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At least 1,081 records · Page 60Linked to original sources
PubMed2005

Ethnic aspects of acute primary angle closure in a UK mulicultural conurbation.

AIM: To investigate the incidence and ethnic distribution of patients with symptomatic acute primary angle closure (APAC) who presented to a UK hospital serving a multicultural conurbation by a population-wide case series investigation. METHODS: Case series chart review of patients aged 30 years and above, who required laser peripheral iridotomy (LPI) for a primary acute angle closure event over a 7-year period. Demographic data for cases were compared to the local resident census data. RESULTS: A total of 46 local residents aged > or =30 years required LPI for APAC. In all, 96% of patients were Caucasian compared to the local resident population of 89% Caucasian. The overall annual APAC rate for Bolton was 4.14 cases per 100 000 population (95% CI 3.03-5.52). The standardised incidence ratio for the South Asian population was 0.78 (95% CI 0.02-4.34) and 26.6 (95% CI 0.67-148.40) for the Chinese population. CONCLUSIONS: APAC incidence in South Asians was similar to that among Caucasians. The incidence of APAC patients treated in this UK department is consistent with international experience. Individuals of Chinese ethnicity were at an enhanced risk of APAC. However, these results should be interpreted with caution, as patient numbers are small.

Acute Disease↗
PubMed2006

To compare argon laser peripheral iridoplasty (ALPI) against systemic medications in treatment of acute primary angle-closure: mid-term results.

PURPOSE: To compare the clinical outcome of argon laser peripheral iridoplasty (ALPI) against systemic medications in treatment of acute primary angle-closure (APAC). METHODS: Consecutive patients with APAC were recruited and randomized to receive one of two treatment options: immediate ALPI or systemic acetazolamide +/- mannitol. All eyes were followed up for at least 6 months after laser iridotomy. Main outcome measures were intraocular pressure (IOP) and requirement for glaucoma medications. RESULTS: A total of 41 eyes (39 patients) were randomized into the ALPI group, and 38 eyes (32 patients) into the medical treatment group. There were no significant differences between the two groups in sex, age, presenting IOP, and duration of attack. Mean follow-up duration +/- SD was 15.7 +/- 5.8 months. There were no significant differences between the two groups in mean final IOP and requirement for glaucoma medications. CONCLUSIONS: There were no statistically significant differences in mean IOP and requirement for glaucoma drugs between APAC eyes treated with ALPI and systemic medications.

Acetazolamide↗
PubMed2006

Ultrasound biomicroscopic quantification of the change in anterior chamber angle following laser peripheral iridotomy in early chronic primary angle closure glaucoma.

AIMS: To prospectively evaluate by ultrasound biomicroscopy (UBM) and gonioscopy the anterior chamber angle widening following laser peripheral iridotomy (LPI) in eyes with early chronic primary angle closure glaucoma (CACG). METHODS: A total of 55 eyes of 55 patients with CACG presenting with less than 180 degrees peripheral anterior synechiae (PAS) were enrolled in the study. Angles were assessed by gonioscopy (Shaffer's grading) and UBM, before and 4 weeks after LPI. The angle opening distance at 250 and 500 microm from the scleral spur (AOD 250 and AOD 500) was computed. Results were analysed using the Wilcoxon signed-rank test. RESULTS: In the quadrant with LPI, the mean gonioscopy grade increased significantly from 0.45 to 1.45 (P<0.001) and the mean AOD 250 and AOD 500 increased from 38.5+/-25.9 to 83.5+/-48.4 microm (P<0.001) and 110.2+/-80.9 to 170.6+/-83.4 microm (P<0.001), respectively. The angles widened significantly in the opposite quadrant on UBM (AOD 250: 48.8+/-31.5-82.7+/-43.9 microm, P<0.001; AOD 500:117.2+/-65.5-172.2+/-81.7 microm; P<0.001), but the median gonioscopy grade remained unchanged. CONCLUSIONS: LPI significantly widened the anterior chamber angle in the quadrant with LPI and the quadrant furthest away in patients of CACG with established glaucomatous damage. This change was much better appreciated by the UBM than gonioscopy.

