1040-5488/14/9101-e018/0 VOL. 91, NO. 1, PP. e18Ye20 OPTOMETRY AND VISION SCIENCE Copyright * 2013 American Academy of Optometry
CLINICAL CASE
Corneal Confocal Microscopy for Vision Disturbance After an Epithelial Abrasion Gabriela Mahelkova*, Kvetoslava Ferrova†, Pavel Pochop*, Milan Odehnal†, and Dagmar Dotrelova*
ABSTRACT Purpose. To demonstrate the use of in vivo corneal confocal microscopy to reveal the reason for persistent disturbance of vision after a corneal abrasion. Case Report. A 49-year-old man presented with a decrease in visual acuity and monocular diplopia after a traumatic corneal abrasion. Anterior segment optical coherence tomography was not beneficial. In vivo corneal confocal microscopy showed abnormal folding in the basal epithelial layer of the cornea. Based on these findings, a therapeutic abrasion of the affected epithelium was performed. Visual acuity returned to 1.0 after therapeutic abrasion, and overall findings on the eye were within physiological limits. Control corneal confocal microscopic examination confirmed reparation of the structure of epithelial cell layers. Conclusions. The in vivo corneal confocal microscopy can reveal corneal pathologic abnormality even in cases where other methods are not beneficial. Alongside other modern methods, it may become an important tool to help locate pathologic abnormality accurately and choose the proper therapeutic strategy. (Optom Vis Sci 2014;91:e18Ye20) Key Words: corneal confocal microscopy, healing of corneal epithelium, traumatic corneal abrasion, corneal basal epithelial cells, visual disturbance
T
raumatic corneal abrasions (removal of part or all of the corneal epithelium) are one of the most common ophthalmic injuries. They generally heal rapidly within 24 to 72 hours and without scarring if Bowman’s membrane is not involved.1,2 However, because the cornea is the major refractive surface of the eye, even minor changes in its structure may result in significant visual problems. We report a case of a patient with persistent deterioration of vision after a superficial corneal abrasion. We used the corneal optical coherence tomography (OCT) and in vivo corneal microscopy to reveal the underlying pathologic abnormality. The latter seemed to be more appropriate in our case.
CASE REPORT A 49-year-old man was treated in our department for a superficial corneal abrasion of the central cornea caused by a *MD, PhD † MD Department of Ophthalmology for Children and Adults, 2nd Faculty of Medicine of Charles University and University Hospital Motol (GM, KF, PP, MO, DD); and Department of Physiology, 2nd Faculty of Medicine of Charles University (GM), Prague, Czech Republic.
child’s fingernail. Initially, he was treated with a topical antibiotic ointment (Ophthalmo-Framykoin, Zentiva, Czech Republic) and eye patching. There was no apparent pathologic abnormality of the other eye. The patient had no history of an eye disease and did not use eyeglasses. The epithelial defect had apparently healed within 3 days. However, the patient continued to suffer from disturbed vision in the affected eye. The patient’s best spectaclecorrected visual acuity was 0.8 in the affected eye (Snellen chart, 6-m distance, high contrast), and he complained about monocular diplopia. The problem did not disappear despite 2 weeks of artificial tears application. Slit lamp examination revealed only a very discrete white linear opacity in the superficial layers, just under the surface near the central cornea. Otherwise, there were no pathological findings on the anterior or posterior segment of the affected eye. We used the corneal OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Germany) and in vivo corneal confocal microscopy (scanning slit corneal microscope; Confoscan 3.0; NIDEK Technologies, Italy) to examine the central part of the cornea. Scanning with the Cirrus OCT was performed using the anterior segment five-line raster scan as well as anterior segment cube scan protocol. The corneal OCT showed no pathological finding. Corneal confocal microscopy equipped with a non-applanating 40 immersion objective lens designed for full-thickness
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
In Vivo Confocal Microscopy After Corneal AbrasionVMahelkova et al.
e19
FIGURE 1.
FIGURE 3.
An abnormal folding in the layer of basal epithelial cells.
