- Email: [email protected]
Implantable Collamer lens for hyperopia after radial keratotomy
CASE REPORT
Implantable Collamer lens for hyperopia after radial keratotomy Kazutaka Kamiya, MD, Kimiya Shimizu, MD
We report a patient in whom an implantable Collamer lens (ICL) (Staar Surgical) was used to correct hyperopia after radial keratotomy (RK). The manifest refraction improved from C5.50 1.5 85 preoperatively, with an uncorrected visual acuity (UCVA) of 0.2 and a best spectacle-corrected visual acuity (BSCVA) of 1.2, to C0.50 1.25 90 postoperatively, with a UCVA of 0.8 and a BSCVA of 1.2. No serious complications or progressive hyperopic shift was observed during the 1-year follow-up. In light of the biomechanical instability of the incised cornea, hyperopic ICL implantation may be an alternative surgical option for the correction of hyperopia after RK. J Cataract Refract Surg 2008; 34:1403–1404 Q 2008 ASCRS and ESCRS
Consecutive hyperopic shift following radial keratectomy (RK) is a significant complication that is often associated with central flattening of the cornea. Surgical options for treating post-RK overcorrection include hyperopic laser in situ keratomileusis (H-LASIK), hyperopic photorefractive keratectomy, laser thermal keratoplasty, and corneal suture. However, because the biomechanical properties of the cornea may be compromised by mechanical incisions and thus the refractive instability may persist for a long period, implantation of a phakic intraocular lens (pIOL) may be a better approach than a laser corneal refractive procedure such as H-LASIK. The Visian implantable Collamer lens (ICL, Staar Surgical), a posterior chamber pIOL, is reported to be effective for the correction of moderate to high myopia1,2 as well as hyperopia.3,4 To our knowledge, there has been no case reports of the management of overcorrection after RK by ICL implantation. In the case we present, hyperopic ICL implantation was beneficial in the correction of refractive hyperopic shift after RK.
CASE REPORT A 49-year-old man who had had bilateral RK to correct myopia 20 years earlier in another clinic was referred to our hospital with a complaint of blurred vision and asthenopia in the right eye. The manifest refraction in that eye was C5.5 1.5 85, with an uncorrected visual acuity (UCVA) of 0.2 and a best spectacle-corrected visual acuity (BSCVA) of 1.2. In the fellow eye, the manifest refraction was 0 0.5 165, with a UCVA of 1.2 and a BSCVA of 1.5. The anterior chamber depth (ACD) was 3.81 mm, the keratometry reading was 34.5/35.3 @ 125, the endothelial cell density (ECD) was 2840 cells/mm2, and the intraocular pressure (IOP) was 13 mm Hg. The corneal topography (ATRAS995, Carl Zeiss Meditec) showed marked central flattening of the cornea (Figure 1). The slitlamp examination also showed central flattening of the cornea with 6 RK incisions. Other ophthalmic examination findings were unremarkable. The ICL power and length calculations were performed by the
Accepted for publication March 24, 2008. From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. Neither author has a financial or proprietary interest in any material or method mentioned. Corresponding author: Kazutaka Kamiya, MD, PhD, Department of Ophthalmology, University of Kitasato School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan. E-mail: [email protected]. Q 2008 ASCRS and ESCRS Published by Elsevier Inc.
Figure 1. Preoperative corneal topography shows marked central flattening of the cornea. 0886-3350/08/$dsee front matter doi:10.1016/j.jcrs.2008.03.045
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CASE REPORT: ICL IMPLANTATION FOR HYPEROPIA AFTER RK
manufacturer (Staar Surgical) using manifest refraction, corneal curvature, ACD, a central corneal thickness of 0.557 mm, and a white-to-white distance of 12.6 mm. After informed consent was obtained, a hyperopic ICL (C8.0 diopters, length 12.5 mm) was implanted in the right eye through a 3.0 mm corneal incision made to avoid the RK incisions. On day 1, the UCVA was 1.0. At 1 month, the manifest refraction was C0.50 1.25 90, with a UCVA of 0.8 and a BSCVA of 1.2, and the keratometry was 34.0/34.5 @ 10. The ECD was 2369 cells/mm2 and the IOP, 12 mm Hg. At 1 year, the manifest refraction and keratometry were unchanged. No vision-threatening complications occurred during the 1-year follow-up.