Adult↗
PubMed2006

Comparison of ultrasound biomicroscopic parameters after laser iridotomy in eyes with primary angle closure and primary angle closure glaucoma.

PURPOSE: To study changes in anterior segment morphology after laser peripheral iridotomy (LPI) in primary angle closure (PAC) and primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). METHODS: Ninety-three eyes of 93 patients underwent anterior segment evaluation including gonioscopy, disc evaluation with + 90D lens, applanation intraocular pressure, and standard achromatic perimetry. UBM was performed before and 2 weeks after Nd:YAG LPI to measure the trabecular-iris angle (TIA), the angle-opening distance (AOD 250/500), and the central anterior chamber depth (ACD). RESULTS: The superior TIA widened from a mean of 7.54+/-3.15 to 15.66+/-6.69 degrees (P=0.0001), the inferior TIA increased from a mean of 9.0+/-4.7 to 15.9+/-6.8 degrees (P=0.0001) after LPI in PAC. In PACG, the mean superior angle changed from 4.55+/-2.5 to 6.12+/-3.8 degrees (P=0.4) and the inferior angle increased from 4.75+/-2.0 to 7.9+/-3.7 degrees (P=0.1). The mean ACD increased from 2.19+/-0.36 to 2.30+/-0.36 mm in PAC group (P=0.0003), with no significant change seen in the PACG group (1.79+/-0.32 vs 1.82+/-0.33 mm, P=0.13). CONCLUSION: LPI leads to a widening of the anterior chamber angle and a deepening of the anterior chamber in eyes with PAC. It does not significantly change any anterior segment parameters in eyes with PACG.

Adult↗
PubMed2002

Laser surgery for angle closure glaucoma.

The angle closure glaucomas are defined by iridotrabecular contact, trabecular dysfunction, and elevated intraocular pressure (IOP). Laser iridotomy successfully eliminates the relative pupillary block component of the angle closure process, regardless of whether the underlying angle closure is related primarily to pupillary block or another mechanism. For those eyes with angle closure originating at an anatomic level posterior to the iris, such as plateau iris, lens-induced angle closure, or posterior segment processes, argon laser peripheral iridoplasty is often useful to further open the angle. The purpose of this article is to review the indications and techniques for laser iridotomy and laser iridoplasty in clinical practice.

Glaucoma, Angle-Closure↗
PubMed2004

Glaucoma management in developing countries: medical, laser, and surgical options for glaucoma management in countries with limited resources.

PURPOSE OF REVIEW: Most people affected by glaucoma live in developing countries. Recent trials and reports provide sound evidence for management of glaucoma. This review extrapolates relevant articles to the developing world. RECENT FINDINGS: The predictive value of gonioscopy for progression of primary angle closure suspects (PACS) to primary angle closure (PAC) is only 22% (95% CI: 9.80-34.2). PACS are not uncommon; laser peripheral iridotomy (LPI) is neither indicated nor feasible for all. Twenty-eight and a half percent of PAC progress to primary angle closure glaucoma; the number needed to treat (NNT) for LPI to prevent progression is only 4. Laser peripheral iridoplasty controls acute angle closure glaucoma (AACG) faster than medical therapy alone. Primary lens extraction has also been suggested as treatment for AACG after control of the acute attack. A 5-year NNT for ocular hypertension (OH) of 20 is too high to allow treatment of all OH. High-risk OH and primary open angle glaucoma (POAG) have an NNT of 5 to 6 and merit treatment. Latanoprost and brimonidine are effective in lowering IOP in Asian eyes with POAG, but primary surgical therapy may be a more viable option. For cataract and coexistent glaucoma requiring filtration, trabeculectomy combined with the Blumenthal technique of cataract surgery may be as effective as trabeculectomy combined with phacoemulsification. SUMMARY: The principles of glaucoma management should be the same the world over. Considering the paucity of resources and competing opportunity costs, countries with limited resources have to extrapolate available information in a sensible and cost-effective manner.

Antihypertensive Agents↗
PubMed2002

Laser peripheral iridoplasty as initial treatment of acute attack of primary angle-closure: a long-term follow-up study.

