Long-term evaluation of trabeculectomy in primary open angle glaucoma and chronic primary angle closure glaucoma in an Asian population

Purpose: A retrospective cohort study was undertaken to evaluate and compare the long‐term results of trabeculectomy in primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (CPACG) in an Asian population. Methods: Yearly diurnal measurements of intraocular pressure (IOP), best‐corrected visual acuity, optic disc and visual field records of patients having primary adult glaucomas who had undergone trabeculectomy, without anti­mitotic agents, with a minimum of 5 years follow up were evaluated. Only one eye of each patient was studied. The success rates for IOP control in POAG and CPACG were statistically analysed. Results: Sixty‐four eyes of 64 patients were studied. The overall probability of success of trabeculectomy in controlling IOP to ≤21 mmHg with or without additional topical antiglaucoma medication was 0.94 and 0.88 at 5 and 10 years, respectively. There was no statistically significant difference in the qualified and absolute success rates for IOP control between POAG and CPACG eyes (log rank test P= 0.6, 0.88, respectively). Twelve of 38 CPACG eyes had a two‐line decrease in visual acuity as compared to four of 26 POAG eyes (P = 0.17). Progression or development of a cataract was the most common cause of visual decline. Conclusions: Trabeculectomy without antimetabolite use appears to be efficacious in lowering IOP and in visual field preservation over a period of 10 years in both POAG and CPACG. Development/progression of cataract especially in eyes with chronic angle closure glaucoma after trabeculectomy must be considered an important issue.     

YAG laser iridotomy treatment for primary angle closure in east Asian eyes

AIM: To assess the efficacy of Nd:YAG laser iridotomy as initial treatment for primary angle closure in a community setting in rural Mongolia. METHODS: Subjects with occludable drainage angles in two glaucoma prevalence surveys in Mongolia (carried out in 1995 and 1997) were treated with YAG laser iridotomy at the time of diagnosis. These patients were re-examined in 1998. Patency of iridotomy, intraocular pressure (IOP), visual acuity, and gonioscopic findings were recorded. Iridotomy was classified unsuccessful in eyes where further surgical intervention was required or in which there was a loss of visual acuity to <3/60 from glaucomatous optic neuropathy. RESULTS: 164 eyes of 98 subjects were examined. Patent peripheral iridotomies were found in 98.1% (157/160) of eyes that had not undergone surgery. Median angle width increased by two Shaffer grades following iridotomy. Iridotomy alone failed in 3% eyes with narrow drainage angles and either peripheral anterior synechiae or raised IOP, but normal optic discs and visual fields. However, in eyes with established glaucomatous optic neuropathy at diagnosis iridotomy failed in 47%. None of the eyes with occludable angles that were normal in all other respects, and underwent iridotomy, developed glaucomatous optic neuropathy or symptomatic angle closure within the follow up period. CONCLUSIONS: Nd: YAG laser iridotomy is effective in widening the drainage angle and reducing elevated IOP in east Asian people with primary angle closure. This suggests that pupil block is a significant mechanism causing closure of the angle in this population. Once glaucomatous optic neuropathy associated with synechial angle closure has occurred, iridotomy alone is less effective at controlling IOP.     

