Abstract
Purpose: :
The aim of the study was to evaluate an adequate follow-up period for healthy subjects regarding the detection of a conversion to glaucoma in different age groups and to find out whether different risk factors, such as central corneal thickness (CCT), positive family history or IOP play a role in conversion.
Methods: :
The ,,Salzburg Moorfields Collaborative Glaucoma Study" (SMCGS) is embedded in a government-supported glaucoma blindness prevention programme in Salzburg county, Austria, which is designed for a screening and follow-up period of at least 15 years. Each subject received a complete ophthalmological examination, including visual field (Humphrey 24-2 full threshold) and TopSS or HRT. Data sets of 1886 healthy subjects were analysed. Pearson's Chi-Sqare Test and Student-t-test were used for data evaluation.
Results: :
In the age group between 40 to 60 years and over 60 years the progression after 5 years from a normal disc to a glaucoma suspect disc was 2,71% respectively 4.16%, to Ocular Hypertension 1,31% resp. 1,46% and to manifest glaucoma 0,2% respectively 1,24%. There was no correlation between a lower CCT or positive family history or IOP and conversion.
Conclusions: :
For population screening, screening intervals of 3 years are internationally accepted and recommended. According to the findings presented, however, a screening interval of 5 years should be sufficient in a healthy population below 60 years. Almost doubling the screening intervals has a major socio-economic impact as it cuts efforts and costs in half.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: risk factor assessment • optic disc