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CONSULTATION SECTION
by masking–smoothing to remove much of the scar and surface irregularities that were generated during the delayed healing. Remember that there is an expected 1.0 diopter (D) hyperopic shift for each 50 pulses of the excimer laser (and 0.25 to 0.40 mm of stromal tissue removal per pulse). This does not apply to the smoothing portion of the procedure because only peaks are exposed and the majority of the stroma is protected from ablation by the masking agent. In my experience, 2.0 to 3.0 D of the induced hyperopia can be safely counteracted by applying hyperopic ablation with MMC at the same treatment. Therefore, before surgery I decide, based on slitlamp examination, how much PTK is required to remove approximately 75% of the opacity and, depending on the amount of stromal PTK needed, whether I will add hyperopic PRK correction after PTK and smoothing. In many of these cases, full removal of the scar is not necessary to alleviate the patient’s symptoms and efforts to remove the entire scar often result in more troubling high hyperopia. Often, I will cover this procedure with oral acyclovir in case the original disorder was related to HSV infection. If the patient wanted to consider correction in the opposite eye, I would favor femtosecond laser–assisted LASIK as long as parameters such as corneal topography and corneal thickness were normal. However, PRK could also be considered because bilateral delayed epithelial healing after PRK is exceedingly rare. Steven E. Wilson, MD Cleveland, Ohio, USA
- Several factors can delay post-PRK reepithelialization and corneal haze, including excessive inflammation, impaired ocular surface, toxicity, and the individual tissue response. Some of these factors were significant in this case. This patient was contact lens intolerant. In many long-term contact lens users with intolerance, the conjunctiva is inflamed, blepharitis is common, and the eyes are dry, which may interfere with normal postoperative epithelial and stromal wound healing. Intraoperative traumatic and aggressive scraping of the epithelium may influence the postoperative reepithelialization rate and stromal response. Postoperatively, poor contact lens fit with excessive lens movement on the cornea or a tight fit increases inflammation and infiltrates and may affect epithelial healing and the stromal response. Topical medications such as NSAIDs and quinolones may upregulate matrix metalloproteinases (MMPs),1,2 which induce an
inflammatory response. In addition, NSAIDs may increase activity of the proinflammatory pathway and decrease corneal sensitivity.3 Massive application of preservatives (eg, preserved artificial tears) causes ocular surface toxicity and inflammation and significantly delays reepithelialization and stromal reaction. Postoperatively, the contact lens absorbs the medications, the preservatives, and the toxic material released by products of the tissue inflammation. The contact lens slowly releases toxic material and further impairs epithelial and stromal healing. Delay of epithelial healing promotes stromal haze formation. Our routine approach emphasizes preoperative evaluation of the tear function and ocular surface. It includes discontinuation of contact lens use for at least 2 to 3 weeks, preoperative treatment of blepharitis and chronic ocular surface inflammation, and application of nonpreserved artificial tears. Preoperatively, all PRK patients receive topical fluorometholone for at least 5 days and oral doxycycline 100 mg/day for 10 days. Postoperatively, doxycycline is given until reepithelialization is complete; doxycycline reduces the influence of postoperative MMPs and promotes epithelial healing. We routinely use dexamethasone phosphate 0.1% 3 times a day for 1 week to control the inflammatory response. Thereafter, fluorometholone drops are given 3 times a day during the first month. Topical gentamicin drops are applied 3 times a day for 3 days and then 2 times a day for 4 more days. Nonpreserved artificial tears are freely used. At the end of the surgery, we fit bandage contact lenses. We routinely follow the patient after 1, 3, and 7 days and 1 month. We expect the reepithelialization to be complete (or almost complete) within 3 days. If a large epithelial defect is observed after 3 days, we exchange the lens and the antibiotic drops to chloramphenicol 2 times a day. If the epithelial defect is still significant after 7 days, which is extremely rare, we discontinue the lens and patch the eye with steroid ointment and chloramphenicol drops 2 times a day. Regarding the surgical approach in the left eye, in this case with delayed epithelial healing and stromal haze formation, it is important to exclude keloid type of scarring in other parts of the body and if possible to control smoking, which may delay corneal reepithelialization. Preoperatively, it is important to reduce ocular surface inflammation in the left eye and to pretreat blepharitis if it exists. Finally, we would recommend LASIK in the left eye. However, if PRK is the only option, we would use topical MMC 0.02% for 10 seconds and closely follow the patient postoperatively. We would minimize the use of preoperative and postoperative preserved medications, avoid NSAIDs and quinolones, and use larger dose of topical steroids, preferably nonpreserved.
