Ignite Creation Date:
2024-05-05 @ 4:58 PM
Last Modification Date:
2024-10-26 @ 9:26 AM
Study NCT ID:
NCT00350428
Status:
COMPLETED
Last Update Posted:
2006-10-24
First Post:
2006-07-07
Brief Title:
Laser Iridotomy Versus Phacoemulsification in Acute Angle Closure
Sponsor:
Singapore National Eye Centre
Organization:
Singapore National Eye Centre
Study Overview
Official Title:
Angle Closure Laser Iridotomy Versus Phacoemulsification Study ACLIPS- A Study of Acute Primary Angle Closure Glaucoma Comparing Two Treatment Modalities Laser Peripheral vs Phacoemulsification With Posterior Intraocular Lens Implant
Status:
COMPLETED
Status Verified Date:
2004-10
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This is a randomised controlled clinical trial to compare laser peripheral iridotomy LPI and primary phacoemulsification with intra-ocular lens implantation phacoIOL in the treatment of acute primary angle-closure glaucoma APACG Following successful medical lowering of raised intra-ocular pressure IOP and control of intraocular inflammation patients presenting to Singapore National Eye Centre and Singapore General Hospital with acute primary angle-closure glaucoma who meet the eligibility are randomised to one of the two treatment arms laser peripheral iridotomy and primary phacoemulsification with intra-ocular lens implantation These patients will be monitored closely for 2 years post-operatively
Detailed Description:
AIMS
The objective of this study is to conduct a randomised controlled clinical trial to compare LPI and primary phacolIOL in the treatment of APACG
The specific aim is to compare long-term IOP control in patients who undergo LPI with patients who undergo primary phacoIOL At the same time the following will be studied
1 To evaluate the safety of these two techniques for the treatment of APACG
2 To assess the development of PAS
3 To establish if LPI and primary phacoIOL are as effective in preventing the recurrence of acute attack in eyes with APACG
TREATMENT PLAN
Initial Medical Treatment
Patients with APACG will be treated initially for the acute attack with medical treatment The initial treatment is standardized to the following
1 Intravenous acetazolamide Diamox 500 mg stat
2 Oral acetazolamide 250 mg tid to qid with Span K 12 g om
3 Topical beta-blocker Timolol 05 bid or Brimonidine bid if beta-blockers are contra-indicated
4 Topical pilocarpine 4 qid
5 Topical steroids
6 Intravenous mannitol 20 at 1-2gkg at 4 hours after initiation of treatment if IOP is not reduced by 20 of initial IOP unless contra-indicated due to systemic disease eg Congestive heart failure
7 A second infusion of intravenous mannitol 20 at 2gkg at 12 hours after initiation of treatment if IOP is still not reduced by 20 of initial IOP
Response to Initial Treatment and Evaluation of Cataract
Patients are divided into 2 categories based on IOP after 24 hours of initiation of medical treatment a APACG with IOP 30 mmHg b APACG with IOP 30 mmHg
Patients with IOP 30 mmHg are evaluated clinically for the presence of cataract and further divided into those with cataract and those without cataract Patients with cataract are defined as those with best corrected visual acuity equal or less than 615 due to lens opacity in the opinion of a consultant grade ophthalmologist
Note Eyes with intumescent cataract phacomorphic glaucoma subluxated lens or anterior chamber depth differing by more than 03 mm are excluded
Eligible patients with informed consent are randomised
Laser Peripheral Iridotomy
1 In addition to the consultants LPI may be performed by registrars senior registrars and fellows who have observed and been taught by the glaucoma consultants and are deemed to be able to perform the procedure to a high standard
2 LPI is performed when the cornea is sufficiently clear usually within 72 hours following the lowering of the IOP medically
3 Technique for LPI to be standardized to sequential argon-Nd-YAG Laser PI
4 LPI should be sited at the superior nasal or superior temporal quadrant
5 The size of opening should be ³ 200mm
6 Following successful LPI topical eyedrops are continued for one week after the procedure Oral Diamox is discontinued