PURPOSE: To study the long-term clinical course and complications of patients with acute primary angle-closure treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy. PATIENTS AND METHODS: Consecutive patients with acute primary angle closure treated with immediate laser peripheral iridoplasty, followed by laser peripheral iridotomy, at the Prince of Wales Hospital from July 1997 through January 2000 were followed up to document the clinical course of their disease and any complications from the laser treatment. Visual acuity, intraocular pressure, gonioscopic findings, corneal and lens clarity, iris appearance, pupillary reaction, and progression of glaucomatous optic neuropathy were evaluated. RESULTS: Thirty eyes of 29 Chinese patients with acute primary angle closure treated initially with either argon or diode laser peripheral iridoplasty were recruited. The mean follow-up period was 33.0 +/- 9.3 months. Twenty-one eyes (70%) had no further attack and maintained normal intraocular pressure without medications, and 9 eyes (30%) developed chronic angle-closure glaucoma with peripheral anterior synechiae. All eyes had pigmented laser marks on the peripheral iris, but none had peripheral corneal burn. CONCLUSIONS: Long-term follow-up data indicated that 30% of Chinese eyes with acute primary angle closure successfully treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy developed peripheral anterior synechiae and an increase in intraocular pressure. There were minimal long-term complications on the cornea and the lens from the laser treatment.

Acute Disease↗
PubMed2002

An ultrasound biomicroscopic study of the anterior segment in Indian eyes with primary angle-closure glaucoma.

PURPOSE: To evaluate the presence of plateau iris in eyes with primary angle-closure glaucoma (PACG) after laser peripheral iridotomy by gonioscopy and ultrasound biomicroscopy and to evaluate the pathogenesis of this condition by comparing the UBM parameters of these eyes with those in normal subjects. PATIENTS AND METHODS: This prospective study was carried out in the Glaucoma clinic of a tertiary eye care center. A detailed clinical examination including applanation tonometry, indentation gonioscopy with a Sussman four-mirror gonioscope, and ultrasound biomicroscopic examination in one randomly selected eye of 55 patients (55 eyes) with PACG who had undergone laser peripheral iridotomy and 22 normal subjects (22 eyes). RESULTS: Among the PACG eyes, 40% (22/55) had an open angle (angle opening distance > 130 microns) and 60% (33/55) eyes had a narrow angle (angle opening distance <or= 130 microns). A large anteriorly placed ciliary process with a narrow ciliary sulcus was found in 9 of the 22 eyes with open angle (40.9%), and 22 of the 33 eyes with narrow angles (66.66%). Trabecular ciliary process distance was significantly larger in the eyes with open angles compared with those with narrow angles ( = 0.001). CONCLUSIONS: Plateau iris was common in the clinic population studied. Anteriorly directed ciliary processes were seen both in eyes with plateau iris as well as in eyes with PACG that had deep anterior chambers after iridotomy.

Adult↗
PubMed2004

Aqueous flow through the iris-lens channel: estimates of differential pressure between the anterior and posterior chambers.

PURPOSE: To explore the hypothesis that differential pressure between the anterior and posterior chambers arises from the dynamics of aqueous flow across the iris-lens channel. METHODS: Navier-Stokes equations of fluid dynamics were derived and evaluated numerically for a viscous homogeneous isotropic fluid (aqueous) passing through the iris-lens channel, which is a spherical disc-shaped region conforming to the lens curvature while maintaining a separation distance (channel height) over a certain disc width (channel length). The effect of iridotomy was assessed using Poiseuille flow dynamics. RESULTS: In the absence of measured values, ranges of anatomic and physiological variables were used for calculations. The magnitude of the posterior to anterior pressure difference was greater with increases in channel length or aqueous flow and with decreases in channel height or pupil diameter. With a nominal channel length of 0.5 mm, aqueous outflow of 2.2 microl/min, and pupil diameter of 1 mm, the pressure difference increased from 0.9 to 10 mm Hg when the channel height decreased from 7 to 3 microm. A channel height of 10 microm or greater reduced the pressure difference below 1 mm Hg for the full range of other channel parameters considered. A 50-microm iridotomy reduced the pressure difference below 1 mm Hg. CONCLUSIONS: The flow of aqueous through the iris-lens channel is driven by the pressure differential between the posterior and anterior chambers. Viscous forces within the aqueous govern the magnitudes of the flow resistance and the pressure differential. The geometry and dimensions of a specific iris-lens channel will determine whether the pressure differential is of clinical significance.

