Materials and Methods: Fifty healthy subjects who have no history of an eye disease and surgery were included in the study. Of the 50 subjects, 32 were female and 18 were male. The average age of the subjects was 37.6±11.3 . Three consecutive measurements of ACD were obtained by using Orbscan II corneal topography system and the mean of the 3 readings was used. Theoric ACD values were calculated with the special formula ACD=[((k₁+k₂)/2)x0.29]+0.5 using keratometric values obtained by Javal keratometry. Iris-lens diaphragm has been found mildly concave backwards and it has been found that iris-lens diaphragm lies 1.0 mm behind the corneal arc instead of being 0.5 mm. New theoric ACD values were calculated by using the constant 1.0 instead of 0.5 in the formula, which is used for ACD calculation. Right and left eyes were analyzed separately.

Results: ACD values obtained by Orbscan II topography were 3.32±0.31 mm for the right eye and 3.33±0.32 mm for the left eye. Theroic ACD values that were calculated following keratometric measurements were 2.78±0.46 mm for the right eye and 2.79±0.43 mm for the left eye. New theroic ACD values were 3.28±0.46 mm for the right eye, and 3.29±0.43 mm for the left eye. No statistical difference was found between ACD values obtained by Orbscan II topography and new theoric ACD values.

Conclusion: Theoric ACD values calculated from the data that were obtained by using keratometry give the ACD values which should be proper for this eye. If the values obtained via this measurement are compared to the other values obtained by using different measurement methods and if it is determined any kind of change in anterior chamber depth, the situations in which iris-lens diaphragm moves forward or backward can be enlightened more easily. Keywords : anterior chamber depth, corneal topography, keratometry