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reshaped cornea that probably already has a significant amount of spherical aberration and coma, combined with the risk for a hyperopic surprise in IOL calculation after refractive surgery and an approximate alignment of the different diopters (new corneal apex after a hyperopic treatment and geometric center of the IOL), would risk poor quality of vision. After the unsuccessful enhancement in the left eye, I am convinced the cornea should not be operated on again. Actually, it has 2 interfacesdthe new flap and the old flap. The curvature maps do not necessarily match the stromal curvature, as can be seen by the evolution of the central pachymetry, which increased from 585 mm to 605 mm 1 month after the enhancement because of the folds on the 2 interfaces. Then, 6 months after the enhancement, the central pachymetry is identical to that before the enhancement (581 mm), even though stromal loss occurred during the enhancement. Central keratometry is improving as time elapses. Thus, it is likely the cornea will continue to improve in the upcoming months. Indeed, stromal healing can take as long as 1 year. Thus, I would recommend that the patient wear rigid contact lenses to smooth the corneal surface. This clinical case highlights that managing complications after LASIK is extremely difficult with demanding patients, who often ask for enhancements. The key seems to be providing comprehensive information and support. Primum non nocere. Viridiana Kocaba, MD Lyons, France
- Although trying to lift the original flap is recommended and OCT or high-resolution OCT might provide better evaluation of the initial flap conditions, relifting is not plausible in some cases. In such cases, noncorneal refractive surgery can be considered. There are reports of higher complications with flap recutting than with flap relifting using a microkeratome1 as well as complications with retreatments performed with a femtosecond laser.2 If recutting is planned, a new deeper flap with a larger diameter is preferred.1 Particularly in hyperopic cases, such as the one presented here, this would lead to better outcomes and fewer risks. Even though ectasia after hyperopic LASIK can occur, the incidence is rare. In the near future, it might be possible to perform hyperopic refractive lenticule extraction under the previous flap. Due to potential regression and haze formation in hyperopic cases, the use of surface ablation in retreatments should be carefully weighed or avoided. However, the actual difference in the efficacy of hyperopic
treatments between LASIK and PRK is still uncertain.3 If the original regression had been myopic in this case, post-LASIK ectasia would have to be ruled out first. Then, if it were a case of mild to moderate residual myopia, PRK with MMC application could be performed. For higher myopia, pIOL implantation or RLE could be explored. In this case, RLE would have been an excellent alternative to the initial retreatment. Although there are risks with RLE, it is well accepted that hyperopic patients older than 45 years, and preferably with posterior vitreous detachment, can obtain excellent outcomes. However, RLE must be avoided in younger patients. Also, posthyperopic LASIK IOL calculations are less complicated than those after myopic LASIK.4 A spherical (positive spherical aberration) monofocal IOL is preferred. If available, a light-adjustable IOL and intraoperative wavefront analysis could be considered. Regarding how to proceed in treating this patient, I would evaluate patient performance with monovision and fit rigid contact lenses. Assuming that these alternatives are not satisfactory, refractive surgical solutions can be considered. The main problem in this case is the irregular astigmatism, which rules out conventional refractive surgery procedures such as another LASIK procedure, PRK, refractive lenticule extraction, RLE, or pIOL implantation. It is likely that wavefront or topography-guided smoothing or refractive treatments would recover CDVA, and concomitant use of MMC is highly recommended. This alternative may also be less invasive. Ideally, very-high-frequency ultrasound scanning is able to separate epithelial and stromal measurements and could be used to improve outcomes.5 Another option would be intrastromal corneal ring segment implantation; however, because of the folds and tissue scarring in this case, it may not improve the CDVA. The last option is keratoplasty, preferably anterior lamellar (superficial lamellar or pachymetry-assisted laser keratoplasty). Superficial lamellar keratoplasty could be assisted by the use of a microkeratome or femtosecond laser to go deeper into the original flap. Deep anterior lamellar keratoplasty and penetrating keratoplasty should be the last options. Alejandro Navas, MD, MSc Mexico City, Mexico REFERENCES 1. Sharma N, Balasubramanya R, Sinha R, Titiyal JS, Vajpayee RB. Retreatment of LASIK. J Refract Surg 2006; 22:396–401 2. Vaddavalli PK, Diakonis VF, Canto AP, Culbertson WW, Wang J, Kankariya VP, Yoo SH. Complications of femtosecond laser-assisted re-treatment for residual refractive errors after LASIK. J Refract Surg 2013; 29:577–580
