Clarifying the nomenclature for primary angle-closure glaucoma

Longitudinal Rates of Change in Structural Parameters of Optical Coherence Tomography in Primary Angle Closure Glaucoma following Laser Iridotomy along with Peripheral Iridoplasty

Background

This study aimed to investigate longitudinal rates of change (LRCs) of structural parameters from optical coherence tomography (OCT) in patients with primary angle closure glaucoma (PACG) after laser iridotomy (LI) along with laser peripheral iridoplasty (PI).

Methods

Among 146 patients diagnosed with PACG, thirty-two subjects (32 eyes) who underwent LI plus PI and accomplished more than five times of reliable OCT tests were included in the current retrospective study. Retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured by spectral-domain OCT with three month interval. LRCs of global and six Garway-Heath sectors were investigated using the linear mixed-effects model which adjusted BMO area, sex, and age. Imaging of dual Scheimpflug analyzer was performed before and at 1 week after LI with PI and yearly thereafter.

Results

The mean follow-up period was 32.28 ± 13.34 months with a mean number of 10.18 ± 3.33 OCT images. Baseline characteristics are as follows: age, 63 ± 7.9 years; female, 62.5%; intraocular pressure(IOP), 15.48 ± 4.79 mmHg; anterior chamber depth, 2.09 ± 0.18 mm; and mean deviation, -7.97 ± 8.48 dB. Global LRC of BMO-MRW was 0.86 ± 1.34 μm/yr and RNFL was -0.64 ± 0.22 μm/yr. IOP decreased significantly to 13.06 ± 2.21 mmHg (p=0.001) while anterior chamber volume (p=0.011) and mean anterior chamber angle (p=0.022) increased significantly after LI along with PI compared to the baseline at the final visit.

Conclusions

LRC of a new parameter, BMO-MRW, and LRC of RNFL were relatively low in patients with PACG, following LI along with PI. After widening of the anterior chamber angle and decrease of IOP due to LI plus PI, PACG might show stable structural prognosis assessed by OCT.

Evaluation of biometric indicators of anterior segment parameters after ICL implantation by swept-source optical coherence tomography

BACKGROUND

To evaluate anterior segment structural alterations after implantable collamer lens (ICL) implantation in myopic patients using swept-source quantitative optical coherence tomography (SS-OCT).

METHODS

This prospective study included 47 eyes in 24 patients with preoperative spherical equivalent ≥ -3.00 D. Patients underwent ICL implantation at Department of Ophthalmology, Peking University Third Hospital, from May 2021 to December 2022. SS-OCT was used to measure anterior chamber width (ACW), angle opening distance (AOD), angle recess area (ARA), trabecular-iris area (TISA), trabecular-iris angle (TIA), iridotrabecular contact (ITC) area, and ITC Index before ICL implantation surgery and at 1 month follow-up. The correlations among the ITC index, vault, and angle parameters were analysed. Receiver operating characteristic (ROC) analysis was used to explore the ability of the vault to identify eyes with suspected angle-closure.

RESULTS

At one month following ICL implantation, the ITC area was 0.396 ± 0.37 mm², and the ITC index is 8.143 ± 5.439%. All angle parameters, except ACW, showed a statistically significant reduction on SS-OCT (P < 0.05). Mean AOD500, AOD750, ARA500, ARA750, TISA500, TISA750, TIA500, and TIA750 values at one month postoperatively decreased by 60.0%, 60.4%, 58.1%, 59.2%, 57.3%, 58.7%, 48.8%, and 50.7%, respectively. The vault was positively correlated with the ITC index and percent change in anterior chamber angle parameters. A vault of > 0.659 mm was found to be optimal for angle-closure suspect with a sensitivity of 85.2% and a specificity of 53.9%.

CONCLUSIONS

Anterior chamber angle parameters decreased one month after ICL implantation, and their percentage changes and ITC index correlated with the vault. When the vault is larger than 0.659 mm, it is necessary to be alert to possible closed angle suspicion.

Long-Term Outcome of Corneal and Anterior Chamber Angle Parameters after Combined Laser Iridotomy and Iridoplasty Using Dual Scheimpflug Analyzer: 1 Year Results

Background: To investigate the outcomes of corneal and anterior chamber angle (ACA) parameters after laser iridotomy (LI) combined with peripheral iridoplasty (PI) using dual Scheimpflug analyzer in the long term. Methods: Fifty-eight eyes (58 subjects) with shallow AC were included in this prospective cohort study. Images of the Dual Scheimpflug analyzer were obtained before, 1 week, and 1 year after LI and PI. Pachymetry from three zones (central, middle, and peripheral), corneal aberration, and spherical equivalent (SE) were acquired. AC depth (ACD), AC volume (ACV), ACA from four quadrants, and intraocular pressure (IOP) were also obtained. For comparison of the results, the linear mixed-effects model was employed. Results: ACD significantly increased from 2.09 ± 0.25 mm to 2.10 ± 0.23 mm at 1 year after laser (all p < 0.05). ACV and ACA increased significantly after laser at 1 year (all p < 0.05). IOP significantly decreased from 15.97 ± 4.20 mmHg to 13.73 ± 2.63 mmHg at 1 year (all p < 0.0001). No significant changes were found in the coma, trefoil, total corneal aberration, pachymetry from three zones, corneal volume, central corneal thickness, and SE after LI and PI until 1 year (all p > 0.05). Conclusions: LI plus PI ameliorated parameters of ACA efficiently and significantly reduced IOP in eyes with shallow AC until 1 year of long-term follow-up. However, parameters of the cornea and SE were not influenced by LI with PI until after 1 year.

Corneal topography and angle parameters after laser iridotomy combined with iridoplasty assessed by dual Scheimpflug analyzer

PURPOSE

To investigate the changes in corneal topography including parameters such as corneal curvature and corneal aberrations, along with anterior chamber angle (ACA) after laser iridotomy (LI) combined with peripheral iridoplasty (PI) using dual Scheimpflug analyzer.

METHODS

In this prospective observational study, dual Scheimpflug analyzer images were acquired before and 1 week after LI plus PI. Corneal curvature of both axial and instantaneous maps from anterior and posterior surface, respectively, and total corneal power (TCP) were acquired. These corneal parameters from three zones (central, middle, and peripheral) and total corneal wavefront aberration, trefoil, and coma were obtained. The ACA from four quadrants, anterior chamber depth (ACD), anterior chamber volume (ACV), and intraocular pressure (IOP) were also inspected.

