Topical glaucoma medication with a teal cap? Prostaglandin analogues – Xalatan® (latanoprost) 0.005% qd – Travatan®(travoprost) 0.004% qd – Lumigan® (bimatoprost) 0.03% qd

Mechanism of action: Prostaglandin analogues Enhances uveoscleral outflow.

Topical glaucoma medication with a yellow cap? non-selective beta blockers 0.50% – Timoptic® (timolol) – Betagan® (levobunolol) β2 selective beta blockers 0.50% – Betoptic S® (betaxolol)

Topical glaucoma medication with a blue cap? non-selective beta blockers 0.25% – Timoptic® (timolol) – Betagan® (levobunolol) β2 selective beta blockers 0.25% – Betoptic S® (betaxolol)

Mechanism of action of beta blockers? reduces aqueous production (by blocking beta-2 receptors on nonpigmented ciliary epithelium)

Topical glaucoma medication with a purple cap? α2 adrenergic agonists – Iopidine® (apraclonidine) 0.5% tid 1.0% bid – Alphagan-P® (brimonidine) 0.1% 0.15% 0.2% bid or tid

Mechanism of action for α2 adrenergic agonists decreases aqueous production increases uveoscleral outflow “Both kinds of glaucoma treatment!”

topical glaucoma medication with a green cap? Cholinergic agonists (miotics) – pilocarpine (0.25% -- 10%) 2% or 4% most often. – carbachol – echothiophate

Mechanism of action for cholinergic agonists increases trabecular outflow may increas uveoscleral outflow

Topical glaucoma medication with an orange cap? carbonic anhydrase inhibitors (CAIs) – Trusopt® (dorzolamide) 2% – Azopt® (brinzolamide) 1%

Mechanism of action for carbonic anhydrase inhibitors decreases aqueous production

Glaucoma medications that increase outflow Uveoscleral: – prostaglandins – α2 adrenergic agonists Trabecular: – cholinergic agonists / miotics

Glaucoma medications that reduce aqueous production β blockers α2 adrenergic agonists carbonic anhydrase inhibitors

“Discussion” points for every glaucoma patient: “controlling a risk factor (high eye pressure) for glaucoma” “in hopes to prevent vision loss” “no guarantee that vision loss will not occur” “like controlling (blood pressure) a risk factor for heart attack and stroke”

Glaucoma standard of care dilation with retinal biomiscropy Goldmann tonometry visual fields gonioscopy pachymetry photography (debatable) OCT/GDx/HRT

OHTS  goals of study Ocular Hypertension Treatment Study Evaluate safety / efficacy of topical glaucoma medications to prevent or delay congenital open angle glaucoma (COAG) in patients with high IOP identify baseline demographic and clinical factors predict which patients will develop COAG

Ocular Hypertension Treatment Study (OHTS) OHTS  Enrollees patients with: – high IOP – normal visual fields (VF) – normal discs patient randomly assigned to medical treatment or observation patient monitored: – VF q 6 months – fundus photos q year – endpoint of COAG: VF evidence disc evidence or both VF and disc evidence

Ocular Hypertension Treatment Study (OHTS) OHTS  results COAG patients: – 55% diagnosed via disc changes without VF changes – 20% reduction in IOP decreased incidence of COAG by 50% at 5 years – black people developed COAG at significantly higher rate

Ocular Hypertension Treatment Study (OHTS) OHTS  Important risk factors for glacomatous damage in ocular hypertensives higher IOP old age large C/D greater pattern standard deviation thin central cornea thickness (CCT)

Ocular Hypertension Treatment Study (OHTS) OHTS  central corneal thickness (CCT) findings patients with CCT less than 555 are 3x more likely to develop POAG Much bigger risk factor than: – race – family history – refractive error – general health Recommendation: pachymetry as standard part of evaluation of ocular hypertensive patients.

Ocular Hypertension Treatment Study (OHTS) OHTS  Guidelines IOP: – or below  low risk – < IOP <  moderate risk – above  high risk CCT (pachymetry): – above 588  low risk – 555 < CCT < 588  moderate risk – 555 or below  high risk vertical C/D – 0.3 or less  low risk – 0.3 < C/D < 0.5  moderate risk – 0.5 or above  high risk

In glaucoma, NFL damage precedes… field loss and disc changes 5 year, 50% “rule”  50% of NFL is lost before a VF will reveal a defect. “we are in the business of preventing any vision loss”

Instruments commonly used to manage patients with glaucoma HRT2 – Heidelbert Retinal Tomograph Stratus OCT – Optical Coherence Tomography from Zeiss Humphrey GDx-VCC nerve fiber analyzer (with variable corneal compensator from Laser Diagnostic Technologies)

HRT, OCT, GDx factoids image the optic disc and/or retinal NFL each has strengths & weaknesses useful for glaucoma suspects  moderate glaucoma patients NOT helpful for advanced glaucoma patients cost: HRT < GDx < OCT

Optic nerve imaging  considerations imaging reimbursable at least once a year, HOWEVER, cannot be reimbursed for fundus photos & imaging on same day. results need to be used within a larger clinical context! – ONH tissue, VF defects and imaging should all correlate & “make sense”

HRT strengths & “considerations” The HRT utilizes confocal scanning laser ophthalmoscopy Strengths – shows topography of optic nerve – detects patient progression – confirms nerve size – evaluates cupping “Considerations” – accuracy depends on drawing contour line correctly the first time. – probably not the best for assessing thickness of RNFL

OCT strengths & “considerations” OCT uses optical back scattering of light to compute tomographic images based on amount of incident light reflected by tissue. Strengths – accurately measures RNFL thickness – correlates highly with VF loss & disc damage – reproducible – image quality monitored during test – awesome for macular holes, edema  CNV mgmt – reason why less fewer FLANs done at UMSL “Considerations” – automatically generated disc contour lies can be somewhat inaccurate – does not determine progression – difficult to determine how much change is clinically significant – requires dilated pupil, minimal media opacity

GDx strengths & “considerations” GDx uses a scanning laser polarimeter Strengths – measures RNFL – very reliable – portable – can do undilated – media opacities least likely to interfere Considerations – image quality cannot be measured during test

GDx NFL analysis Gives ‘NFI’ number: – 0—30  normal, low probability of glaucoma – 31—70  glaucoma suspect – 71—100  high probability of glaucoma The NFI number does NOT indicate severity or progression of glaucoma.