- Email: [email protected]
November Consultation # 6
CONSULTATION SECTION
relatively easy. I would disenclavate the pIOL, rotate the IOL by some degrees (toric implant), and reenclavate the pIOL again, maybe with a little less tissue than shown in Figure 2. In our published case,1 the patient was not very happy with long-term use of a drug (permanent dilation with tropicamide) to solve his problem; therefore, the surgical intervention described above was performed. If residual refractive errors remains, it could be corrected with excimer laser surgery after the main problem has been solved.
My last thoughtdand my having so many may reveal by now how unsure I am about this diagnosisdis the possibility of transient pupillary block resulting in transient forward movement of the Verisyse IOL and myopic shift. Transillumination of the iridotomy or iridectomy along with establishment of bilateral aqueous flow through it on slitlamp biomicroscopy may be helpful. John A. Kanellopoulos, MD Athens, Greece
Thomas Kohnen, MD Frankfurt, Germany REFERENCE 1. Kohnen T, Cichocki M, Bu¨hren J, Baumeister M. Intermittent myopic shift of 4.0 diopters after implantation of an Artisan iris-supported phakic intraocular lens. J Cataract Refract Surg 2005; 31:1444–1447
- It is highly unusual to have great fluctuations of correction in a Verisyse IOL patient, especially 1 month after surgery. I have followed closely several patients in my European practice as well as during my experiences as U.S. Food and Drug Administrator investigator in New York. I have several thoughts in regard to this unusual transient myopic shift of this patient. A possible etiology may be hormonal, poor glucose levels, or both. In this case, the possibility of this patient being pregnant or diabetic should be investigated. Because the imaging shown does not suggest IOL movement, a change in the crystalline lens secondary to this etiology may provide an explanation. A second possible etiology is a background of Marfan’s or Marfanoid body habitus. In this case, the abnormal collagen makeup may affect scleral rigidity at the incision site and produce refraction fluctuations. A careful family history and general physical assessment may contribute to this diagnosisdan important one, especially because of the high risk for anatomic vascular and cardiac complications. I have seen a case in which the IOL claw haptic eroded through the iris it was holding onto. As a result, the IOL offered slight movement as the now-touching ends of the claw haptic moved freely through an iris tunnel, keeping the lens flush on the iris but changing its torsional position on the iris without moving in regard to the rest of the anterior chamber. This should also be apparent with careful slitlamp biomicroscopy. Another etiology may be fluctuation of the keratometric cylinder caused by an unstable wound. This could be manifested on serial topographies.
- Verisyse IOL implantation would also be my technique of choice for this patient. I have many patients with this IOL, and the results are generally excellent. It would be interesting to measure the thickness of the natural crystalline lens with the Visante and other devices under conditions of normal vision and low vision to see whether there is any difference and to evaluate the relationship between the status of accommodation and the visual performance, again with the Visante. Is the event the consequence of transitory edema of the lens? Is it accommodative spasm? I would treat the patient with atropine for 1 week and evaluate the result. Lucio Buratto, MD Milan, Italy
- I would do further examinations. The first step would be to apply a mydriatic eyedrop (eg, tropicamide) at the time of the next decrease in visual acuity in the left eye to evaluate whether the visual acuity increases with these mydriatic drops. The objective refraction can be measured at different pupil sizes after application of tropicamide using wavefront analysis to evaluate the relationship between pupil size and refraction (spherical equivalent).1 Before and after cycloplegia, the distance of the pIOL to the crystalline lens would be measured using OCT or Scheimpflug imaging technology. To exclude an impact of the relative position of the pIOL to the line of sight, I would determine the centration of the pIOL optic, especially torus orientation relative to the center of the pupil.2 Regarding etiology of the phenomenon, various possible explanations for the very rare influence of the pIOL on the intermittent refractive shift have been reported.3 These include a shifting distance between the pIOL and the crystalline lens or the triggering of tractive power on the ciliary
J CATARACT REFRACT SURG - VOL 32, NOVEMBER 2006
1905
CONSULTATION SECTION