Outcomes following acute primary angle closure in an Asian population

Background:  Data regarding development of primary angle closure glaucoma (PACG) following acute primary angle closure (APAC) is conflicting. This study looks at outcomes after an APAC episode with a secondary aim to identify any risk factors that could predict progression to PACG.
Methods:  This is a retrospective review of the charts of consecutive patients who were diagnosed with APAC from December 2003 to June 2006. All were treated in a standard manner with initial intensive medical therapy or laser iridoplasty followed by early laser peripheral iridotomy within 24 h of presentation.
Results:  Forty-two eyes of 41 patients were analysed. The mean follow-up period was 27.3 ± 16.2 months. Nine eyes (21.4%) developed an increase in intraocular pressure (IOP) within a mean of 11.9 months (median 5 months) after resolution of APAC. Eight eyes went on to have trabeculectomy or glaucoma drainage device. At final follow up, the mean IOP of attack eye was 13.3 ± 2.92 mmHg. None of the eyes, including those that underwent surgery, required topical medication to control IOP. Thirty-eight eyes (90.5%) have BCVA of 6/6 to 6/12. The duration of symptoms before presentation ( P  = 0.00) and duration taken to abort the acute attack ( P  = 0.01) were found to be significantly associated with development of PACG.
Conclusion:  The results of this study suggest that outcomes following successful treatment of APAC may not be as poor as described previously. Early aggressive management of the acute episode may have a role to play in preventing development of PACG after APAC.     

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.     

Five-year risk of progression of primary angle closure to primary angle closure glaucoma: a population-based study

OBJECTIVE: To report the 5-year progression to primary angle closure glaucoma (PACG) in a population-based cohort of primary angle closure (PAC) subjects. METHODS: A total of 37 patients diagnosed as PAC during a population-based study in 1995 were invited for re-examination in 2000. Patients underwent a complete ophthalmic examination including ocular biometry. Progression to PACG was based on optic disc damage and field defects on automated perimetry. RESULTS: In all, 28 of 32 PAC subjects who could be contacted presented for examination. Eight (28.5%; 95% CI 12-45%) had progressed to PACG; two of seven with appositional and six of 21 with synechial closure. All were advised laser peripheral iridotomy (LPI) in 1995; one of the nine who underwent LPI progressed compared to seven of 19 who refused LPI. Four of those originally diagnosed with appositional closure developed peripheral anterior synechiae. One eye of a person previously diagnosed with appositional PAC was reclassified as a primary angle closure suspect (PACS). There was no significant difference in biometric parameters between those who progressed and those who did not. None developed acute PACG or blindness due to glaucoma. CONCLUSION: In this population-based study of primary angle closure, the 5-year incidence of PACG was eight patients (28.5%; 95% CI 12-45%). We were unable to identify any features that predicted progression.     

Heidelberg Retinal Tomograph (HRT 2) parameters in primary open angle glaucoma and primary angle closure glaucoma: a comparative study in an Indian population

AIMS: To compare the Heidelberg Retinal Tomograph (HRT 2) parameters in patients with primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) in an Indian population. MATERIALS AND METHODS: Two groups of patients were recruited: group I comprised 78 eyes (78 patients) with POAG and group II 58 eyes (58 patients) with PACG. Based on visual field defects detected by automated perimetry, the groups were further classified into early, moderate, and severe glaucoma. All patients underwent a complete ophthalmic examination as well as an HRT 2 examination. The HRT parameters for the two groups were compared and the sensitivity and specificity of the parameters calculated. RESULTS: All HRT parameters were similar in both groups: 85.9% (95% CI: 78.2, 93.6) of POAG and 81% (95% CI: 72.3, 89.3) of PACG had a positive F. S. Mikeleberg (FSM) discriminant function. Considering outside normal limits and borderline as abnormal, the Moorefield regression analysis had 83.3% (95% CI: 75, 91.6) sensitivity in POAG and 75.9% (95% CI: 64.9, 86.9) in PACG. In early POAG, the FSM discriminant function had a sensitivity of 74.3% (95% CI: 59.8, 88.8) compared to 58.3% (95% CI: 38.9, 77.7) for early PACG. The cup shape measure (p = 0.018) and the Moorfield regression analysis (p = 0.011) had significantly higher sensitivity for early POAG than for early PACG: cup shape measure sensitivity 62.9% (95% CI 46.9, 78.9) for early POAG versus 33.3% (95% CI: 14.4, 52.2) for early PACG and Moorefield regression analysis 74.3% (95% CI: 59.8, 88.8) versus 45.8% (95% CI: 39.9, 65.7). CONCLUSIONS: HRT has moderate sensitivity in the detection of damage leading to glaucomatous field defects. The sensitivity of HRT for early PACG appears to be less than that for early POAG. This may indicate a difference in pathophysiology.     