RESULTS

ACD increased significantly from 2.15 ± 0.25 to 2.18 ± 0.24 mm (P = 0.002). ACV and ACA from all four quadrants increased significantly after the laser treatment (all P < 0.05). IOP decreased significantly from 16.9 ± 3.1 to 14.7 ± 2.9 mmHg following LI plus PI (P = 0.000). No significant changes were detected in corneal axial and instantaneous curvature from three zones on the anterior and posterior corneal surface after LI plus PI (all P > 0.05). The TCP, total corneal wavefront aberration, trefoil, and coma also revealed no significant changes after the laser procedure (all P > 0.05).

CONCLUSIONS

Treatment with LI combined with PI did not affect the corneal topographic parameters from both anterior and posterior surfaces. However, LI plus PI improved ACA parameters significantly and effectively.

Increased choroidal thickness in primary angle closure measured by swept-source optical coherence tomography in Caucasian population

PURPOSE

A role of the choroid has been suggested in the pathophysiology of angle closure. We assessed the choroidal thickness (CT) in Caucasian patients with primary angle closure (PAC) and in a subgroup of patients with plateau iris using swept-source optical coherence tomography (SS-OCT) compared to normal eyes.

METHODS

This prospective cohort study in a hospital-based population in a tertiary center compared consecutive patients with PAC to healthy controls. A subgroup analysis of patients with plateau iris was also performed. Choroidal thickness was measured by SS-OCT in the subfoveal area (SFCT) and at 1- and 3-mm eccentricity superiorly, inferiorly, nasally and temporally from the fovea.

RESULTS

Compared to the 25 eyes of 13 control patients [7 women, mean (SD) age, 56.6 (15.7) years], the 45 eyes of 25 patients with PAC [15 women, mean (SD) age, 55.7 (10.7) years] had a significantly increased SFCT. SFCT was 355.36 μm (SD 85.97) in PAC eyes versus 286.08 μm (SD 98.09) in control eyes (p = 0.009). The CT was also significantly increased compared to control eyes in other macular areas (p < 0.05), except at 3 mm temporal to the fovea. In the plateau iris subgroup, a not significant (except 3 mm nasal to the fovea) trend toward an increased CT was observed in all studied macular areas compared to control eyes.

CONCLUSION

In eyes of Caucasian patients with PAC, the CT is increased compared to controls. Increased CT could contribute to the pathophysiology of PAC with a possible choroidal expansion and dysfunction of choroidal ganglion cells.

Trabeculectomy With Mitomycin-C: Outcomes and Risk Factors for Failure in Primary Angle-closure Glaucoma

PURPOSE

There are no reported large series of trabeculectomy with mitomycin-C (MMC) in Western patients with primary angle-closure glaucoma (PACG). Our study evaluates long-term tonometric outcomes of trabeculectomy in PACG.

MATERIALS AND METHODS

This is a retrospective cohort study. The primary outcomes were the Kaplan-Meier success rates on survival analyses using 3 criteria, with or without adjunctive medication: (A) intraocular pressure (IOP) ≤18 mm Hg and IOP reduction of 20%; (B) IOP≤15 mm Hg and IOP reduction 25%; and (C) IOP≤12 mm Hg and IOP reduction 30%. In total, 136 eyes (102 patients) with PACG who underwent trabeculectomy MMC were included. The Cox proportional hazard regression analysis was used to identify risk factors for failure with multivariate analysis (P<0.05).

RESULTS

The qualified success rates (±SD) after 1, 3, and 5 years of follow-up for criterion A were 92% (±2.2%), 78% (±3.8%), and 72% (±4.3%); for criterion B, 86% (±3.0%), 65% (±4.4%), and 59% (±4.7%); and for criterion C, 62% (±4.2%), 40% (±4.5%), and 32% (±4.4%). Baseline factors associated with failure were: family history, absence of laser peripheral iridotomy, higher IOP, and presence of a crystalline lens.

CONCLUSIONS

Trabeculectomy with MMC effectively reduces IOP in PACG. Long-term IOP reduction is achieved for target IOP levels in the mid-teens. Presence of a crystalline lens, lack of iridotomy and higher preoperative IOP were associated with higher risks of failure.

Contemporary approach to the diagnosis and management of primary angle-closure disease

The primary angle-closure disease spectrum varies from a narrow angle to advanced glaucoma. A variety of imaging technologies may assist the clinician in determining the pathophysiology and diagnosis of primary angle closure, but gonioscopy remains a mainstay of clinical evaluation. Laser iridotomy effectively eliminates the pupillary block component of angle closure; however, studies show that, in many patients, the iridocorneal angle remains narrow from underlying anatomic issues, and increasing lens size often leads to further narrowing over time. Recent studies have further characterized the role of the lens in angle-closure disease, and cataract or clear lens extraction is increasingly used earlier in its management. As a first surgical step in angle-closure glaucoma, lens extraction alone often effectively controls the pressure with less risk of complications than concurrent or stand-alone glaucoma surgery, but may not be sufficient in more advanced or severe disease. We provide a comprehensive review on the primary angle-closure disease nomenclature, imaging, and current laser and surgical management.

Long-term evaluation of ocular hypertension with primary angle closure and primary open angles

PURPOSE

To evaluate the long-term course of primary angle-closure ocular hypertension and primary open-angle ocular hypertension and possible risk factors for progression to glaucoma.

METHODS

A total of 109 eyes of 109 ocular hypertension (OHT) patients with a minimum follow-up period of 5 years having complete ocular/medical records were evaluated. They were classified into primary angle closure or primary open angle based on gonioscopy at baseline. Baseline and review data of Humphrey field analyser, HFA, and Heidelberg retinal tomography, HRT, were recorded. Guided progression analysis (GPA) and univariate Cox regression were used for time to event analysis in identifying progression to glaucoma.

RESULTS

Over a mean follow-up of 12.18 ± 4.8 years, progression to glaucoma was 17.43% (19 eyes), out of whom 5.5% (6 eyes) showed ≥ 3 loci on GPA. Sub-classifying them, progression to primary angle-closure glaucoma was 19.72%, and that of primary open-angle glaucoma was 13.16%. The mean time to progression was 9.34 ± 3.6 years. Significant risk factors included small disc area (≤ 1.99 sq.mm on HRT), requirement of ≥ 2 drugs to maintain target IOP and those engaged in activities yielding a Valsalva effect in daily life. Coronary artery disease (CAD) and systemic use of steroids were associated with increased severity.

CONCLUSION

Overall progression of OHT to glaucoma was 17.43% over a mean of 9 years, with target IOP of ≤ 18 mm Hg. Patients with smaller discs, CAD, exercising Valsalva type activities and using ≥ 2 glaucoma medications or systemic steroids should be closely monitored.