Activated keratocytes presented in the anterior stroma.
examination of the cornea, with a working distance of 1.92 mm (Achroplan; Zeiss, Oberkochen, Germany), was used to scan the corneal tissue. The objective lens of the confocal microscope was disinfected (isopropyl alcohol 70% vol/vol, swabs), and one drop of viscous isotonic gel (Vidisic gel; Bausch and Lomb) was applied to the tip of the lens and advanced forward until the gel touched the cornea, allowing optical but not physical contact between the objective lens and corneal epithelium. Using in vivo corneal confocal microscopy, we found an abnormal folding in the layer of basal epithelial cells (Fig. 1). The more superficial epithelial layers showed irregular morphology and increased reflectivity (Fig. 2). We found only a couple of activated keratocytes in the anterior stroma (Fig. 3). These findings suggested that a therapeutic abrasion of the epithelial layers in the affected area was warranted. After the abrasion, a contact lens was applied, and antibiotic drops were recommended. After another 4 days, the epithelial defect had healed, and the visual problems had resolved. The final visual acuity was 1.0. After 14 days, the control corneal
confocal microscopic examination revealed lower basal epithelial cell density in the affected eye (4663 cells/mm2) relative to the other healthy eye (6580 cells/mm2) and activated keratocytes presented in the anterior stroma. Otherwise, the findings were normal within the corneal layers.
FIGURE 2. The increased reflectivity and irregular morphology is apparent within the more superficial epithelial layers of the affected eye prior to the therapeutic abrasion.
DISCUSSION Traumatic corneal abrasions result from cutting, scratching, or abrading of the corneal surface. Simple corneal abrasions rarely become complicated, and in most cases, a complete recovery occurs in few days. However, potential complications include infection and, especially in the case of deeper scratches, corneal scarring. The centrally located scars may affect visual acuity significantly.1,2 Modern imaging methods used in corneal refractive surgery can often show irregularities in the structure of the cornea (e.g., corneal topography, aberrometry). However, they have limited value for accurate localization of pathologic abnormality in the individual layers of the cornea. This is essential for eventual treatment planning. The possible use of anterior segment OCT to evaluate the corneal changes in patients with recurrent epithelial erosions and to monitor the changes caused by the wound-healing response in patients receiving phototherapeutic keratectomy was reported.3Y6 Given the exact height and depth of the affected tissue, the ablation of the appropriate amount of tissue may be planned. Optical coherence tomography is a high-resolution technology that can create precise cross-sectional images of the cornea. The variations in the corneal and epithelial thickness and the tissue reflectivity could be evaluated. However, bright central flare caused by the very strong specular reflection at the corneal vertex may worsen the detailed evaluation of this area. We were not able to depict the pathological changes in the corneal structure using the OCT in our patient. In vivo corneal confocal microscopy allows noninvasive realtime spatial sectioning of living corneal tissue at the cellular level. It is capable of examining changes in the corneal cells layer by layer and of identifying corneal microstructural changes in
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
e20 In Vivo Confocal Microscopy After Corneal AbrasionVMahelkova et al.
different corneal pathologies (e.g., corneal dystrophies) as well as after refractive surgery.7Y15 The cornea must be totally transparent to refract light properly. The exact organization of all the structural elements is necessary at all the layers. Using in vivo corneal confocal microscopy, we were able to see abnormal folding in the basal epithelial layer and signs of epithelial cell hyperplasia in the affected eye. We found no scarring in the Bowman’s layer or in the stroma. This may be the reason why the OCT failed to display the pathology. The therapeutic abrasion of the affected epithelium led to satisfactory healing and resolved the visual problem. The lower basal epithelial cell density remaining on the affected eye and the activated keratocytes presented in the anterior stroma corresponded to previously published works on the stages of epithelium healing and stromal-epithelial interaction after corneal injury observable by corneal confocal microscopy.14,16 Thus, in vivo corneal confocal microscopy may reveal the underlying pathologic abnormality even in cases where the corneal OCT is not beneficial. The main limitation of this method is that it has only limited ability to precisely target a desired area, and only a very small area is examined with each scan. However, with improvement of this limitation in a new device generation, corneal confocal microscopy, in addition to the other modern methods, may become an important tool to help us locate a pathologic abnormality accurately and choose the proper therapeutic strategy (e.g., simple epithelial abrasion vs. removal of the scar using PTK).