Five year risk of progression of primary angle closure suspects to primary angle closure: a population based study

AIM: To report progression of primary angle closure suspects (PACS) to primary angle closure (PAC) at the 5 year follow up of a population based sample. METHODS: 82 of 118 PACS who could be contacted and 110 randomly selected normals from a population based survey in 1995 were invited for a follow up examination in 2000. Progression to PAC was based on the development of raised IOP or synechiae in a PACS. RESULTS: 50 of the 82 PACS contacted were examined. 11 (22%; 95% CI 9.8 to 34.2) developed PAC (seven synechial and four appositional); all were bilateral PACS. Two of 50 people previously diagnosed as PACS were reclassified as normal. One person among the 110 normals progressed to PAC. The relative risk of progression among PACS was 24 (95% CI 3.2 to 182.4). There was no significant difference in axial length, anterior chamber depth, or lens thickness between those who progressed and those who did not. None of the patients developed optic disc or field damage attributable to angle closure. One angle closure suspect was diagnosed to have normotensive glaucoma. CONCLUSION: In this population based study of PACS the 5 year incidence of PAC was 22%; none developed functional damage. Bilateral PACS was a clinical risk factor for progression.     

Viscogonioplasty: an effective procedure for lowering intraocular pressure in primary angle closure glaucoma

PURPOSE: To evaluate the safety and intraocular pressure (IOP) lowering effect of combined phacoemulsification and viscogonioplasty (Phaco-VGP) in managing primary acute closed-angle glaucoma (ACAG) unresponsive to conventional therapy (patent PI). PATIENT AND METHODS: In all, 15 consecutive eyes of patients with refractory ACAG and greater than 270 degrees peripheral anterior synechiae (PAS) underwent VGP. The technique of VGP involved routine phacoemulsification with intraocular lens implantation (Phaco/IOL) under topical anaesthetic. Following IOL implantation a heavy viscoelastic was used to deepen the anterior chamber and then injected near the angle for 360 degrees (without touching the trabecular meshwork) to break the PAS. No surgical instrument was used to physically break the PAS. Upon completion of VGP, automated irrigation with balanced salt solution to remove the viscoelastic was performed. RESULTS: Mean IOP reduced from 52.1 to 14.1 mmHg by Phaco-VGP at 6-months review. 14/15 patients were free of glaucoma medications at 6-month review. All angles showed exposure of the trabecular meshwork over 360 degrees postoperatively without evidence of residual synechiae. No untoward complications were observed in any patient. CONCLUSION: VGP may have a role in controlling IOP effectively and safely in patients with refractory ACAG. It produces a large drop in the IOP and opening of the angle. It is a relatively simple technique to learn and we would recommend its use in the eyes of all patients who have had ACAG and are undergoing cataract extraction.     

Argon laser iridoplasty: a primary mode of therapy in primary angle closure glaucoma.

Argon laser iridoplasty was performed in 40 eyes of 33 patients of primary angle closure glaucoma. There were 12 male and 21 female patients. The mean ages of the male and female patients were 51 years and 48.4 years respectively. Forty eyes were divided into two groups. Group I consisted of ten eyes of subacute angle closure glaucoma and group II included thirty eyes of chronic angle closure glaucoma. Argon laser iridoplasty was performed with Coherent 9000 model using laser settings of spot size 200 micron, duration 0.2 second and power 0.7 watt. A total of 80 spots were applied over 360 degree circumference. The intraocular pressure control (below 22 mm Hg) was achieved after iridoplasty in all the eyes (100%) in group I, where as in group II the intraocular pressure was controlled in 70% eyes. The follow up period varied from 3 months to one year with a mean of eight months. The success rate with iridoplasty was directly related to the extent of peripheral anterior synechiae, optic disc cupping and presence of visual field changes.     

