CONSULTATION SECTION
If the patient refuses this solution, it is unrealistic to consider improving corneal regularity using an excimer laser, topography guided or not. Anterior lamellar keratoplasty also gives disappointing results in these cases. Although the graft is very regular, it will be positioned on a recipient bed that will be irregular. The AS-OCT image shows that the nasal epithelial ingrowth tends to lift the corneal flap, causing bulging of the cornea that increases the irregular astigmatism. It is easy to remove the island of epithelial ingrowth without having to lift the flap. One could press on the cornea using a blunt cannula to externalize all the epithelial ingrowth through the small hole at the trephination area around 4 hours. This can be performed at the slitlamp. If visual recovery were not satisfactory, I would pursue a more aggressive treatment. Removal of the flap could be attempted because it is possible there is a more regular stromal bed under the flap. However, the result would still be unsatisfactory, and I would suggest this solution only if the patient refuses corneal transplantation. The best solution is DALK, the only technique that removes the entire stroma while maintaining the corneal endothelium. The technical difficulty of DALK is related to the presence of the flap. I would not risk a large-diameter transplantation (ie, greater than 9.5 mm). If a femtosecond laser were available, a possibility would be to perform a mushroom-shaped DALK. The cut would have a depth of 550 mm, an anterior diameter of 9.0 mm, and a posterior diameter of 7.0 mm. The anterior stroma would be removed with a spatula, Descemet membrane would be bared using a big-bubble technique, and a mushroom graftd prepared with the femtosecond laser (without endothelium)dwould be sutured in place. If a femtosecond laser is not available, I would suggest manually removing the flap first, cleaning both areas of epithelial invasion, and placing an 8.0 mm top hat–shaped lamellar graft. This graft can easily be prepared manually on an artificial anterior chamber. After a 550 mm deep nonpenetrating trephination of 8.0 mm diameter is created, I would perform a lamellar dissection over 360 degrees up to the limbus using a spatula to obtain a peripheral skirt that is 150 mm thick. The endothelium would then be removed. The same dissection would be performed on the recipient, the anterior stroma removed using a spatula, and Descemet membrane bared using a bigbubble technique. The skirt of the top-hat lamellar graft would be introduced into the peripheral posterior pocket of the recipient. Subsequently, the thickness of the graft would be equivalent to the thickness of the peripheral
1573
stroma of the recipient. The graft would then be sutured in the usual manner. Marc Muraine, MD, PhD Rouen, France
- The main problem with taking a superficial approach (flap amputation, epithelial ingrowth scraping, topography-guided ablation for the irregular astigmatism, or a combination) is the depth of the opacity, as seen on the AS-OCT image. In the best scenario, there will be significant residual paracentral opacity, some degree of residual irregular astigmatism and, possibly, a significant hyperopic shift, which could be managed with contact lens fitting. However, this seems unacceptable for this patient. I would purpose performing descemetic DALK with a diameter of 8.0 to 8.5 mm. At least 18 months later, once all the sutures have been removed, I would correct the refractive error, if needed, through an intraocular procedure. Jose L. G€ uell, MD Barcelona, Spain
- This case shows the potential risks of retreatments after refractive surgery, including insufficiently treated astigmatism, a hyperopic outcome, and epithelial ingrowth. Given the patient's medical history, and before beginning a treatment regimen, it is important to discuss at length the options for treatment and their related outcomes. The patient's motivation for wearing a contact lens after developing a contact lens–related Pseudomonas ulcer, and in view of his profession, is understandably low and underlines the necessity for a more definite solution. If flap amputation is considered, one has to be aware of a more hyperopic outcome, worse UDVA, and a flat cornea. Fitting a contact lens on a central flat cornea, even when performed by an experienced technician or optometrist, is difficult and the patient's motivation for contact lens wear will be low. I would avoid treating the stromal scar. Retreating a stromal scar with a topography-guided excimer laser treatment, possibly in combination with removal of the epithelial ingrowth, will lead to more flattening of the cornea and another unpredictable outcome. The amount of tissue that will have to be removed will lead to thinning of the stromal bed, and the irregularity may remain the same or become worse. I would discuss the possibility of anterior lamellar graft excision in combination with the use of lamellar
J CATARACT REFRACT SURG - VOL 40, SEPTEMBER 2014
1574
CONSULTATION SECTION
