126 eyes (63 with glaucoma, 63 controls) of 90 patients older than 40 years underwent measurement of peripapillary retinal nerve fibre layer (RNFL) thickness by OCT and GDx, and assessment of ONH structural parameters (HRT). Discriminant analysis and neural network was applied to photo grading, HRT global parameters, OCT 12-sector RNFL thickness, and GDx summary parameters. Measurements were made of RNFL thickness by 30° sectors (OCT, GDx) and HRT rim area in 6 standard sectors.

Discriminant analysis results are shown in table 2. Stereophotography, HRT, and OCT distinguished the controls from patients with glaucoma significantly better than GDx (ROC area p < 0.05). The sensitivity and specificity for the neural network analysis was 81% and 92%, respectively. Best agreement (k) was between photos/HRT (0.70) compared with photos/OCT (0.54), HRT/OCT (0.52), and HRT/GDx (0.52).

Table 2. Discriminant analysis results to distinguish early glaucomatous field defects

ROC area Sensitivity Specificity Optic nerve head stereophotographs 0.93 86% 92% Heidelberg retina tomograph 0.91 83% 89% Optical coherence tomography 0.90 78% 90% Scanning laser polarimetry 0.81 65% 83%

 

In conclusion, HRT and stereophoto-graphs distinguish healthy subjects from those with early glaucoma equally well and better than either OCT or GDx.

European Trials of Latanoprost or Timolol plus Dorzolamide in Open Angle Glaucoma

Alain Bron University
Hospital Dijon,
France

Dr Bron described an analysis of pooled data of 5 multicentre, randomised, 3-month, observer-masked trials to compare the efficacy and safety of latanoprost mono-therapy with dorzolamide combined with timolol. Patients currently using a b-blocker or dual therapy where one agent was a b-blocker were eligible after a 2 to 4 week run-in period with timolol 0.5% twice daily. Patients then either discontinued timolol treatment and received latanoprost monotherapy (n = 345) or continued with timolol and received dorzolamide add-on therapy (n = 352).

From an overall baseline of 22.8 mm Hg the mean intraocular pressure (IOP) reduction was 4.8 mm Hg (21%) for patients receiving latanoprost and 4.1 mm Hg (18%) for timolol plus dorzolamide-treated patients. A reduction in diurnal IOP of 25% was achieved in 39% of the latanoprost-treated patients compared with 26% of the timolol plus dorzolamide-treated patients. There were no marked differences between the 2 groups in the incidence of ocular and systemic events.

Dr Bron concluded that this meta-analysis provides further support for a switch to latanoprost monotherapy as an alternative to combined treatment with timolol plus dorzolamide.

Meta-analysis of 8 Global Studies Comparing Latanoprost With Timolol in Open Angle Glaucoma

Katarina Hedman
Pharmacia & Upjohn AB
Uppsala, Sweden

A pooled data analysis of 8 randomised, multicentre studies comparing the intraocular pressure (IOP) reducing effect of latanoprost 0.005% once daily and timolol 0.5% twice daily was performed. The studies were performed in the UK, USA, Scandinavia, Japan, The Philippines, Mexico, Korea, and China. The treatment time was 6 months in the UK, USA, and Scandinavian trials and 3 months in the other studies. 1213 patients with open-angle glaucoma or ocular hypertension (646 treated with latanoprost and 567 with timolol) completed the studies and were included in the analysis.

After 3 to 6 months' treatment, the diurnal IOP (mean ± SEM), from an overall baseline of 24.5 mm Hg, was significantly reduced by 8.2 ± 0.1 mm Hg in the group given latanoprost (p < 0.001) compared with 6.5 ± 0.1 mm Hg in the timolol-treated group (p < 0.001). The difference of 1.7 mm Hg between treatments was significantly in favour of latanoprost (p < 0.001). An IOP reduction of 30% or more was obtained by 60% of the latanoprost-treated patients compared with 34% of the timolol-treated patients. These researchers concluded that latanoprost was significantly more effective than timolol for reducing IOP in patients with glaucoma or ocular hypertension.

Height of Ciliary Body Face not Related to Latanoprost Efficacy

Robert Ritch New York Eye and Ear Infirmary New York, NY, USA

Dr Ritch described a study performed to assess the relationship between the intra-ocular (IOP) lowering efficacy of latanoprost 0.005% and angle anatomy as assessed by ultrasound biomicroscopy (UBM). 58 eyes of 58 patients with ocular hypertension or open angle glaucoma and no previous history of latanoprost treatment were enrolled in this prospective clinical trial. The positions of Schwalbe's line, scleral spur, and iris insertion were obtained by UBM.