.02) and the number of previous operations performed before implant surgery (OR, 1.57; 95% CI, 1.07-2.31; P = 0.01) were found to be correlated positively with failure. CONCLUSIONS: In Asian eyes with complicated glaucoma, Baerveldt glaucoma implants achieve stable and satisfactory IOP reduction with low incidence of complications in the intermediate term after surgery.

Adolescent↗

PubMed2002

Investigating the association between OPA1 polymorphisms and glaucoma: comparison between normal tension and high tension primary open angle glaucoma.

OPA1, the gene responsible for autosomal dominant optic atrophy, represents a good candidate gene for glaucoma, as there are similarities in the clinical phenotype and OPA1 is expressed in the optic nerve. Single nucleotide polymorphisms on intervening sequence (IVS) 8 of the OPA1gene (genotype IVS8+4 C/T;+32T/C) were recently found to be strongly associated with normal tension glaucoma (NTG). In order to investigate whether this association exists in patients with high-tension glaucoma (HTG), 90 well-characterized HTG patients were examined for the presence of these OPA1polymorphisms by PCR amplification followed by bi-directional sequencing. Five out of 90 HTG subjects (5.6%; 95% CI 1.8-12.5) were found to carry the OPA1 genotype IVS 8+4 C/T; +32 T/C, compared with 32/163 (19.6%; 95% CI 13.8-26.6) NTG subjects [chi(2)=9.2, P=0.002, OR 4.1 (95% CI 1.6-11.1)], and 7/186 (3.8%; 95% CI 1.5-7.6) control subjects [chi(2)=0.47, P=0.49, OR 1.5 (95% CI 0.5-4.9)]. These results indicate that unlike NTG, the OPA1 genotype IVS8+4 C/T,+32T/C is not significantly associated with high-tension primary open angle glaucoma, and suggest genetic heterogeneity between the conditions.

GTP Phosphohydrolases↗

PubMed2002

Efficacy of latanoprost in reducing intraocular pressure in patients with primary angle-closure glaucoma.

Two independent, prospective trials were recently conducted to assess the efficacy of latanoprost in reducing intraocular pressure (IOP) in patients with primary angle-closure glaucoma (PACG). The first study was a 2-week, randomized, double-masked comparison of latanoprost treatment and timolol treatment in patients with PACG. Patients were randomized to one of two parallel treatment groups, receiving either placebo in the morning and latanoprost 0.005% in the evening, or timolol 0.5% twice daily. The mean IOP reduction in latanoprost group was 8.8 +/- 1.1 mm Hg (mean +/- SEM, p < 0.001; 34.2%) from a mean baseline IOP of 25.7 +/- 0.9 mm Hg, and the corresponding figures for the timolol group were 5.7 +/- 0.9 mm Hg (p < 0.001; 22.6%) from a mean baseline IOP of 25.2 +/- 1.1 mm Hg. A significantly greater IOP reduction of 3.1 +/- 1.5 mm Hg (95% confidence interval: 0.1 to 6.0) was achieved in the latanoprost group compared to the timolol treatment group (p = 0.04). In the second study, latanoprost 0.005% once a day was added adjunctively to PACG patients with persistently elevated IOP after iridectomy, despite treatment with beta-blockers and pilocarpine. The IOP decreased by about 21% during the first 3 months, and showed a reduction of about 36% at the end of 1 year. At the 1-year follow-up, IOP was <20 mm Hg in all eyes. In both studies, latanoprost was well tolerated with few adverse events. These results demonstrate that latanoprost is effective in reducing IOP in patients with PACG.

Adrenergic beta-Antagonists↗

PubMed2002

Chronic angle-closure with glaucomatous damage: long-term clinical course in a North American population and comparison with an Asian population.

PURPOSE: To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients. DESIGN: A retrospective, interventional case-control study series. PARTICIPANTS: Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI). METHODS: The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period. MAIN OUTCOME MEASURES: The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. RESULTS: The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery. CONCLUSIONS: Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.

Aged↗

PubMed2002

Medical management of angle closure glaucoma.

Management of angle closure glaucoma requires an understanding of the underlying pathophysiologic mechanisms. Treatment is aimed at eliminating pupillary block and other causes of angle closure, re-opening the angle, and preventing further damage to the optic nerve by lowering intraocular pressure. Medical therapy plays an important role in the successful management of this condition. This article describes commonly used pharmacologic agents, as well as newer classes of drugs such as topical carbonic anhydrase inhibitors, prostaglandin analogues and selective alpha2- adrenergic agonists. Use of these drugs in several clinically distinct angle closure syndromes and modes of presentation are discussed.

Adrenergic Agonists↗