Anterior Chamber↗
PubMed2004

Recurrent herpetic keratouveitis following YAG laser peripheral iridotomy.

OBJECTIVE: To report recurrent herpetic keratouveitis following YAG laser peripheral iridotomy. METHODS: Case report. RESULTS: A 64-year-old woman with a history of dendritic keratitis underwent Nd:YAG laser peripheral iridotomy and developed geographic epithelial keratitis with stromal keratouveitis. Culture of a corneal swab grew herpes simplex virus type I. Keratouveitis subsided with acyclovir and corticosteroid therapy. CONCLUSIONS: Recurrent herpetic keratouveitis may be induced by YAG laser iridotomy.

Acyclovir↗
PubMed2005

The effect of laser iridotomy on the anterior segment anatomy of patients with plateau iris configuration.

PURPOSE: To determine if laser iridotomy altered the anterior segment anatomy of patients with plateau iris configuration. METHODS: Twenty eyes of 9 female and 1 male patients were imaged using an ultrasound biomicroscope within 19 weeks before and 52 weeks after laser iridotomy. Measurements obtained included the anterior chamber depth (ACD), trabecular-ciliary process distance (TCPD), iris thickness (IT), angle opening distance at 500 micrometers (AOD), iridozonular distance (IZD), and trabecular-iris angle (TIA). Comparisons of the pre- and post- iridotomy measurements were made using a two-tailed paired t test. RESULTS: Laser iridotomy elicited no statistically significant change in ACD, TCPD, IT, AOD, or TIA. However, IZD was decreased (P < 0.05) in both eyes after laser iridotomy. Configuration of the irides was flat before and after laser iridotomies. CONCLUSION: This study suggests that laser iridotomy did not alter anterior segment anatomy, probably because of the fixed anterior insertion of the iris and ciliary body in plateau iris configuration. The decrease in IZD distance may be the result of a small posterior movement of the iris due to a reduction in relative pupillary block, secondary to laser iridotomy. The small reduction in relative papillary block in plateau iris configuration does not alter the width of the anterior chamber angle as measured by AOD and TIA.

Adult↗
PubMed2005

The influence of peripheral iridotomy on the intraocular pressure course in patients with pigmentary glaucoma.

PURPOSE: To evaluate the influence of laser peripheral iridotomy on the long-term intraocular pressure course for patients with pigmentary glaucoma. PATIENTS AND METHODS: Retrospective analysis of data contributed by members of the American Glaucoma Society on patients with bilateral pigmentary glaucoma, who received uniocular laser iridotomy. The main outcome measure was the post-laser intraocular pressure course of the treated eyes, compared with the fellow, untreated eyes. RESULTS: Sixty patients were included in the study, 46 of whom were observed for a minimum of 2 years (mean 70.3 +/- 26.0 months; range 24-113 months). Among the 14 patients who were observed for less than 2 years, the mean intraocular pressure in the treated eyes increased 0.36 +/- 2.63 mm Hg, compared with the fellow, untreated eyes. Among the 46 patients, observed for 2 years or more, the mean intraocular pressure in the treated eyes decreased 4.0 +/- 5.4 mm Hg, compared with 1.9 +/- 3.8 mm Hg in the fellow eyes (P = 0.005). However, analysis by linear models indicates that a higher mean baseline intraocular pressure in the treated eyes accounts for the apparent treatment effect of laser peripheral iridotomy. CONCLUSION: The study does not provide support for the benefit of laser peripheral iridotomy in the long-term intraocular pressure control of patients with pigmentary glaucoma, when the data are subjected to rigid statistical analysis. This does not disprove the benefit of laser iridotomy in this patient population, but underscores the need for a large, prospective study to address the question.

Adult↗