DISCUSSION Although H-LASIK following RK provides predictable results,5–9 there is a potential risk for complications such as intraoperative incision opening,5 irregular apposition of the flap,5 epithelial ingrowth,5,6 and keratectasia.7 Moreover, H-LASIK retreatment is not as effective and predictable as myopic LASIK retreatment.7 Avoiding the RK incisions may be a unique challenge in these cases. In a recent report, implantation of iris-supported toric pIOLs helped manage the residual myopic astigmatism after RK, although the enhancement ablation was difficult because of a theoretical risk for keratectasia.10 Pesando et al.4 report the long-term safety, efficacy, accuracy, and predictability of hyperopic ICL implantation in a study of 59 eyes, including 3 eyes with progressive hyperopia after RK; however, the individual outcomes of post-RK eyes are not mentioned. Because toric hyperopic ICLs are not currently available, we selected a spherical ICL for hyperopia in this case. Although the residual astigmatism remained after surgery, the patient was satisfied with the postoperative visual outcome, presumably because the anisometropic asthenopia disappeared. Toric hyperopic ICL implantation may prove to be more appropriate for the correction of hyperopic astigmatism after RK. The indications for ICL implantation in hyperopic eyes are often reduced in number in clinical use because of the presence of a shallow ACD. As shown in the current case, eyes that are hyperopic due to keratorefractive surgery appear to be suitable for ICL implantation because the ACD is naturally deep as a result of the high myopia. Another possible advantage of ICL implantation over keratorefractive surgery is that the procedure is reversible, so these pIOLs can be safely exchanged even if progressive hyperopic shifts caused by biomechanical weakening of the cornea occur after surgery. There are ongoing concerns about ICL power calculation after keratorefractive surgery. It should be easier than IOL power calculation for post-RK cataract
patients because it is less dependent on corneal power than on refraction, but it is still difficult to measure the postoperative corneal power precisely. Further investigation of the role of corneal power determination in accurate ICL power selection is needed. Our case report suggests that the use of a hyperopic ICL may be an alternative for the treatment of overcorrection after RK. Although we have to improve the accuracy of ICL power calculation after RK, the preliminary results are encouraging. A further study of a large series of patients should be conducted to assess the long-term safety and stability of this surgical procedure. REFERENCES 1. Implantable Contact Lens in Treatment of Myopia (ITM) Study Group. U.S. Food and Drug Administration clinical trial of the implantable contact lens for moderate to high myopia. Ophthalmology 2003; 110:255–266 2. ICL in Treatment of Myopia (ITM) Study Group. United States Food and Drug Administration clinical trial of the Implantable Collamer Lens (ICL) for moderate to high myopia; three-year follow-up. Ophthalmology 2004; 111:1683–1692 3. Davidorf JM, Zaldivar R, Oscherow S. Posterior chamber phakic intraocular lens for hyperopia of C4 to C11 diopters. J Refract Surg 1998; 14:306–311 4. Pesando PM, Ghiringhello MP, Di Meglio G, Fanton G. Posterior chamber phakic intraocular lens (ICL) for hyperopia: ten-year follow-up. J Cataract Refract Surg 2007; 33:1579–1584 5. Clausse MA, Boutros G, Khanjian G, Wagner C, Garabet AL. A retrospective study of laser in situ keratomileusis after radial keratotomy. J Refract Surg 2001; 17:S200–S201 6. Francesconi CM, Nose´ RAM, Nose´ W. Hyperopic laser-assisted in situ keratomileusis for radial keratotomy-induced hyperopia. Ophthalmology 2002; 109:602–605 7. Lyle WA. Jin GJC Laser in situ keratomileusis for consecutive hyperopia after myopic LASIK and radial keratotomy. J Cataract Refract Surg 2003; 29:879–888 8. Lipshitz I, Man O, Shemesh G, Lazar M, Loewenstein A. Laser in situ keratomileusis to correct hyperopic shift after radial keratotomy. J Cataract Refract Surg 2001; 27:273–276 9. Oral D, Awwad ST, Seward MS, Bowman RW, McCulley JP, Cavanagh HD. Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy. J Cataract Refract Surg 2005; 31:1561–1568 10. Tahzib NG, Eggink FAGJ, Odenthal MTP, Nuijts RMMA. Artisan iris-fixated toric phakic and aphakic intraocular lens implantation for the correction of astigmatic refractive error after radial keratotomy. J Cataract Refract Surg 2007; 33: 531–535
