Practical approach to medical management of glaucoma DR. RATHINI LILIAN DAVID

Transcription

1 Practical approach to medical management of glaucoma DR. RATHINI LILIAN DAVID

2 Glaucoma is one of the major causes of visual loss worldwide. The philosophy of glaucoma management is to preserve the visual function and quality of life (QOL) of the individual. Providing maximum benefit with minimal side effects. Quigley HA. Number of people with glaucoma worldwide. Br J Ophthalmol. 1996;80: Foster PJ, Buhrmann R, Quigley HA, Johnson GJ. The definition and classification of glaucoma in prevalence surveys. Br J Ophthalmol. 2002;86:238 42

3 Principles of medical management Establish a diagnosis Establish a baseline IOP Set a target IOP Initiate therapy and lower IOP to target Maximum Medical Treatment Follow-up

4 Diagnosis

5 Establish a baseline IOP IOP being the prime suspect for causation of neuropathy, its reduction is the mainstay of Rx One time reading maybe misleading Diurnal variation test suspected NTG Asia Pacific Glaucoma Guidelines 2008

6 Target IOP Target IOP- defined as the level below which further ONH damage does not occur That IOP at which the sum of the HRQOL * from preserved vision and the HRQOL from not having side effects from treatment is maximum *Health Related Quality of life Jampel HD. Target pressure in glaucoma therapy. J Glaucoma. 1997;6:133 8 Roger Hitchings, FRCOphth, and James Tan, FRCOphth,J Glaucoma 2001 Vol 10, No 5 S Target Pressures

7 Asia Pacific Glaucoma Guidelines 2008 Asia Pacific Glaucoma Guidelines 2008

8 Limitations of target IOP Infrequent IOP measurement Fluctuation of IOP Inability to determine the level of IOP at which glaucoma damage occurred

9 Formulae Target Range = [Initial IOP x(1-initial IOP ) Z +Y ]+/- 1mm Hg 100 Z ONH damage severity factor Y- Burden of therapy factor ( e.g. : Baseline 30 mm Hg with mild ONH damage, in a healthy adult Target =30x(1-30/100)-1+0=19-21mm Hg ) Jampel HD. Target pressure in glaucoma therapy. J Glaucoma. 1997;6:133 8

10 Grading scale Value of Z and Y Z Optic nerve damage Y- Burden of therapy 0 Normal disc, normal visual field 1 Abnormal disc, normal visual field 2 Visual field loss not threatening fixation 3 Visual field loss threatening or involving fixation No effect on patient s QOL Small effect Moderate effect Large effect

11 Staging of glaucomatous damage Stage Disc Damage HVF Defects HVF 24-2 MD Early Mild glaucomatous disc damage, VCDR <0.65 Mild VF defects MD < 6 db Moderate Moderate glaucomatous disc damage, VCDR VF defects not within 5ºof fixation, Only one hemifield may have a point with sensitivity of <15 db within 5 ºof fixation MD 6-12dB Severe Advanced glaucomatous damage, VCDR >0.9 VF defects within 5º of fixation Points within the central 5º with sensitivity <15 db in both MD >12dB

12 Rule of thumb Mild glaucoma 20 % reduction in IOP from baseline Moderate glaucoma- 30% reduction in IOP from baseline Severe glaucoma 40% reduction in IOP from baseline

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14 Effect of ageing alone Slow rate of progression Older patient diagnosed with glaucoma Younger patient diagnosed with glaucoma Rapid rate of progression Patients with severe functional loss or younger patients with manifest disease should have more aggressive treatment and closer follow-up than patients with little or no risk European Glaucoma Society. Terminology and Guidelines for Glaucoma. 4th ed.

15 Trials The effectiveness of IOP lowering has been established in several well-designed prospective RCTs. The Early-Manifest Glaucoma Treatment Study (EMGTS) was designed specifically to evaluate the effect of IOP lowering on progression of glaucoma. Patients were either randomized to Laser trabeculoplasty and Betaxolol or no Rx, results showed that IOP reduction by at least 25% reduced progression from 62%to 45% in the treated group compared to the untreated group Heijl A, Leske MC, Bengtsson B, Hyman L, Bengtsson B, Hussein M, et al. Reduction of intraocular pressure and glaucoma progression: Results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002;120:

16 Leske et al reported that each mmhg of mean IOP lowering may decrease the risk of glaucoma progression by 10% High risk - Bilaterality - High Baseline IOP - PXF Leske MC, Heijl A, Hussein M, Bengtsson B, Hyman L, Komaroff E, et al. Factors for glaucoma progression and the effect of treatment:the early manifest glaucoma trial. Arch Ophthalmol. 2003;121:48 56

17 The Collaborative Initial Glaucoma Treatment Study (CIGTS) eyes were randomized to either no Rx or Rx(either medical or surgical ) the IOP was lowered by 30% Demonstrated equivalence of medical and surgical treatment. Among those treated 20% progressed, 80% of the patients survived; among those not treated 60% progressed and 40% did not progress. Feiner L, Piltz-Seymour JR. Collaborative Initial Glaucoma Treatment Study: A summary of results to date. Curr Opin Ophthalmol. 2003;14:106 11

