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Refractive surgical problem
CONSULTATION SECTION
placing a 3-piece IOL anterior to the previously placed IOL, which eliminates the aberrant rays that occupy the space between the IOL and posterior iris. The second piggyback lens has zero power, and its haptics are placed in the ciliary sulcus. If the disturbing optical phenomena are related to dysphotopsia from the IOL, I would proceed with this procedure first and then perform a corrective refractive procedure of the cornea afterward. Paul H. Ernest, MD Jackson, Michigan, USA
- The surgery in both eyes was uneventful. The postoperative visual acuity was excellent; only the refractive outcome in the left eye does not seem to be satisfactory to the patient. I presume that the patient does not use spectacles for daily life or under night conditions. The patient is disturbed by uncorrected residual myopic astigmatism. The visual phenomena are stronger because of the dilated pupil at night. In my opinion, the reason for the change in the axis of the astigmatism and the residual astigmatism is incorrect positioning of the IOL’s astigmatism axis during surgery or postoperative rotation of the IOL with misalignment of the cornea’s and IOL’s axes of astigmatism. In the case report, there are no comments about the position of the IOL’s astigmatism axis; however, the residual postoperative refractive astigmatism and the change in the refractive axis from preoperatively to postoperatively with no change in the corneal axis regarding corneal topography make the above explanation the only reasonable one to me. This situation may also explain the visual problems under night conditions. The noncongruent axes are inducing HOA wavefront aberrations, especially under scotopic conditions. If the patient is severely disturbed by the optical phenomena, I would propose, as a first choice, additional surgery in the left eye during which the IOL would be rotated
toward the axis described by corneal topography. This might be difficult because the capsular bag may have shrunk as a result of delayed surgery and the typical haptic design of the IOL used. If IOL rotation fails, sulcus positioning of the IOL haptic or IOL exchange with sulcus positioning could be considered. In my opinion, laser treatment of the cornea should only be performed as a second choice. The treatment must be wavefront guided, and because of the wide scotopic pupil, the final outcome is not perfectly predictable. I would consider this treatment only if IOL rotation does not meet the patient’s visual expectations. Christian Skorpik, MD Vienna, Austria
- The reported disturbing optical phenomena under night conditions are probably caused by the resulting 3 different cylinders and their different axes. First is the cylinder of the spectacles; second, that of the cornea; and third, that of the toric IOL. The actual refraction 18 months after implantation of the toric IOL indicates that the IOL rotated after implantation by about 15 degrees or that it was implanted 15 degrees in a wrong position. The resulting mixture of the different cylinders and different axes are probably the reason for the disturbing optical phenomena. To correct this problem, I would suggest a topographically driven LASIK correction of the refractive cylinder of ÿ1.50 D. The other possibility would be to correct the position of the toric IOL. But 1½ years after surgery, it would be nearly impossible because of the Z-haptic of the MicroSil MS 6116 TU toric IOL. To rotate this type of IOL in a completely sealed capsular bag would be very difficult and could cause several intraocular complications.
J CATARACT REFRACT SURG - VOL 31, SEPTEMBER 2005
Claus D. Quentin, MD Go¨ttingen, Germany
1693
placing a 3-piece IOL anterior to the previously placed IOL, which eliminates the aberrant rays that occupy the space between the IOL and posterior iris. The second piggyback lens has zero power, and its haptics are placed in the ciliary sulcus. If the disturbing optical phenomena are related to dysphotopsia from the IOL, I would proceed with this procedure first and then perform a corrective refractive procedure of the cornea afterward. Paul H. Ernest, MD Jackson, Michigan, USA
- The surgery in both eyes was uneventful. The postoperative visual acuity was excellent; only the refractive outcome in the left eye does not seem to be satisfactory to the patient. I presume that the patient does not use spectacles for daily life or under night conditions. The patient is disturbed by uncorrected residual myopic astigmatism. The visual phenomena are stronger because of the dilated pupil at night. In my opinion, the reason for the change in the axis of the astigmatism and the residual astigmatism is incorrect positioning of the IOL’s astigmatism axis during surgery or postoperative rotation of the IOL with misalignment of the cornea’s and IOL’s axes of astigmatism. In the case report, there are no comments about the position of the IOL’s astigmatism axis; however, the residual postoperative refractive astigmatism and the change in the refractive axis from preoperatively to postoperatively with no change in the corneal axis regarding corneal topography make the above explanation the only reasonable one to me. This situation may also explain the visual problems under night conditions. The noncongruent axes are inducing HOA wavefront aberrations, especially under scotopic conditions. If the patient is severely disturbed by the optical phenomena, I would propose, as a first choice, additional surgery in the left eye during which the IOL would be rotated
toward the axis described by corneal topography. This might be difficult because the capsular bag may have shrunk as a result of delayed surgery and the typical haptic design of the IOL used. If IOL rotation fails, sulcus positioning of the IOL haptic or IOL exchange with sulcus positioning could be considered. In my opinion, laser treatment of the cornea should only be performed as a second choice. The treatment must be wavefront guided, and because of the wide scotopic pupil, the final outcome is not perfectly predictable. I would consider this treatment only if IOL rotation does not meet the patient’s visual expectations. Christian Skorpik, MD Vienna, Austria
- The reported disturbing optical phenomena under night conditions are probably caused by the resulting 3 different cylinders and their different axes. First is the cylinder of the spectacles; second, that of the cornea; and third, that of the toric IOL. The actual refraction 18 months after implantation of the toric IOL indicates that the IOL rotated after implantation by about 15 degrees or that it was implanted 15 degrees in a wrong position. The resulting mixture of the different cylinders and different axes are probably the reason for the disturbing optical phenomena. To correct this problem, I would suggest a topographically driven LASIK correction of the refractive cylinder of ÿ1.50 D. The other possibility would be to correct the position of the toric IOL. But 1½ years after surgery, it would be nearly impossible because of the Z-haptic of the MicroSil MS 6116 TU toric IOL. To rotate this type of IOL in a completely sealed capsular bag would be very difficult and could cause several intraocular complications.
J CATARACT REFRACT SURG - VOL 31, SEPTEMBER 2005
Claus D. Quentin, MD Go¨ttingen, Germany
1693