donor tissue. I would advise creating a deep lamellar cut using a big-bubble technique or a femtosecond laser. The diameter must be at least the size of the flap (approximately 9.0 mm overall). The goal must be to restore the curvature of the cornea and create a translucent cornea without a scar. The depth of removal of the anterior stroma must be more than 70% of the central thickness. Among the things that have to be discussed with the patient are the visual and refractive outcomes, interface-related problems, and refractive correction after the surgery. Once the sutures are removed, the final refractive outcome can be managed by performing a refractive lens exchange. The last suggested option, a (penetrating) mushroom-shaped keratoplasty, is not yet necessary because the endothelial cell count remains the same after excimer laser surgery. The visual outcomes of a penetrating procedure are potentially better than those of a lamellar procedure; however, the wound architecture, graft rejection period, and long period of topical medication use make this treatment less preferable than lamellar grafting. Annette J.M. Geerards, MD Rotterdam, the Netherlands
rejection and early cataract formation, and the patient must be informed about this. As an alternative, the corneal flap can be relifted where there is epithelial ingrowth and removed. Removing the epithelial ingrowth will allow the corneal flap to heal. Then, pachymetry-assisted laser keratoplasty can be performed using an excimer laser; however, this will entail 2 separate operations. The reason for epithelial removal is because the trapped epithelium undergoes degeneration, which forms foamy cells. These foamy cells will be soft and liquefied and will not ablate uniformly with an excimer laser. Without the epithelial ingrowth, pachymetry-assisted laser keratoplasty would be easy to perform because the excimer laser is guided by pachymetry and not topography. The residual bed can be set to a minimum of 80 mm using an Amaris laser (Schwind). However, in this case, I would not advise this because of the presence of epithelial ingrowth of at least 60 mm estimated from the corneal OCT. Because of the thinness of the cornea, lamellar keratoplasty is required and for the best optical quality, DALK is still the top option. Jerry Tan, MD Singapore
- This case has many interesting clinical dilemmas and many learning points. Relift enhancements increase the risk for epithelial ingrowth, especially in microkeratome cuts with their sloping edges. In my experience, a higher number of relift enhancements increases the risk for epithelial ingrowth. Hyperopic relift enhancements also increase the risk for epithelial ingrowth due to excimer laser ablation damage to the edge of the stromal bed exposed by relifting the microkeratome flap. Mixed astigmatism is one of the hardest types of corrections to perform because excimer laser algorithms in many laser machines are not perfected for mixed astigmatism. There is no real possibility of treatment in this patient because he has a refraction of +8.00 6.00 150. Recurrent epithelial ingrowths are exceedingly difficult to treat and cause irregular astigmatism with refractive problems. There is also an increased risk for infection with recurrent epithelial ingrowths. In this case, I believe the simplest method to resolve the problem is to perform DALK; exposing Descemet layer using a big-bubble technique will give the best interface and quality of vision. However, there is always a risk for Descemet perforation, particularly in younger patients. In such cases, a full corneal transplantation would be required. There is also a risk for
- I would spend some time and discuss with the patient all possible options. This is a complicated case, and medicolegal action is possible. Thus, attention to adequate chair time and thorough documentation is warranted. In my mind, there are 5 possible options. The first is to relift the flap, or part of it, to remove the large area of ingrowth around 3 o'clock on the stromal side and the underside of the flap. Then, suture the flap with 7 interrupted sutures to avoid regrowth. (The corneal epithelium usually needs a feeder fistula to grow under the flap. It usually regresses if it has no direct relation to the tear film). If this were successful, I would remove the sutures in approximately 1 month (removing those that loosen before that time) and follow the refractions, Placido-disk topography changes or color light-emitting diode reflection topography, and epithelial remodeling on AS-OCT for signs of stabilization.1 I would not trust Scheimpflug-based imaging because it might be biased by the corneal opacity. In my experience, the cornea will be quite stable in approximately 3 to 4 months. If that occurs, I would consider combined topography-guided photorefractive keratectomy (PRK) followed by a 50 mm phototherapeutic keratectomy to use the epithelium as a masking agent.2–4 (Almost invariably it will be quite abnormal over the scar, which usually flattens the cornea.) This would normalize the anterior corneal curvature with the use
J CATARACT REFRACT SURG - VOL 40, SEPTEMBER 2014
