Table 4.
Summary of the randomized clinical trials in glaucoma along with their Likert impact scores
| Study name (Likert score: 0–5)a |
Study population | Treatment and control groups | Outcome | Clinical impact |
|---|---|---|---|---|
| OHTS (4.47) | Patients with ocular hypertension (no glaucoma) | T: IOP lowered by 20% (using any means) C: Observation |
Neuroprotection when IOP was lowered (>24 mm Hg) in OHTN | Prophylactic lowering of IOP for OHTN patients Importance of CCT |
| EMGT (3.48) | Patients newly diagnosed with open-angle glaucoma | T: IOP lowered by 30% (using a β-blocker and ALT) C: Observation |
A decrease in progression of glaucoma by 50% when IOP was lowered | Importance of IOP lowering in slowing disease progression |
| CNTGS (4.13) | Normal-tension glaucoma patients | T: IOP lowered by 30% C: Observation |
No significant difference in glaucoma progression except when excluding cataract patients | Lowering of IOP not proven effective in normal-tension glaucoma patients |
| LoPGTSb | Normal-tension glaucoma patients | T: Brimonidine C: Timolol |
Similar IOP lowering-results, but with brimonidine-treated subjects less likely to progress | Superior results with brimonidine in normal-tension glaucoma patients |
| EGPS (2.69) | Patients with moderate risk for glaucoma | T: Dorzolamide C: Placebo |
No difference in glaucoma progression | Clinical impact lowest |
| GLT (3.39) | Newly diagnosed open-angle glaucoma patients | T: ALT (argon laser trabeculectomy) C: Timolol |
No difference in IOP-lowering effect at 1yr | Established long-term efficacy of ALT |
| AGIS (3.78) | Advanced glaucoma patients with failed medical therapy | T: ATT (argon laser trabeculoplasty, trabeculectomy, trabeculectomy) C: TAT (trabeculectomy, argon laser trabeculoplasty, trabeculectomy) |
Decreased failure rate (repeat intervention) for African Americans in the ATT arm | Trabeculectomy not necessarily superior to laser trabeculoplasty in advanced glaucoma |
| CIGTS (3.44) | Newly diagnosed open-angle glaucoma patients | T: Medical therapy C: Surgical trabeculectomy |
Effective lowering of IOP for both, with more adverse effects associated with surgery | Confirmed conservative approach to surgical management |
aThe Likert scale is a psychosomatic scale that gauges responses to questionnaire data and quantifies the clinical impact of each randomized clinical trial. Abbreviations used: T, treatment arm; C, control arm; OHTS, Ocular Hypertension Treatment Study; EMGT, Early Manifest Glaucoma Trial; CNTGS, Collaborative Normal Tension Glaucoma Study; LoPGTS, Low-Pressure Glaucoma Treatment Study; EGPS, European Glaucoma Prevention Study; GLT, Glaucoma Laser Trial; AGIS, Advanced Glaucoma Intervention Study; CIGTS, Collaborative Initial Treatment Study; OHTN, ocular hypertension; CCT, central corneal thickness.
bLikert score not available.