The object of this study was to investigate the perceptibility of changes in the topography of the optic nerve head during follow up with laser scanning tomography (LST), with a minimum observation period of 24 months.
Methods: We evaluated the changes in cup and rim area, cup volume, and mean and maximum cup depth in 50 eyes (8 control eyes, 21 glaucomatous eyes, 21 eyes in which glaucoma was suspected by LST over a mean follow-up time of 36 +/- 10 (range 24-49) months and compared them with the results of computerized static perimetry (Octopus). Changes were considered to be significant if they were larger than three times the maximum deviation measured in one parameter and larger than the maximum deviation in one other parameter [27].
Results: Among 10 eyes that showed increasing cup values, 5 initially presented with striking disc cups, and no pathologic function tests; in none of these eyes was functional loss revealed by perimetry during the follow-up period. Of the 5 glaucomatous eyes in which progression was found on optic disc morphometry, 4 had increasing defects revealed by computerized static perimetry (Octopus 500).
Conclusion: The results confirm the value of LST. In 6 eyes in which LST revealed a significant increase in the optic cup values, perimetry did not demonstrate progression of the functional loss. Therefore, LST should be used in the follow up of all patients with glaucoma or suspected glaucoma, in addition to conventional computerized perimetry.