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3. Settas G, Settas C, Minos E, Yeung IYL. Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction. Cochrane Database Syst Rev(2):CD007112 4. Shammas HJ, Shammas MC, Hill WE. Intraocular lens power calculation in eyes with previous hyperopic laser in situ keratomileusis. J Cataract Refract Surg 2013; 39:739–744 5. Reinstein DZ, Archer TJ, Gobbe M. Refractive and topographic errors in topography-guided ablation produced by epithelial compensation predicted by 3D Artemis VHF digital ultrasound stromal and epithelial thickness mapping. J Refract Surg 2012; 28:657–663
contact lenses to give the patient better optical quality. A surgical treatment would be topography guided. A topography-guided treatment would probably be the best way to reestablish the corneal curvature and restore visual quality if it is possible to proceed with this treatment while respecting safety limits. Newton Kara-Junior, MD, PhD S~ao Paulo, Brazil
- I would have first approached this case with flap relifting. Laser in situ keratomileusis flaps created with a mechanical microkeratome are usually easy to lift, even years after the original surgery. For this patient, this would have been the best option with the best outcomes. I would not consider a new side cut with a femtosecond laser. First, it is difficult to determine an adequate diameter for the new side cut in a hyperopic retreatment. Second, this approach is not free of complications because slivers of tissue can be created and the same complication might occur. If it were a myopic case in which a smaller diameter side cut were possible, this would have been my first option. If flap lift were not possible, I would have treated with surface ablation and MMC 0.02% for 40 seconds. Refractive lens exchange would have been another reasonable option in terms of visual acuity results. In this case I would have chosen a standard spherical monofocal IOL or spherical aberration–neutral IOL to counterbalance the spherical aberration of the cornea after the hyperopic treatment. After the unsuccessful enhancement, I would recommend patience because the epithelium will heal and help make the corneal surface more regular. Before considering surgery, I would prescribe RGP
- This shows the need for case-by-case decisions regarding the type of refractive procedure to use. Because the patient was a 47 year old with presbyopic hyperopia at presentation, our option would have been RLE. We would implant a monofocal IOL to avoid further issues with contrast sensitivity, glare, and haloes in this already complicated eye. A spherical aberration– neutral or spherical IOL would be preferred. We would try to convince the patient to have RLE; if she adamantly declined, the next safer option would be advanced surface ablation, despite the higher incidence of regression. A larger treatment zone with a transition zone extending up to 9.5 mm often prevents regression that may otherwise occur secondary to sudden transitions between ablated and unablated corneas. Newer machines and algorithms with topography- and wavefront-guided treatments offer good outcomes for low to moderate hyperopia (!+5.00 D). With hyperopic LASIK and advanced surface ablation, care must be taken to avoid small optical zones and decentration, which cause loss of CDVA. With enhancements, it is necessary to avoid issues that make the situation worse. A decentered primary ablation can further worsen the situation. Larger flaps, even up to 10.0 mm, are recommended for hyperopic LASIK, although these may be difficult to create in small eyes. The smaller 8.5 mm flap used in this case
Figure 4. A: Similar case in which a thinner femtosecond laser–created flap was cut in a 7-year-old microkeratome flap. This shows the femtosecond flap being dissected. B: The posterior part of the old flap was accidentally dissected while trying to lift the flap from the opposite side. C: The posterior portion of the old flap was carefully and gently laid back and excimer laser ablation performed. The final UDVA was 20/20 3. J CATARACT REFRACT SURG - VOL 40, JUNE 2014