body by the enclavated haptic. The traction of the iris can force the ciliary body to move inward and forward, which would be in the same direction the ciliary muscle contracts during accommodation. If the drug-induced cycloplegia resolves the refractive problem, relaxation of the iris and the ciliary muscle would underline this hypothesis. Moreover, an irritation of vessels or nerves might induce ciliary muscle contraction because of the anatomic proximity to the ciliary body. Fortunately, only few very similar cases have been published until now. Iris-fixated pIOLs are enclavated in iris tissue for permanent fixation and do not rotate over several years.4,5 If the myopic shift of the pIOL is connected with the enclavation of the iris-fixated pIOL, I would reenclavate the iris via a small tunnel incision with less iris tissue first. If the reenclavation did not solve the problem, I would exchange the pIOL for another model of toric pIOL with the torus orientation perpendicular to the current direction to
1906
allow repositioning 90 degrees from the current enclavation position. H. Burkhard Dick, MD Bochum, Germany REFERENCES 1. Dick HB, Aliyeva S, Tehrani M. Change in pupil size after implantation of an iris-fixated toric phakic intraocular lens. J Cataract Refract Surg 2005; 31:302–307 2. Kottler UB, Tehrani M, Dick HB. Impact of the line of sight on toric phakic intraocular lenses for hyperopia. J Cataract Refract Surg 2004; 30:1799–1801 3. Kohnen T, Cichoki M, Bu¨hren J, Baumeister M. Intermittent myopic shift of 4.0 diopters after implantation of an Artisan iris-supported phakic intraocular lens. J Cataract Refract Surg 2005; 31:1444–1447 4. Dick HB, Alio´ J, Bianchetti M, et al. Toric phakic intraocular lens: European multicenter study. Ophthalmology 2003; 110:150–162 5. Tehrani M, Dick HB. Iris-fixated toric phakic intraocular lens: three-year follow-up. J Cataract Refract Surg 2006; 32:1301–1306
J CATARACT REFRACT SURG - VOL 32, NOVEMBER 2006
relatively easy. I would disenclavate the pIOL, rotate the IOL by some degrees (toric implant), and reenclavate the pIOL again, maybe with a little less tissue than shown in Figure 2. In our published case,1 the patient was not very happy with long-term use of a drug (permanent dilation with tropicamide) to solve his problem; therefore, the surgical intervention described above was performed. If residual refractive errors remains, it could be corrected with excimer laser surgery after the main problem has been solved.
My last thoughtdand my having so many may reveal by now how unsure I am about this diagnosisdis the possibility of transient pupillary block resulting in transient forward movement of the Verisyse IOL and myopic shift. Transillumination of the iridotomy or iridectomy along with establishment of bilateral aqueous flow through it on slitlamp biomicroscopy may be helpful. John A. Kanellopoulos, MD Athens, Greece
Thomas Kohnen, MD Frankfurt, Germany REFERENCE 1. Kohnen T, Cichocki M, Bu¨hren J, Baumeister M. Intermittent myopic shift of 4.0 diopters after implantation of an Artisan iris-supported phakic intraocular lens. J Cataract Refract Surg 2005; 31:1444–1447
- It is highly unusual to have great fluctuations of correction in a Verisyse IOL patient, especially 1 month after surgery. I have followed closely several patients in my European practice as well as during my experiences as U.S. Food and Drug Administrator investigator in New York. I have several thoughts in regard to this unusual transient myopic shift of this patient. A possible etiology may be hormonal, poor glucose levels, or both. In this case, the possibility of this patient being pregnant or diabetic should be investigated. Because the imaging shown does not suggest IOL movement, a change in the crystalline lens secondary to this etiology may provide an explanation. A second possible etiology is a background of Marfan’s or Marfanoid body habitus. In this case, the abnormal collagen makeup may affect scleral rigidity at the incision site and produce refraction fluctuations. A careful family history and general physical assessment may contribute to this diagnosisdan important one, especially because of the high risk for anatomic vascular and cardiac complications. I have seen a case in which the IOL claw haptic eroded through the iris it was holding onto. As a result, the IOL offered slight movement as the now-touching ends of the claw haptic moved freely through an iris tunnel, keeping the lens flush on the iris but changing its torsional position on the iris without moving in regard to the rest of the anterior chamber. This should also be apparent with careful slitlamp biomicroscopy. Another etiology may be fluctuation of the keratometric cylinder caused by an unstable wound. This could be manifested on serial topographies.
