I was surprised that the articles regarding the Ocular HypertensionTreatment Study (OHTS)1,2 didnot refer to 2 previous publications, each more than 20 years old, in whichsimilar results were found.3,4 Itis true that there were significant differences between these earlier studiesand the OHTS. The earlier studies were retrospective, unlike the OHTS, whichwas prospective. The earlier studies used Goldmann visual fields instead ofcomputerized fields; therefore, in some patients, optic nerve damage may haveexisted at the start of the study, although visual fields were normal. Entryinto the study was not randomized but based on the existence of stereoscopicdisc photographs, which may have preselected eyes more susceptible to futuredamage. All patients were untreated until they developed a reproducible glaucomatousvisual field and thus were diagnosed as having glaucoma. Nevertheless, asin the OHTS, 2 groups of patients with ocular hypertension were compared,all of whom had normal visual fields at the start of the study and were observedfor at least 5 years.