Progression rate to primary angle closure following laser peripheral iridotomy in primary angle-closure suspects: a randomised study

AIM: To report the progression rate (PR) to primary angle closure (PAC) following laser peripheral iridotomy (LPI) in PAC suspects (PACS). METHODS: Prospective, randomized controlled interventional clinical trial conducted at the Handan Eye Hospital, China. Totally 134 bilateral PACS, defined as non-visibility of the posterior trabecular meshwork for ≥180 degrees on gonioscopy were randomly assigned to undergo LPI in one eye. Gonioscopy and Goldmann applanation tonometry were performed prior to, on day 7 and 12mo post LPI. RESULTS: Eighty of 134 patients (59.7%) could be followed up at one year. The mean intraocular pressure (IOP) in treated eyes was 15.9±2.6 mm Hg at baseline, 15.4±3.0 mm Hg on day 7; 16.5±2.9 mm Hg at one month, and 15.5±2.9 mm Hg at 12mo; the IOP in untreated eyes was similar (P=0.834). One or more quadrants of the angle opened in 93.7% of the LPI treated eyes, but 67.0% (53/79) remained closed in two or more quadrants. The PR to PAC in untreated eyes was 3.75% and one developed acute angle-closure glaucoma (AACG); the PR to PAC in treated eyes was 2.5% and none had developed peripheral anterior synechia (PAS) or AACG. CONCLUSION: LPI can open some of the occludable angle in the majority of eyes with PACS, but 67% continue to have non-visibility of the trabecular meshwork for over 180 degrees.     

Ocular biometry in occludable angles and angle closure glaucoma: a population based survey

Aim: To compare ocular biometric values in a population based sample of eyes with occludable angles, angle closure glaucoma, and normal subjects. METHOD: 2850 subjects from a population based glaucoma prevalence study underwent complete ocular examination including indentation gonioscopy. Ocular biometry was performed in all subjects classified to have occludable angles (n = 143); angle closure glaucoma (n = 22), and a random subgroup of 419 normal subjects. Ocular biometry readings between the groups were compared and statistically analysed using "t," "z," and Mann-Whitney U tests. RESULTS: The mean age among subjects with occludable angles (54.43 (SD 9.53) years) and angle closure glaucoma (57.45 (8.5) years) was significantly higher (p<0.001) than normal subjects (49.95 (9.95) years). Axial length was shorter (p<0.001) in the occludable angle group (22.07 (0.69) mm) compared to the normal group (22.76 (0.78) mm). Anterior chamber depth (ACD) was shallower (p<0.001) among subjects with occludable angles (2.53 (0.26) mm) than normal subjects (3.00 (0.30) mm). Lens thickness (LT) was greater (p<0.001) in people with occludable angles (4.40 (0.53) mm) compared to normal subjects (4.31 (0.31) mm). No significant difference was noted in axial length, ACD (p = 0.451), and LT (p = 0.302) between angle closure glaucoma and occludable eyes. CONCLUSION: South Indian eyes with angle closure glaucoma and occludable angles seem to have significantly shorter axial lengths, shallower anterior chambers and greater lens thickness compared to the normal group.     

Comparative evaluation of bimatoprost monotherapy in primary chronic angle closure and primary open angle glaucoma eyes: a three-year study.

