A Trial of China Laser and Surgery Study Glaucoma in Rural China

Glaucoma Clinical Trial

Official title:

The China Laser and Surgery Study : A Mixed Methods Study With an Random Control Trial Comparing Outcomes From Selective Laser Trabeculoplasty Versus Surgical Treatment (Trabeculectomy) for Glaucoma in Rural China .

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02955849
• Other study ID #: SLT in rural China
• Status: Completed
• Phase: Early Phase 1
• Start date: September 2016
• Est. completion date: December 2019

Study information

• Verified date: November 2016
• Source: Sun Yat-sen University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Aims and Objectives (Quantitative) Aim: To compare the effectiveness of selective laser trabeculoplasty with trabeculoplasty in lowering the intraocular pressure in patients with medically uncontrolled open angle glaucoma in rural China, taking into account the impact of patient acceptance of each type of treatment

Hypothesis: Mean intraocular pressure after treatment with selective laser trabeculoplasty will be lower than with surgery due to higher acceptance rates among patients randomized to receive this treatment and therefore treatment provided at an earlier stage of disease progression.

Description:

Glaucoma is one of the three leading causes of blindness in China. Although this condition can be controlled with medication to lower intraocular pressure , such treatment must continue over a patient's lifetime. This is not practical in resource-poor settings due to cost and inconvenience for patients. Trabeculectomy is the standard treatment offered in rural China but is rarely used because of the following issues:

1. need for hospitalization, which increases patient expense and inconvenience

2. high refusal rates by patients for all ocular surgery

3. high rates of infection due to poor quality instruments and material

4. need for multiple follow-up visits post-surgery (our earlier work shows a return rate of only 30% 1 month post-surgery among rural patients in China).

A viable alternative for patients in rural China is selective laser trabeculoplasty , based on the following advantages:

1. simplicity (done as a 5-minute out-patient procedure requiring only topical anaesthesia)

2. effectiveness (18-32% reduction in intraocular pressure, which is comparable to medication)

3. safety (complications are rare and do not include serious infectious as with trabeculotemy)

4. convenience (minimal follow-up, with one visit within 6 weeks post-surgery)

5. cost-effectiveness (compared to other glaucoma therapies in many settings)

6. acceptability to patients (due to low-cost out-patient care with easy follow-up).

Study Design (Quantitative) This phase of the proposed China Laser and Surgery Study research project is a multi-centre open-label pragmatic randomised controlled trial.

Expected timeline:

• Enrolment: 12 months

• Follow-up: 12 months

• Data analysis: 4 months

Patient Population and Setting: Patients presenting with glaucoma at rural hospitals (n=4) in Guangdong province, China, all of whom are currently capable of performing trabeculectomy surgery, and have been provided an selective laser trabeculoplasty machine and training in its use.

Sample Size: One hundred ninety patients (95 in each group) will be needed to obtain a power of 0.90, with a two-sided alpha of 0.05. Patients are the unit of randomization. Expected IOP difference between groups of 3.0 mm Hg + 4.0 mmg HG, and a correlation of 0.30 between baseline and final intraocular pressure, allowing for loss to follow up of 30%.

Baseline Data:

aseline data (to be collected prior to determination of eligibility and randomization but after obtaining informed consent) include the following:

• Presence or absence of relevant pre-existing health conditions (i.e., hypertension, diabetes, cardiovascular disease)

• Ophthamologic test results

• Best corrected visual acuity and presenting visual acuity in both eyes

• Intraocular pressure in both eyes

• Cup to disk ratio in both eyes

• presence or absence of visually significant cataract in both eyes; if cataract present in study eye, whether cataract surgery has already been performed

• degrees of visible Trabecular Meshwork in the study eye on gonioscopy without "dynamic gonioscopy"

• score on glaucoma knowledge test using a simple, previously validated questionnaire

• Demographic data

• date of birth or self-reported age in years

• sex

• Contact information

• Address

• mobile phone number where can be reached (own or neighbours, etc.)

• Socioeconomic status

• completed education in years

• wealth, as measured by ownership of items on a pre-determined list of 13 common household devices in China

• job title/description

• Level of difficulty traveling to hospital with eye clinic

• distance traveled

• time spent traveling

• direct or out-of-pocket costs for travel, meals, etc.

Main analyses:

• Following requirements for intention-to-treat analyses, we will measure mean intraocular pressure at 12 months comparing the two groups and adjusting for baseline intraocular pressure, including all subjects who accepted and refused treatment (primary analysis, unadjusted). We will also measure intraocular pressure as above, adjusting for cataract surgery, age, gender, prior use of medication, degrees of open angle in study eye at baseline, and severity of glaucoma (Cup to disk ratio) in study eye at baseline (primary analysis, adjusted). Both of the above analyses will be repeated using a per protocol approach (including only patients who accepted their assigned therapy, or secondary analysis).