Evaluation of circumferential angle closure using iridotrabecular contact index after laser iridotomy by swept-source optical coherence tomography

PURPOSE

To investigate the quantitative changes of circumferential angle closure after laser iridotomy (LI) using the iridotrabecular contact (ITC) index by Swept-Source optical coherence tomography (OCT).

METHODS

In this prospective observational study conducted in a hospital setting, 42 eyes of 36 patients (five males, 31 females) who underwent LI were included. The mean age was 65.00 ± 8.13 years old and the diagnosis included primary angle closure (PAC, 21 eyes), PAC suspect (16 eyes) and PAC glaucoma (five eyes). Optical coherence tomography (OCT) images were obtained pre-LI and at 1 week post-LI. In each image frame, the scleral spur (SS) and the ITC end-point were marked, from which the ITC index was calculated as a percentage of the angle closure across 360°. Measurements inspected before and after LI included: central anterior chamber depth (ACD), anterior chamber volume (ACV), lens vault (LV), nasal and temporal angle opening distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA), trabecular-iris angle (TIA) at 500 μm and 750 μm from the SS and intraocular pressure (IOP).

RESULTS

The ITC index and IOP decreased significantly after LI from 71.52 ± 26.29 to 35.31 ± 27.19 and from 20.64 ± 12.72 mmHg to 14.02 ± 3.49 mmHg, respectively (p < 0.001 and p < 0.001). Central ACD (1.94 ± 0.31 mm pre-LI) and LV (1.13 ± 0.32 mm pre-LI) did not show a significant change after LI (all p > 0.05), but ACV increased significantly after LI (p < 0.001). Most of the angle parameters except for nasal TIAs increased significantly after LI (all p < 0.05).

CONCLUSION

The ITC index from patients with shallow anterior chamber angle showed a significant decrease after LI, but part of the angle closure was not relieved after LI. Other mechanisms besides pupillary block may play a role together in causing angle closure.

Angle Closure Scoring System (ACSS)-A Scoring System for Stratification of Angle Closure Disease

Purpose

To evaluate the angle closure scoring system (ACSS) for stratifying primary angle course disease.

Methods

This observational cross sectional institutional study included patients with primary open angle glaucoma suspects (n = 21) and primary angle closure disease (primary angle closure, PAC, n = 63 and primary angle course glaucoma, PACG, n = 58 (defined by International society of Geographical and Epidemiological Ophthalmology, ISGEO). Two independent examiners blinded to clinical details, graded good quality pre-laser goniophotographs of the patients incorporating quadrants of peripheral anterior synechieae (PAS), non-visibility of posterior trabecular meshwork (PTM) and blotchy pigments (ranging from 1–4 quadrants), iris configuration, angle recess (sum of above depicting ACSS_g) and lens thickness/axial length ratio (LT/AL), cup disc ratio and baseline intraocular pressure (IOP) to give total score (ACSS_t).

Result

There were significant differences in ACSSg scores within the same ISGEO stage of PAC and PACG between eyes that required nil or >1medicines after laser iridotomy, p<0.001. The ACSSg was associated with need for >1 medicines in both PAC and PACG eyes, p<0.001. An ACSSg score>12 and 14 in PAC (odds ratio = 2.7(95% CI-1.7–5.9) and PACG (Odds ratio = 1.6(95%CI-1.19–2.2) predicted need for single medicines while ACSSg scores >14 and 19 predicted need for ≥2 medicines in PAC and PACG eyes, respectively. The LT/Al ratio, IOP score or cup disc score did not influence the need for medical treatment independently.

Conclusion

The ACSS can be a useful clinical adjunct to the ISGEO system to predict need for medicines and prognosticate each stage more accurately.

Evolving Paradigms in Classification of Primary Angle Closure Glaucoma

PURPOSE

To review the old and existing classification systems for primary angle closure disease.

METHODS

Literature review and new proposed classification system.

RESULTS

Existing classification systems have several shortcomings which cannot be applied in a clinical setting. This can be addressed by a proposed scoring system.

CONCLUSION

A scoring system would be most appropriate for any clinical setting as well as for prognosticating primary angle closure disease.

Diurnal intraocular pressure changes in eyes affected with acute primary angle closure and fellow eyes after laser peripheral iridotomy

PURPOSE

To evaluate diurnal curves of intraocular pressure (IOP) in eyes affected with unilateral acute primary angle closure (APAC) after laser peripheral iridotomy (LPI), and fellow eyes.

METHODS

The medical records of 22 female patients (44 eyes) with unilateral APAC and LPI performed OU were reviewed along with those of 48 normal control subjects (48 eyes). None of the subjects used glaucoma medications after LPI. IOP was measured with a Goldman applanation tonometer during waking hours and in a sitting position every 2 h between 09:00 and 23:00. IOP profiles were compared including the means, peaks, trough IOPs, and IOP fluctuations of the affected, fellow, and normal eyes.

RESULTS

The IOPs of the affected eyes were significantly higher than those of normal eyes at every time point measured, including peak and trough IOPs. The diurnal IOPs of fellow eyes were higher than those of normal eyes, though not significantly. There were no significant differences in IOP fluctuation between the affected, fellow, and normal eyes. IOP diurnal curves for APAC affected, fellow, and normal eyes were not statistically different (repeated measures ANOVA, p = 0.865). The mean coefficient of IOP in affected and fellow eyes ranged from 0.486 to 0.604.

CONCLUSIONS

There were no clinically significant differences among the three groups in terms of IOP diurnal curves, and thus LPI did not have a significant effect on diurnal patterns of IOP. Though the diurnal IOPs of affected eyes after LPI was significantly higher than those of normal eyes, the IOP range was not acute.

Comparison of Combined Phacoemulsification, Intraocular Lens Implantation, and Goniosynechialysis With Phacotrabeculectomy in the Treatment of Primary Angle-Closure Glaucoma and Cataract

PURPOSE

This study aimed to compare the efficacy and safety of combined phacoemulsification, intraocular lens implantation, and goniosynechialysis with phacotrabeculectomy in the treatment of primary angle-closure glaucoma (PACG) and cataract.

DESIGN

A comparative case series.

METHODS

Sixty-five patients (65 eyes) with PACG and cataract from the Fifth Affiliated Hospital of Sun Yat-Sen University were enrolled for this study between October 2009 and July 2011. Of these, 33 underwent combined phacoemulsification, intraocular lens implantation, and goniosynechialysis (treatment group), and 32 underwent phacotrabeculectomy (control group). The effects on intraocular pressure, best-corrected visual acuity, anterior chamber angle, number of antiglaucoma medications, and complications were evaluated.