AIMS: The aim of this study was to compare the long-term efficacy of bimatoprost 0.03% monotherapy in primary open angle glaucoma (POAG) versus primary chronic angle closure glaucoma (PCACG) eyes. METHODS: A total of 55 consecutive primary adult glaucoma patients on bimatoprost monotherapy were prospectively evaluated in this 3-year, open-labeled, uncontrolled study. The primary outcome was the evaluation of a difference in the response to therapy of POAG eyes, as compared to PCACG eyes over a follow-up of 3 years. RESULTS: In the POAG group, the mean intraocular pressure (IOP) at the 36-month followup was found to be increased by 2.10 (+/-3.90) mmHg (confidence interval [CI], 0.975-4.185), compared to the mean IOP at 1 month (P = 0.047). In the PCACG group, the mean IOP at the 36-month follow-up was increased by 3.66) (+/- 3.34) mmHg (CI, 6.241-1.092), compared to the mean IOP at 1 month (P = 0.011). This upward drift in IOP was higher in the PCACG group, compared to the POAG group, but this was not statistically significant (P = 0.54). Patients with POAG and PCACG showed a 50% and 40% chance of having an IOP of <18 mmHg with bimatoprost monotherapy (P = 0.23), respectively, at the 3-year follow-up. CONCLUSIONS: This study showed that bimatoprost 0.03% monotherapy significantly lowers IOP in both POAG and PCACG eyes over a period of 3 years, though its efficacy appeared to decrease over time, to a similar extent, in both groups.     

Immediate diode laser peripheral iridoplasty as treatment of acute attack of primary angle closure glaucoma: a preliminary study

PURPOSE: To study the efficacy and safety of diode laser peripheral iridoplasty as a first-line treatment of acute primary angle-closure glaucoma (PACG) without the use of systemic anti-glaucoma medications. PATIENTS AND METHODS: Nine consecutive patients with acute PACG were recruited into the study. Each patient received topical pilocarpine (4%), timolol (0.5%), apraclonidine (1%), and immediate diode laser peripheral iridoplasty as primary treatment. The intraocular pressures (IOPs) 15, 30, and 60 minutes after diode laser peripheral iridoplasty were documented by Goldmann applanation tonometry. RESULTS: The mean IOP of this group of patients was reduced from 66.3 +/- 9.7 mm Hg, before diode laser peripheral iridoplasty, to 36.6 +/- 16.4 mm Hg at 15 minutes, 26.3 +/- 12.6 mm Hg at 30 minutes, and 18.9 +/- 8.4 mm Hg at 60 minutes after diode laser peripheral iridoplasty. In seven of the nine patients, the corneal edema cleared up 1 hour after diode laser peripheral iridoplasty. In the remaining patient, the cornea cleared up 12 hours after diode laser peripheral iridoplasty. No significant complications were encountered. CONCLUSION: Diode laser peripheral iridoplasty, together with topical antiglaucoma medications without adjunctive systemic carbonic anhydrase inhibitors and hyperosmotic agents, appeared to be effective and safe in controlling the IOP in acute PACG.     

Screening for amblyopia in preschool children: Results of a population-based,randomised controlled trial

INTRODUCTION The rationale for preschool vision screening programmes has recently been questioned. Evidence about the effects of early treatment is needed, but it is not known how early the target conditions can reliably be detected. In this study, an intensive programme comprising several different screening methods, used at different ages up to 37 months, was compared with the usual practice of visual surveillance and ad hoc referrals.

METHODS Two groups were randomly selected from children in a population birth cohort study. The control group (n = 1461) received visual surveillance only. The intervention group (n = 2029) was offered in addition a programme of regular visual assessments by orthoptists testing visual acuity, ocular alignment, stereopsis and non-cycloplegic photorefraction.

RESULTS The intervention group programme yielded more children with amblyopia (1.6% vs. 0.5%, p < 0.01), and was more specific (95% vs. 92%, p < 0.01), than the control programme. The individual components of the intervention programme were compared. The cover test and visual acuity tests were poorly sensitive until the children were 37 months, but were always >99% specific. Photorefraction was more sensitive than acuity testing at all ages below 37 months, with specificity >95% at 31 and 37 months.

CONCLUSIONS Photorefraction would have detected more children less than 37 months of age with straight-eyed amblyopia than did visual acuity testing, but with more false positives. At 37 months, photore-fraction plus a cover test would have been comparable in effectiveness to visual acuity testing plus a cover test.