ABSTRACT
Because of the high false positive and negative rates for detection of suspects when screening for glaucoma by tonometry, we screened 12 156 subjects over the age of 40 years or with a stated family history of glaucoma by examining the optic discs. This was followed by Schiotz tonometry. Eight hundred and twelve (6.7%) suspects were referred to their primary physician for investigation by an ophthalmologists. A database program was used to send out follow-up letters to both suspects and ophthalmologists. Three hundred and seventy-nine replies were received from ophthalmologists: 100 (26.4%) of these suspects had ocular hypertension and 68 (17.9%) had glaucoma. Of these 68, 60 (15.8%) had chronic simple glaucoma, five (1.3%) had secondary open-angle glaucoma, and three (0.79%) had primary closed-angle glaucoma. The prevalence of all types of glaucoma in this group for which follow-up was obtained was at least 0.56% of the total number screened. Assuming that the prevalence was similar for the group for whom no replies were obtained, the prevalence of glaucoma in this population is approximately 1.19%. Screening by optic disc examination is therefore likely to detect most cases of glaucoma.
Subject(s)
Glaucoma/diagnosis , Mass Screening/methods , Optic Disk/pathology , Aged , Follow-Up Studies , Glaucoma/pathology , Glaucoma/physiopathology , Glaucoma, Open-Angle/diagnosis , Glaucoma, Open-Angle/pathology , Glaucoma, Open-Angle/physiopathology , Humans , Intraocular Pressure , Middle AgedABSTRACT
We used multiple logistic regression to analyze cross-sectional data on 1,006 patients with diabetes mellitus who were examined in a rural diabetic screening program. The factors found to have independent and significant associations with the presence of retinopathy were duration of diabetes, albuminuria, serum creatinine, glycosylated hemoglobin, and plasma glucose levels, blood pressure, and percentage of desirable weight. By comparing the contribution of each significant factor to the deviance from the regression models, we estimated the relative importance of each. Duration of diabetes was by far the most important predictive factor. The logistic model provided a good fit to the observed prevalence rates in various risk groups but was less satisfactory for predicting the presence or absence of retinopathy in individual patients. The discovery of presently unknown risk factors may improve this situation.
Subject(s)
Diabetic Retinopathy/epidemiology , Adolescent , Adult , Aged , Child , Diabetic Retinopathy/blood , Female , Humans , Male , Middle Aged , RiskABSTRACT
Observations of intraocular pressure (IOP) variations in response to CO2, adrenaline, speech and compression of the neck veins were documented by continual monitoring of IOP by radiotelemetry. Carbon dioxide increased IOP in the supine, but not in the erect, conscious subject. Adrenaline 2% caused a rapid short-lived painful increase in IOP, followed by a profound decrease. This was due to an increase in facility of outflow and was associated with paralysis of the sympathetic supply to the iris. Speech caused a small rise in IOP which was reversed by rest in silence. Compression of the neck veins caused a variable increase in IOP. These physiological variations in IOP may contribute to the errors of tonometry.
Subject(s)
Glaucoma/physiopathology , Intraocular Pressure , Monitoring, Physiologic/standards , Tonometry, Ocular/standards , Carbon Dioxide/pharmacology , Epinephrine/pharmacology , Humans , Intraocular Pressure/drug effects , Iris/innervation , Neck , Posture , Speech , Sympathetic Nervous System/drug effects , Venous PressureABSTRACT
A new method has been devised for continual monitoring of intraocular pressure by radiotelemetry. The use of this instrument for monitoring intraocular pressure by a variety of ophthalmic conditions is described.
