Optometry Landmark Studies

DRCR.net Protocol U

Compared IV steroids to IV Anti VEGF, this study demonstrated that in patients with DME both have the same efficacy however steroids are associated with higher risk therefore anti VEGF is preferred.

DRCR.net Protocol I

Compared Ranibizumab to macula grid laser and Ranibizumab in the treatment of DME. This study showed Ranibizumab monotherapy or combination therapy provided superior visual outcomes compared to macula grid laser alone.

DRCR.net Protocol S

In patients with PDR, this study compared initial PRP to initial ranibizumab. Both are equally as effective however if the patient has macula edema Anti VEGF will treat both NV and DME. PRP however is preferred if the patient is likely to be lost to follow up.

DRCR.net Protocol T

For eyes with visual impairment due to DME it compared Aflibercept to Ranibizumab and Bevacizumab and demonstrated for eyes with VA better than 6/12 there is no difference in visual outcomes however for eyes worse than 6/15 Aflibercept had superior outcomes.

DRCR.net Protocol V

For eyes with centre involving DME compared grid laser with deferred aflibercept with IV aflibercept with deferred laser. It was found that observing until VA is worse than 6/12.

UKPDS

This study had 2 arms, it assessed the effect of BP control and glucose control in patients with T2DM. It demonstrated the ideal BP was 140/80 and that glucose control had no effect on mortality however it was shown to reduce microvascular complications by 25%

ETDRS

All eyes had a low risk of severe vision loss (SVL - classified as less than 6/240), even with severe NPDR the risk was only reduced from 3.2% to 2.8%. Additionally Aspirin had no effect on DR or DME development.

DRS

Assessed Argon Laser and Xenon laser in PRP for the treatment of PDR, this showed a 50% reduction in severe vision loss at 2 years. Both were associated with constriction of visual field however xenon laser was worse than argon laser.

RESTORE

Compared the efficacy of laser with ranibizumab and laser in the treatment of DME in T1 and T2DM, this showed a improved VA gain in the Ranibizumab and combination group compared to laser monotherapy in patients with DME

WESDR

Epidemiological study looking at risk factors and found

*Long duration of diabetes

T1DM had 99% chance of DR , T2DM had 60% chance of DR

*Male

*High HbA1c

*Vascular Hypertension

*Smoking

*Pregnancy

DESIR

Aimed to test the hypothesis that smokers have a higher frequency of metabolic syndrome and found metabolic syndrome abnormalities was more prevalent in smokers than non smokers

DRIL (Disorganisation of Inner Retinal Layers)

OCT structural analysis revealed inner retinal thinning with some out retinal thinning, the presence of DRIL was associated with higher BMI and longer duration of diabetes

DCCT

Assessed conventional vs intensive glucose therapy in reducing long term eye disease and found 7% HbA1c was ideal. In this study, patients which were not responding to conventional therapy was switched to intensive glucose therapy. However when comparing patients which were in the intensive group from the start and patients which switched over -> Indicates compounding effect worsening with long duration.

OHTS

This study assessed the use of topical ocular hypotensive with OHT (IOP between 24 and 32mmHg) and found the progression to POAG was reduced from 9.5% to 4.4%.

AGIS

This study assessed the effectiveness of TAT and ATT in treatment of POAG. It found patients with advanced glaucoma should be treated with trabeculectomy as it had less VF loss. Patients which had diabetes or were African American showed more progression likely because diabetics are prone to fibrosis and African Americans have heavily pigmented irises and surgical abrasion liberates pigmented risking blockage of the angle.

CIGTS

Compared topical ocular hypotensive to trabeculectomy and found patients with IOP less than 18mmHg over 6 years had close to no change on visual field defect score. This shows that IOP was associated with reduced VF defect progression.

LIGHTS

Compared SLT to topical medical therapy and found that no differences were found in relation to QoL SLT provides better long term disease control than medical and also reduced the need for incisional glaucoma surgery over 6 years.

CNTGS

Aimed to determine if IOP reduction reduces the progression of VF loss by reducing IOP by 30%. This showed a reduction in progression of VF defects however only if cataract is not caused by the intervention.

HORIZON

Compared cataract surgery with intracanalicular microstent to cataract surgery alone and found that microstent with cataract surgery resulted in safe IOP reduction and reduced the need for post operative surgery

EAGLE

Clear lens extraction compared to prophylactic iridotomy and found QoL was superior to PI at 3 years however should only be done with the patient is

*Older than 50 years

*IOP greater than 30mmHg

*Or has Open Angle Glaucoma

ZAP

Prophylactic Iridotomy in patients with bilateral PACS and found PI should only be done on high risk AC patients and is not recommended on a population basis.

CVOS

Compared Macula Grid Laser to Observation in patients with macula edema secondary to CRVO of VA worse than 6/15

CRUISE

Compared 0.3% and 0.5% ranibizumab injections in treatment of ME secondary to CRVO. Both dosages had rapid improvement in VA

SCORE

This compared IVTA (1mg and 4mg) to the standard of care (Observation) and found that both IVTA injections showed superior VA outcomes in patients with macula edema

SCORE2

Compared IV bevacizumab and IV aflibercept both showed 18 VA letter improvement however aflibercept showed 54% complete resolution of macula edema compared to bevaizumab which had 28%

COPERNICUS/GALILEO

Patients with macula edema were given IV aflibercept or sham injections. the percentage of patients achieving 15 VA letter improvement was 56% to 12.3%

BVOS

Two outcomes,

1. Efficacy of macula grid laser in ME treatment compared to no treatment

2. Efficacy of sectoral PRP compared to control

It found macula grid laser for gold standard at the time

Sectoral PRP is gold standard for prevention of NV and vitreous haemorrhage but should not be done prophylactically