J CATARACT REFRACT SURG - VOL 34, AUGUST 2008
First author: Kazutaka Kamiya, MD Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
Implantable Collamer lens for hyperopia after radial keratotomy Kazutaka Kamiya, MD, Kimiya Shimizu, MD
We report a patient in whom an implantable Collamer lens (ICL) (Staar Surgical) was used to correct hyperopia after radial keratotomy (RK). The manifest refraction improved from C5.50 1.5 85 preoperatively, with an uncorrected visual acuity (UCVA) of 0.2 and a best spectacle-corrected visual acuity (BSCVA) of 1.2, to C0.50 1.25 90 postoperatively, with a UCVA of 0.8 and a BSCVA of 1.2. No serious complications or progressive hyperopic shift was observed during the 1-year follow-up. In light of the biomechanical instability of the incised cornea, hyperopic ICL implantation may be an alternative surgical option for the correction of hyperopia after RK. J Cataract Refract Surg 2008; 34:1403–1404 Q 2008 ASCRS and ESCRS
Consecutive hyperopic shift following radial keratectomy (RK) is a significant complication that is often associated with central flattening of the cornea. Surgical options for treating post-RK overcorrection include hyperopic laser in situ keratomileusis (H-LASIK), hyperopic photorefractive keratectomy, laser thermal keratoplasty, and corneal suture. However, because the biomechanical properties of the cornea may be compromised by mechanical incisions and thus the refractive instability may persist for a long period, implantation of a phakic intraocular lens (pIOL) may be a better approach than a laser corneal refractive procedure such as H-LASIK. The Visian implantable Collamer lens (ICL, Staar Surgical), a posterior chamber pIOL, is reported to be effective for the correction of moderate to high myopia1,2 as well as hyperopia.3,4 To our knowledge, there has been no case reports of the management of overcorrection after RK by ICL implantation. In the case we present, hyperopic ICL implantation was beneficial in the correction of refractive hyperopic shift after RK.
CASE REPORT A 49-year-old man who had had bilateral RK to correct myopia 20 years earlier in another clinic was referred to our hospital with a complaint of blurred vision and asthenopia in the right eye. The manifest refraction in that eye was C5.5 1.5 85, with an uncorrected visual acuity (UCVA) of 0.2 and a best spectacle-corrected visual acuity (BSCVA) of 1.2. In the fellow eye, the manifest refraction was 0 0.5 165, with a UCVA of 1.2 and a BSCVA of 1.5. The anterior chamber depth (ACD) was 3.81 mm, the keratometry reading was 34.5/35.3 @ 125, the endothelial cell density (ECD) was 2840 cells/mm2, and the intraocular pressure (IOP) was 13 mm Hg. The corneal topography (ATRAS995, Carl Zeiss Meditec) showed marked central flattening of the cornea (Figure 1). The slitlamp examination also showed central flattening of the cornea with 6 RK incisions. Other ophthalmic examination findings were unremarkable. The ICL power and length calculations were performed by the
Accepted for publication March 24, 2008. From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. Neither author has a financial or proprietary interest in any material or method mentioned. Corresponding author: Kazutaka Kamiya, MD, PhD, Department of Ophthalmology, University of Kitasato School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan. E-mail: [email protected]. Q 2008 ASCRS and ESCRS Published by Elsevier Inc.
Figure 1. Preoperative corneal topography shows marked central flattening of the cornea. 0886-3350/08/$dsee front matter doi:10.1016/j.jcrs.2008.03.045
1403
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CASE REPORT: ICL IMPLANTATION FOR HYPEROPIA AFTER RK
manufacturer (Staar Surgical) using manifest refraction, corneal curvature, ACD, a central corneal thickness of 0.557 mm, and a white-to-white distance of 12.6 mm. After informed consent was obtained, a hyperopic ICL (C8.0 diopters, length 12.5 mm) was implanted in the right eye through a 3.0 mm corneal incision made to avoid the RK incisions. On day 1, the UCVA was 1.0. At 1 month, the manifest refraction was C0.50 1.25 90, with a UCVA of 0.8 and a BSCVA of 1.2, and the keratometry was 34.0/34.5 @ 10. The ECD was 2369 cells/mm2 and the IOP, 12 mm Hg. At 1 year, the manifest refraction and keratometry were unchanged. No vision-threatening complications occurred during the 1-year follow-up.