J CATARACT REFRACT SURG - VOL 40, MARCH 2014
CONSULTATION SECTION
The right eye with 20/16 acuity should not be treated for the residual haze, which will decrease in time. Joseph Frucht-Pery, MD Denise Wajnsztajn, MD Jerusalem, Israel
REFERENCES 1. Reviglio VE, Rana TS, Li QJ, Ashraf MF, Daly MK, O’Brien TP. Effects of topical nonsteroidal antiinflammatory drugs on the expression of matrix metalloproteinases in the cornea. J Cataract Refract Surg 2003; 29:989–997 2. Reviglio VE, Hakim MA, Song JK, O’Brien TP. Effect of topical fluoroquinolones on the expression of matrix metalloproteinases in the cornea. BMC Ophthalmol 2003; 3:10. Available at: http:// www.biomedcentral.com/content/pdf/1471-2415-3-10.pdf. Accessed December 20, 2013 3. Seitz B, Sorken K, LaBree LD, Garbus JJ, McDonnell PJ. Corneal sensitivity and burning sensation; comparing topical ketorolac and diclofenac. Arch Ophthalmol 1996; 114:921–924
- From the OCT image, it appears as though the opacity is a hypertrophic scar rather than haze within the stroma. The overlying epithelium is slightly thinned, and the resulting topography is quite regular. The UDVA is 20/16. Six months postoperatively, wound healing is not complete. Over the next 6 months. I would presume the scar would fade somewhat and thin slightly, resulting in less photophobia and hazy vision. I would recommend that the patient wait for natural improvement in visual acuity. If the patient does not accept this, I would suggest transepithelial ablation of the scar, probably performed as incremental transepithelial PTK. Preoperatively, the patient must be given clear and detailed information and told that spontaneous improvement might occur and that there is an increased risk for delayed wound healing, which could compromise the result. I would also consider applying MMC 0.02% for 20 seconds after ablation just at the denuded stroma. Normally, I use chloramphenicol and fluorometholone drops and nonpreserved diclofenac drops 4 times daily. In this case, I would consider using chloramphenicol ointment (instead of drops) 3 to 4 times daily and follow the patient daily until healing. Normally, I do not use bandage contact lenses postoperatively because sterile infiltrates and keratitis are more common with their use. Often, patients with a bandage lens develop some irritation 2 or 3 days postoperatively, and I prefer to take an additional look at those patients. However, my patients often live quite far from the clinic, and taking this additional look is
505
logistically difficult. Thus, I sometimes place bandage contact lenses postoperatively. If healing is delayed, I first change to chloramphenicol ointment and reduce the fluorometholone and diclofenac. If this does not improve healing, I apply a contact lens. If healing is still not complete within 4 days, I use serum drops (allogeneic; prepared at the university hospital clinical immunologic department) 8 times daily. If there is still no improvement over 2 weeks, I would apply an amniotic bandage membrane over the cornea. Before treating the left eye, I would measure tear production and quality (Schirmer test and tear breakup time) and measure corneal sensitivity (Cochet-Bonnet). If these functions are normal, I would suggest transepithelial PRK or small-incision lenticule extraction because the latter does not involve creation of an epithelial defect, such as in PRK, or a flap, such as in LASIK. In either case, I would follow the patient closely postoperatively to ensure proper healing. Although the wound-healing response of the 2 eyes of the same individual is interdependent, there is a good chance this patient will have a satisfying result in the left eye. Jesper Hjortdal, MD, PhD Aarhus, Denmark
- Preoperatively, the case appears to be a straightforward PRK treatment to correct myopia in the right eye of a young patient. The postoperative course, however, is complicated by severely delayed epithelial healing and mild central stromal haze formation. Six months postoperatively, the UDVA is excellent, the corneal topography is normal, and there appears to be no unforeseen loss of stromal tissue, as can occur in an inflammatory reaction. The corneal OCT is normal, and the slitlamp image shows superficial central scar formation that is clinically significant given the patient’s reports of hazy vision and photophobia. The good visual recovery over the first 6 months warrants a conservative approach. I would prescribe topical prednisolone 4 times a day (tapering over several weeks to months according to the clinical course) and monitor contrast sensitivity and intraocular pressure. If there is no clinical or subjective improvement, a secondary procedure with epithelial abrasion, PTK, and application of MMC 0.02% for 30 seconds would be a good option. Autologous serum drops can be used to promote epithelial healing.1 Before further corneal procedures (PTK in the right eye or myopia correction in the left eye) are performed,
J CATARACT REFRACT SURG - VOL 40, MARCH 2014
CONSULTATION SECTION