• We will test for differences in baseline characteristics by study group with t-tests (for continuous variables) and Chi-square tests (for categorical variables). We will use generalized linear models with Poisson regression (for variables with binary outcomes) and linear regression (for variables with continuous outcomes) to estimate the relative risk for the intervention arm. Multiple imputation in Stata 13.1 (StataCorp, College Station, TX, USA) will be used to address missing data. All statistical analysis will be performed using Stata 13.1. A two-tailed P-value of <0.05 will be considered statistically significant.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 200
• Est. completion date: December 2019
• Est. primary completion date: December 2019
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• diagnosis of glaucoma (Cup to disk ratio, or CDR > 0.6 with optic nerve appearance and/or visual field findings consistent with glaucoma in the study eye)

• angle configuration > 180° of trabecular meshwork visible in the study eye

• no previous ocular incisional surgery or ocular laser treatment except refractive or cataract surgery in the study eye

• Best corrected visual acuity > 6/60 metres in both eyes

Exclusion Criteria:

• Intraocular pressure > 35 in the study eye

• Cup to disk ratio > 0.9 in the study eye

• Inability to give informed consent.

Related Conditions & MeSH terms

• Glaucoma

Intervention

Device:
• SLT laser
Patients will be offered initial SLT laser by doctors

Locations

Country	Name	City	State
China	Blindness Preventment and Treatment Department	Guangzhou	Guangdong

Sponsors (1)

Lead Sponsor	Collaborator
Sun Yat-sen University

Country where clinical trial is conducted

China, 

References & Publications (8)

Adekoya BJ, Akinsola FB, Balogun BG, Balogun MM, Ibidapo OO. Patient refusal of glaucoma surgery and associated factors in Lagos, Nigeria. Middle East Afr J Ophthalmol. 2013 Apr-Jun;20(2):168-73. doi: 10.4103/0974-9233.110612. — View Citation

Ang GS, Varga Z, Shaarawy T. Postoperative infection in penetrating versus non-penetrating glaucoma surgery. Br J Ophthalmol. 2010 Dec;94(12):1571-6. doi: 10.1136/bjo.2009.163923. Epub 2009 Nov 5. Review. — View Citation

Liang YB, Friedman DS, Wong TY, Zhan SY, Sun LP, Wang JJ, Duan XR, Yang XH, Wang FH, Zhou Q, Wang NL; Handan Eye Study Group. Prevalence and causes of low vision and blindness in a rural chinese adult population: the Handan Eye Study. Ophthalmology. 2008 Nov;115(11):1965-72. doi: 10.1016/j.ophtha.2008.05.030. Epub 2008 Aug 5. — View Citation

Liu T, Congdon N, Yan X, Jin L, Wu Y, Friedman D, He M. A randomized, controlled trial of an intervention promoting cataract surgery acceptance in rural China: the Guangzhou Uptake of Surgery Trial (GUSTO). Invest Ophthalmol Vis Sci. 2012 Aug 13;53(9):5271-8. doi: 10.1167/iovs.12-9798. — View Citation

Narayanaswamy A, Leung CK, Istiantoro DV, Perera SA, Ho CL, Nongpiur ME, Baskaran M, Htoon HM, Wong TT, Goh D, Su DH, Belkin M, Aung T. Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial. JAMA Ophthalmol. 2015 Feb;133(2):206-12. doi: 10.1001/jamaophthalmol.2014.4893. — View Citation

Realini T. Selective laser trabeculoplasty for the management of open-angle glaucoma in St. Lucia. JAMA Ophthalmol. 2013 Mar;131(3):321-7. doi: 10.1001/jamaophthalmol.2013.1706. — View Citation

Wittenborn JS, Rein DB. Cost-effectiveness of glaucoma interventions in Barbados and Ghana. Optom Vis Sci. 2011 Jan;88(1):155-63. doi: 10.1097/OPX.0b013e3181fc30f3. — View Citation

Zhang XJ, Liang YB, Liu YP, Jhanji V, Musch DC, Peng Y, Zheng CR, Zhang HX, Chen P, Tang X, Lam DS. Implementation of a free cataract surgery program in rural China: a community-based randomized interventional study. Ophthalmology. 2013 Feb;120(2):260-5. doi: 10.1016/j.ophtha.2012.07.087. Epub 2012 Oct 27. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Intraocular pressure	intraocular pressure in study eye 12 months after receiving treatment (laser or surgery); the intraocular pressure of patients refusing their allocated intervention will still be recorded at 12 months post-refusal and will be considered in the analysis; patients accepting the allocated treatment > 3 months after initial offer of treatment will be considered as having refused and their outcome intraocular pressure will be the last reading prior to treatment	12 months
Secondary	Visual quality of life	use the scale "NEI-VQ 25" to assess the patient's visual quality of life	12 months
Secondary	Satisfaction score	Using a Surgical Satisfaction Questionnaire previously validated in rural China	12 months
Secondary	Cataract surgery	Cataract surgery performed in conjunction with allocated treatment (Yes/No)	12 months
Secondary	Allocated treatment	use acceptance questionnaire form to calculate surgical receiving rate	12 months