Canadian study sees benefits of tomography

The benefits of using scanning laser tomography (SLT), in particular the Heidelberg Retinal Tomograph, to determine optic disc changes in glaucoma patients have been highlighted in a new paper.
Reported in the American medical journal Archives of Ophthalmology, the paper is the result of a six-year study conducted by a team at Dalhousie University Halifax, Canada.
Led by Dr Bal Chauhan, the team investigated the relationship between optic disc changes measured with scanning laser tomography, using the Heidelberg Retinal Tomograph, and those measured with conventional perimetry (CP) and optic disc photography.
The study involved 77 patients Ð 41 men and 36 women Ð with an average age of 58 years, who were examined on 12 occasions over the six-year study.
Dr Chauhan and his team found 21 (27 per cent) of the patients showed no progression with either test method, while 31 (40 per cent) showed progression with scanning laser tomography only. In addition, 22 (29 per cent) showed progression with both SLT and CP, while only three (4 per cent) showed progression with conventional perimetry. A total of 53 patients (69 per cent) showed progression with SLT and 25 (32 per cent) with CP.
The study was carried out using the original version of the Heidelberg Retinal Tomograph, the HRT, which has now been superseded by the HRT II.
Krysten Williams, marketing manager at Haag-Streit UK, which distributes Heidelberg ophthalmic equipment, said: ÔThis study has demonstrated that the small, more frequent changes in optic disc topography, as opposed to the less frequent visual field changes determined with CP, can be detected using analytical techniques in conjunction with the HRT and the HRT II.Õ
u A full transcript of the paper is available on www.archopthal mol.com