RESULTS

Both the treatment group and the control group had lowered intraocular pressure, reduced the use of antiglaucoma medications, and improved vision in patients with PACG and cataract. Complications were 8 (24.2%) of 33 in the treatment group and 12 (37.5%) of 32 in the control group.

CONCLUSIONS

Combined phacoemulsification, intraocular lens implantation, and goniosynechialysis appears to be a preferred method for the treatment of PACG and cataract because it seems to have the same efficacy as phacotrabeculectomy and has much less surgical complications.

Phenotypic features of Chinese family members with primary angle closure

OBJECTIVE

To describe ocular phenotypic features in Chinese families with primary angle closure (PAC).

DESIGN

Prospective cohort study.

PARTICIPANTS

428 individuals of 103 eligible families.

METHODS

Probands identified in clinic and their relatives were examined. Measurements included intraocular pressure, anterior chamber depth, lens thickness, axial length, and gonioscopic features related to the anterior chamber angle. Electroretinogram (ERG) testing for dark and light adaptation on both eyes of each individual examined was also obtained.

RESULTS

There were 144 PAC affected patients (33.7%), 60 suspects (14%), and 224 unaffected individuals (52.3%). There were more than 2 affected members in 51 families (49.5%). Compared with unaffected individuals, affected individuals were more likely to be female, have shallower peripheral and central anterior chamber depths, narrower angles, thicker lenses, and shorter axial lengths (p<0.001). Affected patients and suspects had similar axial lengths (p>0.05). Compared with unaffected individuals, affected and suspect individuals showed ERG adaptation abnormalities (p<0.05). Of 45 unaffected individuals with mean axial length ≤ 22.00 mm (10.51%), 20 individuals (4.67%) showed ERG adaptation abnormalities similar to affected patients and suspects (p> 0.05).

CONCLUSIONS

Patients with PAC were significantly more likely to be female, have shorter axial length, and have thicker lenses compared with unaffected individuals. PAC suspects showed similar axial lengths to affected individuals. ERG abnormalities mainly occurred in affected patients and suspects, but also occurred in unaffected individuals with short axial length.

Recent advances in pharmacotherapy of glaucoma

Glaucoma is a slow progressive degeneration of the retinal ganglion cells (RGCs) and the optic nerve axons, leading to irreversible blindness if left undiagnosed and untreated. Although increased intraocular pressure is a major risk factor of glaucoma, other factors include increased glutamate levels, alterations in nitric oxide (NO) metabolism, vascular alterations and oxidative damage caused by reactive oxygen species. Glaucoma is the second leading cause of blindness globally, accounting for 12.3% of the total blindness. Glaucoma has been broadly classified as primary or secondary open-angle or angle-closure glaucoma. The primary goal in management of glaucoma is to prevent the risk factor, especially elevated intraocular pressure (IOP), using medications, laser therapy or conventional surgery. The first-line treatment of glaucoma usually begins with the use of a topical selective or nonselective blocker or a prostaglandin analog. Second-line drugs of choice include alpha-agonists and topical carbonic anhydrase inhibitors. Cholinergic agonists are considered third-line treatment options. When a single therapy is not sufficient to lower the IOP, a combination therapy is indicated. To enhance the patient compliance, drug delivery systems like electronic devices, ocular inserts, tansdermal and mechanical drug delivery systems have been developed. Use of viscoelastic agents in ophthalmic formulations, emulsions and soluble ophthalmic drug inserts (SODI) enhance patience compliance and ocular drug delivery in patients in long-term glaucoma therapy. For patients who do not respond to antiglaucoma medications, laser trabeculoplasty and incisional surgery are recommended. Several nutrients and botanicals hold promise for the treatment of glaucoma, but most studies are preliminary, and larger, controlled studies are required. Future directions for the development of a novel therapy glaucoma may target glutamate inhibition, NMDA receptor blockade, exogenously applied neurotrophins, open channel blockers, antioxidants, protease inhibitors and gene therapy.

Damage patterns of retinal nerve fiber layer in acute and chronic intraocular pressure elevation in primary angle closure glaucoma

AIM

To observe the differences of damage patterns of retinal nerve fiber layer (RNFL) between acute and chronic intraocular pressure (IOP) elevation in primary angle closure glaucoma (PACG) using optical coherence tomography (OCT).

METHODS

Twenty-four patients (48 eyes) with unilateral acute PACG (APACG) attack in the 6 months after admission and 36 patients (64 eyes) with chronic PACG (CPACG) were included in this prospective study. For all cases, IOP has been controlled under 21mmHg after treatment. Using stratus OCT, the RNFL thickness was assessed in eyes with PACG within 3 days, 2 weeks, 1, 3 and 6 months after IOP was controlled. Repeated measures ANOVA was used to examine the changes of RNFL thickness at different time after IOP being controlled in both acute attack eyes and unaffected fellow eyes of APACG and eyes with CPACG.

RESULTS

The mean RNFL thickness for the APACG-attacked eyes increased significantly within 3 days (121.49±23.84)µm after acute onset and then became thinner along with time [(107.22±24.72)µm at 2 weeks,(93.58±18.37)µm at 1 month, (84.10±19.89)µm at 3 months and (78.98±19.17)µm at 6 months]. In APACG-attacked eyes, there were significant differences of average RNFL thickness at 5 different times after IOP was controlled (P<0.001). In the APACG unaffected fellow eyes and CPACG eyes, there were no significant differences in mean RNFL thickness at 5 different times(F=0.450, P=0.104 in APACG unaffected fellow eyes and F=1.558, P=0.200 in CPACG eyes). There was significant difference for interaction between time periods and groups (F=1.912, P=0.003).

CONCLUSION

RNFL damage patterns are different under different IOP elevated courses. In APACG, RNFL was found to be swollen and thickening right after acute attack and then becomes thinning and atrophy along with the time, while RNFL was found to be diffused thinness in CPACG.

Prognostic factors for the success of laser iridotomy for acute primary angle closure glaucoma

Purpose

To identify the prognostic factors for successful laser iridotomy for acute angle-closure glaucoma (AACG).

Methods

We retrospectively reviewed the medical records of 77 eyes of 77 patients with AACG with initial intraocular pressure (IOP) above 40 mmHg. All of the patients received maximum tolerable medical therapy (MTMT) followed by laser iridotomy. In order to comparatively analyze the factors affecting successful laser iridotomy, an increase in IOP on follow-up was defined as increase in IOP greater than 21 mmHg requiring medical or surgical treatment.

