Landmark glau studies

Monday, March 11, 13

Landmark Glaucoma Studies

Cesar A. Perez Jr MD DPBOClinical Associate Professor

UP-PGH

Philippine Glaucoma Society


Intro

• Alphabet Soup

• OHTS

• CIGTS

• TVT

• EMGT

• CNTGS

• AGIS


“Doctor, why do we need to put those expensive eye drops for glaucoma?”


OHTS

• Ocular Hypertension Study

- Aim: To determine if glaucoma drops delays or prevents glaucoma in ocular hypertensives


OHTS

• Ocular Hypertension Study

- 1,636 patients

- 10 years of follow-up

- Main Outcome Measures: AVFs and stereoscopic optic disc photos

Arch Ophthalmol 120: 701-713, 2002


OHTS Ocular Hypertension Study

• Entry criteria: ages 40 to 80; normal visual fields and normal optic discs; untreated IOP of 24 to 32 mmHg in one eye, 21 to 32 mmHg in fellow eye

• Initially randomized to:

- observation

- stepped topical medical regimen



• KEY FINDINGS

- First to demonstrate that lowering IOP delays/prevents glaucoma

- Identified risk factors in developing POAG



• First to demonstrate that lowering IOP delays/prevents glaucoma

- treated group: 4.4% developed POAG

- observation: 9.5%



• Identified risk factors in developing POAG

- IOP, age, central corneal thickness, vertical cup to disc ratio, PSD

- established low-, mid- to high-risk groups



• Lessons for Clinicians

- Take risk categories into account

- Consider observation before treatment in some patients




- Treat those with:

‣ older age

‣ high cup to disk ratio

‣ high PSD in AVFs

‣ thin corneas


“Doctor, I just learned I have glaucoma, which is better - drops or surgery?”


CIGTS Collaborative Initial Glaucoma Treatment Study

• Trabeculectomy vs drugs for initial therapy

- Effect on early diagnosed open-angle glaucoma of treatment with topical meds or trabeculectomy

Ophthalmology 106: 653-62, 1999


CIGTS

• Collaborative Initial Glaucoma Treatment Study

- 607 patients

- 5-9 years of follow-up

- Main Outcome Measure: AVFs



• Entry criteria: IOP of 20 mmHg or greater; optic nerve damage and / or visual field loss in one or both eyes

• Randomized initial treatment:

- with stepped topical medication

- trabeculectomy



• KEY FINDINGS

- Aggressive IOP targets yield results

- Quality of Life measured



• Aggressive IOP targets yield results

- 35% reduction from medication

- 48% reduction from surgery




- Consider surgery first in patients with moderate or advanced disease

- Keep IOP steady

- Major surgical complications are few




- Surgery resulted in:

‣ lower IOP

‣ more cataracts

‣ more ocular side effects

‣ initial decreased vision

‣ initial decreased visual field


“Doctor, I stopped my glaucoma medications, what will happen to my eyes?”


EMGT Early Manifest Glaucoma Trial

• Treat IOP early, follow progress closely

Arch Ophthalmol 120: 1268-1279, 2002.


EMGT

• Early Manifest Glaucoma Trial

- 255 patients

- 7 to 11 years of follow-up

- Main Outcome Measures: AVFs and optic disc photos



• Entry criteria: median visual field mean deviation of –4 dB and median IOP of 20 mmHg

• Randomized to:

- initial treatment with a selective beta-blocker and ALT

- left untreated until signs of progression appeared



• KEY FINDINGS

- Treatment effect validated

- Every 1 mmHg reduction matters

- Disease progression is variable

- Mean IOP is vital



• Lessons for clinicians

- Follow progression closely; reset target as needed

- Exfoliation as a risk factor

- Strive for the lower IOP




- Aggressive treatment if:

‣ pseudoexfoliation

‣ bilateral disease

‣ older patient

‣ higher IOP

‣ worse mean deviation

‣ disc hemorrhage


“Doctor, why do I have glaucoma if my pressure is 20 mmHg?”


CNTGS Collaborative Normal-Tension Glaucoma Study

• IOP reduction important even for normotensives

Curr Opin Ophthalmol. 2003;14(2):86-90.


CNTGS

• Collaborative Normal-Tension Glaucoma Study

- 260 patients

- > 5 years of follow up

- Main Outcome Measures: AVF



• Entry criteria: eyes with either progressive NTG or NTG with field defects impinging on the point of fixation

• Randomized to receive:

• no therapy

• IOP lowering by 30 percent with medication (pilocarpine or carbonic anhydrase inhibitor), laser, filtering surgery or a combination



• KEY FINDINGS

- IOP plays a role in NTG

- Cataract confounders

- Over half of patients did not progress without treatment at 5 years




- Distinguish between progressive and non-progressive disease

- Surgery may not be necessary




- Aggressive treatment if:

- female patient

- presence of migraine

- disc hemorrhages


“Doctor, which treatment is better for my glaucoma - trabeculectomy or laser?”


AGIS Advanced Glaucoma Interventional Study

• Aim: To assess the outcome of sequences of laser and surgical interventions in eyes that have failed on medical treatment

Controlled Clinical Trials 15(4): 299-325, 1994.


AGIS

• Advanced Glaucoma Interventional Study

- 591 patients

- 8-11 years of follow up

- Main Outcome Measures: sustained decrease of visual field and visual acuity



• Entry criteria: patient on maximum tolerated medical therapy, baseline VA score 56 or better in the study eye, baseline AGIS visual field score of 1 to 16


• ALT > trabeculectomy > trabeculectomy (ATT)

• trabeculectomy > ALT > trabeculectomy (TAT)



• KEY FINDINGS

- Reducing IOP slows visual field loss

- Many patients achieved stability

- Race affected outcomes




- Take race into account when choosing therapy

- Blacks should have laser first

- Whites should have trabeculectomy first


“Doctor, which surgery is better for my glaucoma - trabeculectomy or tube?”


TVT

• Trabeculectomy vs Tube Study

- 212 patients

- 5 years of follow-up

- Main Outcome Measures: IOP, VA, AVF, surgical complications, treatment failures

Am J Ophthalmol. 2009;148(5):670-684.


TVT Trabeculectomy vs Tube Study

• Entry criteria: prior cataract or glaucoma filtering surgery and uncontrolled glaucoma with IOP of 18 mmHg to 40 mmHg on maximum tolerated medical therapy


• either tube shunt surgery and/or

• trabeculectomy with mitomycin C (MMC)



• KEY FINDINGS

- Trab vs. shunt: no clear winner

- Complications and failure rates




- Put tubes in armamentarium

- Assess patient’s unique needs


Recap

• Present glaucoma clinical practice guidelines have strong evidences

• Identification of risk factors, degree of disease and quality of life is key

• Customize treatment


Thank you for your attention :)


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