Abstract
Purpose :
It has been suggested that a diagnosis of glaucoma cannot be certain until progression is confirmed during follow-up. Therefore, we aimed at investigating the proportion of patients who received a correct diagnosis of glaucoma using a comprehensive examination at two initial visits, but without any follow-up data.
Methods :
We studied patients included in the Early Manifest Glaucoma Trial (EMGT). Glaucoma patients were mostly recruited from a large population screening. Patients who screened positive based on IOP and disc appearance were diagnosed with glaucoma if they showed repeatable visual field defects at two consecutive visits, with a Glaucoma Hemifield Test outside the normal limits in the same sector of the visual field or borderline, if corresponding optic disc findings were present. Intraocular pressure was not included in the definition of the disease. During the long follow-up, patients were examined prospectively and frequently with threshold perimetry and optic disc photography.
Patients followed for 15 years or more were included, and follow-up data was used to confirm or reject the initial diagnosis of glaucoma. At least one of the following four criteria had to be fulfilled in order to confirm the diagnosis:
1. Visual field progression in at least one of the eyes of the patient according to the EMGT criterion.
2. Optic disc progression in fundus photographs in at least one of the eyes of the patient.
3. Development of glaucoma in the fellow-eye in patients with one eye only originally included in the study.
4. Optic disc hemorrhages in optic disc photographs in at least one of the eyes.
Results :
Of the initial 255 randomized patients, 117 were followed for 15 years or longer resulting in 148 eligible study eyes. Among these, all but 13 eyes of 13 patients (11%) showed visual field progression. Among the latter 13 patients, four (3%) did not meet any of the four criteria to confirm the diagnosis. Thus, a correct diagnosis was made in 97% of cases already at the initial visits.
Conclusions :
The results strongly suggest that a diagnosis made using strict criteria including both visual field and optic disc findings can be correct in a very great majority of cases and with such initial examinations the risk of making a false positive diagnosis is small.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.