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
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