7 If the initial attempt is unsuccessful LPI at a second alternative site will be attempted If the second attempt remains unsuccessful patient will be considered as failure
Phacoemulsification with Intra-ocular Lens Implantation
1 All phacoemulsification with intraocular lens implantation are to be performed by consultant surgeons The panel of surgeons is formed from the group of co-investigators of this study
2 Phacoemulsification will be carried out between 5 to 7 days following the lowering of the IOP This is to allow for improved corneal clarity and reduction of intra-ocular inflammation
3 Gutt pilocarpine to be stopped on morning of operation
4 Pre-operative intravenous mannitol 20 at 1-2gkg is given 2 hours before the start of operation for those subjects with an IOP persistently raised above 21mmHg
5 Clear corneal incision
6 Viscoelastic agent to be injected 360 degrees circumferentially in the angles to deepen the anterior chamber There will be no other angle augmentation procedure using surgical instruments
7 A standard foldable IOL Type of IOL Acrysof MA60
8 Viscoelastic agent should be removed at the end of operation as far as possible
9 Oral Diamox 250 mg to be given stat post-operatively to reduce post-operative IOP spike
10 Following successful phacoemulsification with IOL implantation topical steroids and antibiotics are given Topical pilocarpine timolol and oral Diamox are stopped
IOP Lowering Medication
With regard to the determination of endpoints IOP evaluation will be considered from post-operative week 3 onward This is to allow for treatment of short-term surgery related IOP fluctuation
During the follow up period if a rise of IOP occurs ie IOP is between 22 to 24 mmHg on two occasions within one month or IOP ³ 25 mmHg on one occasion IOP lowering medication will be started
FOLLOW-UP
Post operation visit Window period
1st week 2 days 3rd week 5 days 6th week 7 days 3rd month 2 weeks 6th month to 2nd year 3 weeks
At the completion of the trial patient will receive normal clinical follow up of 4-6 monthly thereafter whilst the data will not be collected for this study
The primary objective of the study is to compare IOP control between these two treatment groups
STATISTICAL CONSIDERATIONS
Sample Size Calculation
The primary objective of the study is to compare long-term intra-ocular pressure IOP control between the two groups
The proportion of the subjects whose IOP are not successfully controlled in the LPI group can be estimated as 60 Aung T 2001 And the proportion of the subjects whose IOP are not successfully controlled in the phacoemulsification with intra-ocular lens implant group is about 20 under clinical estimation Hence the study needs a sample size of 70 patients Machin Campbell Fayers Pinol 1997 35 in each group This will be sufficient to detect a 60 vs 20 of proportion of the subjects who develop increasing IOP between two groups with a two-sided test with a power 90 while the significance level is controlled at 5
Statistical Analysis Plan
All statistical analysis will be carried out on an intention-to-treat basis In the event of lost to follow-up patients will still be included in the analysis for the duration that they are observed and the last IOP which is assessed before lost to follow-up will be used for data analysis
To compare long-term IOP control between two treatments Pearson χ2 test or Fishers exact test will be used The evaluation of the incidence of recurrence of an acute attack in eyes with APACG will be carried out using Fishers exact test Logistic regression will be carried out to adjust for relevant covariates
The time interval for the subsequent increase in IOP to occur after LPI or phacolIOL is to be recorded Kaplan-Meier life table analysis can be applied to assess the survival time failure being defined as any need for further glaucoma treatment of two groups and Log rank test will be used to compare the two survival curves In addition The Cox regression will be used to adjust for covariates where applicable
An interim statistical analysis will be carried out after all patients have completed 6 months follow-up
REFERENCES
