vol1 - Page 209

 each drug family. A patient progresses to
 the next drug family when a tolerance to the
 previous drug develops. Frec_ently, a
 ..... patient will be prescribed a combination of
 dz_/g families in o_ to achieve successful
 management of IOP_ _u_
 Hepler continues:
 > Xt is not unusual for chronic open-angle
 :: glaucoma patients to develop tolerances to
 all of these conventional medication
 families_ Such a tolerance exists when the
 medication fails to lower the patientS, IOP
 to a safe range, even when the
 high_1
 :.,_ allowed dosage level has been used. _-_r
 Dr. John MeETitt estimated that 25% to 30% of all
 glaucoma patients re_aire some form of combination drug
 therapy. _-q/
 Even aggressive_ combination drug therapies may,
 however, prove ineffective in adequately reducing a patient's
 intraocular pressure to the so_called _safe u :range [below 20 mm
 Hg]. _-I/ Thus the .chemicals currently used in the treatment of
 glaucoma may prove inadequate in providing patients with
 therapeutically-effective reductions in !OPo Simply stated,
 patients may be using all four families of lOP-lowering agents in
 combination and at the highest recommended dosages [known as
 ___/ Affidavit of Robert Randall, Exhibit B, Affidavit of
 Robert S. Hepler, April, 1978, at 8o ___ _i__: Cross-
 examination of Dr. Richard North, Tro 7-.73. Note: The
 introduction of Timoptio_ a beta-blocking drug, into glaucoma
 therapy in 1978 has expanded treatment options. Timoptic is now
 used as the initial drug of therapy.
 _-
 4_/ /_. Exhibit B _ 9-10o
 __q/ Cross-examination of Dr. John Merritt, Tr ° 10-71
 __i/ Affidavit Robert Randall, Exhibit B; Affidavit of
 Dr. Robert Hepler, _ 9.
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