Trabeculectomy using mitomycin C versus an atelocollagen implant: clinical results of a randomized trial and histopathologic findings.

PURPOSE: To assess the efficacy of trabeculectomy with a biodegradable Ologen™ implant (OLO) versus mitomycin C (MMC) in patients in a prospective randomized clinical trial. METHODS: In the MMC group (15 patients), trabeculectomy was performed according to standard protocols. In the OLO group (15 patients) after standard trabeculectomy, the implant was positioned on top of the scleral flap, and no MMC was applied. RESULTS: Mean preoperative intraocular pressure (IOP) levels (OLO: 28.0 ± 9.4; MMC: 23.9 ± 5.0 mm Hg; p = 0.21) and medication score (OLO: 3.4 ± 1.6; MMC: 3.6 ± 1.5; p = 0.56) were comparable in both groups. One year after surgery, the mean IOP was 15.9 ± 4.5 mm Hg in the OLO group (p < 0.01, 43% reduction) and 11.0 ± 2.6 mm Hg in the MMC group (p < 0.01, 54% reduction). The surgical success rate 12 months after surgery was 93.3% in the MMC group and 40% in the OLO group (p = 0.01). CONCLUSIONS: With the atelocollagen-glycosaminoglycan matrix OLO it was not possible to reach the surgical success rate and pressure reduction achieved in the MMC group.

Previous cyclodestruction is a risk factor for late-onset hypotony and suprachoroidal haemorrhage after glaucoma drainage device surgery.

AIM: To investigate whether previous cyclodestructive (eg, cyclophotocoagulation and cyclocryodestruction) procedures have any influence on the general outcome and pressure level after glaucoma drainage device (GDD) surgery. METHODS: Retrospective analysis of 110 consecutive patients who had undergone GDD (Baerveldt 250 mm(2) and 350 mm(2) implant, AMO, USA) surgery with a minimum follow-up of 3 months. The patients were divided into patients with previous cyclodestructive surgery before GDD surgery (I; 47 patients) and patients without previous cyclodestructive surgery (II; 63 patients). Intraocular pressure (IOP), medication score, best-corrected visual acuity and surgical treatments were recorded before and after drainage device implantation. RESULTS: Patients of group I had a mean preoperative IOP of 32.1 mm Hg and a mean medication score of 4.8; patients of group II had a mean preoperative IOP of 29.2 mm Hg (p=0.18) and a mean medication score of 4.9 (p=0.84). All patients who developed suprachoroidal haemorrhage (six cases) belonged to group I (6/47=12.8%), no patient of group II (0/63=0%) developed suprachoroidal haemorrhage (Fisher's test: p=0.01). Twelve patients developed late-onset (>6 weeks after GDD surgery) hypotony, nine of them belonging to group I (9/47=19.1%) and three of them to group II (3/63=4.8%) (Fisher's test: p=0.03). CONCLUSIONS: While taking potential bias arising from the retrospective nature of the study into consideration, a history of previous cyclodestructive procedures before GDD surgery seems to be a major risk factor for suprachoroidal haemorrhage and for late-onset postoperative hypotony.

Clinical use of a new position-independent rebound tonometer.

PURPOSE: To compare intraocular pressure (IOP) measurements obtained by rebound tonometry (Icare PRO tonometer), applanation tonometry (Goldmann and Perkins tonometry), and dynamic contour tonometry in the upright and the supine positions, and to investigate the influence of axial length and central corneal thickness. METHODS: Ninety-nine right eyes of 99 patients with glaucoma or suspect for glaucoma, admitted to our department between November 2010 and January 2011 to obtain an IOP profile including supine measurements, were included in our study. IOP measurements were obtained in an upright position using an Icare PRO rebound (RTPRO), a Goldmann applanation (GAT), and a Pascal dynamic contour tonometer (DCT). In the supine position, IOP measurements were taken using the RTPRO and a Perkins hand-held applanation tonometer (PAT). The means and SDs for all tonometers were compared. Agreement between the tonometers was calculated using the Bland-Altman method. RESULTS: The mean IOPs obtained in the upright position were 17.7 ± 8.0 mm Hg (RTPRO), 17.6 ± 7.8 mm Hg (GAT), and 19.9 ± 6.6 mm Hg (DCT). Correlation analysis of these data indicated a good correlation between IOP readings obtained using RTPRO and GAT (r=0.951; P<0.001), and RTPRO and DCT (r=0.897; P<0.001). Bland-Altman analysis revealed mean differences (bias) between RTPRO and GAT, and between RTPRO and DCT of 0.1 mm Hg and -1.8 mm Hg, with 95% limits of agreement of -3.6 to 3.8 mm Hg and -7.3 to 3.6 mm Hg, respectively. In the supine position, the mean IOPs were 19.2 ± 6.4 mm Hg using the RTPRO and 19.6 ± 6.2 mm Hg using the PAT. CONCLUSIONS: Measurements obtained with the RTPRO, either in the upright or in the supine position, show good correlation and agreement with those provided by applanation and dynamic contour tonometry. The study was registered with the DRKS (German Clinical Trials Register; http://www.germanctr.de; DRKS00000581).

A new rebound tonometer for home monitoring of intraocular pressure.

BACKGROUND: To compare intraocular pressure (IOP) measurements obtained by the Icare ONE rebound tonometer (RTONE) and the Goldmann applanation tonometer (GAT) in healthy persons and glaucoma patients in a prospective study, and to investigate the influence of central corneal thickness (CCT). METHODS: Measurements on 126 right eyes were obtained by three equally skilled ophthalmologists with each of the above-mentioned tonometers. In addition, patients measured their own IOP with the RTONE (RTONE(p)). The means and standard deviation for all tonometers were compared. Agreement between the tonometers was calculated using the Bland-Altman method. RESULTS: A total of 95 (75.3%) patients were able to perform correct self-tonometry. Mean IOPs obtained were 17.1 ± 5.9 mmHg (RTONE performed by ophthalmologist: RTONE (o)), 17.3 ± 5.6 mmHg (RTONE(p)) and 16.5 ± 5.1 mmHg (GAT). Correlation analysis indicated a good correlation between IOP readings obtained using RTONE(o) and RTONE(p) (ρ = 0.916; p < 0.001) and RTONE(o) and GAT (ρ = 0.901; p < 0.001). Bland-Altman analysis revealed a mean difference (bias) between RTONE(o) and RTONE(p), between RTONE(o) and GAT, and between RTONE(p) and GAT of -0.2, 0.6, and 0.8 mmHg, respectively, with 95% limits of agreement of -5.0 to 4.5, -4.4 to 5.6, and -4.6 to 6.1 mmHg, respectively. The difference between RTONE(o) and GAT significantly increased with increasing CCT (ρ = 0.004), with a 10% increase in CCT resulting in a 1.8% increase in the difference. CONCLUSIONS: Measurements obtained with the RTONE, either by an ophthalmologist or by the patient, showed an excellent correlation with those provided by applanation tonometry. RTONE generally tends to overestimate IOP compared to GAT readings and displays a dependence on CCT. This study was registered with the DRKS (German Clinical Trials Register; www.germanctr.de ; DRKS00000478).