13.7  Glaucoma

GLT [lxix]

Glaucoma laser trial

Newly diagnosed OAG: No difference between ALT and drops (superseded by SLT). ALT as effective as timolol 0.5% at 7yrs

Spaeth, G.L. 1985. The Glaucoma Laser Trial (GLT). Ophthalmic Surg 16(4) 227-228.

EMGT [lxx]

Early Manifest Glaucoma Trial

Newly diagnosed OAG: Decreasing IOP by 25% reduces progression by 1/3 (ALT + betaxolol vs. nothing), 45% of treated still progressed. Treatment delayed progression by 18 months

Leske, M.C., Heijl, A., Hyman, L. et al. 1999. Early Manifest Glaucoma Trial: design and baseline data. Ophthalmology 106(11) 2144-2153.

CIGTS [lxxi]

Collaborative Initial Glaucoma Treatment Study (Early)

Newly diagnosed OAG: Initial treatment with drops or trab

Drops = trab for initial Rx of newly diagnosed OAG (regarding VF loss)

Trab lower IOP but higher risk vision loss and cataract progression

Individualised target IOP (medical, laser or surgery) reduces progression of OAG (fixed reduction inadequate)

(Reversibility of cupping) – more in surgery

Eyes with variability of IOP do better with surgery

Patients with advanced glaucoma do better with surgery

CNGTS [lxxii]

Collaborative Normal Tension Glaucoma Study

NTG: Decreased IOP by 30% by any means reduces progression by 2/3 (35% → 12%) [Pilo/ALT/Trab]

Risk factors for NTG prevalence (not progression): disc haemorrhage, female, migraine

AGIS [lxxiii]

Advanced Glaucoma Intervention Study

Advanced OAG: ALT vs. trabeculectomy

ALT superior for African-American, trabs superior for Caucasians

No progression if IOP always < 18 or little fluctuation

Eyes with early average IOP > 17.5 had worsening of VF progression compared with IOP < 14

OHTS [lxxiv]

Ocular Hypertension Treatment Study IOP 24-32 one eye, 21-32 other eye

Ocular Hypertension: Decreased IOP by any medication by 20% halves progression to OAG (10% → 5%) NNT = 20 Risk factors for progression:

  • Thin CCT <555um
  • Older age
  • Larger vertical CDR
  • ↑ IOP
  • Greater HVF PSD

Confirmed by European Glaucoma Prevention Study

Gordon, M.O., Beiser, J.A., Brandt, J.D. et al. 2002. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol 120(6) 714-720; discussion 829-730.

TUBE vs. TRAB [lxxv]

Primary trab failed or previous cataract surgery (NOT for secondary glaucoma)

Tube – lower failure rate, less additional surgery.

Both had equal IOP reduction and use of supplemental therapy

Can achieve low IOP with tubes (mean 14mmHg)

Gedde, S.J., Schiffman, J.C., Feuer, W.J. et al. 2012. Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up. Am J Ophthalmol 153(5) 789-803.e782.

EAGLE [lxxv]

CLE (clear lens extraction) vs LPI/drops/trab

PACG (IOP > 21) or PAC (IOP > 30) without cataract:

  • LPI, drops and trabeculectomy is still effective
  • CLE is better than standard of care from a QOL perspective
  • CLE gives: more significant IOP reduction, less drops, less surgery

UKGTS [lxxvii]

Lantanoprost vs placebo

Phase III for UK to approve xalatan:

  • Progression in 15% xalatan vs 26% placebo over 2 years (very short trial)
  • Time to progression faster in placebo group
  • ↓ IOP 3.8 with xalatan cf. 0.9 with placebo
  • Not all glaucoma patients need to be treated
  • Side effects, even in placebo group

Garway-Heath, D.F., Crabb, D.P., Bunce, C. et al. 2015. Latanoprost for open-angle glaucoma (UKGTS): a randomised, multicentre, placebo-controlled trial. Lancet 385(9975) 1295-1304.

LOGTS [lxxviii]

Brimonidone vs timolol

Used as evidence for neuroprotection but many problems with this study limit applicability

Consider brimonidine as a second-line agent in a patient who is progressing despite good IOP and surgery is not appropriate

High drop-out rate in brimonidine group due to side effects

PTVT [lxxix]

Primary Tube vs Trabeculectomy

1 year follow up. No prior glaucoma surgery. MMT

Trabeculectomy 59% complete success; Tube 14% complete success

3-year data suggests that trabeculectomy and tube both successful in reducing pressure. Tube may be better with higher starting IOP, trabeculectomy may result in overall lower IOP

Gedde, S.J., Feuer, W.J., Lim, K.S. et al. 2020. Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 3 Years of Follow-up. Ophthalmology 127(3) 333-345.

ZAP [lxxx,lxxxi]

Zhongshan Angle Closure Prevention Trial Efficacy of LPI in preventing PACG for PACS patients. Outcome = incidence of PAC (acute angle closure, raised IOP, and PAS) at 6 years

Significantly lower incidence of PAC for eye subject to LPI, although is incidence very low (~ 0.5%/yr). 4% reached primary endpoint in control vs 2% in LPI group.

Although LPI is protective it isn’t recommended for all PACS. Only Chinese patients aged 50 - 70

LiGHT [lxxxii]

SLT versus drops for first-line treatment of ocular hypertension and glaucoma

Target IOP set according to glaucoma severity

End point of Quality of life, also compared health costs

~ 75% at 36 months of SLT participants did not need drops

SLT more cost effective for the health system

Gazzard, G., Konstantakopoulou, E., Garway-Heath, D. et al. 2019. Selective laser trabeculoplasty versus drops for newly diagnosed ocular hypertension and glaucoma: the LiGHT RCT. Health Technol Assess 23(31) 1-102.


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