1 Acton J Salmon JF Scholtz R Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma J Cataract Refract Surg 1997 Jul-Aug236930-4
2 Aung T Ang LP Chan SP Chew PT Acute primary angle-closure long-term intraocular pressure outcome in Asian eyes Am J Ophthalmol 200113117-12
3 Chylack LTJ Wolfe JK Singer DM et al The Lens Opacities Classification System III Arch Ophthalmol 1993111831-836
4 Fleiss JL Statistical methods for rates and proportions New YorkWiley 19812nd edition
5 Greve EL Primary angle closure glaucoma extracapsular cataract extraction or filtering procedure Int Ophthalmol 1988123157-62
6 Gunning FP Greve EL Uncontrolled primary angle closure glaucoma results of early intercapsular cataract extraction and posterior chamber lens implantation Int Ophthalmol 1991 Jul154237-47
7 Gunning FP Greve EL Lens extraction for uncontrolled angle-closure glaucoma long-term follow-up J Cataract Refract Surg 1998 Oct24101347-56
8 Ho T Fan R Sequential argon-Yag laser iridotomies in dark irides Br J Ophthalmol 1992 76329 -331
9 Hoffer KJ Axial dimensions of the human cataractous lens Arch Ophthalmol 1993 1117914-8
10 Hong C Kitazawa Y Tanishima H Influence of argon laser treatment of glaucoma on corneal endothelium Japan J Ophthalmol 1983274567-74
11 Ishikawa H Ritch R Liebmann J Quantitative assessment of the anterior segment using Ultrasound Biomicroscopy Current Opinions In Ophthalmology 200011133-139
12 Lim L Seah SKL Lim ASM Comparison of argon laser iridotomy and sequential argon laser and NdYAG laser iridotomy in dark irides Ophthalmic surgery and lasers 199627492-95
13 Lowe RF Aetiology of the anatomical basis for primary angle-closure glaucomabiometrical comparisons between normal eyes and eyes with primary angle-closure glaucoma Br J Ophthalmol 1970 543161-9
14 Lowe RF Primary angle-closure glaucoma a review of ocular biometry Aust NZ J Ophthalmol 1977 59
15 Lowe RF Clinical types of primary angle-closure glaucoma Aust NZ J Ophthalmol 198816245-50
16 Obstbaum SA Glaucoma and intraocular lens implantation J Cataract Refract Surg 198612257-61
17 PavlinCJ FosterFS Ultrasound biomicroscopy in glaucoma Review Acta Ophthalmologica - Supplement 19927-9
18 Roberts TV Francis IC Lertusumitkul S Kappagoda MB Coroneo MT Primary phacoemulsification for uncontrolled angle-closure glaucoma J Cataract Refract Surg 2000261012-16
19 Teekhasaenee C Ritch R Combined phacoemulsification and goniosynechialysis for uncontrolled chronic angle-closure glaucoma after acute angle-closure glaucoma Ophthalmology 1999 Apr1064669-74
20 Wishart PK Atkinson PL Extracapsular cataract extraction and posterior chamber lens implantation in patients with primary chronic angle-closure glaucoma effect on intraocular pressure control Eye 19893 Pt 6706-12
The objective of this study is to conduct a randomised controlled clinical trial to compare LPI and primary phacolIOL in the treatment of APACG
The specific aim is to compare long-term IOP control in patients who undergo LPI with patients who undergo primary phacoIOL At the same time the following will be studied
1 To evaluate the safety of these two techniques for the treatment of APACG
2 To assess the development of PAS
3 To establish if LPI and primary phacoIOL are as effective in preventing the recurrence of acute attack in eyes with APACG
TREATMENT PLAN
Initial Medical Treatment
Patients with APACG will be treated initially for the acute attack with medical treatment The initial treatment is standardized to the following
1 Intravenous acetazolamide Diamox 500 mg stat
2 Oral acetazolamide 250 mg tid to qid with Span K 12 g om
3 Topical beta-blocker Timolol 05 bid or Brimonidine bid if beta-blockers are contra-indicated
4 Topical pilocarpine 4 qid
5 Topical steroids
6 Intravenous mannitol 20 at 1-2gkg at 4 hours after initiation of treatment if IOP is not reduced by 20 of initial IOP unless contra-indicated due to systemic disease eg Congestive heart failure
7 A second infusion of intravenous mannitol 20 at 2gkg at 12 hours after initiation of treatment if IOP is still not reduced by 20 of initial IOP
Response to Initial Treatment and Evaluation of Cataract
