Glaucoma

Glaucoma Laser Trial (GLT), 1990 ⏩ and ⏩
n=271, 2y (+5)
Study question: New POAG: Argon laser trabeculoplasty versus medical tx. Then as needed tx/sx.
Study results: 44% of "ALT first" did not need additional tx, 70% controlled with topical tx (vs 30% controlled with timolol only, 66% controlled with sx/tx. Final IOP reduction better in the ALT group by 1.2mmHg. No major differences in changes in VA or VF.


Advanced Glaucoma intervention Study (AGIS), 1994-2004 ⏩
n=591, 11y
Study Question: Advanced glaucoma with MTMT for ATT (ALT, Trabeculectomy, Trabeculectomy) vs TAT. Study results: IOP <18 or averaging 14 did not progress - fluctuation in IOP had negative effect (see EMGT). TAT better for white patients, ATT better for African-American population.


Collaborative normal tension glaucoma study (CNTGS), 2003 ⏩ and ⏩
n=145, 5y
Study question: Progressing NTG patients (IOP<20): observation vs 30% IOP reduction (in any way). Study results: Excluding cataract formation, 80% of the tx arm did not progress vs 40% in the controls at 5 years. Risk factors from this study: Female gender, disc hemorrhages, migraine, thin cornea, large cup to disc ratio. Did not show effect: Family hx. Age, Maximal IOP or fluctuations in IOP.


Early Manifest Glaucoma Trial (EMGT), 2002 ⏩
n=255, 6y
Study question: Early glaucoma with IOP < 30. Laser trabeculoplasty plus topical betaxolol hydrochloride (n = 129) VS no initial treatment (n = 126)
Study results: Target IOP reduction of 25%, progression was 45% during tx and 62% for controls, reduction seen Significantly later in tx. Risk factor for progression: Splinter hemorrhage, low CCT, high IOP, bilaterality, low perfusion pressure. 10% risk for every 1mmHg. Fluctuations in IOP did not show effect (see AGIS). Rage of progression was worse (despite similar IOP) in PXF compared w\ POAG and the least in NTG. Low efficacy of laser when initial IOP is low (<15).


The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma (OHTS), 2002 ⏩
n=1636, 5y
Study Question: Progression to glaucoma in eyes with IOP 24-32, topcal tx vs observation.
Study results: probability of developing POAG was 4.4% in the medication group and 9.5% in the observation group. Risk factors: 1mmHg=10%, 10 years of age =22%, 0.2 PSD = 22%, 0.1 CD = 32%. 40ɥ Central corneal thickness = 81%. Diabetes was found to be "protective" factor. See EGPS below.



Results of the European Glaucoma Prevention Study (EGPS), 2005 ⏩

n=1081, 5y

Study question: IOP range 22-29 with normal optic disc and normal VF were assigned to either palcebo or dorzolamid.

Study results: Dorzolamide reduced IOP by 15% to 22% throughout the 5 years of the trial. However, placebo also reduced IOP by mean of 19% after 5 years. Therefor, EGPS failed to detect a statistically significant difference between medical therapy and placebo in reducing the incidence of POAG. Similar risk factors found in the OHTS (see above) but Diabetes was not protective.

Collaborative initial Glaucoma treatment study (CIGTS), 2009 ⏩
N=607, 13y
Study Question: POAG/PXFG. IOP>20. Topical Tx (1 drug, alternate 1 drug, 2 drugs, 3 drugs, ALT) vs Surgery as initial tx (Trabeculectomy, ALT, topical tx, Trabeculectomy, medication).
Study results: IOP lower in Sx - Average IOP reduced 38% Tx and 46% Sx. IOP fluctuations led to progression only in Tx. No difference in VF worsening (21% Sx vs 25% tx). Sx first better for advanced damage. Worse for patients with diabetes. Tx and Sx had similar QOL.

The Tube Versus Trabeculectomy Study (TVT), 2012 ⏩
n=212, 5y
Study question: Trabeculectomy versus Barveld for patients wtih MTMT (could be s/p trabeculectomy or cataract surgery). Study results: Both reduced IOP to low teens. Number of medications lower for tube. Visual loss similar. Trabeculectomy had higher rates of surgical failure and reoperation compared with tube-shunt surgery. Early complications were more frequent after trabeculectomy with MMC relative to tube-shunt surgery, but both procedures had similar rates of late postoperative complications and serious complications. See PTVT below.


The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes (AVB), 2016 ⏩
n=238, 5y
Study Question: Uncontrolled glaucoma w/ MTMT. Either s/p trabeculectomy or high risk for failure.
Study Results: Complication rate similar (Ahmed 63%, Bervald 69%). Significant higher  failure rate 53% in the Ahmed group vs 40% in the Baerveldt. Hypotony leading to failure only in Barveld. Ahmed 47% reduction in IOP vs 57% in Bervald. Medication use reduced 44% in the Ahmed group  vs 61% reduction in Bervald. Intervention rates similar (Ahmed 41%, Baerveldt 41%).

Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 1 Year of Follow-up (PTVT), 2018 ⏩
n=242, 1y on-going
See also TVT above. Study question: 350-mm2 Baerveldt glaucoma implant VS trabeculectomy with mitomycin C for uncontrolled glaucoma. No prior surgery.
Study results: The cumulative probability of failure (IOP > 21 mmHg or reduced by less than 20%, IOP <= 5, reoperation, or loss of light perception). 17.3% in the tube group and 7.9% in the trabeculectomy group. Trabeculectomy had significant lower IOP (12.4 vs 13.4) and less topical tx (0.9 vs 2.1) but more complications (41% vs 29% in the tube group). Serious complications requiring reoperation or producing a loss of 2 Snellen lines or more occurred in 1 patient (1%) in the tube group and 8 patients (7%) in the trabeculectomy group.
 

 

Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma sutdy (LiGHT), 2019 ⏩

n=718, 36m

Study Question: SLT (followed by topical medications as required) VS topical treatment as first line therapy for OAG or ocular hypertension.

Study Results: Life quality EQ-5D score was not statically different between the study arms. 74.2% of the SLT group required no drops to maintain intraocular pressure. SLT group were within target intracoluar  pressure at more visits (93·0% vs 91·3%). Target IOP was achieved 

without drops in 78.2% of the SLT group. More eyes in the drops group required glaucoma surgery. The groups had similar endpoint visual acuity, 

intraocular pressure, and visual field loss mean deviation

Abbreviations used on this page:
ALT - Argon laser trabeculoplasty
AVG - Average
CCT - central corneal thickness
DM - Diabetes mellitus
IOP - intraocular pressure
MMC - Mytomycin C
MTMT - maximal tolerated topical treatment
NTG - Normal tension glaucoma
POAG - primary open angle glaucoma
PXF - Pseudo-expholiation syndrome
PXFG- PXF glaucoma

SLT - Selective Laser Treatment
s/p - status post
Sx - Surgery
Tx - treatments
VA - visual acuity
VF - visual field
QOL - quality of life

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⭐ For additional information take a look at this AAO article: "Landmark Glaucoma Studies: Key Findings and Treatment Lessons"

⭐Another excellent list of glaucoma trials on EyeWiki

🚧 Please remember this page is still a work in progress, so additional studies will be add as we go on. If you have any remarks or suggestion please feel free to contact us using the form at the bottom of the page...