- Oulun yliopisto
- Lapin yliopisto / University of Lapland
- Lapland University Press / Lapin yliopistokustannus
- Itä-Suomen yliopisto
- Centria-ammattikorkeakoulu, Centria-kirjasto Kokkola
- Vaasan yliopisto
- Tampere University Press. TUP
- Viipurin Suomalainen Kirjallisuusseura
- Humanistinen ammattikorkeakoulu- Humak
- Tampereen teknillisen yliopiston julkaisut
THE HEIDELBERG RETINA TOMOGRAPH IN THE DIAGNOSIS OF GLAUCOMA
Glaucoma is a group of eye diseases characterized by a chronic, progressive optic neuropathy.
During the disease process, the axon damage of the retinal ganglion cells leads to changes in the retinal nerve fiber layer, causing optic nerve head, and visual field defects typical of glaucoma.
The Heidelberg Retina Tomograph (HRT) is a confocal scanning laser imaging device
acquiring and analysing three-dimensional data of the ocular fundus wit good accuracy and
Conventional planimetric measurements were compared to those taken with the HRT in a pilot
study of 12 eyes with early glaucomatous optic disc, retinal nerve fiber layer and/or visual field abnormalities. The neuroretinal rim area measurements and cup-to-disc area ratio did not differ statistically from each other when using these two different methods.
The effect of four different reference levels on the HRT parameter measurement values was
tested in two separate studies. In the first study there were 67 eyes, 40 of the eyes were healthy and 27 eyes had glaucoma of different stages. Then, 279 eyes, 180 of which were non-glaucomatous and 99 glaucoma eyes, were included in another study. The flexible reference level gave the most reliable HRT parameter measurement values in both non-glaucomatous and glaucomatous eyes.
The ability of the HRT parameters to separate between non-glaucomatous and glaucomatous
eyes was tested in 77 eyes, 40 of the eyes were non-glaucomatous, 10 ocular hypertensives and 27 eyes had different stages of glaucoma. The reference level dependent HRT parameters cup-to-disc area ratio, vertical linear cup-to-disc ratio, mean retinal nerve fiber layer thickness (RNFLt) and rim volume as well as the reference level non-dependent HRT parameter, cup shape measure (CSM), separated best between the clinical groups.
The best combination of the HRT and other structural and functional parameters in separating
between non-glaucomatous and glaucomatous eyes was studied in 55 eyes. There were 32 nonglaucomatous eyes and 23 eyes with ocular hypertension or glaucoma. CSM, RNFLt, together with age- and lens coloration-corrected mean deviation of the B/Y perimetry showed good discrimination (ROC area 0.91) between non-glaucomatous and glaucomatous eyes.
- ACTA UNIVERSITATIS OULUENSIS D Medica
- Oulun yliopisto
- VIHANNINJOKI KYÖSTI