CONSULTATION SECTION
reshaped cornea that probably already has a significant amount of spherical aberration and coma, combined with the risk for a hyperopic surprise in IOL calculation after refractive surgery and an approximate alignment of the different diopters (new corneal apex after a hyperopic treatment and geometric center of the IOL), would risk poor quality of vision. After the unsuccessful enhancement in the left eye, I am convinced the cornea should not be operated on again. Actually, it has 2 interfacesdthe new flap and the old flap. The curvature maps do not necessarily match the stromal curvature, as can be seen by the evolution of the central pachymetry, which increased from 585 mm to 605 mm 1 month after the enhancement because of the folds on the 2 interfaces. Then, 6 months after the enhancement, the central pachymetry is identical to that before the enhancement (581 mm), even though stromal loss occurred during the enhancement. Central keratometry is improving as time elapses. Thus, it is likely the cornea will continue to improve in the upcoming months. Indeed, stromal healing can take as long as 1 year. Thus, I would recommend that the patient wear rigid contact lenses to smooth the corneal surface. This clinical case highlights that managing complications after LASIK is extremely difficult with demanding patients, who often ask for enhancements. The key seems to be providing comprehensive information and support. Primum non nocere. Viridiana Kocaba, MD Lyons, France
- Although trying to lift the original flap is recommended and OCT or high-resolution OCT might provide better evaluation of the initial flap conditions, relifting is not plausible in some cases. In such cases, noncorneal refractive surgery can be considered. There are reports of higher complications with flap recutting than with flap relifting using a microkeratome1 as well as complications with retreatments performed with a femtosecond laser.2 If recutting is planned, a new deeper flap with a larger diameter is preferred.1 Particularly in hyperopic cases, such as the one presented here, this would lead to better outcomes and fewer risks. Even though ectasia after hyperopic LASIK can occur, the incidence is rare. In the near future, it might be possible to perform hyperopic refractive lenticule extraction under the previous flap. Due to potential regression and haze formation in hyperopic cases, the use of surface ablation in retreatments should be carefully weighed or avoided. However, the actual difference in the efficacy of hyperopic
treatments between LASIK and PRK is still uncertain.3 If the original regression had been myopic in this case, post-LASIK ectasia would have to be ruled out first. Then, if it were a case of mild to moderate residual myopia, PRK with MMC application could be performed. For higher myopia, pIOL implantation or RLE could be explored. In this case, RLE would have been an excellent alternative to the initial retreatment. Although there are risks with RLE, it is well accepted that hyperopic patients older than 45 years, and preferably with posterior vitreous detachment, can obtain excellent outcomes. However, RLE must be avoided in younger patients. Also, posthyperopic LASIK IOL calculations are less complicated than those after myopic LASIK.4 A spherical (positive spherical aberration) monofocal IOL is preferred. If available, a light-adjustable IOL and intraoperative wavefront analysis could be considered. Regarding how to proceed in treating this patient, I would evaluate patient performance with monovision and fit rigid contact lenses. Assuming that these alternatives are not satisfactory, refractive surgical solutions can be considered. The main problem in this case is the irregular astigmatism, which rules out conventional refractive surgery procedures such as another LASIK procedure, PRK, refractive lenticule extraction, RLE, or pIOL implantation. It is likely that wavefront or topography-guided smoothing or refractive treatments would recover CDVA, and concomitant use of MMC is highly recommended. This alternative may also be less invasive. Ideally, very-high-frequency ultrasound scanning is able to separate epithelial and stromal measurements and could be used to improve outcomes.5 Another option would be intrastromal corneal ring segment implantation; however, because of the folds and tissue scarring in this case, it may not improve the CDVA. The last option is keratoplasty, preferably anterior lamellar (superficial lamellar or pachymetry-assisted laser keratoplasty). Superficial lamellar keratoplasty could be assisted by the use of a microkeratome or femtosecond laser to go deeper into the original flap. Deep anterior lamellar keratoplasty and penetrating keratoplasty should be the last options. Alejandro Navas, MD, MSc Mexico City, Mexico REFERENCES 1. Sharma N, Balasubramanya R, Sinha R, Titiyal JS, Vajpayee RB. Retreatment of LASIK. J Refract Surg 2006; 22:396–401 2. Vaddavalli PK, Diakonis VF, Canto AP, Culbertson WW, Wang J, Kankariya VP, Yoo SH. Complications of femtosecond laser-assisted re-treatment for residual refractive errors after LASIK. J Refract Surg 2013; 29:577–580