DISCUSSION Although H-LASIK following RK provides predictable results,5–9 there is a potential risk for complications such as intraoperative incision opening,5 irregular apposition of the flap,5 epithelial ingrowth,5,6 and keratectasia.7 Moreover, H-LASIK retreatment is not as effective and predictable as myopic LASIK retreatment.7 Avoiding the RK incisions may be a unique challenge in these cases. In a recent report, implantation of iris-supported toric pIOLs helped manage the residual myopic astigmatism after RK, although the enhancement ablation was difficult because of a theoretical risk for keratectasia.10 Pesando et al.4 report the long-term safety, efficacy, accuracy, and predictability of hyperopic ICL implantation in a study of 59 eyes, including 3 eyes with progressive hyperopia after RK; however, the individual outcomes of post-RK eyes are not mentioned. Because toric hyperopic ICLs are not currently available, we selected a spherical ICL for hyperopia in this case. Although the residual astigmatism remained after surgery, the patient was satisfied with the postoperative visual outcome, presumably because the anisometropic asthenopia disappeared. Toric hyperopic ICL implantation may prove to be more appropriate for the correction of hyperopic astigmatism after RK. The indications for ICL implantation in hyperopic eyes are often reduced in number in clinical use because of the presence of a shallow ACD. As shown in the current case, eyes that are hyperopic due to keratorefractive surgery appear to be suitable for ICL implantation because the ACD is naturally deep as a result of the high myopia. Another possible advantage of ICL implantation over keratorefractive surgery is that the procedure is reversible, so these pIOLs can be safely exchanged even if progressive hyperopic shifts caused by biomechanical weakening of the cornea occur after surgery. There are ongoing concerns about ICL power calculation after keratorefractive surgery. It should be easier than IOL power calculation for post-RK cataract
patients because it is less dependent on corneal power than on refraction, but it is still difficult to measure the postoperative corneal power precisely. Further investigation of the role of corneal power determination in accurate ICL power selection is needed. Our case report suggests that the use of a hyperopic ICL may be an alternative for the treatment of overcorrection after RK. Although we have to improve the accuracy of ICL power calculation after RK, the preliminary results are encouraging. A further study of a large series of patients should be conducted to assess the long-term safety and stability of this surgical procedure. REFERENCES 1. Implantable Contact Lens in Treatment of Myopia (ITM) Study Group. U.S. Food and Drug Administration clinical trial of the implantable contact lens for moderate to high myopia. Ophthalmology 2003; 110:255–266 2. ICL in Treatment of Myopia (ITM) Study Group. United States Food and Drug Administration clinical trial of the Implantable Collamer Lens (ICL) for moderate to high myopia; three-year follow-up. Ophthalmology 2004; 111:1683–1692 3. Davidorf JM, Zaldivar R, Oscherow S. Posterior chamber phakic intraocular lens for hyperopia of C4 to C11 diopters. J Refract Surg 1998; 14:306–311 4. Pesando PM, Ghiringhello MP, Di Meglio G, Fanton G. Posterior chamber phakic intraocular lens (ICL) for hyperopia: ten-year follow-up. J Cataract Refract Surg 2007; 33:1579–1584 5. Clausse MA, Boutros G, Khanjian G, Wagner C, Garabet AL. A retrospective study of laser in situ keratomileusis after radial keratotomy. J Refract Surg 2001; 17:S200–S201 6. Francesconi CM, Nose´ RAM, Nose´ W. Hyperopic laser-assisted in situ keratomileusis for radial keratotomy-induced hyperopia. Ophthalmology 2002; 109:602–605 7. Lyle WA. Jin GJC Laser in situ keratomileusis for consecutive hyperopia after myopic LASIK and radial keratotomy. J Cataract Refract Surg 2003; 29:879–888 8. Lipshitz I, Man O, Shemesh G, Lazar M, Loewenstein A. Laser in situ keratomileusis to correct hyperopic shift after radial keratotomy. J Cataract Refract Surg 2001; 27:273–276 9. Oral D, Awwad ST, Seward MS, Bowman RW, McCulley JP, Cavanagh HD. Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy. J Cataract Refract Surg 2005; 31:1561–1568 10. Tahzib NG, Eggink FAGJ, Odenthal MTP, Nuijts RMMA. Artisan iris-fixated toric phakic and aphakic intraocular lens implantation for the correction of astigmatic refractive error after radial keratotomy. J Cataract Refract Surg 2007; 33: 531–535
J CATARACT REFRACT SURG - VOL 34, AUGUST 2008
First author: Kazutaka Kamiya, MD Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan