Comparing the Baerveldt and Paul Glaucoma Drainage Devices and Their Effects on the Corneal Endothelium

Oogziekenhuis Rotterdam160 enrolled

Overview

Rationale: The Baerveldt glaucoma drainage device (GDD) successfully reduces intraocular pressure but also involves a risk of corneal endothelial deterioration. Supposedly, the tip of a GDD tube with a thinner diameter, such as the Paul implant, will remain at a larger distance from the cornea and, thereby, cause less damage. Objective: To determine whether the Paul tube induces less damage to the corneal endothelium than the Baerveldt GDD. Study design: Randomized clinical trial. Study population: Phakic patients scheduled for surgical GDD implantation. Intervention: Either a Baerveldt or a Paul GDD implant. Main study parameters/endpoints: Endothelial cell density and tube position at 24 months. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The Paul GDD may have a less harmful effect on corneal endothelium. Otherwise, both GDDs will probably have a similar risk/benefit profile. The risks of study-related assessments are negligible, burden is low, extra time is about 5 x 1.5 h (total 7.5 h) in two years.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

160

Conditions

Glaucoma

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 100 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age \> 18 years. * Informed consent. * Caucasian ethnicity (to facilitate comparison of results with those of earlier work). Ethnicity will be based on self-reported origin of subject and/or parents. * Primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma. Exclusion Criteria: * History of intraocular surgery (e.g. vitrectomy, cataract surgery, cyclodestructive procedures etc). * History of ocular comorbidity (e.g. active uveitis, proliferative diabetic retinopathy). * Pseudophakia. * Functionally monocular patients. * Need for glaucoma surgery combined with other ocular procedures (i.e. cataract surgery, keratoplasty, or retinal surgery) or an anticipated need for additional ocular surgery. * Narrow anterior chamber angle. * Best corrected visual acuity less than 0.1. * Severe blepharitis.

Outcomes

Primary Outcomes

Change of endothelial cell density (ECD).

ECD will be assessed at the center of the cornea and close to the tube.

Time frame: Baseline and 2 years

Secondary Outcomes

Endothelial cell density (ECD).

ECD will be assessed at the center of the cornea and close to the tube.

Time frame: Baseline, 3, 6, 12, 24 months.

Intraocular pressure.

Time frame: Baseline, 1, 3, 6, 12, 24 months.

Orthoptic assessment.

Prism cover test: total deviation at 30 cm; Goldmann: monocular ductions in 8 directions starting from primary position, binocular field of single vision.