18 In the Ocular Hypertensive study OHTS The relationship between IOP lowering treatment and conversion to POAG was as follows: in the treated group the mean IOP reduction was 22.5%, in the control group the decrease of IOP was 4.0%. At 60 months, 4.4% in treated eyes and 9% in controls developed POAG Risk Factors Thin CCT, Age,High CD Ratio, RNFLD 50% reduction of risk. Ocular Hypertension Treatment Study (OHTS) commentary Brian L. Lee, MD, and M. Roy Wilson, MD, MS Current Opinion in Ophthalmology 2003, 14:74 77

19 In the European Glaucoma Prevention Study designed to investigate whether onset of POAG can be prevented by treating OHT, one group randomized to be treated with Dorzolamide other group to placebo, Dorzolamide reduced IOP by 15-22%, at the completion of the study,there was no statistical difference between the 2 groups

20 According to the Advanced Glaucoma Intervention study AGIS, eyes with advanced glaucoma on MMT were randomized either to one of the two treatment sequences ( ATT vs TAT), eyes with average IOP <18 mm Hg on all visits over 6 years showed no visual field deterioration compared to the eyes with IOP >18 mmhg on fewer than 50 % of visits The Advanced Glaucoma Intervention Study (AGIS): 7. The Relationship Between Control of Intraocular Pressure and Visual Field Deterioration,AGIS Investigatos, AMJO,Oct 2000 VOL. 130, NO. 4 Review of recent publications of the Advanced Glaucoma Intervention Study Allen D. Beck, MD Current Opinion in Ophthalmology 2003, 14:83 85

21 Management Begins With Monotherapy First-Line Topical Agents for Glaucoma 1-4 Mechanism of action Average IOP reduction Prostaglandin Analogs Increase aqueous outflow β-blockers α 2 -Agonists Carbonic Anhydrase Inhibitors Reduce aqueous humor production Reduce aqueous humor production and increase outflow 20% 25% 20% Reduce aqueous humor production Dosing QD BID BID TID BID TID Key adverse effects Conjunctival hyperemia Lengthening/darkening of eyelashes Discoloration of iris, uveitis, macular edema Ocular irritation Dry eyes Systemic cardiac and respiratory effects Ocular irritation Dry eyes Allergic reaction Ocular irritation Dry eyes Burning sensation BID=twice a day; IOP=intraocular pressure; QD=once a day; TID=three times a day. 1. European Glaucoma Society. Terminology and Guidelines for Glaucoma. 4th ed. Savona, Italy: 2014; 2. Sambhara D, Aref AA. Ther Adv Chronic Dis. 2014;5(1):30-43; 3. Weinreb RN et al. JAMA. 2014;311(18): ; 4. American Academy of Ophthalmology Glaucoma Panel. Preferred Practice Pattern Guidelines. San Francisco, CA: 2010.

22 Treatment Algorithm

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24 HOW TO START MEDICAL THERAPY South East Asia Glaucoma Interest Group. Asia Pacific Glaucoma Guidelines. 3rd ed

25 Monotherapies May Not Sustain Target IOP Percentage of Patients Requiring 2 IOP-Lowering Medications >75% after 2 years Patients, % 40% by 5 years Ocular Hypertension Treatment Study (OHTS) (N=1636) 1 Collaborative Initial Glaucoma Treatment Study (CIGTS) (N=607) 2,3 1. Kass MA et al. Arch Ophthalmol. 2002;120(6): ; 2. Lichter PR et al. Ophthalmology. 2001;108(11): ; 3. Cantor LB. Ther Clin Risk Manag. 2006;2(4):

26 PRINCIPLES OF ADDING SECOND THERAPY If monotherapy is well tolerated and has IOP-lowering efficacy but has not achieved target pressure, consider adding or substituting a second agent Combine different mechanisms of action Consider challenges of multiple topical treatments Treatment complexity Adherence Washout Preservative exposure 1. European Glaucoma Society. Terminology and Guidelines for Glaucoma. 4th ed. Savona, Italy; 2014; 2. American Academy of Ophthalmology Glaucoma Panel. Preferred Practice

27 POTENTIAL BENEFITS OF FIXED COMBINATIONS } Single bottle for multiple drugs 1-5 } Potentially less complex regimen } Fewer drops to instill 1,2 } Reduced risk of medication washout 4 } Lower exposure to preservatives 4 1. Konstas AGP et al. Eye (Lond). 2000;14(pt 5): ; 2. Higgenbotham EJ. Clin Ophthalmol. 2010;4:1-9; 3. Walt J, Alexander F. Drops, drops, and more drops. In: Gunvan

28 Maximum Tolerated Medical Treatment The proliferation of AGM has been explosive The selection of adjunctive treatment must be rational. Drugs with different mechanism may not be additive Optimal medical treatment-least amount of medication to achieve desired target Incisional Glaucoma surgery is the most potent IOP lowering intervention Fechtner RD, Singh K. Maximal glaucoma therapy. J Glaucoma. 2001;10:S73 5.

29 South East Asia Glaucoma Interest Group. Asia Pacific Glaucoma Guidelines. 3rd ed

30 Follow UP Progression in glaucoma assessed by structure (optic disc,rnfl evaluation) and function(visual field) Monitor IOP Structure Function

31 Assess IOP - reestablish target IOP if required, DVT Gonioscopy maintain baseline - atleast once in 1 yr - increased synechiae -increased pigmentation -decreased angle width

32 Progression in structure : # new disc hemorhage # RNFLD # Change in NRR Progression on visual fields # Over view # GPA

33 Progression on imaging technologies HRT trend analysis, Topographic change analysis Cirrus SD OCT- Guided progression analysis

34 Follow up

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