Examining the Accuracy of One-Eye Trials
Examining the Accuracy of One-Eye Trials
The efficacy of topical medications in the treatment of glaucoma has often been judged by a one-eye trial (OET), during which an antiocular hypertensive agent is used in one eye and the fellow eye is used as a control to help judge the rate of response and efficacy of treatment. This technique was called into question in a study that compared the intraocular pressure (IOP) in patients with glaucoma. A lack of correlation was noted between the IOP responses of fellow eyes to the same medication in an OET. This lack of correlation in the response of one eye in comparison to the other to a particular topical agent would make the OET much less useful clinically. The authors of this prospective study compared the correlation of the response of the fellow eyes in an OET performed with topical latanoprost. Instead of using glaucoma patients, this study assessed the correlation of IOP in normal subjects.
Discrepancy of the Intraocular Pressure Response Between Fellow Eyes in One-Eye Trials Versus Bilateral Treatment: Verification With Normal Subjects
Takahashi M, Higashide T, Sakurai M, Sugiyama K
J Glaucoma. 2008;17:169-174
Summary
The authors studied 41 normal subjects. An OET was conducted with topical latanoprost applied once daily in the right eye for 7 days. This was followed by treatment of the left eye. Treatment with latanoprost reduced IOP significantly in the first OET and in the fellow eye. The correlation of the reduction of mean diurnal IOP between the 2 trials was poor.
Comment
The authors reported that in normal subjects, the fellow eyes showed a symmetrical response to short-term treatment with latanoprost. However, the response to short-term treatment in the fellow eyes was not symmetric to that of the initially treated eye in the OET. The authors suggested that the difference in the 2 responses may be caused by a differential response to latanoprost during each trial. These findings continue to call into question the long-standing practice of the OET in determining a treatment effect from topical pressure-lowering agents.
Abstract
The efficacy of topical medications in the treatment of glaucoma has often been judged by a one-eye trial (OET), during which an antiocular hypertensive agent is used in one eye and the fellow eye is used as a control to help judge the rate of response and efficacy of treatment. This technique was called into question in a study that compared the intraocular pressure (IOP) in patients with glaucoma. A lack of correlation was noted between the IOP responses of fellow eyes to the same medication in an OET. This lack of correlation in the response of one eye in comparison to the other to a particular topical agent would make the OET much less useful clinically. The authors of this prospective study compared the correlation of the response of the fellow eyes in an OET performed with topical latanoprost. Instead of using glaucoma patients, this study assessed the correlation of IOP in normal subjects.
Discrepancy of the Intraocular Pressure Response Between Fellow Eyes in One-Eye Trials Versus Bilateral Treatment: Verification With Normal Subjects
Takahashi M, Higashide T, Sakurai M, Sugiyama K
J Glaucoma. 2008;17:169-174
Summary
The authors studied 41 normal subjects. An OET was conducted with topical latanoprost applied once daily in the right eye for 7 days. This was followed by treatment of the left eye. Treatment with latanoprost reduced IOP significantly in the first OET and in the fellow eye. The correlation of the reduction of mean diurnal IOP between the 2 trials was poor.
Comment
The authors reported that in normal subjects, the fellow eyes showed a symmetrical response to short-term treatment with latanoprost. However, the response to short-term treatment in the fellow eyes was not symmetric to that of the initially treated eye in the OET. The authors suggested that the difference in the 2 responses may be caused by a differential response to latanoprost during each trial. These findings continue to call into question the long-standing practice of the OET in determining a treatment effect from topical pressure-lowering agents.
Abstract
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