Patients are divided into 2 categories based on IOP after 24 hours of initiation of medical treatment a APACG with IOP 30 mmHg b APACG with IOP 30 mmHg
Patients with IOP 30 mmHg are evaluated clinically for the presence of cataract and further divided into those with cataract and those without cataract Patients with cataract are defined as those with best corrected visual acuity equal or less than 615 due to lens opacity in the opinion of a consultant grade ophthalmologist
Note Eyes with intumescent cataract phacomorphic glaucoma subluxated lens or anterior chamber depth differing by more than 03 mm are excluded
Eligible patients with informed consent are randomised
Laser Peripheral Iridotomy
1 In addition to the consultants LPI may be performed by registrars senior registrars and fellows who have observed and been taught by the glaucoma consultants and are deemed to be able to perform the procedure to a high standard
2 LPI is performed when the cornea is sufficiently clear usually within 72 hours following the lowering of the IOP medically
3 Technique for LPI to be standardized to sequential argon-Nd-YAG Laser PI
4 LPI should be sited at the superior nasal or superior temporal quadrant
5 The size of opening should be ³ 200mm
6 Following successful LPI topical eyedrops are continued for one week after the procedure Oral Diamox is discontinued
7 If the initial attempt is unsuccessful LPI at a second alternative site will be attempted If the second attempt remains unsuccessful patient will be considered as failure
Phacoemulsification with Intra-ocular Lens Implantation
1 All phacoemulsification with intraocular lens implantation are to be performed by consultant surgeons The panel of surgeons is formed from the group of co-investigators of this study
2 Phacoemulsification will be carried out between 5 to 7 days following the lowering of the IOP This is to allow for improved corneal clarity and reduction of intra-ocular inflammation
3 Gutt pilocarpine to be stopped on morning of operation
4 Pre-operative intravenous mannitol 20 at 1-2gkg is given 2 hours before the start of operation for those subjects with an IOP persistently raised above 21mmHg
5 Clear corneal incision
6 Viscoelastic agent to be injected 360 degrees circumferentially in the angles to deepen the anterior chamber There will be no other angle augmentation procedure using surgical instruments
7 A standard foldable IOL Type of IOL Acrysof MA60
8 Viscoelastic agent should be removed at the end of operation as far as possible
9 Oral Diamox 250 mg to be given stat post-operatively to reduce post-operative IOP spike
10 Following successful phacoemulsification with IOL implantation topical steroids and antibiotics are given Topical pilocarpine timolol and oral Diamox are stopped
IOP Lowering Medication
With regard to the determination of endpoints IOP evaluation will be considered from post-operative week 3 onward This is to allow for treatment of short-term surgery related IOP fluctuation
During the follow up period if a rise of IOP occurs ie IOP is between 22 to 24 mmHg on two occasions within one month or IOP ³ 25 mmHg on one occasion IOP lowering medication will be started
FOLLOW-UP
Post operation visit Window period
1st week 2 days 3rd week 5 days 6th week 7 days 3rd month 2 weeks 6th month to 2nd year 3 weeks
At the completion of the trial patient will receive normal clinical follow up of 4-6 monthly thereafter whilst the data will not be collected for this study
The primary objective of the study is to compare IOP control between these two treatment groups
STATISTICAL CONSIDERATIONS
Sample Size Calculation
The primary objective of the study is to compare long-term intra-ocular pressure IOP control between the two groups
The proportion of the subjects whose IOP are not successfully controlled in the LPI group can be estimated as 60 Aung T 2001 And the proportion of the subjects whose IOP are not successfully controlled in the phacoemulsification with intra-ocular lens implant group is about 20 under clinical estimation Hence the study needs a sample size of 70 patients Machin Campbell Fayers Pinol 1997 35 in each group This will be sufficient to detect a 60 vs 20 of proportion of the subjects who develop increasing IOP between two groups with a two-sided test with a power 90 while the significance level is controlled at 5