Results

Successful laser iridotomy was achieved in 59.7% (46/77 eyes). Thirty-one eyes (40.3%) exhibited increased IOP on follow-up, and of these, 30 eyes developed an increase in IOP within six months after the first attack. The success rate was higher (92.9%) in 42 patients who had greater than 30% IOP reduction by MTMT at the first attack compared to the 35 patients whose IOP reduction was less than 30%, of which 24 eyes (72.7%) showed more than 30% IOP reduction after intravenous hyperosmotic agent treatment (p=0.012). The success rate was higher in patients treated within seven days after the development of symptoms than in those treated after seven days (Odds ratio, 4.51; 95% confidence interval, 1.38 to 14.75).

Conclusions

Our data suggest that we can expect successful IOP control after laser iridotomy in eyes with AACG if the patient can be treated within seven days after the development of symptoms and if the IOP reduction was more than 30% by MTMT.

Angle-closure glaucoma: the role of the lens in the pathogenesis, prevention, and treatment

Primary angle-closure glaucoma is a major cause of blindness worldwide. It is a disease of ocular anatomy that is related to pupillary-block and angle-crowding mechanisms of filtration angle closure. Eyes at increased risk for primary angle-closure are small with decreased axial length, anterior chamber depth, and filtration angle width, associated with a proportionately large lens. Angle-closure glaucoma afflicts Asian and Eskimo eyes more frequently than eyes in other races with similar predisposing dimensions. The treatment of primary angle closure addresses its causal mechanisms. Laser peripheral iridotomy equalizes the anterior and posterior pressures and widens the filtration angle by reducing the effect of pupillary block. Argon laser peripheral iridoplasty contracts the iris stroma to reduce angle crowding and is helpful for some affected eyes. Lensectomy dramatically widens the angle and eliminates pupillary block. Clinical reports of lensectomy with posterior chamber intraocular lens implantation in the treatment of acute, chronic, and secondary angle-closure glaucoma describe very favorable results. The appropriate role for lensectomy in the management of primary angle closure, however, remains unproven. Prospective, randomized clinical trials are ongoing to determine the value and comparative risks and efficacy of lensectomy versus medical therapy, laser peripheral iridotomy, laser iridoplasty, and filtration procedures for the treatment of acute and chronic primary angle closure and for the prevention of chronic angle-closure glaucoma, both after and in place of laser peripheral iridotomy.

The long-term effect of Nd:YAG laser iridotomy on intraocular pressure in Taiwanese eyes with primary angle-closure glaucoma

BACKGROUND

To investigate the long-term effect of Nd:YAG laser iridotomy on intraocular pressure (IOP) in Taiwanese eyes with primary angle-closure glaucoma (PACG).

METHODS

The medical records of 81 patients (130 eyes) who were diagnosed with PACG and who had undergone Nd:YAG laser iridotomy between 1998 and 2002 were reviewed. According to the presence of symptomatic glaucoma attack, eyes were divided into an acute angle-closure glaucoma (AACG) group and chronic angle-closure glaucoma (CACG) group. In the AACG group, the acute episode was treated and resolved after Nd:YAG laser iridotomy. These eyes were diagnosed to have or developed glaucoma during the follow-up period. All patients were followed-up for at least 24 months. The presenting features, treatment and IOP during the follow-up period were analyzed.

RESULTS

The mean follow-up period was 44.1 +/- 17.8 months (median, 36 months). There were 27 eyes (from 25 patients) in the AACG group. Only 2 eyes (7.4%) did not require any treatment after Nd:YAG laser iridotomy. Eleven eyes (40.7%) eventually underwent filtering surgery at a mean of 3.2 months (median, 3 months) after Nd:YAG laser iridotomy. There were 103 eyes (from 56 patients) in the CACG group. Eighty-five eyes (82.5%) required further medical treatment, of which 21 eyes (20.4%) eventually received filtering surgery at a mean of 9.8 months (median, 5 months) after Nd:YAG laser iridotomy.

CONCLUSION

For most Taiwanese eyes with PACG after Nd:YAG laser iridotomy, additional medicine and surgery are required in the long term. Eyes in the AACG group needed more surgical intervention than those in the CACG group.

Current Understanding of the Treatment and Outcome of Acute Primary Angle Closure Glaucoma: An Asian Perspective

Introduction: Primary angle-closure glaucoma (PACG) is a major cause of blindness among Asians. A better understanding of the disease will improve the treatment and outcome of this condition. Methods: A literature review of all recent publications on PACG was carried out. Articles were retrieved using a key word search of MEDLINE, PubMed and Science Citation Index databases. Results: Following laser peripheral iritodomy for acute angle-closure, Asians were found to have a higher tendency to develop a subsequent rise in intraocular pressure compared to Caucasians. Furthermore, the extent and severity of visual field damage was more severe in Asians than Caucasians, particularly in eyes that presented insidiously with chronic PACG. Prophylactic laser iridotomy in the contralateral eye was found to be highly effective in preventing acute angle-closure attacks. Conclusion: PACG is more difficult to manage and is associated with more severe long-term visual morbidity in Asians than Caucasians. Regular follow-up of patients with PACG is important for the early detection of progression of the disease and visual field deterioration.

Peripheral anterior synechiae and ultrasound biomicroscopic parameters in angle-closure glaucoma suspects

PURPOSE

To investigate the correlation between peripheral anterior synechia (PAS) and the quantitative anterior chamber angle parameters measured by ultrasound microscopy (UBM) in angle-closure glaucoma suspect (ACGS) eyes.

METHODS

Eyes were defined ACGS as having occludable angles and intraocular pressure less than 21 mm Hg without glaucomatous optic nerve head. The gonioscopic criteria for ACGS were the trabecular meshwork invisible in 3 or more quadrants of the entire angle and the angular width less than 20 degrees by Shaffer classification. Twenty-seven eyes of 20 patients underwent anterior chamber angle and ciliary body imaging with UBM. Angle opening distance (AOD(500)), angle recess area (ARA), trabecular-ciliary process distance (TCPD) and trabecular-iris angle (TIA) were measured from the UBM images at each quadrant.

RESULTS

The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant. However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05).

CONCLUSIONS

The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

Comparison of the Effects of Latanoprost and Travoprost on Intraocular Pressure in Chronic Angle-Closure Glaucoma

PURPOSE

The aim of this study was to compare the intraocular pressure (IOP)-lowering effect of latanoprost and travoprost as primary therapy in patients with chronic angle-closure glaucoma (CACG) after peripheral iridotomy.