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3. Settas G, Settas C, Minos E, Yeung IYL. Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction. Cochrane Database Syst Rev(2):CD007112 4. Shammas HJ, Shammas MC, Hill WE. Intraocular lens power calculation in eyes with previous hyperopic laser in situ keratomileusis. J Cataract Refract Surg 2013; 39:739–744 5. Reinstein DZ, Archer TJ, Gobbe M. Refractive and topographic errors in topography-guided ablation produced by epithelial compensation predicted by 3D Artemis VHF digital ultrasound stromal and epithelial thickness mapping. J Refract Surg 2012; 28:657–663
contact lenses to give the patient better optical quality. A surgical treatment would be topography guided. A topography-guided treatment would probably be the best way to reestablish the corneal curvature and restore visual quality if it is possible to proceed with this treatment while respecting safety limits. Newton Kara-Junior, MD, PhD S~ao Paulo, Brazil
- I would have first approached this case with flap relifting. Laser in situ keratomileusis flaps created with a mechanical microkeratome are usually easy to lift, even years after the original surgery. For this patient, this would have been the best option with the best outcomes. I would not consider a new side cut with a femtosecond laser. First, it is difficult to determine an adequate diameter for the new side cut in a hyperopic retreatment. Second, this approach is not free of complications because slivers of tissue can be created and the same complication might occur. If it were a myopic case in which a smaller diameter side cut were possible, this would have been my first option. If flap lift were not possible, I would have treated with surface ablation and MMC 0.02% for 40 seconds. Refractive lens exchange would have been another reasonable option in terms of visual acuity results. In this case I would have chosen a standard spherical monofocal IOL or spherical aberration–neutral IOL to counterbalance the spherical aberration of the cornea after the hyperopic treatment. After the unsuccessful enhancement, I would recommend patience because the epithelium will heal and help make the corneal surface more regular. Before considering surgery, I would prescribe RGP
- This shows the need for case-by-case decisions regarding the type of refractive procedure to use. Because the patient was a 47 year old with presbyopic hyperopia at presentation, our option would have been RLE. We would implant a monofocal IOL to avoid further issues with contrast sensitivity, glare, and haloes in this already complicated eye. A spherical aberration– neutral or spherical IOL would be preferred. We would try to convince the patient to have RLE; if she adamantly declined, the next safer option would be advanced surface ablation, despite the higher incidence of regression. A larger treatment zone with a transition zone extending up to 9.5 mm often prevents regression that may otherwise occur secondary to sudden transitions between ablated and unablated corneas. Newer machines and algorithms with topography- and wavefront-guided treatments offer good outcomes for low to moderate hyperopia (!+5.00 D). With hyperopic LASIK and advanced surface ablation, care must be taken to avoid small optical zones and decentration, which cause loss of CDVA. With enhancements, it is necessary to avoid issues that make the situation worse. A decentered primary ablation can further worsen the situation. Larger flaps, even up to 10.0 mm, are recommended for hyperopic LASIK, although these may be difficult to create in small eyes. The smaller 8.5 mm flap used in this case
Figure 4. A: Similar case in which a thinner femtosecond laser–created flap was cut in a 7-year-old microkeratome flap. This shows the femtosecond flap being dissected. B: The posterior part of the old flap was accidentally dissected while trying to lift the flap from the opposite side. C: The posterior portion of the old flap was carefully and gently laid back and excimer laser ablation performed. The final UDVA was 20/20 3. J CATARACT REFRACT SURG - VOL 40, JUNE 2014
