The accuracy of finger tension for estimating intraocular pressure after penetrating keratoplasty.

BACKGROUND AND OBJECTIVE: Intraocular pressure (IOP) estimation by Goldmann tonometry is inaccurate in the immediate postoperative period after penetrating keratoplasty. For this reason, many corneal surgeons use a finger tension (FT) IOP estimation technique in the early post-keratoplasty period. The authors performed a prospective clinical study to evaluate the accuracy of this traditional technique.

PATIENTS AND METHODS: FT estimates were performed by three experienced corneal surgeons on 68 patients on the first and second days after penetrating keratoplasty. These estimates were compared with MacKay-Marg (MM) tonometry readings for these patients.

RESULTS: The mean confident FT from the pooled data of the three surgeons exceeded the MM reading by 5.0 mm Hg (22.6 vs. 17.6). The mean FT exceeded the MM reading by only 3.9 mm Hg for the most accurate surgeon. Some observers were significantly more accurate than others, however, lid edema and tenderness of the globe markedly diminished the FT accuracy of all of the observers at significance levels of P < .001 and P < .01, respectively. Among all of the FT estimates, in only one patient (2%) did the FT underestimate the MM reading by more than 10 mm Hg.

CONCLUSION: The authors' results suggest that for some patients, and for some surgeons, the FT or digital method of IOP estimation remains useful for detecting elevated IOP early after corneal transplantation if the proper technique is used and substantial lid edema and patient discomfort are absent.