METHODS

Seventy-three (73) CACG patients with IOP>19 mmHg after peripheral iridotomy and without previous antiglaucoma medication were consecutively recruited. CACG was defined as the presence of chronically elevated IOP, glaucomatous optic neuropathy, and a corresponding visual field defect in eyes with occludable angle and peripheral anterior synechiae on gonioscopy. Patients were randomly assigned to 2 groups, based on daily treatment with either latanoprost 0.005% or travoprost 0.004% in the evening for 12 weeks. The IOP was measured at 9 AM and 4 PM at baseline and at 4, 8, and 12 weeks. Between-group differences in mean diurnal IOP and IOP reduction were analyzed.

RESULTS

After 12 weeks of treatment, mean IOP for both the latanoprost and travoprost groups was significantly reduced, when compared to the baseline IOP (from 21.3+/-1.8 mmHg to 16.0+/-2.3 mmHg and 21.7+/-1.7 to 16.7+/-2.2 mmHg; P<0.001 for both). There was no significant difference in IOP reduction between the 2 treatment groups (P=0.19). At 4 and 8 weeks, the IOP changes from the baseline were statistically significant at all time points for both drugs (all P<0.001).

CONCLUSIONS

Both latanoprost and travoprost significantly reduced IOP in our sample of CACG patients after peripheral iridotomy.

Distribution and characteristics of peripheral anterior synechiae in primary angle-closure glaucoma

Purpose

To evaluate the characteristics of peripheral anterior synechiae (PAS) in primary angle-closure glaucoma (PACG).

Methods

We reviewed the charts of 155 patients (244 eyes) with PACG. We divided these patients into one of four clinical subtypes: acute angle-closure glaucoma (ACG), chronic ACG, angle-closure hypertension, and ACG suspect. The prevalence, extent, and location of PAS were evaluated according to PACG subtypes. Correlation analysis was used to evaluate relationships between the highest IOP level without treatment and the extent of PAS.

Results

The average degree of angle-closure with PAS was 14.6±9.1 in eyes that were classified as ACG suspect, 83.8±48.3 in angle closure hypertension, 140.5±31.3 in acute ACG, and 180.3±31.9 in chronic ACG (ANOVA test, P<0.05). PAS was most frequently found in the superior part of the eye, especially from 12 to 1 o' clock. The incidence of broad PAS (PAS over 30 degrees in width) was highest in superior part, but the medium and narrow PAS (PAS limited to within 30 degrees in width) was distributed throughout all 12 sectors relatively equally. Prior to a laser iridotomy (LI) and other medical treatments, a positive correlation was found between the highest IOP (intraocular pressure) levels and the extent of PAS in chronic ACG (r=0.423, P<0.0001). However, statistically significant relationships were not found between the highest IOP levels before treatment and the extent of PAS in any of the other clinical subtypes.

Conclusions

Our results suggest that acute and chronic ACG patients are most likely to have a greater extent of PAS than patients in the angle closure hypertension or are ACG suspect subtypes. PAS may be narrower in earlier stages and broader in later stages. PAS was also found most frequently in the superior part of the eye. The extent of synechial closure of the angle may play a role in raising IOP levels in later stages of the disease rather than early on.

OCT-Goniometrie vor und nach Iridotomie beim Engwinkelglaukom

PURPOSE

Visualization of the anterior chamber angle is an important diagnostic method in patients with angle-closure glaucoma. In this study, optical coherence tomography (OCT) was used to image the angle width, the iris configuration, and the iris thickness in patients with angle-closure glaucoma.

METHODS

Thirteen eyes of 11 patients suffering from angle-closure glaucoma were studied with slitlamp-adapted OCT. All patients were treated with Nd:YAG laser iridotomy. The angle width ( degrees ), the angle opening distance (AOD) (microm), and the iris thickness (microm) were measured with OCT. The configuration of the iris was classified as steeply convex, convex, or flat.

RESULTS

The mean angle width was preoperatively 5.1+/-5.0 degrees (0-15 degrees ) and enlarged significantly (p=0.007) to 10.4+/-5.5 degrees (0-19 degrees ) postoperatively. The AOD changed from 71+/-55 microm (0-157 microm) preoperatively to 143+/-74 microm (0-256 microm) postoperatively (p<0.001). The mean iris thickness was 338+/-33 microm. With the exception of two eyes the predominant iris configuration changed from convex to flat.

CONCLUSIONS

OCT allowed visualization and noninvasive assessment of the anterior chamber angle region in patients with angle-closure glaucoma. Our results suggest that goniometry with OCT could improve the evaluation in patients with narrow or closed anterior chamber angles.

Progression of peripheral anterior synechiae after laser iridotomy

PURPOSE

To determine the incidence and to characterize the risk factors of peripheral anterior synechiae (PAS) progression after laser iridotomy (LI).

DESIGN

Retrospective observational cohort study.

METHODS

The extents of pre- and postlaser PAS and ocular and systemic data were obtained from the charts of 54 primary angle-closure glaucoma patients (59 eyes), all of whom had undergone LI.

RESULTS

PAS progressed in 19 of the 59 eyes (32.2%), during a mean follow-up period of 34.4 months (range, 6-95 months). Multivariate analysis showed that the presence of plateau iris (P = .024), and a high intraocular pressure 1 hour before LI (P = .042) were risk factors of PAS progression.

CONCLUSION

Approximately one of three of the eyes showed PAS progression during a 3-year follow-up period after LI. The probability of progression was found to be higher in the eyes that exhibited plateau iris and in eyes that proved to be relatively unresponsive to medication before LI.

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

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.

METHODS

Sixteen Chinese patients who had history of APAC and subsequent successful treatment with laser peripheral iridotomy were examined. Fourteen additional control subjects were studied. Gonioscopy and ultrasound biomicroscopic examination were performed in the dark. Gonioscopic appearance of the angle was assessed, and quantitative measurements of the angle from the ultrasound biomicroscopic images were taken.

RESULTS

Of the APAC eyes 55.6% had appositionally closed angle clinically and in 38.9% only Schwalbe's line was visible on gonioscopy. Ultrasound biomicroscopy confirmed structurally different anterior segments between eyes with APAC and the control eyes. In particular, the trabecular-ciliary-process distances were markedly different between the two groups.

CONCLUSION

This study documented a high prevalence of appositional closure in iridotomized eyes after APAC in Chinese patients. The anteriorly positioned ciliary body, as documented in these cases by ultrasound biomicroscopy, is the likely mechanism of the angle crowding in this patient population.

Comparison of Glaucomatous Optic Nerve Damage in Primary Angle-Closure Glaucoma with and without Acute Attack

PURPOSE

To compare the glaucomatous optic nerve damage in primary angle-closure glaucoma (PACG) with acute attack (acute PACG; AACG) and PACG without acute attack (chronic PACG; CACG).

