CONSULTATION SECTION
ectasia after laser in situ keratomileusis. J Cataract Refract Surg 2012; 38:2117–2124 3. Poli M, Cornut P-L, Balmitgere T, Aptel F, Janin H, Burillon C. Prospective study of corneal collagen cross-linking efficacy and tolerance in the treatment of keratoconus and corneal ectasia: 3-year results. Cornea 2013; 32:583–590 4. Pallikaris IG, Kymionis GD, Astyrakakis NI. Corneal ectasia induced by laser in situ keratomileusis. J Cataract Refract Surg 2001; 27:1796–1802
- The data support the history that this patient was at low risk for ectasia, considering the preoperative parameters for the LASIK procedure. My approach to this case would be corneal CXL because I believe the progression of the ectasia may continue in the future. Unfortunately, in my experience, post-LASIK ectasia does not observe the usual “rules” of keratoconus, which usually include stabilization after the age of 40 years. We have studied thoroughly several markers that may help document progressive ectasia and have reported that surprisingly, the markers are the index of surface variance (ISV) and the index of height decentration (IHD), both of which are asymmetry indices provided by Pentacam imaging (Oculus). The ISV and IHD appear far more sensitive in monitoring corneal ectasia than traditionally evaluated acuity, average keratometry, and corneal thickness.1 I would not suggest observing this case because I believe there is significant ectasia already. I would consult the patient to determine whether there is any eye rubbing, and considering the significant corneal and refractive irregularity and the reduced CDVA, I would offer this patient not only CXL but high-fluence corneal CXL combined with “frugal” topography-guided PRK normalization of the irregularity to CDVA (with spectacles). We introduced a topography-guided platform2 to use in a therapeutic manner in these cases. We have since reported that this approach, the Athens protocol, provides excellent ectasia stabilization and relatively satisfactory results in visual rehabilitation.3–7 In our latest long-term assessment of keratoconus cases,8 we found that Scheimpflug-driven excimer laser normalization may be better than using a Placidodisk platform. This intervention may require several weeks to heal compared with simple CXL, and ectasia cases usually require additional refractive correction with spectacles and/or soft contact lenses posttreatment. The resulting refractive change is usually a myopic shift because the normalization of such inferior steepening will attempt to steepen the central cornea and flatten the inferior ectasia, normalizing the central cornea.
1937
If the residual refractive error could not be corrected after this procedure, I would wait at least 3 to 6 months to ascertain what that refraction would be, with spectacles or contact lenses as an option, as well as the possibility of phakic IOL implantation. In Europe, we can implant toric IOLs that may address this problem. Last, looking at this significant complication, one may argue whether prophylactic CXL treatment with very high fluence at the completion of the primary LASIK procedure would have prevented the ectasia. We have introduced9 and reported prophylactic CXL in LASIK with encouraging preliminary results in LASIK stability, which were confirmed by higher hyperopic LASIK stability over a long-term follow-up.10,11 A. John Kanellopoulos, MD Athens, Greece New York City, New York, USA Dr. Kanellopoulos has a financial interest in Alcon Laboratories, Inc. and Avedro. REFERENCES 1. Kanellopoulos AJ, Asimellis G. Revisiting keratoconus diagnosis and progression classification based on evaluation of corneal asymmetry indices, derived from Scheimpflug imaging in keratoconic and suspect cases. Clin Ophthalmol 2013; 7:1539–1548. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC 3735334/pdf/opth-7-1539.pdf. Accessed September 23, 2013 2. Kanellopoulos AJ, Binder PS. Collagen cross-linking (CCL) sequential topography-guided PRK; a temporizing alternative for keratoconus to penetrating keratoplasty. Cornea 2007; 26:891–895 3. Kanellopoulos AJ. Comparison of sequential vs same-day simultaneous collagen cross-linking and topography-guided PRK for treatment of keratoconus. J Refract Surg 2009; 25:S812–S818 4. Kanellopoulos AJ. Collagen cross-linking in early keratoconus with riboflavin in a femtosecond laser-created pocket: initial clinical results. J Refract Surg 2009; 25:1034–1037 5. Krueger RR, Kanellopoulos AJ. Stability of simultaneous topography-guided photorefractive keratectomy and riboflavin/ UVA cross-linking for progressive keratoconus: case reports. J Refract Surg 2010; 26:S827–S832 6. Kanellopoulos AJ, Binder PS. Management of corneal ectasia after LASIK with combined, same-day, topography-guided partial transepithelial PRK and collagen cross-linking: the Athens Protocol. J Refract Surg 2011; 27:323–331 7. Kanellopoulos AJ. Long term results of a prospective randomized bilateral eye comparison trial of higher fluence, shorter duration ultraviolet A radiation, and riboflavin collagen cross linking for progressive keratoconus. Clin Ophthalmol 2012; 6:97–101. