Laser Scanning Ophthalmoscopy can improve the accuracy of diagnosis for glaucoma.

Recently published results from the European Optic Disc Assessment Trial show that the accuracy of glaucoma diagnosis can be improved when laser scanning ophthalmoscopy is used. Two commonly available instruments were tested: The GDX with variable corneal compensation (VCC) and the Heidelberg Retinal Tomorgraph (HRT) against the diagnostic ability of 243 ophthalmologists from eleven countries across Europe. The ophthalmologists achieved an accurate diagnosis in 80.5% of cases with the GDX instrument achieving 93.2% and the HRT 89.8% with the most significant improvement being in people with early to moderate glaucoma.

An improvement of nearly 12% in diagnostic accuracy is of particular importance in a condition such as glaucoma where early diagnosis is the key to the control of visual loss. Dr Nicolaas Reus of the Rotterdam Eye Hospital commented that:

‘Glaucoma is a leading cause of blindness in the developed world and late diagnosis can lead to irreversible damage to the optic nerve and loss of sight. The imaging devices in this trial had a high diagnostic accuracy and should there be used to support clinical assessment and improve early detection of this debilitating condition across Europe. Importantly, the progression of glaucoma can be slowed with early and accurate diagnosis if followed up with appropriate treatments to reduce intraocular pressure.’

Of the 875 ophthalmologists who were asked to participate in the study, 243 completed and returned their score sheets which were based on 110 slides of optic discs comprising 40 healthy eyes, 48 glaucomatous eyes and 6 cases of ocular hypertension. Two grading options were offered: glaucomatous or normal. For each participant and for both imaging instruments the sensitivity, specificity and overall accuracy of diagnosis was calculated with the clinicians’ accuracy varying between 61.4% and 94.3% (means average 80.5%) and the imaging instruments achieving 93.2% for the GDX and 89.8% for the HRT.

The study authors suggest that high variability of the ophthalmologists’ results show a need for improved post graduate training for ophthalmologists in optic disc assessment and that the imaging devices should be used to support clinical assessment and to improve early detection of glaucoma.

Mr Clive Migdal, President of the European Glaucoma Society said:

‘Glaucoma is a devastating disease for so many Europeans and has a negative impact on their quality of life if it is not detected in its early stages and treated appropriately. Crucially, the results from this important study highlight the need for further training to improve the rates of early diagnosis and alleviate patients’ potential suffering. As stated in the 2008 edition of the EGS Guidelines, a diagnosis should never be solely on imaging devices as these are unable to compete with a clinician’s many years of training and expertise.’

This study was funded by an investigator-initiated research grant from Pfizer Limited.