Clinical trial NCT03166566: Laminar Drainage Implant: Safety of a Novel Surgical Treatment for Refractory Glaucoma.
Official title: Laminar Drainage Implant: Safety of a Novel Surgical Treatment for Refractory Glaucoma.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Glaucoma
Blindness, Acquired
End-Stage Glaucoma
Glaucoma Traumatic
Keywords: glaucoma
glaucoma surgery
glaucoma drainage device
glaucoma implant
blindness
Lead sponsor: Federal University of Minas Gerais
Sponsor class: OTHER
First posted: 2017-05-25
Enrollment: 15
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DEVICE_FEASIBILITY

Brief summary: Purpose: To assess the feasibility of a surgical technique and present the preliminary safety results of a new glaucoma device devoid of a tube in painful blind eyes.

Methods: Fifteen end-stage glaucomatous eyes without light perception vision were treated with a novel laminar drainage implant. Intraocular pressure was measured preoperatively and up to 24 months after surgery using a Goldmann applanation tonometer. A scale ranging from 0 to 10 was used to evaluate ocular pain. Conjunctival hyperemia, discharge, erosion or retraction, aqueous humor leakage, corneal edema, hyphema, anterior chamber cells and depth, dislocation of the implant, and filtering bleb height were assessed by slit-lamp biomicroscopy. Anterior segment optical coherence tomography was also assessed.

Detailed description: Methods: Light perception was tested in the preoperative assessment. The following parameters were evaluated at the pre- and postoperative visits: morning Goldmann applanation tonometry; anterior segment biomicroscopy, gonioscopy, and eye pain intensity. Postoperative visits occurred on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years. The criteria for IOP reduction success were 15 mmHg and a 20% reduction compared to the baseline preoperative IOP. Biomicroscopy variables included the presence or absence of hyperemia, discharge, conjunctival erosion and retraction, aqueous humor leakage (Seidel test), corneal edema, hyphema, AC reaction and depth, and device dislocation. A shallow AC was considered a Spaeth classification grade of I or II and a flat AC was considered grade III. A filtering bleb height above the LDI profile was considered elevated; otherwise, it was classified as flat. Gonioscopy was performed preoperatively and postoperatively. Ocular pain intensity was assessed before and after surgery using a verbal Numerical Rating Scale ranging from zero to 10, with zero representing the absence of pain and 10 representing the worst eye pain ever felt before surgery.

Anterior segment optical coherence tomography (AS-OCT) (Visante®, Carl Zeiss Meditec®, Inc., Dublin, CA, USA) was performed postoperatively at the highest resolution (enhanced high-resolution corneal mode).

Reoperations to unblock the internal ostium were not considered failures; thereafter, the day of the second surgery was considered postoperative day 0.

LDI A human LDI was designed by one of the authors (S.J.) after a preclinical trial in rabbits with a similar device. It is a 150-µm-thick foil made of polymethylmethacrylate (PMMA), composed of three functional areas (Fig. 1): 1) the tip, which has a triangular shape and is inserted into the AC angle; 2) the intermediate portion, which has a rectangular shape (4.5 mm long × 4.0 mm wide) and is positioned inside a scleral tunnel; and 3) the posterior plate, which has a round shape (diameter = 12.5 mm) and is positioned between the sclera and conjunctiva. The LDI plate is positioned only 4.5 mm from the corneoscleral limbus and no allograft coverage is necessary. Its hypothetical mechanism of action is similar to those of popular GDIs and shunts the aqueous humor from the AC to the subconjunctival plate. The difference between their designs is the absence of a tube in the LDI. Thus, aqueous humor drainage is supposed to occur in the space between the inner walls of the scleral tunnel and LDI and/or thought is cleft.

LDI Surgery All surgeries were performed under local peribulbar anesthesia by the same surgeon (S.J.).

Statistical Analysis The sample size was calculated based on IOP standard deviation values from the first seven patients who were operated on (an internal pilot study) while considering 15 mmHg as the minimal clinically relevant difference to be detected.

Histogram inspection and Shapiro-Wilk tests were used to assess the assumption of the normality of variables. Wilcoxon's rank-sum test was used to compare the median pain intensity at each postoperative visit to that at the preoperative visit. Conjunctival hyperemia, AC cells, corneal edema, and hyphema variables were analyzed using McNemar's test. The comparison between the pre- and postoperative mean IOP was performed using Student's two-tailed paired t-test. Results were analyzed using SPSS® (Statistical Package for the Social Sciences) for Windows version 18.0 (IBM, Chicago, IL, USA) and the alpha level (type I error) was set at 0.05.

Eligibility criteria: Inclusion Criteria:

* patients aged 18 years or older with a painful blind eye refractory to clinical treatment and an intraocular pressure (IOP) ≥ 30 mmHg.

Exclusion Criteria:

* eyes with extensive conjunctival scarring, a disorganized anterior segment, or retinal detachment identified by ophthalmoscopy or B-scan ultrasonography.

Primary outcomes:
measure: Change for baseline of intra-ocular pressure (Goldmann applanation tonometry)
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
Secondary outcomes:
measure: Ocular pain intensity ratting change from baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Conjunctival discharge presence/absence change from baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Conjunctival erosion or retraction appearence after surgery
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Corneal edema presence change from baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Anterior chamber depth (gonioscopy) change from baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Optic coherence tomography (OCT) assessment qualitative study after surgery
timeFrame: from 6 months to two years after surgery.
measure: Filtering bleg height variation from baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
measure: Conjunctival hyperemia change comparing to baseline
timeFrame: on days 1, 3, 7, 14, and 30, once a month up to 6 months, and every 6 months from 6 months to 2 years.
Other outcomes:
Locations:
Study officials:
affiliation: Hospital São Geraldo-Universidade Federal de Minas Gerais
name: Sebastião C. Sobrinho, Md, Ph.D
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wolf A, Hod Y, Buckman G, Stein N, Geyer O. Use of Autologous Scleral Graft in Ahmed Glaucoma Valve Surgery. J Glaucoma. 2016 Apr;25(4):365-70. doi: 10.1097/IJG.0000000000000232.
citation: Hjermstad MJ, Fayers PM, Haugen DF, Caraceni A, Hanks GW, Loge JH, Fainsinger R, Aass N, Kaasa S; European Palliative Care Research Collaborative (EPCRC). Studies comparing Numerical Rating Scales, Verbal Rating Scales, and Visual Analogue Scales for assessment of pain intensity in adults: a systematic literature review. J Pain Symptom Manage. 2011 Jun;41(6):1073-93. doi: 10.1016/j.jpainsymman.2010.08.016.
citation: Christakis PG, Zhang D, Budenz DL, Barton K, Tsai JC, Ahmed IIK; ABC-AVB Study Groups. Five-Year Pooled Data Analysis of the Ahmed Baerveldt Comparison Study and the Ahmed Versus Baerveldt Study. Am J Ophthalmol. 2017 Apr;176:118-126. doi: 10.1016/j.ajo.2017.01.003. Epub 2017 Jan 17.
citation: Thieme H, Choritz L, Schuart C, Wecke T. [Tube versus trabeculectomy study]. Ophthalmologe. 2013 Aug;110(8):728-32. doi: 10.1007/s00347-013-2840-z. German.
citation: Aref AA, Gedde SJ, Budenz DL. Glaucoma Drainage Implant Surgery. Dev Ophthalmol. 2017;59:43-52. doi: 10.1159/000458485. Epub 2017 Apr 25.