Brett G. Bence, OD FAAO Northwest Eye Surgeons, PC … Conference/2017... · Informative visual for counseling ... Brett G. Bence, OD FAAO Northwest Eye Surgeons, PC Seattle, Washington

Brett G. Bence, OD FAAO

Northwest Eye Surgeons, PC

Seattle, Washington

• Leading cause of irreversible blindness in the world

• 60.5 million impacted in 2010

• Projections: almost 80 million by 2020

• Best strategy to manage?

Rochester Epidemiology Project

•Longitudinal retrospective study

•Olmsted County, Minnesota (Rochester)

•20% blind in one eye after 34 year follow-up period

Characteristics • Age at diagnosis of glau

• Gender – male

• Family Hx of glau

• Diabetes

• IOP at final visit

• Mean individual IOP range

• Normal VF at diagnosis

• % having filtration surgery

Blind (n=56) Non-blind (n=234)

• 69 ± 12 65 ± 14

• 36% 37%

• 21% 21%

• 4% 9%

• 16.3 mmHg 18.4 mmHg

• 9.9 mmHg 6.8mmHg

• 34% 75%

• 38% 14%

- Oliver, et.al, Am J Ophthal 2002 Jun;133(6):764-72

• Elevated IOP

( Harbin et al 1976; Kolker 1977; Anderson 1989; O’Brien et al 1991; Araie et al 1994; Quigley et al 1994; Gherghel

et al 2000; King et al 2000; Stewart et al 2000; The AGIS Investigators 2000; Kwan et al 2001).

• Large diurnal variations

(The AGIS Investigators 2000; Oliver et al 2002).

• Older age

(Quigley et al 1994; Hattenhauer et al 1998; Stewart et al 2000).

Kooner et al, Clinical Ophthalmology. 2008:2(4) 757-762.

• Advanced VF damage at diagnosis

(Harrington 1959; Kolker 1977; Grant and Burke 1982; Leski 1983; Quigley et al 1994; Oliver et al 2002; Chen 2003).

• Noncompliance

(Spaeth 1971; Grant and Burke 1982; Chen 2003).

• Late detection

(Spaeth 1971; Perkins 1978; Grant and Burke 1982; Fraser et al 1999).

Kooner et al, Clinical Ophthalmology. 2008:2(4) 757-762.

91 years old WF

Retired nurse; compliant on meds

36 years glau Dx

IOT Tmax 20 / 22; pachy 515/505; c/d 0.95 / 0.99

VFI (2014) OD 27%; OS not able/poor fixation

MD -20dB OD (20/50); OS (20/200)

OS trab; SLTx2 OU, Trav, dorzol OU

Patient declines further surgery

IOT fluctuated 10-16, generally near target of 12

Could OCT have been a harbinger for VF loss?

Risks: older, thin pachy, low BP, erratic, 30+ years Dx

“Frailty” factor, declining health, non-exudative AMD

“Enough is enough, no more surgery”

Tube implant?

Collaborative Normal Tension Glaucoma Study (CNTGS)

♦Prior progression

♦Disc hemorrhage

♦Migraine

♦Female gender

Ocular Hypertension Treatment Study (OHTS)

•Thin corneas** (newly discovered)

•Older age

•IOT

•VF / PSD

•Larger vertical C/D ratio

•(not significant from OHTS: Fam Hx, race as an independent factor, diabetes)

Early Manifest Glaucoma Trial (EMGT)

•Increased IOT

♦1mmHg lowered avg IOT = 10% risk reduction of progression

•Low blood pressure

•((other vascular factors: sleep apnea, cardiac/CHF, anemia, severe

bl loss, migraine, Raynaud’s dz, systemic beta blockers at night,

etc.))

65 YO woman

OHTN age 56 - referred

Tmax OD and OS 24; pachy 495 / 504

C/D: R 0.65/0.6; L 0.75/0.6 inf thin rim

≈ Small discs

SLT OU; latanoprost + Cosopt OU

h/o migraine; FHx, compliant on meds

Thin corneas

≈ Early onset (mid 50s)

Migraine

Vertical rim thinning

(≈ Fam Hx, mother )

VF: severe focal loss early

•Absolute loss (0) at fixation (24-2) age 65

Next steps, target IOT?

Stabile or progressing?

VF subjectivity vs technology variability

Fixation errors? Signal strength? etc.

Structure-function correlation: perfect world

Structure tests helpful, SAP: gold standard

Redundancy of RGCs

Pre-perimetric loss of GCC and RNFL is leading the current

discussion

Do we treat prior to VF loss?

