advertisement
Abstract #15976 Published in IGR 2-3
If intraocular pressure measurement is only an estimate-then what? (editorial)
Mills RPOphthalmology 2000; 107: 1807-8
The second guest editorial on the accuracy of pressure measurement is a more philosophical article. We know that tonometry has always suffered from multiple sources of error. An astute clinician recognizes the sources of error and makes adjustments in the interpretations of the test result. This author first points out that we have to agree on what is the normal value for CCT and subsequently what is the adequate conversion factor if we want to converse at all. He points out some limitations for the conversion factors for CCT. One of them is that the relationship between CCT and IOP is non-linear. It would be convincing according to this author if the routine measurements of CCT resulted in improved routine clinical decision making. However he points out that in most clinical circumstances the absolute IOP level is not particularly important. Changes in IOP over time take a greater clinical significance. Additionally in the vast majority of patients the rule of thumb correction factor for CCT is only 1 or 2 mmHg, within the range of repeatability of tonometry. He suggests an alternative strategy: to measure CCT when an important clinical decision hangs on the absolute IOP level such as a decision to initiate therapy in a patient with ocular hypertension as soon as IOP is estimated as being more than 30 mmHg. He feels that patients targeted for CCT measurements would represent at most 10% of the glaucoma patients. In fact he does not feel that CCT measurements should be part of routine measurements of IOP in glaucoma patients.
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