by masking–smoothing to remove much of the scar and surface irregularities that were generated during the delayed healing. Remember that there is an expected 1.0 diopter (D) hyperopic shift for each 50 pulses of the excimer laser (and 0.25 to 0.40 mm of stromal tissue removal per pulse). This does not apply to the smoothing portion of the procedure because only peaks are exposed and the majority of the stroma is protected from ablation by the masking agent. In my experience, 2.0 to 3.0 D of the induced hyperopia can be safely counteracted by applying hyperopic ablation with MMC at the same treatment. Therefore, before surgery I decide, based on slitlamp examination, how much PTK is required to remove approximately 75% of the opacity and, depending on the amount of stromal PTK needed, whether I will add hyperopic PRK correction after PTK and smoothing. In many of these cases, full removal of the scar is not necessary to alleviate the patient’s symptoms and efforts to remove the entire scar often result in more troubling high hyperopia. Often, I will cover this procedure with oral acyclovir in case the original disorder was related to HSV infection. If the patient wanted to consider correction in the opposite eye, I would favor femtosecond laser–assisted LASIK as long as parameters such as corneal topography and corneal thickness were normal. However, PRK could also be considered because bilateral delayed epithelial healing after PRK is exceedingly rare. Steven E. Wilson, MD Cleveland, Ohio, USA
- Several factors can delay post-PRK reepithelialization and corneal haze, including excessive inflammation, impaired ocular surface, toxicity, and the individual tissue response. Some of these factors were significant in this case. This patient was contact lens intolerant. In many long-term contact lens users with intolerance, the conjunctiva is inflamed, blepharitis is common, and the eyes are dry, which may interfere with normal postoperative epithelial and stromal wound healing. Intraoperative traumatic and aggressive scraping of the epithelium may influence the postoperative reepithelialization rate and stromal response. Postoperatively, poor contact lens fit with excessive lens movement on the cornea or a tight fit increases inflammation and infiltrates and may affect epithelial healing and the stromal response. Topical medications such as NSAIDs and quinolones may upregulate matrix metalloproteinases (MMPs),1,2 which induce an
inflammatory response. In addition, NSAIDs may increase activity of the proinflammatory pathway and decrease corneal sensitivity.3 Massive application of preservatives (eg, preserved artificial tears) causes ocular surface toxicity and inflammation and significantly delays reepithelialization and stromal reaction. Postoperatively, the contact lens absorbs the medications, the preservatives, and the toxic material released by products of the tissue inflammation. The contact lens slowly releases toxic material and further impairs epithelial and stromal healing. Delay of epithelial healing promotes stromal haze formation. Our routine approach emphasizes preoperative evaluation of the tear function and ocular surface. It includes discontinuation of contact lens use for at least 2 to 3 weeks, preoperative treatment of blepharitis and chronic ocular surface inflammation, and application of nonpreserved artificial tears. Preoperatively, all PRK patients receive topical fluorometholone for at least 5 days and oral doxycycline 100 mg/day for 10 days. Postoperatively, doxycycline is given until reepithelialization is complete; doxycycline reduces the influence of postoperative MMPs and promotes epithelial healing. We routinely use dexamethasone phosphate 0.1% 3 times a day for 1 week to control the inflammatory response. Thereafter, fluorometholone drops are given 3 times a day during the first month. Topical gentamicin drops are applied 3 times a day for 3 days and then 2 times a day for 4 more days. Nonpreserved artificial tears are freely used. At the end of the surgery, we fit bandage contact lenses. We routinely follow the patient after 1, 3, and 7 days and 1 month. We expect the reepithelialization to be complete (or almost complete) within 3 days. If a large epithelial defect is observed after 3 days, we exchange the lens and the antibiotic drops to chloramphenicol 2 times a day. If the epithelial defect is still significant after 7 days, which is extremely rare, we discontinue the lens and patch the eye with steroid ointment and chloramphenicol drops 2 times a day. Regarding the surgical approach in the left eye, in this case with delayed epithelial healing and stromal haze formation, it is important to exclude keloid type of scarring in other parts of the body and if possible to control smoking, which may delay corneal reepithelialization. Preoperatively, it is important to reduce ocular surface inflammation in the left eye and to pretreat blepharitis if it exists. Finally, we would recommend LASIK in the left eye. However, if PRK is the only option, we would use topical MMC 0.02% for 10 seconds and closely follow the patient postoperatively. We would minimize the use of preoperative and postoperative preserved medications, avoid NSAIDs and quinolones, and use larger dose of topical steroids, preferably nonpreserved.