58% showed change first on OCT

34% showed change first with VF

7% showed concurrent change

Progression software

Emphasize: RNFL vertical quadrants

Instrument errors from retinal pathology

•E.g. ERM, thick ILM, retinal edema add to RNFL

Insurance reimbursement limits

Test/retest accuracy

•Heidelberg Spectralis: global error 5μm1

•Cirrus OCT: global (+/-) 4.5-5μm2

•Cirrus OCT: quadrant (+/-) 8μm2

•Cirrus OCT: clock hours (+/-) 12μm2

1 Ghasis FF, et.al. Reproducibility of Spectral Domain OCT…J Glau 2013 May

2 Mwanza JC, et.al. Reproducibility of Peripapillary RNFL…Invest Ophthal Vis Sci 2010;51:11:5724-30

OCT has “bottomed out”

Stratus OCT ≈ 45μm

Cirrus OCT ≈ 55μm •Vessels impact thicknesses

Even blind pts have OCT thickness

•Glial cells, supportive tissue, degenerated RNFL…

1. Event-based (Humphrey)

•Answers: is the VF changing?

•Statistically significant change, focal defects

•Good sensitivity ≈ early loss

•Changes in PD (less influence w/ cataract)

•24-2 > 30-2, both qualify for progression analysis

Uses EMGT criteria

3+ worsened test pts on 2 successive tests

•“Possible Progression”

3+ worsened test pts on 3 successive tests

•“Likely Progression”

≈96% sensitivity; ≈89% specificity

2. Trend-based

•Rate of change over time

•5 VFs over 3 years, includes 2 baseline

•Uses age-adjusted VFI; practical

•Asymmetric central weighting; RGCs > central 100

•Better with severe disease

Uses VFI

Age-corrected

Mirrors RGC loss

Disproportionate weighting

Central points carry more

influence (unlike MD)

A Heijl, et.al.,Effective Perimetry 2012, p68

1 VF/year: glau suspect, controled glau

2 VF/year: uncontrolled glau

3 VF/year: extreme cases, monocular patients

If medically indicated, submit beyond these parameters

66 YO WF

CC: “dark spot” in upper vision OS x 1 year

VA 20/25 OD and OS

IOT: 17 / 18; Tmax: 28 / 30; moderate variability, ↓compliance

Meds: Lumigan; Azopt bid OU

Pachy and gonio: normal

Cupping: 0.8 / 0.75 OD and OS, rim notch 6pm OU

SLE: no PDS, PXE, trace NS

• Signal strength

• Global

• Disc size

• RNFL deviation map

• Neuro-retinal rim

• Quadrant RNFL

2006-2009

2009-2014

July 2015 - OS

OS VFI: 63%

Absolute loss at fixation

VFI Rate of Progression 2008-2015:

Sup arcuate, nasal step

Absolute loss at fixation

VFI 88%

MD: -3.17

PSD 6.76

Early onset (mid-50s)

IOT high, variable

Poor compliance

Vertical thinning, normal-sized disc

Exponential decline of VF and RNFL

VFs, OCT correlate

Surgery?

•Young, meds - poor control, noncompliant, steep GPA slope

A strong tool for decision making

MD ≈ less short term fluctuation

May be less reliable in severe glau

Humphrey 24-2 or 30-2

Informative visual for counseling

VFI favored over MD

Acta Ophthalmologica Volume 91, Issue 1, pages 92-99, 15 FEB 2012

Wide variation in slope

EMGT

•Avg rate ↓ 1dB/yr entire cohort

♦30 years → ?

•LTG avg rate: 0.4dB / year

•Untreated PXG: > 3dB / year

- Nml VF to blind: +/- 10 yrs

Anders, H Acta Ophthal. 2013: 91: 92-99

IOT reduction

- CNTGS: 30% drop in IOT = 3 fold benefit

- EMGT: 5mmHg reduction = 50% decrease in glaucoma

- OHTS: Relative risk reduction of 50% if treatment

- AGIS: 12.3 avg IOT ≈ no change; ↓ 14 did best

Prioritize risk factors

•PXE, ↑IOT, thin cornea, ↑PSD, thin vertical rim, disc hem, FHx

•Vascular: low BP, sleep apnea, blood loss, migraine, Raynaud’s

Early detection

Trend analysis, 5 VFs, OCTs 1st 3 years

“I hate VFs”

VFI …. clinical utility, real-world

Limit progression to ↓1dB/yr (MD)

VFI above 50% / MD -15dB

OCT progression? Credible? Future SOC?

•Helps validate diagnosis when patients deny glau, VF outcome

Transparency, education – Re: risks

The doctor-patient team

•Narrative medicine

•What would you do if you were in the exam chair?

Brett G. Bence, OD FAAO

Northwest Eye Surgeons, PC

Seattle, Washington