Global Risk Assessment Risk Assessment in Ocular Hypertension Michael Chaglasian, OD Illinois Eye Institute Illinois College of Optometry mchaglas@ico.edu What is global risk assessment? Estimates a patient s overall risk for onset and progression based on multiple rather than single risk factors Ideally based on evidence from well-controlled clinical trials and long-term studies How is it used? Helps guide treatment decisions for optimal patient care Girkin et al. Am J Ophthalmol.. 2004;138:S11-S18. S18. Risk Calculators Framingham Cardiovascular Risk Calculator 1998 Cardiovascular Medicine Pioneered Global Risk Assessment Demonstrated that risk assessment using multiple rather than individual risk factors could lead to improved patient outcomes Supported by large clinical trials Changed practice pattern from management to early detection and prevention Risk Assessment Tool for Estimating Your 10-year Risk of Having a Heart Attack Girkin et al. Am J Ophthalmol.. 2004;138:S11-S18; S18; Dzau et al. Am Heart J.. 1990;121:1244-1263. 1263. Risk Calculator First Version Slide Rule Version www.deverseye.org/grc_web/grc.cfm Adapted from Medeiros et al. Arch Ophthalmol.. 2005;123:1351-1360. 1360. 1
Risk Calculator Risk Calc: First Step Okay, Williams, we ll vote... how many here say the heart has four chambers? Medeiros, Arch Ophthalmol. 2005 Second Generation How Accurate is OHTS-EGPS Prediction Model for POAG? EGPS/OHTS Calculator The newest version of the calculator, the EGPS/OHTS, was developed from the manuscript by Gordon, et al. This calculator includes data from both the Ocular Hypertension Treatment Study and the European Glaucoma Prevention Study. This calculator does not include diabetes as part of the calculation. Ophthalmology 2007;114:10 19 Probability 0.36 0.32 0.28 0.24 0.20 0.16 0.12 0.08 0.04 0.00 Observed Predicted 1 2 3 4 5 6 7 8 9 10 Decile of Predicted 5-Year Risk Ophthalmology 2007;114:10 19 OHTS-EGPS Prediction Model Online OHTS Risk Calculator http://ohts.wustl.edu/risk/calculator.html http://ohts.wustl.edu/risk/calculator.html 2
Case 65 year old African American male presented to the Illinois Eye Institute for a general exam with a complaint of blurred vision at far and near. His medical history is significant for NIDDM, HTN. The patient s ocular history is remarkable for bifocal glasses. Family ocular is significant for glaucoma which his father had. Clinical Information BCVA was 20/20 OD, OS. SRx: -3.00 D.S. OD, -3.75 D.S. OS with +2.50 add OU. Pupils, EOM s and confrontation fields were normal OU. Slit lamp examination was significant for grade 1 nuclear sclerosis OU. The angles by von Herrick were 4+ deep OU. IOP: 24mmHg OD, 25 mmhg OS. Central corneal thickness: 501 OD, 504 OS. Disc Photos Left VFs Right GDx OHTS Risk Calculator 3
Risk Calculator Outcomes: Guide to Patient Management 5-Year Risk for Progression of OHTN Glaucoma Risk Level Range Recommendations Low 5% Monitor Moderate 5%-15% Consider treatment High 15% Treatment OHTS EGPS Limitations? A number of factors described as predictive in previous studies either did not add to the explanatory power of the OHTS EGPS pooled model or were not assessed in this study. These include: 1. Myopia, Disc Hemes 2. Diabetes 3. Race (?) 4. cardiovascular disease 5. family history of glaucoma 6. exfoliation syndrome and pigment dispersion Other Limitations Life Expectancy (LE) Risk for 50 yo is much higher OHTS RC is only 5yrs; LE is 28 yrs (75m/80f) Older Patient t @ 75 yrs LE is 12yrs not 3 yrs; Likely need to treat 85 yo patient: LE is 6 yrs Rate of Progression Key piece, currently not included Physicians Compared to Calculator The probability of developing glaucoma from ocular hypertension determined by ophthalmologists in comparison to a risk calculator. CONCLUSIONS: The ophthalmologists showed a high range of estimates for the probability of developing glaucoma in the same ocular hypertensive patients. This may lead to either under or over treatment of patients. Clinicians need a more exact method to determine the probability of glaucoma from ocular hypertension. Mansberger SL, J Glaucoma 15: 2006 Physicians Compared to Calculator The probability of developing glaucoma from ocular hypertension determined by ophthalmologists in comparison to a risk calculator. CONCLUSIONS: The ophthalmologists showed a high range of estimates for the probability of developing glaucoma in the same ocular hypertensive patients. This may lead to either under or over treatment of patients. Clinicians need a more exact method to determine the probability of glaucoma from ocular hypertension. Mansberger SL, J Glaucoma 15: 2006 24 OHTS 2010 Kass, et al. Arch Ophthalmol. 2010 4
OHTS 2010 OHTS 2010 Results Compare the two groups: Those treated from beginning of study (13yrs) with Those observed from the beginning and then treated (5.5 yrs) Is there a benefit to early treatment? 25 OHTS 2010 OHTS 2010 Editorial Found little evidence that delaying prophylactic treatment by 71 2 years increased the severity of visual field loss among those who subsequently developed glaucoma; minimally increased the likelihood of bilateral glaucomatous visual field loss. It may be ok to delay treatment for ALL OHTN until glaucomatous change is detected It probably still makes sense that young patients with lots of high risk factors should receive prophylaxis, while elderly patients with few risk factors should not. I, for one, will spend my time reminding people that there is nothing magic about an IOP of 21 mm Hg; it is merely 2 SD above the mean in some Western adult populations! Alfred Sommer, MD, MHS 28 Arch Ophthalmol. 2010 Cost of Over Treatment NNT Number Needed to Treat Number people treated, to prevent 1 person from developing the disease over 5 years NNT from OHTS = 42 (defined by VF defect) Cost = $242,000 (using PGA) To prevent 1 person from developing glaucoma Summary 1. Early treatment does help some individuals, particularly those at highest risk 2. There is little benefit of early treatment to those with low risk 3. Treatment t is safe and effective for most 4. Individuals continue to develop POAG throughout follow up 5. Self identified African Americans develop POAG at a higher rate than those with the same IOP. - Difference is related to baseline RFs (CCT) and not race per se. Mansberger. J Glaucoma 15:426, 2006 5