Comparison of refractive results achieved by the triple-procedure versus cataract operation and keratoplasty in two seperate steps
R. Keuch, R. Vogt, H. Bleckmann
There are various options for the management of a combined cataract and corneal disease: The triple-procedure, operation of the cataract first, followed by keratoplasty and a splitted procedure in the opposite order. We studied the refractive outcome of the three different approaches taking special interest in the rate of achieved isometropia.
Material and Methods: We analysed a total of 46 eyes in this retrospective study. All patients had a combined cataract and corneal desease. The patients were splitted into three groups: Group 1 (n=10) had a cataract operation in the first place, followed by a perforating keratoplasty, group 2 (n=15) had a triple-procedure and the patients belonging to group 3 (n=21) had a keratoplasty first, followed by a cataract operation. Isometropia was the refractive goal in all cases, while the IOL-calculation was performed using the SRK-II fomula. The postoperatve refractive results were tested by subjective and objective measurement of each eye.
Results: The final visual acuity was better in all of the patients, reaching the best results within group 3. All group s showed a myopic shift in comparison to the calculated refractive values. The number of patients achieving a refraction of a 2 dpt. arround isometropia varied between the three group s, giving group 3 the best results (group 1: 33%, group 2: 50%, group 3: 75%).
Discussion: Achieving satisfactory results is not only a question of aiming for a better visual acuity but also a question of reaching postoperative isometropia in order to rehabilitate stereopsis and to avoid aniseikonia. Conceming to our results this goal can be reached best if the cataract operation is the second step after having performed a keratoplasty. The rate of group l transplant decompensation showed not to be higher, if the phacoemulsification was the second step of the combined procedure. We believe that our result are based on the fact, that the measurement of the corneal curvature was much easier and more reproducible within the corneal transplant and that the curvature values that went into the lOL-calculation were more accurate.
Conclusion: Eccept for amblyopic or low-vision eyes, we reccomend the perfomance of the keratoplasty before operating on the cataract later.
Schlosspark-Klinik, Augenabteilung, Heubnerweg 2, D-14059 Berlin