METHODS

The study subjects were 84 normal individuals, 130 AACG patients, and 86 CACG patients. Color optic disc photographs were evaluated for the presence or absence of 10 qualitative signs to differentiate between normal and glaucomatous optic discs.

RESULTS

Abnormally shaped rim width (alteration of ISN'T rule), bared circumlinear vessel, vessel bayonetting, rim width narrower than the temporal sector, and zone beta (nasal and superotemporal sectors) were detected more frequently in the CACG group than in the AACG group (P<0.05). The most accurate qualitative sign was abnormally shaped rim width in both groups. The specificity and sensitivity of abnormally shaped rim width were 71.4% and 60.8% for AACG, and 71.4% and 81.4% for CACG, respectively.

CONCLUSIONS

The optic disc damage is greater in CACG than in AACG.

The epidemiology of primary angle closure and associated glaucomatous optic neuropathy

Angle closure glaucoma is emerging as a leading cause of blindness in the densely populated countries of Asia. It has a greater propensity to cause bilateral blindness than either primary open-angle glaucoma or secondary glaucoma. An estimated 9.4 million people in China aged 40 years and older have glaucomatous optic neuropathy. Approximately 5.2 million people (55%) would be blind in at least one eye. Around 1.7 million (18.1%) would be blind in both eyes. it is likely that PACG is responsible for the vast majority (91%) of bilateral glaucoma blindness in China. The number of Chinese people with an "occludable" drainage angle is in the region of 28.2 million, and of these 9.1 million have significant angle closure. There is a growing emphasis on a revised method of classifying the disease, which reserves the term "glaucoma" for cases with glaucomatous optic neuropathy. The term primary angle closure (PAC) is used in cases with a closed angle and peripheral anterior synechiae or raised intraocular pressure. Risk factors for PAC include older age, female gender, Chinese ethnicity, all of which are associated with anatomical risk factors of central and/or peripherally shallow anterior chambers (usually associated with a thicker, anteriorly-positioned lens), and a shorter axial length of the globe.

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.

Relationship between the Extent of Peripheral Anterior Synechiae and the Severity of Visual Field Defects in Primary Angle-closure Glaucoma

We investigated the relationship between the circumferential extent of peripheral anterior synechiae (PAS) and the severity of visual field defects in primary angle-closure glaucoma (PACG). Correlations between visual field defects and the extent of PAS were analyzed in 73 eyes; 28 with and 45 without acute attacks. Spearman's correlation coefficient between the severity of visual field defects and the extent of PAS was 0.348 (P = 0.003) in all subjects (n = 73), 0.377 (P = 0.012) in the PACG eyes without acute attacks (n = 45), and 0.338 (P = 0.079) in the eyes with acute attacks (n = 28). Our results showed a statistically significant correlation between the extent of PAS and the severity of visual field damage in PACG overall, and especially in PACG patients without a history of acute attacks.

Combined phacoemulsification, intraocular lens implantation and trabeculectomy for chronic angle closure glaucoma

PURPOSE

To investigate the results of combined phacoemulsification, intraocular lens implantation and trabeculectomy in Asian patients with chronic angle closure glaucoma (CACG).

METHODS

This was a retrospective non-comparative case series of 55 consecutive patients (57 eyes) who underwent phacoemulsification, posterior chamber intraocular lens implantation and trabeculectomy for CACG at the Singapore National Eye Centre between 1997-1998. The surgical outcome was assessed in terms of intraocular pressure (IOP), the incidence of complications and the visual acuity at last follow-up. Success was defined as final IOP < or = 21 mmHg without medication and qualified success as final IOP < or = 21 mmHg with medication. Patients with final IOP > 21 mmHg who required further glaucoma surgery, lost light perception or became pthisical, were classified as failures. The eyes were further categorized into two groups according to whether single-site or separate-site surgery was performed. The outcome was also compared among eyes in which per-operative antimetabolites were applied to the trabeculectomy site and those without antimetabolites.

RESULTS

The mean follow up was 22.0 +/- 5.6 months (mean +/- SD). Success was achieved in 46 (81%) eyes, qualified success in 10 (17%) eyes, and failure in 1 (2%) eye. In terms of IOP outcome, the success rate was similar in the two surgical groups (single-site or separate-site). There was no significant difference in IOP outcome among eyes in which per-operative antimetabolites were used and eyes with no per-operative antimetabolites use. Forty-one eyes (72%) had 6/12 or better vision. There were no cases of intraoperative complications and the incidence of postoperative complications was low.

CONCLUSIONS

Combined phacoemulsification, intraocular lens implantation and trabeculectomy is associated with good intraocular pressure control and visual outcome in patients with CACG.

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.

Acute primary angle-closure: long-term intraocular pressure outcome in Asian eyes

PURPOSE

To report the long-term outcome of intraocular pressure after laser peripheral iridotomy in Asian eyes with acute primary angle-closure.

METHODS

Retrospective study of 111 eyes of 96 consecutive patients with acute primary angle-closure, presenting at the National University Hospital, Singapore, from 1990 to 1994. The presenting features of the affected eye and the treatment instituted were recorded. The subsequent long-term intraocular pressure outcome was analyzed. An increase in intraocular pressure on follow-up was defined as increase in intraocular pressure greater than 21 mm Hg and requiring treatment by medication or surgery.

RESULTS

The mean follow-up period was 50.3 months (range, 9 to 107 months). The mean presenting intraocular pressure was 52.8 mm Hg (range, 28 to 80 mm Hg). One hundred ten eyes were treated with laser peripheral iridotomy, with resolution of the acute episode and intraocular pressure less than 21 mm Hg in all eyes after laser peripheral iridotomy. Of these, only 46 eyes (41.8%) were successfully treated with laser peripheral iridotomy alone in the long term. Sixty-four eyes (58.1%) developed an increase in intraocular pressure (requiring treatment) on follow-up, of which 49 eyes developed an increase in intraocular pressure within the first 6 months after acute primary angle-closure. Thirty-six eyes (32.7%) eventually underwent trabeculectomy because of uncontrolled intraocular pressure despite laser and medical therapy.

CONCLUSIONS

In this study of Asian eyes, a high proportion (58.1%) of eyes with acute primary angle-closure developed an increase in intraocular pressure on long-term follow-up after resolution of the acute attack, despite the presence of a patent laser peripheral iridotomy. These results suggest a racial difference in the outcome of laser peripheral iridotomy after acute primary angle-closure in Asians, compared with Caucasians. Because a majority of eyes that develop an increase in intraocular pressure do so within the first 6 months of presentation, close monitoring of intraocular pressure is advised in the follow-up of patients with acute primary angle-closure.