Statistical Analysis Plan
All statistical analysis will be carried out on an intention-to-treat basis In the event of lost to follow-up patients will still be included in the analysis for the duration that they are observed and the last IOP which is assessed before lost to follow-up will be used for data analysis
To compare long-term IOP control between two treatments Pearson χ2 test or Fishers exact test will be used The evaluation of the incidence of recurrence of an acute attack in eyes with APACG will be carried out using Fishers exact test Logistic regression will be carried out to adjust for relevant covariates
The time interval for the subsequent increase in IOP to occur after LPI or phacolIOL is to be recorded Kaplan-Meier life table analysis can be applied to assess the survival time failure being defined as any need for further glaucoma treatment of two groups and Log rank test will be used to compare the two survival curves In addition The Cox regression will be used to adjust for covariates where applicable
An interim statistical analysis will be carried out after all patients have completed 6 months follow-up
REFERENCES
1 Acton J Salmon JF Scholtz R Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma J Cataract Refract Surg 1997 Jul-Aug236930-4
2 Aung T Ang LP Chan SP Chew PT Acute primary angle-closure long-term intraocular pressure outcome in Asian eyes Am J Ophthalmol 200113117-12
3 Chylack LTJ Wolfe JK Singer DM et al The Lens Opacities Classification System III Arch Ophthalmol 1993111831-836
4 Fleiss JL Statistical methods for rates and proportions New YorkWiley 19812nd edition
5 Greve EL Primary angle closure glaucoma extracapsular cataract extraction or filtering procedure Int Ophthalmol 1988123157-62
6 Gunning FP Greve EL Uncontrolled primary angle closure glaucoma results of early intercapsular cataract extraction and posterior chamber lens implantation Int Ophthalmol 1991 Jul154237-47
7 Gunning FP Greve EL Lens extraction for uncontrolled angle-closure glaucoma long-term follow-up J Cataract Refract Surg 1998 Oct24101347-56
8 Ho T Fan R Sequential argon-Yag laser iridotomies in dark irides Br J Ophthalmol 1992 76329 -331
9 Hoffer KJ Axial dimensions of the human cataractous lens Arch Ophthalmol 1993 1117914-8
10 Hong C Kitazawa Y Tanishima H Influence of argon laser treatment of glaucoma on corneal endothelium Japan J Ophthalmol 1983274567-74
11 Ishikawa H Ritch R Liebmann J Quantitative assessment of the anterior segment using Ultrasound Biomicroscopy Current Opinions In Ophthalmology 200011133-139
12 Lim L Seah SKL Lim ASM Comparison of argon laser iridotomy and sequential argon laser and NdYAG laser iridotomy in dark irides Ophthalmic surgery and lasers 199627492-95
13 Lowe RF Aetiology of the anatomical basis for primary angle-closure glaucomabiometrical comparisons between normal eyes and eyes with primary angle-closure glaucoma Br J Ophthalmol 1970 543161-9
14 Lowe RF Primary angle-closure glaucoma a review of ocular biometry Aust NZ J Ophthalmol 1977 59
15 Lowe RF Clinical types of primary angle-closure glaucoma Aust NZ J Ophthalmol 198816245-50
16 Obstbaum SA Glaucoma and intraocular lens implantation J Cataract Refract Surg 198612257-61
17 PavlinCJ FosterFS Ultrasound biomicroscopy in glaucoma Review Acta Ophthalmologica - Supplement 19927-9
18 Roberts TV Francis IC Lertusumitkul S Kappagoda MB Coroneo MT Primary phacoemulsification for uncontrolled angle-closure glaucoma J Cataract Refract Surg 2000261012-16
19 Teekhasaenee C Ritch R Combined phacoemulsification and goniosynechialysis for uncontrolled chronic angle-closure glaucoma after acute angle-closure glaucoma Ophthalmology 1999 Apr1064669-74
20 Wishart PK Atkinson PL Extracapsular cataract extraction and posterior chamber lens implantation in patients with primary chronic angle-closure glaucoma effect on intraocular pressure control Eye 19893 Pt 6706-12
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| SQGL05 | None | None | None |