J CATARACT REFRACT SURG - VOL 40, MARCH 2014
CONSULTATION SECTION
The right eye with 20/16 acuity should not be treated for the residual haze, which will decrease in time. Joseph Frucht-Pery, MD Denise Wajnsztajn, MD Jerusalem, Israel
REFERENCES 1. Reviglio VE, Rana TS, Li QJ, Ashraf MF, Daly MK, O’Brien TP. Effects of topical nonsteroidal antiinflammatory drugs on the expression of matrix metalloproteinases in the cornea. J Cataract Refract Surg 2003; 29:989–997 2. Reviglio VE, Hakim MA, Song JK, O’Brien TP. Effect of topical fluoroquinolones on the expression of matrix metalloproteinases in the cornea. BMC Ophthalmol 2003; 3:10. Available at: http:// www.biomedcentral.com/content/pdf/1471-2415-3-10.pdf. Accessed December 20, 2013 3. Seitz B, Sorken K, LaBree LD, Garbus JJ, McDonnell PJ. Corneal sensitivity and burning sensation; comparing topical ketorolac and diclofenac. Arch Ophthalmol 1996; 114:921–924
- From the OCT image, it appears as though the opacity is a hypertrophic scar rather than haze within the stroma. The overlying epithelium is slightly thinned, and the resulting topography is quite regular. The UDVA is 20/16. Six months postoperatively, wound healing is not complete. Over the next 6 months. I would presume the scar would fade somewhat and thin slightly, resulting in less photophobia and hazy vision. I would recommend that the patient wait for natural improvement in visual acuity. If the patient does not accept this, I would suggest transepithelial ablation of the scar, probably performed as incremental transepithelial PTK. Preoperatively, the patient must be given clear and detailed information and told that spontaneous improvement might occur and that there is an increased risk for delayed wound healing, which could compromise the result. I would also consider applying MMC 0.02% for 20 seconds after ablation just at the denuded stroma. Normally, I use chloramphenicol and fluorometholone drops and nonpreserved diclofenac drops 4 times daily. In this case, I would consider using chloramphenicol ointment (instead of drops) 3 to 4 times daily and follow the patient daily until healing. Normally, I do not use bandage contact lenses postoperatively because sterile infiltrates and keratitis are more common with their use. Often, patients with a bandage lens develop some irritation 2 or 3 days postoperatively, and I prefer to take an additional look at those patients. However, my patients often live quite far from the clinic, and taking this additional look is
505
logistically difficult. Thus, I sometimes place bandage contact lenses postoperatively. If healing is delayed, I first change to chloramphenicol ointment and reduce the fluorometholone and diclofenac. If this does not improve healing, I apply a contact lens. If healing is still not complete within 4 days, I use serum drops (allogeneic; prepared at the university hospital clinical immunologic department) 8 times daily. If there is still no improvement over 2 weeks, I would apply an amniotic bandage membrane over the cornea. Before treating the left eye, I would measure tear production and quality (Schirmer test and tear breakup time) and measure corneal sensitivity (Cochet-Bonnet). If these functions are normal, I would suggest transepithelial PRK or small-incision lenticule extraction because the latter does not involve creation of an epithelial defect, such as in PRK, or a flap, such as in LASIK. In either case, I would follow the patient closely postoperatively to ensure proper healing. Although the wound-healing response of the 2 eyes of the same individual is interdependent, there is a good chance this patient will have a satisfying result in the left eye. Jesper Hjortdal, MD, PhD Aarhus, Denmark
- Preoperatively, the case appears to be a straightforward PRK treatment to correct myopia in the right eye of a young patient. The postoperative course, however, is complicated by severely delayed epithelial healing and mild central stromal haze formation. Six months postoperatively, the UDVA is excellent, the corneal topography is normal, and there appears to be no unforeseen loss of stromal tissue, as can occur in an inflammatory reaction. The corneal OCT is normal, and the slitlamp image shows superficial central scar formation that is clinically significant given the patient’s reports of hazy vision and photophobia. The good visual recovery over the first 6 months warrants a conservative approach. I would prescribe topical prednisolone 4 times a day (tapering over several weeks to months according to the clinical course) and monitor contrast sensitivity and intraocular pressure. If there is no clinical or subjective improvement, a secondary procedure with epithelial abrasion, PTK, and application of MMC 0.02% for 30 seconds would be a good option. Autologous serum drops can be used to promote epithelial healing.1 Before further corneal procedures (PTK in the right eye or myopia correction in the left eye) are performed,
J CATARACT REFRACT SURG - VOL 40, MARCH 2014