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC 3261695/pdf/opth-6-097.pdf. Accessed September 12, 2013 8. Kanellopoulos AJ, Asimellis G. Comparison of Placido disc and Scheimpflug image-derived topography-guided excimer laser surface normalization combined with higher fluence CXL: the Athens Protocol, in progressive keratoconus. Clin Ophthalmol 2013; 7:1385–1396. Available at: http://www.ncbi.nlm.nih.gov/ pmc/articles/PMC3720663/pdf/opth-7-1385.pdf. Accessed September 23, 2013
J CATARACT REFRACT SURG - VOL 39, DECEMBER 2013
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9. Kanellopoulos AJ. Long-term safety and efficacy follow-up of prophylactic higher fluence collagen cross-linking in high myopic laser-assisted in situ keratomileusis. Clin Ophthalmol 2012; 6:1125–1130. Available at: http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3413339/pdf/opth-6-1125.pdf. Accessed September 12, 2013 10. Kanellopoulos AJ, Khan J. Topography-guided hyperopic LASIK with and without high irradiance collagen cross-linking: initial comparative clinical findings in a contralateral eye study of 34 consecutive patients. J Refract Surg 2012; 28:S837–S840 11. Kanellopoulos AJ, Pamel GJ. Review of current indications for combined very high fluence collagen cross-linking and laser in situ keratomileusis surgery. Indian J Ophthalmol 2013; 61:430– 432. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/ PMC3775081/?reportZprintable. Accessed September 23, 2013
- This patient has an advanced case of ectasia after LASIK. I would perform CXL immediately and would not wait for progression. I would also combine the CXL with PRK. I would not lift the flap because it may stabilize the cornea a little. Rather, I would remove the epithelium; perform topography-guided PRK, undercorrecting by approximately 20%; soak the cornea with riboflavin for 10 minutes; and then irradiate with UV light for 30 minutes or 10 minutes, depending on the equipment used. I would limit the ablation depth to 60 mm, which means my optical zone would be approximately 5.0 mm. I would advise the patient that the chance of a good result, meaning good vision with spectacles only, is not very high but that alternatives, such as corneal transplantation, can be used later if the CXL fails. The reason I like to combine CXL and PRK is that the CXL alone will not improve vision in most cases. The downside of potentially poorer predictability of a combined versus a staged procedure is outweighed by the advantage that vision improves earlier. Michael C. Knorz, MD Mannheim, Germany
EDITOR’S COMMENT Corneal ectasia, or progressive steepening and thinning of the cornea after excimer laser ablation, is a rare but well-known cause of reduced CDVA (with spectacles). Abnormal corneal topography, young age, treatment of high myopia and the subsequent high amount of tissue ablated, low RSB thickness, and low preoperative CCT are thought to be risk factors for developing postLASIK ectasia, and surgeons often take these factors into account when evaluating refractive surgery candidates. It is a challenging situation when ectasia occurs after LASIK despite normal preoperative topography and/or a low preoperative risk. Fortunately, there is scientific evidence that we have an option to halt the progression and, in some cases, to regularize the cornea, subsequently improving visual acuity. The bulk of the respondents suggested that CXL should be performed as soon as possible as the best option to slow or halt the progression of the ectasia that is related to refractive surgery. Most respondents would also add a procedure to make the cornea more regular to improve CDVA. There is some divergence, however, in terms of which procedure to use to regularize the cornea; ICRS and topography-guided or Scheimpflug map–guided procedures are equally popular and advocated to be safe and effective if some limits are respected. Most respondents believe that the flap was thicker than expected, thus playing a significant role in the ectasia despite normal preoperative parameters.