If the patient refuses this solution, it is unrealistic to consider improving corneal regularity using an excimer laser, topography guided or not. Anterior lamellar keratoplasty also gives disappointing results in these cases. Although the graft is very regular, it will be positioned on a recipient bed that will be irregular. The AS-OCT image shows that the nasal epithelial ingrowth tends to lift the corneal flap, causing bulging of the cornea that increases the irregular astigmatism. It is easy to remove the island of epithelial ingrowth without having to lift the flap. One could press on the cornea using a blunt cannula to externalize all the epithelial ingrowth through the small hole at the trephination area around 4 hours. This can be performed at the slitlamp. If visual recovery were not satisfactory, I would pursue a more aggressive treatment. Removal of the flap could be attempted because it is possible there is a more regular stromal bed under the flap. However, the result would still be unsatisfactory, and I would suggest this solution only if the patient refuses corneal transplantation. The best solution is DALK, the only technique that removes the entire stroma while maintaining the corneal endothelium. The technical difficulty of DALK is related to the presence of the flap. I would not risk a large-diameter transplantation (ie, greater than 9.5 mm). If a femtosecond laser were available, a possibility would be to perform a mushroom-shaped DALK. The cut would have a depth of 550 mm, an anterior diameter of 9.0 mm, and a posterior diameter of 7.0 mm. The anterior stroma would be removed with a spatula, Descemet membrane would be bared using a big-bubble technique, and a mushroom graftd prepared with the femtosecond laser (without endothelium)dwould be sutured in place. If a femtosecond laser is not available, I would suggest manually removing the flap first, cleaning both areas of epithelial invasion, and placing an 8.0 mm top hat–shaped lamellar graft. This graft can easily be prepared manually on an artificial anterior chamber. After a 550 mm deep nonpenetrating trephination of 8.0 mm diameter is created, I would perform a lamellar dissection over 360 degrees up to the limbus using a spatula to obtain a peripheral skirt that is 150 mm thick. The endothelium would then be removed. The same dissection would be performed on the recipient, the anterior stroma removed using a spatula, and Descemet membrane bared using a bigbubble technique. The skirt of the top-hat lamellar graft would be introduced into the peripheral posterior pocket of the recipient. Subsequently, the thickness of the graft would be equivalent to the thickness of the peripheral
1573
stroma of the recipient. The graft would then be sutured in the usual manner. Marc Muraine, MD, PhD Rouen, France
- The main problem with taking a superficial approach (flap amputation, epithelial ingrowth scraping, topography-guided ablation for the irregular astigmatism, or a combination) is the depth of the opacity, as seen on the AS-OCT image. In the best scenario, there will be significant residual paracentral opacity, some degree of residual irregular astigmatism and, possibly, a significant hyperopic shift, which could be managed with contact lens fitting. However, this seems unacceptable for this patient. I would purpose performing descemetic DALK with a diameter of 8.0 to 8.5 mm. At least 18 months later, once all the sutures have been removed, I would correct the refractive error, if needed, through an intraocular procedure. Jose L. G€ uell, MD Barcelona, Spain
- This case shows the potential risks of retreatments after refractive surgery, including insufficiently treated astigmatism, a hyperopic outcome, and epithelial ingrowth. Given the patient's medical history, and before beginning a treatment regimen, it is important to discuss at length the options for treatment and their related outcomes. The patient's motivation for wearing a contact lens after developing a contact lens–related Pseudomonas ulcer, and in view of his profession, is understandably low and underlines the necessity for a more definite solution. If flap amputation is considered, one has to be aware of a more hyperopic outcome, worse UDVA, and a flat cornea. Fitting a contact lens on a central flat cornea, even when performed by an experienced technician or optometrist, is difficult and the patient's motivation for contact lens wear will be low. I would avoid treating the stromal scar. Retreating a stromal scar with a topography-guided excimer laser treatment, possibly in combination with removal of the epithelial ingrowth, will lead to more flattening of the cornea and another unpredictable outcome. The amount of tissue that will have to be removed will lead to thinning of the stromal bed, and the irregularity may remain the same or become worse. I would discuss the possibility of anterior lamellar graft excision in combination with the use of lamellar
J CATARACT REFRACT SURG - VOL 40, SEPTEMBER 2014
1574
CONSULTATION SECTION
