Clinical Guidelines prev next

Mar 29 2006

CCT: Is is time to say YES?

posted by: J. James Thimons, OD, FAAO

The Ocular Hypertension Treatment Study established the role of CCT in clinical practice for our ocular hypertensive patients. Several authors have investigated the applications for select sub-types of glaucoma (NTG, Afro-Caribbean etc.) but to date the impact of this technology in a general practice had not been elaborated.

A study by Shih and associates (Shih,CY et al. “Clinical Significance of Central Corneal Thickness in the Management of Glaucoma� Arch Ophthalmol 2004;322: 1270-1275) utilized a cross sectional retrospective study of the addition of a CCT measurement to the examination of 188 consecutive patients with diagnoses of Ocular Hypertension, Glaucoma Suspect and POAG.

Utilizing the Orssengo-Pye exponential correction scale, an assessment of Measurement Signifcance was made after adjusting IOP’s based on the CCT reading. Using the linear correction scale (Corrected IOP= Measured IOP-(CCT-545)/50x 2.5mmHg), 56% (105/188) of patients had at least a Measurement Significant adjustment: 36% had between 1.5 and 3.0mmHg adjustments and 20% had greater than 3.0mmHg adjustment to baseline IOP. Of the 188 patients, 9% had changes in medical therapy, 2% had a change regarding laser therapy, and 3% had a change in the decision regarding glaucoma surgery.

The outcomes in this study present an interesting view of the role of CCT in clinical decision making and underscore the importance of this test in glaucoma management today. Given that data from this and several other studies show the clinical significance of this technology and that guidelines in this area have been developed by the American Academy of Ophthalmology, the question should be put to rest as to the reasonableness of attempting to diagnose and therapeutically intervene in patients with Ocular Hypertension, Glaucoma Suspect and POAG status. It appears that the time has come for all clinicians to acknowledge and implement the technology in their practice.