Contribution of multiple glaucoma medications to visual function and quality of life in patients with glaucoma.

BACKGROUND: Previous studies examining the correlation between medical treatment and overall quality of life in patients with glaucoma assessed differences between a glaucoma population and a matched group (without glaucoma) and were not aimed specifically at detecting a relation between visual acuity, visual field status and medication use, and visual function and quality of life. We performed a study to determine this relation in patients with chronic open-angle glaucoma (COAG). METHODS: The study was cross-sectional. Of 235 English-speaking patients with a diagnosis of COAG, normal-pressure glaucoma or suspected glaucoma (receiving therapy) seen in a university-based glaucoma practice between Feb. 1 and Apr. 30, 1998, 224 (95.3%) agreed to participate. All subjects completed two questionnaires: the Visual Function Assessment and the EQ-5D, assessing health status (quality of life). Visual acuity, diagnosis, age, sex, country of birth, type and number of medications for topical and for oral use, dosage, and history of laser treatment and surgery were extracted from the medical record. Pearson rank correlation and multivariate analyses were performed. RESULTS: On univariate analysis visual function was correlated with age, visual acuity, number of glaucoma medications, number of applications of eyedrops, mean deviation in better eye, mean deviation in worse eye, and lower hemifield involvement in both eyes. On multivariate analysis only visual acuity and visual field status were independently associated with visual function. Univariate analysis showed that health status was correlated with age, visual function and number of medications for oral use; however, age failed to retain statistical significance in the regression analysis. INTERPRETATION: Our results suggest that the number of glaucoma medications is not predictive of quality of life.

Reliability and reproducibility of a Chinese-language visual function assessment.

OBJECTIVE: The purpose of the study was to validate a Chinese-language visual function assessment within the context of a routine cataract surgery practice and to assess the contribution of the method of questionnaire administration. DESIGN: The visual function assessment (VFA) was translated into Chinese. Two groups of study subjects were recruited: Chinese who did not speak English and Chinese conversant in English. Consecutive preoperative cataract patients of Chinese ancestry presenting to an urban ophthalmology practice were recruited. The questionnaire was administered in person or by telephone interview. Pre-operative visual acuity was recorded. Visual function scores were analyzed to assess reliability and correlation with visual acuity. RESULTS: Among the 186 potential study subjects, 155 patients completed the study The Chinese-language visual function assessment had good internal consistency (Cronbach alpha = 0.97, inter-item correlations = 0.43 to 0.96) . Reliability (with regard to the English version) and test-retest reproducibility of the Chinese questionnaire were strong with intraclass correlation coefficients greater than 0.60. The method of administration contributed to the measures of reliability and reproducibility. CONCLUSION: These results show that a Chinese-language version of the VFA questionnaire is reliable and valid. In industrialized countries with large Chinese-speaking populations and newly developed countries of East and Southeast Asia, the visual function assessment may be helpful in assisting routine clinical patient evaluation and cross-cultural outcome assessment programmes. Our findings also suggest that self-administered visual function assessments may be more reliable and valid than interview-generated assessments.

Prophylactic scleral buckle for prevention of retinal detachment following vitrectomy for macular hole.

AIM: To review the rate of retinal detachment after macular hole surgery in patients who received vitrectomy and scleral buckle versus those who had vitrectomy alone. METHODS: All patient charts and hospital records were examined for patients who underwent vitrectomy surgery for macular hole between September 1993 and June 1997. A total of 326 patients were identified and all were followed for a minimum of 6 months. Clinical records were examined for details of the surgical procedure, visual acuity, hole closure status, adjuvant therapies used, and postoperative retinal attachment status. Relative risks (the ratio of the incidence rate in the exposed to that in the unexposed) with 95% confidence intervals and chi(2) tests were calculated to determine which variables were associated with retinal detachment. The primary outcome measure in this review was retinal attachment status. RESULTS: Of 326 eyes which underwent surgery for macular hole during the study period, scleral buckles were utilised in 152 (46.6%) patients. Analysis revealed a detachment rate of 13.2% in patients who did not receive a scleral buckle compared with 5.9% detachment rate in those who did. Analysis of these results indicated a 2.42 times greater risk of developing a retinal detachment in patients without a scleral buckle. Complications related to the use of scleral buckles occurred in two of 152 cases (1.3%) CONCLUSIONS: A reduction in the rate of retinal detachment was noted in patients receiving prophylactic scleral buckles. Those finding suggest a possible beneficial effect of this adjunctive procedure in preventing postoperative retinal detachments. The authors are currently preparing a multicentred, prospective, clinical trial to further study this hypothesis

An epidemiologic investigation of unexpected refractive errors following cataract surgery.

OBJECTIVE: To determine the extent and magnitude of unexpected refractive errors following cataract surgery with intraocular lens (IOL) implantation and to determine what characteristics were associated with the errors. DESIGN: In this nonconcurrent prospective study, preoperative, intraoperative and postoperative information was collected from the charts of the 523 consecutive patients who underwent cataract extraction and polymethylmethacrylate IOL implantation performed by one of nine participating surgeons between Jan. 1 and Apr. 30, 1995, or the same dates in 1996. SETTING: University-affiliated eye care centre in Vancouver. OUTCOME MEASURE: Postoperative excess correction, calculated for each patient by subtracting the actual postoperative spherical equivalent from the expected spherical equivalent. Eyes with an excess correction of more than 1.00 dioptre were considered "overcorrected." RESULTS: Univariate analysis showed that the formula used to calculate the lens power, axial length, year of surgery, A-constant/surgeon factor used and lens manufacturer were associated with overcorrection. In a logistic regression model, lens manufacturer was the only variable independently associated with overcorrection. CONCLUSIONS: Routine reporting and follow-up is necessary to identify this kind of "outbreak" and the associated factors. The current guidelines of the Health Protection Branch, Health Canada, for evaluation of IOLs that have changed manufacturers are not adequate to identify the kind of error that we detected.