donor tissue. I would advise creating a deep lamellar cut using a big-bubble technique or a femtosecond laser. The diameter must be at least the size of the flap (approximately 9.0 mm overall). The goal must be to restore the curvature of the cornea and create a translucent cornea without a scar. The depth of removal of the anterior stroma must be more than 70% of the central thickness. Among the things that have to be discussed with the patient are the visual and refractive outcomes, interface-related problems, and refractive correction after the surgery. Once the sutures are removed, the final refractive outcome can be managed by performing a refractive lens exchange. The last suggested option, a (penetrating) mushroom-shaped keratoplasty, is not yet necessary because the endothelial cell count remains the same after excimer laser surgery. The visual outcomes of a penetrating procedure are potentially better than those of a lamellar procedure; however, the wound architecture, graft rejection period, and long period of topical medication use make this treatment less preferable than lamellar grafting. Annette J.M. Geerards, MD Rotterdam, the Netherlands
rejection and early cataract formation, and the patient must be informed about this. As an alternative, the corneal flap can be relifted where there is epithelial ingrowth and removed. Removing the epithelial ingrowth will allow the corneal flap to heal. Then, pachymetry-assisted laser keratoplasty can be performed using an excimer laser; however, this will entail 2 separate operations. The reason for epithelial removal is because the trapped epithelium undergoes degeneration, which forms foamy cells. These foamy cells will be soft and liquefied and will not ablate uniformly with an excimer laser. Without the epithelial ingrowth, pachymetry-assisted laser keratoplasty would be easy to perform because the excimer laser is guided by pachymetry and not topography. The residual bed can be set to a minimum of 80 mm using an Amaris laser (Schwind). However, in this case, I would not advise this because of the presence of epithelial ingrowth of at least 60 mm estimated from the corneal OCT. Because of the thinness of the cornea, lamellar keratoplasty is required and for the best optical quality, DALK is still the top option. Jerry Tan, MD Singapore
- This case has many interesting clinical dilemmas and many learning points. Relift enhancements increase the risk for epithelial ingrowth, especially in microkeratome cuts with their sloping edges. In my experience, a higher number of relift enhancements increases the risk for epithelial ingrowth. Hyperopic relift enhancements also increase the risk for epithelial ingrowth due to excimer laser ablation damage to the edge of the stromal bed exposed by relifting the microkeratome flap. Mixed astigmatism is one of the hardest types of corrections to perform because excimer laser algorithms in many laser machines are not perfected for mixed astigmatism. There is no real possibility of treatment in this patient because he has a refraction of +8.00 6.00 150. Recurrent epithelial ingrowths are exceedingly difficult to treat and cause irregular astigmatism with refractive problems. There is also an increased risk for infection with recurrent epithelial ingrowths. In this case, I believe the simplest method to resolve the problem is to perform DALK; exposing Descemet layer using a big-bubble technique will give the best interface and quality of vision. However, there is always a risk for Descemet perforation, particularly in younger patients. In such cases, a full corneal transplantation would be required. There is also a risk for
- I would spend some time and discuss with the patient all possible options. This is a complicated case, and medicolegal action is possible. Thus, attention to adequate chair time and thorough documentation is warranted. In my mind, there are 5 possible options. The first is to relift the flap, or part of it, to remove the large area of ingrowth around 3 o'clock on the stromal side and the underside of the flap. Then, suture the flap with 7 interrupted sutures to avoid regrowth. (The corneal epithelium usually needs a feeder fistula to grow under the flap. It usually regresses if it has no direct relation to the tear film). If this were successful, I would remove the sutures in approximately 1 month (removing those that loosen before that time) and follow the refractions, Placido-disk topography changes or color light-emitting diode reflection topography, and epithelial remodeling on AS-OCT for signs of stabilization.1 I would not trust Scheimpflug-based imaging because it might be biased by the corneal opacity. In my experience, the cornea will be quite stable in approximately 3 to 4 months. If that occurs, I would consider combined topography-guided photorefractive keratectomy (PRK) followed by a 50 mm phototherapeutic keratectomy to use the epithelium as a masking agent.2–4 (Almost invariably it will be quite abnormal over the scar, which usually flattens the cornea.) This would normalize the anterior corneal curvature with the use
J CATARACT REFRACT SURG - VOL 40, SEPTEMBER 2014
