CW
Connie M. Wu, MD
Glaucoma and Cataract Specialist
Glaucoma Pearls

Landmark studies in glaucoma

Scroll down for a list of important studies that have implications for clinical practice. This abbreviated list only includes take-away points relevant to clinical care. You are encouraged to access the full articles to gain a better understanding of each study’s findings.

Landmark studies in glaucoma main illustration

AGIS (1994)↗

  • lower IOP (<14) = slower VF progression
  • disparate treatment outcomes are associated with race
  • IOP fluctuation is an independent predictor of progression of OAG eyes with lower baseline IOPs, but not in those with higher baseline IOPs

EMGT (1999)↗

  • 25% decrease of IOP from baseline cuts risk of progression in half
  • Each 1mmHg IOP reduction from baseline = 10% reduction in progression risk
  • Risk factors for progression: higher baseline IOP, older age, PXF, bilateral disease, worse mean deviation, frequent disc hemorrhages
  • IOP fluctuation not found to be a risk factor

CNTGS (1998)↗

  • risk factors for NTG outside of IOP: female sex, migraines, disc hemorrhages
  • reducing IOP by 30% significantly reduces VF progression in NTG

LoGTS (1998)↗

  • brimonidine and timolol lower IOP similarly in NTG
  • brimonidine has higher allergy risk
  • brimonidine may reduce VF progression vs timolol in NTG

CIGTS (1999)↗

  • initial trabeculectomy had more risks than initial medication, resulted in similar IOP reductions, and similar visual field outcomes up to 9 years in patients with OAG (primary, pigmentary, PXF)
  • IOP fluctuation was a risk factor for progression in the medically treated group but not the trabeculectomy group
  • visual acuity and quality of life overall similar, but more symptoms reported in trabeculectomy group

OHTS (2002)↗

  • Identified 5-year risk factors for developing POAG: older age, larger vertical and horizontal cup-to-disc ratios, higher pattern standard deviation, higher baseline IOP, decreased central corneal thickness, African descent
  • Risk calculator for glaucoma
  • Treat high risk patients early, observe low risk patients with OHT

EGPS (2002)↗

  • Independently validated the PHTS prediction model for the development of POAG

TVT (2005)↗

  • For eyes with prior intraocular cataract or trabeculectomy surgery, a non-valved tube shunt is preferable to a trabeculectomy (durability of success, less post-op hypotony, fewer re-operations)
  • Note: excluded refractory glaucoma (e.g. NVG), MMC used for 4 min

AVB (2011)↗

  • Both Ahmed and Baerveldt successfully lower IOP and reduce medications
  • Ahmed lowers IOP immediately, Baerveldt lowers IOP more in the long run
  • 5 year IOP was 16 in Ahmed group, 13.6 in Baerveldt group on fewer meds
  • Baerveldt confers small risk of hypotony, not seen in Ahmed group

EAGLE (2011)↗

  • Clear-lens extraction showed greater efficacy and was more cost-effective than laser peripheral iridotomy, and should be considered an option for first-line treatment for primary angle closure with IOP >30 or primary angle closure glaucoma with IOP >21

LiGHT (2019)↗

  • SLT is clinically effective and cost effective first line treatment option for OHTN and POAG
  • SLT resulted in achievement of IOP target off drops in approximately 3 out of 4 treated patients over 3 years
  • Note: study looked at treatment-naïve eyes

ZAP (2019)↗

  • It is okay to observe most PACS eyes
  • only 1 in 20 untreated PACS eyes developed PAC in 6 years
  • Consider LPI in patients who have symptoms (headaches, eye pain suggestive of primary angle closure), a family history of angle closure, PAS, IOP elevation, a vaulted anterior lens, need routine dilated exams, or may not be able to follow up regularly