Long-term clinical course of primary angle-closure glaucoma in an Asian population

PURPOSE

To study the long-term clinical course of patients with primary angle-closure glaucoma (PACG).

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Sixty-five consecutive patients who were diagnosed with PACG at one Singapore hospital from January 1990 through December 1994.

METHODS

Primary angle-closure glaucoma was defined as the presence of glaucomatous optic neuropathy and compatible visual field loss associated with a closed angle in the same eye. All study eyes underwent laser peripheral iridotomy (LPI). There were two groups of patients studied. Group A consisted of those with a past documented history of an episode of acute angle closure (that had resolved after LPI). Group B consisted of those with no previous acute episode. The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed.

MAIN OUTCOME MEASURES

Intraocular pressure and the need for further glaucoma treatment.

RESULTS

The follow-up period was 63 +/- 29 months (mean +/- standard deviation). The mean presenting IOP was 40 +/- 16 mmHg, and the presenting vertical cup-to-disc ratio was 0.6 +/- 0.2. Of the 83 eyes, only five eyes (6%) did not require any treatment after LPI in the long term. In group A (35 eyes), all eyes required further treatment with antiglaucoma medications. Twenty-two eyes (62. 9%) eventually underwent filtering surgery at a mean of 7.3 months after the commencement of treatment. In group B (48 eyes), 43 eyes (89.6%) underwent further medical therapy, of which 22 eyes (45.8%) eventually underwent filtering surgery at a mean of 18.4 months after the commencement of treatment.

CONCLUSIONS

Despite the presence of a patent LPI, most eyes with established PACG require further treatment to control IOP. Medical therapy fails in most cases, necessitating filtering surgery. Patients risk experiencing further glaucomatous visual damage if this trend is not detected.

Acute primary angle closure in an Asian population: long-term outcome of the fellow eye after prophylactic laser peripheral iridotomy

PURPOSE

To study the long-term outcome of fellow eyes of Asian patients with acute primary angle closure (APAC) who underwent prophylactic laser peripheral iridotomy (LPI).

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Ninety-six consecutive patients with APAC at presentation to one Singapore hospital from January 1990 through December 1994.

METHODS

The presenting features of the fellow eye were recorded, and the subsequent long-term intraocular pressure (IOP) outcome after LPI was analyzed. All fellow eyes were initially treated with pilocarpine 2% eyedrops four times daily before LPI, which was performed within 1 week of presentation. For any eye, a rise in IOP during follow-up was defined as a rise in IOP requiring treatment by medication or surgery.

MAIN OUTCOME MEASURES

Incidence of acute angle closure and IOP.

RESULTS

The mean follow-up period was 50.8 months (range, 9-99 months). Of the 96 patients, 15 patients had bilateral APAC, and APAC developed in one fellow eye before LPI could be performed. The remaining 80 fellow eyes were studied. No cases of APAC developed after prophylactic LPI. Seventy-one fellow eyes (88.8%) were successfully treated with LPI alone without the need for additional glaucoma treatment in the long term. Seven eyes (8.8%) had IOPs of 21 mmHg or less on presentation, but a rise in IOP developed on follow-up despite the presence of a patent LPI. Two fellow eyes (2.5%) had signs of preexisting chronic angle closure glaucoma at presentation and required further glaucoma treatment even after LPI. There were no significant complications from the procedure in any of the fellow eyes studied.

CONCLUSIONS

In this Asian population with APAC, prophylactic LPI is safe and effective in preventing acute angle closure in fellow eyes. In addition, prophylactic LPI prevents long-term rise in IOP in 88.8% of fellow eyes (with approximately 4 years of follow-up). However, because a small proportion of fellow eyes did experience a rise in IOP within the first year, despite the presence of a patent LPI, close monitoring is still advised in the follow-up of fellow eyes of patients with APAC.

Ocular parameters in the subgroups of angle closure glaucoma

PURPOSE

This study was conducted to compare anatomical parameters, thought to be responsible for causing angle closure glaucoma (ACG), among eyes having acute, subacute or chronic ACG.

METHODS

Ninety consecutive patients diagnosed with a subgroup of ACG, and 30 age, sex and refraction matched controls, provided a total of 240 eyes for a prospective study. The refractive error, corneal diameter, keratometry, pachymetry, lens thickness and axial length were measured and the relative lens position was calculated. The data were analysed by paired t-test, ANOVA, signed rank test and multivariate analysis.

RESULTS

Acute ACG eyes were mildly hyperopic. All the ACG subgroups had similarly short eyeballs and a steeper corneal curvature compared to control eyes. Acute ACG lenses were thicker than all the other groups (P < 0.001), but all ACG eyes had thicker lenses than the controls. Corneal diameters and anterior chamber depths were decreased in acute and chronic ACG eyes compared with subacute ACG and controls (P < 0.001). The uninvolved fellow eyes in each subgroup differed from affected eyes only in having more posteriorly positioned lenses.

CONCLUSIONS

There was a spectrum of anatomical variations seen in the subgroups of ACG. Acute ACG eyes expressed an extreme shift of anatomical features away from normal, especially, smaller corneal diameters, leading to a large mobile lens in an already crowded anterior segment. This predisposed them to a severe relative pupillary block, and to a form of ciliary block glaucoma. Chronic ACG eyes were less divergent from normal and therefore could have suffered a milder form of the same kind of angle closure, but over a more prolonged period. Subacute ACG eyes deviated least from controls, and therefore exhibited mild signs and spontaneous resolution. Further work is required to elucidate completely the pathophysiology that leads to ACG.

Efficacy of latanoprost as an adjunct to medical therapy for residual angle-closure glaucoma after iridectomy

Residual primary angle-closure glaucoma (PACG) after iridectomy is an important issue among Asians, especially Chinese. In this study, we tested the effectiveness of latanoprost as an intraocular pressure (IOP) lowering agent in cases of residual PACG. Twenty-six eyes of 26 PACG patients with persistently elevated IOP after iridectomy, despite treatment with conventional IOP lowering drugs (beta blockers and pilocarpine) were included. Latanoprost 0.005%, one drop daily, was added adjunctively to all eyes. Measurement of IOP at baseline and after the start of treatment with latanoprost indicated a significant IOP reduction. The IOP decreased by about 21% (p < 0.005) during the first 3 months, and showed a reduction of about 36% at the end of 1 year. At the 1-year follow up, the IOP was well controlled (below 20 mmHg) in all eyes. These findings show that, in combination with beta blockade and pilocarpine, latanoprost can ameliorate residual PACG after iridectomy and could potentially forestall the need for further therapeutic intervention.