Marcony R. Santhiago, MD, PhD Rio de Janeiro, Brazil
J CATARACT REFRACT SURG - VOL 39, DECEMBER 2013
ectasia after laser in situ keratomileusis. J Cataract Refract Surg 2012; 38:2117–2124 3. Poli M, Cornut P-L, Balmitgere T, Aptel F, Janin H, Burillon C. Prospective study of corneal collagen cross-linking efficacy and tolerance in the treatment of keratoconus and corneal ectasia: 3-year results. Cornea 2013; 32:583–590 4. Pallikaris IG, Kymionis GD, Astyrakakis NI. Corneal ectasia induced by laser in situ keratomileusis. J Cataract Refract Surg 2001; 27:1796–1802
- The data support the history that this patient was at low risk for ectasia, considering the preoperative parameters for the LASIK procedure. My approach to this case would be corneal CXL because I believe the progression of the ectasia may continue in the future. Unfortunately, in my experience, post-LASIK ectasia does not observe the usual “rules” of keratoconus, which usually include stabilization after the age of 40 years. We have studied thoroughly several markers that may help document progressive ectasia and have reported that surprisingly, the markers are the index of surface variance (ISV) and the index of height decentration (IHD), both of which are asymmetry indices provided by Pentacam imaging (Oculus). The ISV and IHD appear far more sensitive in monitoring corneal ectasia than traditionally evaluated acuity, average keratometry, and corneal thickness.1 I would not suggest observing this case because I believe there is significant ectasia already. I would consult the patient to determine whether there is any eye rubbing, and considering the significant corneal and refractive irregularity and the reduced CDVA, I would offer this patient not only CXL but high-fluence corneal CXL combined with “frugal” topography-guided PRK normalization of the irregularity to CDVA (with spectacles). We introduced a topography-guided platform2 to use in a therapeutic manner in these cases. We have since reported that this approach, the Athens protocol, provides excellent ectasia stabilization and relatively satisfactory results in visual rehabilitation.3–7 In our latest long-term assessment of keratoconus cases,8 we found that Scheimpflug-driven excimer laser normalization may be better than using a Placidodisk platform. This intervention may require several weeks to heal compared with simple CXL, and ectasia cases usually require additional refractive correction with spectacles and/or soft contact lenses posttreatment. The resulting refractive change is usually a myopic shift because the normalization of such inferior steepening will attempt to steepen the central cornea and flatten the inferior ectasia, normalizing the central cornea.
1937
If the residual refractive error could not be corrected after this procedure, I would wait at least 3 to 6 months to ascertain what that refraction would be, with spectacles or contact lenses as an option, as well as the possibility of phakic IOL implantation. In Europe, we can implant toric IOLs that may address this problem. Last, looking at this significant complication, one may argue whether prophylactic CXL treatment with very high fluence at the completion of the primary LASIK procedure would have prevented the ectasia. We have introduced9 and reported prophylactic CXL in LASIK with encouraging preliminary results in LASIK stability, which were confirmed by higher hyperopic LASIK stability over a long-term follow-up.10,11 A. John Kanellopoulos, MD Athens, Greece New York City, New York, USA Dr. Kanellopoulos has a financial interest in Alcon Laboratories, Inc. and Avedro. REFERENCES 1. Kanellopoulos AJ, Asimellis G. Revisiting keratoconus diagnosis and progression classification based on evaluation of corneal asymmetry indices, derived from Scheimpflug imaging in keratoconic and suspect cases. Clin Ophthalmol 2013; 7:1539–1548. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC 3735334/pdf/opth-7-1539.pdf. Accessed September 23, 2013 2. Kanellopoulos AJ, Binder PS. Collagen cross-linking (CCL) sequential topography-guided PRK; a temporizing alternative for keratoconus to penetrating keratoplasty. Cornea 2007; 26:891–895 3. Kanellopoulos AJ. Comparison of sequential vs same-day simultaneous collagen cross-linking and topography-guided PRK for treatment of keratoconus. J Refract Surg 2009; 25:S812–S818 4. Kanellopoulos AJ. Collagen cross-linking in early keratoconus with riboflavin in a femtosecond laser-created pocket: initial clinical results. J Refract Surg 2009; 25:1034–1037 5. Krueger RR, Kanellopoulos AJ. Stability of simultaneous topography-guided photorefractive keratectomy and riboflavin/ UVA cross-linking for progressive keratoconus: case reports. J Refract Surg 2010; 26:S827–S832 6. Kanellopoulos AJ, Binder PS. Management of corneal ectasia after LASIK with combined, same-day, topography-guided partial transepithelial PRK and collagen cross-linking: the Athens Protocol. J Refract Surg 2011; 27:323–331 7. Kanellopoulos AJ. Long term results of a prospective randomized bilateral eye comparison trial of higher fluence, shorter duration ultraviolet A radiation, and riboflavin collagen cross linking for progressive keratoconus. Clin Ophthalmol 2012; 6:97–101. