Time Series Observations of Outcome Variables and the Factors Associated with the Improvement in the Patient Outcomes of Cataract Surgery
Korean Journal of Preventive Medicine (예방의학회지)
Korean Journal of Preventive Medicine (예방의학회지), Vol.34(2) : 175~181, 2001
Objectives : To compare the multiple outcomes of patients with cataract surgery at perioperative time,3-4 months and 12 months after surgery and to assess patient outcomes associated with visual improvement(visual acuity of operated eye, visual function-14(VF-14), symptom score). Methods : For this assessment, a prospective study was conducted with 389 patients who had undergone cataract surgery for either one eye or both eyes. The surgery was peformed by 20 ophthalmologists who were practicing at university hospitals and general hospitals. Patients were interviewed and clinical data were obtained. Doctors were questioned with self-reported questionnaire forms. Medical records were examined in order to measure variables related to the surgical process such as surgical methods and ocular comorbidity. The survey was 'conducted at 4 stages' : preoperative time(389 cases), perioperative time(344 cases, 88.4%), postoperative 3-4 months (343 cases, 88.2%), and postoperative 12 months (281 cases, 72.2%). After excluding cases with incomplete data, 198 cases were enrolled in the study. Patient outcomes was measured for any improvement in the functional outcomes(visual acuity of operated eye, visual function, symptom score) at postoperative 3-4 months. Results : The visual acuity(operated, weighted average), symptom score, VF-14 score, satisfaction with vision, and subjective health status were shown to be improved at the perioperative time, postoperative 3-4 months and 12 mouths. An improvement in the Snellen visual acuity score was observed in 190 patients(96.0%), whereas improvements of the VF-14 score and cataract symptom sure were observed in 151 patients(76.3%) and 179 patients(90.4%), respectively. All three outcome measures demonstrated improvement in 137 patients(09.2%). The improvement of the three functional outcomes at 3-4 months after receiving surgery was associated with a lower level of visual function and a higher level of cataract symptom score at perioperative time, as well as a greater experience level of the surgeon. Conclusions : In this study, the estimates of the proportion of patients benefiting from cataract surgery varied with the outcome measure of benefit. Preoperative VF-14 score, a measure of functional impairment related to vision, and symptom score may be better measures of the benefit derived from cataract surgery than the change in visual acuity.