- Verisyse IOL implantation would also be my technique of choice for this patient. I have many patients with this IOL, and the results are generally excellent. It would be interesting to measure the thickness of the natural crystalline lens with the Visante and other devices under conditions of normal vision and low vision to see whether there is any difference and to evaluate the relationship between the status of accommodation and the visual performance, again with the Visante. Is the event the consequence of transitory edema of the lens? Is it accommodative spasm? I would treat the patient with atropine for 1 week and evaluate the result. Lucio Buratto, MD Milan, Italy
- I would do further examinations. The first step would be to apply a mydriatic eyedrop (eg, tropicamide) at the time of the next decrease in visual acuity in the left eye to evaluate whether the visual acuity increases with these mydriatic drops. The objective refraction can be measured at different pupil sizes after application of tropicamide using wavefront analysis to evaluate the relationship between pupil size and refraction (spherical equivalent).1 Before and after cycloplegia, the distance of the pIOL to the crystalline lens would be measured using OCT or Scheimpflug imaging technology. To exclude an impact of the relative position of the pIOL to the line of sight, I would determine the centration of the pIOL optic, especially torus orientation relative to the center of the pupil.2 Regarding etiology of the phenomenon, various possible explanations for the very rare influence of the pIOL on the intermittent refractive shift have been reported.3 These include a shifting distance between the pIOL and the crystalline lens or the triggering of tractive power on the ciliary
J CATARACT REFRACT SURG - VOL 32, NOVEMBER 2006
1905
CONSULTATION SECTION
body by the enclavated haptic. The traction of the iris can force the ciliary body to move inward and forward, which would be in the same direction the ciliary muscle contracts during accommodation. If the drug-induced cycloplegia resolves the refractive problem, relaxation of the iris and the ciliary muscle would underline this hypothesis. Moreover, an irritation of vessels or nerves might induce ciliary muscle contraction because of the anatomic proximity to the ciliary body. Fortunately, only few very similar cases have been published until now. Iris-fixated pIOLs are enclavated in iris tissue for permanent fixation and do not rotate over several years.4,5 If the myopic shift of the pIOL is connected with the enclavation of the iris-fixated pIOL, I would reenclavate the iris via a small tunnel incision with less iris tissue first. If the reenclavation did not solve the problem, I would exchange the pIOL for another model of toric pIOL with the torus orientation perpendicular to the current direction to
1906
allow repositioning 90 degrees from the current enclavation position. H. Burkhard Dick, MD Bochum, Germany REFERENCES 1. Dick HB, Aliyeva S, Tehrani M. Change in pupil size after implantation of an iris-fixated toric phakic intraocular lens. J Cataract Refract Surg 2005; 31:302–307 2. Kottler UB, Tehrani M, Dick HB. Impact of the line of sight on toric phakic intraocular lenses for hyperopia. J Cataract Refract Surg 2004; 30:1799–1801 3. Kohnen T, Cichoki M, Bu¨hren J, Baumeister M. Intermittent myopic shift of 4.0 diopters after implantation of an Artisan iris-supported phakic intraocular lens. J Cataract Refract Surg 2005; 31:1444–1447 4. Dick HB, Alio´ J, Bianchetti M, et al. Toric phakic intraocular lens: European multicenter study. Ophthalmology 2003; 110:150–162 5. Tehrani M, Dick HB. Iris-fixated toric phakic intraocular lens: three-year follow-up. J Cataract Refract Surg 2006; 32:1301–1306
J CATARACT REFRACT SURG - VOL 32, NOVEMBER 2006