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC 3261695/pdf/opth-6-097.pdf. Accessed September 12, 2013 8. Kanellopoulos AJ, Asimellis G. Comparison of Placido disc and Scheimpflug image-derived topography-guided excimer laser surface normalization combined with higher fluence CXL: the Athens Protocol, in progressive keratoconus. Clin Ophthalmol 2013; 7:1385–1396. Available at: http://www.ncbi.nlm.nih.gov/ pmc/articles/PMC3720663/pdf/opth-7-1385.pdf. Accessed September 23, 2013
J CATARACT REFRACT SURG - VOL 39, DECEMBER 2013
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9. Kanellopoulos AJ. Long-term safety and efficacy follow-up of prophylactic higher fluence collagen cross-linking in high myopic laser-assisted in situ keratomileusis. Clin Ophthalmol 2012; 6:1125–1130. Available at: http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3413339/pdf/opth-6-1125.pdf. Accessed September 12, 2013 10. Kanellopoulos AJ, Khan J. Topography-guided hyperopic LASIK with and without high irradiance collagen cross-linking: initial comparative clinical findings in a contralateral eye study of 34 consecutive patients. J Refract Surg 2012; 28:S837–S840 11. Kanellopoulos AJ, Pamel GJ. Review of current indications for combined very high fluence collagen cross-linking and laser in situ keratomileusis surgery. Indian J Ophthalmol 2013; 61:430– 432. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/ PMC3775081/?reportZprintable. Accessed September 23, 2013
- This patient has an advanced case of ectasia after LASIK. I would perform CXL immediately and would not wait for progression. I would also combine the CXL with PRK. I would not lift the flap because it may stabilize the cornea a little. Rather, I would remove the epithelium; perform topography-guided PRK, undercorrecting by approximately 20%; soak the cornea with riboflavin for 10 minutes; and then irradiate with UV light for 30 minutes or 10 minutes, depending on the equipment used. I would limit the ablation depth to 60 mm, which means my optical zone would be approximately 5.0 mm. I would advise the patient that the chance of a good result, meaning good vision with spectacles only, is not very high but that alternatives, such as corneal transplantation, can be used later if the CXL fails. The reason I like to combine CXL and PRK is that the CXL alone will not improve vision in most cases. The downside of potentially poorer predictability of a combined versus a staged procedure is outweighed by the advantage that vision improves earlier. Michael C. Knorz, MD Mannheim, Germany
EDITOR’S COMMENT Corneal ectasia, or progressive steepening and thinning of the cornea after excimer laser ablation, is a rare but well-known cause of reduced CDVA (with spectacles). Abnormal corneal topography, young age, treatment of high myopia and the subsequent high amount of tissue ablated, low RSB thickness, and low preoperative CCT are thought to be risk factors for developing postLASIK ectasia, and surgeons often take these factors into account when evaluating refractive surgery candidates. It is a challenging situation when ectasia occurs after LASIK despite normal preoperative topography and/or a low preoperative risk. Fortunately, there is scientific evidence that we have an option to halt the progression and, in some cases, to regularize the cornea, subsequently improving visual acuity. The bulk of the respondents suggested that CXL should be performed as soon as possible as the best option to slow or halt the progression of the ectasia that is related to refractive surgery. Most respondents would also add a procedure to make the cornea more regular to improve CDVA. There is some divergence, however, in terms of which procedure to use to regularize the cornea; ICRS and topography-guided or Scheimpflug map–guided procedures are equally popular and advocated to be safe and effective if some limits are respected. Most respondents believe that the flap was thicker than expected, thus playing a significant role in the ectasia despite normal preoperative parameters.
Marcony R. Santhiago, MD, PhD Rio de Janeiro, Brazil
J CATARACT REFRACT SURG - VOL 39, DECEMBER 2013