ACKNOWLEDGMENTS The study was supported by the project (Ministry of Health, Czech Republic) for conceptual development of research organization 00064203 (University Hospital Motol, Prague, Czech Republic) and CZ.2.16/3.1.00/24022. The study was performed following all the guidelines required by the Institutional Ethics Committee. The authors declare no financial conflict of interest. The work was presented at XII Congress of Czech Vitreoretinal Society, November 23 to 24, 2012, in Pruhonice, Czech Republic (in Czech language). Received June 5, 2013; accepted September 17, 2013.
REFERENCES 1. Fraser S. Corneal abrasion. Clin Ophthalmol 2010;4:387Y90. 2. Wilson SA, Last A. Management of corneal abrasions. Am Fam Physician 2004;70:123Y8. 3. Ma JJ, Tseng SS, Yarascavitch BA. Anterior segment optical coherence tomography for transepithelial phototherapeutic keratectomy in central corneal stromal scarring. Cornea 2009;28:927Y9.
4. Wirbelauer C, Pham DT. Monitoring corneal structures with slitlamp-adapted optical coherence tomography in laser in situ keratomileusis. J Cataract Refract Surg 2004;30:1851Y60. 5. Wirbelauer C, Scholz C, Haberle H, Laqua H, Pham DT. Corneal optical coherence tomography before and after phototherapeutic keratectomy for recurrent epithelial erosions(2). J Cataract Refract Surg 2002;28:1629Y35. 6. Sayegh RR, Pineda R, 2nd. Practical applications of anterior segment optical coherence tomography imaging following corneal surgery. Semin Ophthalmol 2012;27:125Y32. 7. Mustonen RK, McDonald MB, Srivannaboon S, Tan AL, Doubrava MW, Kim CK. Normal human corneal cell populations evaluated by in vivo scanning slit confocal microscopy. Cornea 1998;17:485Y92. 8. Jalbert I, Stapleton F, Papas E, Sweeney DF, Coroneo M. In vivo confocal microscopy of the human cornea. Br J Ophthalmol 2003;87: 225Y36. 9. Chiou AG, Kaufman SC, Kaufman HE, Beuerman RW. Clinical corneal confocal microscopy. Surv Ophthalmol 2006;51:482Y500. 10. Dhaliwal JS, Kaufman SC, Chiou AG. Current applications of clinical confocal microscopy. Curr Opin Ophthalmol 2007;18:300Y7. 11. Patel DV, McGhee CN. Contemporary in vivo confocal microscopy of the living human cornea using white light and laser scanning techniques: a major review. Clin Exp Ophthalmol 2007;35:71Y88. 12. Pirnerova´ L, Hora´cˇkova´ M, Vlkova´ E, Hlinomazova´ Z, Trnkova´ V, Strmenova´ E. [The use of confocal corneal microscopy in the clinical practice]. Cesk Slov Oftalmol 2010;66:239Y47. 13. Chikama T, Takahashi N, Wakuta M, Morishige N, Nishida T. In vivo biopsy by laser confocal microscopy for evaluation of traumatic recurrent corneal erosion. Mol Vis 2008;14:2333Y9. 14. Chen WL, Shen EP, Hsieh YT, Yeh PT, Wang TJ, Hu FR. Comparison of in vivo confocal microscopic findings between epi-LASIK procedures with different management of the epithelial flaps. Invest Ophthalmol Vis Sci 2011;52:3640Y7. 15. Kobayashi A, Yokogawa H, Sugiyama K. In vivo laser confocal microscopy findings in patients with map-dot-fingerprint (epithelial basement membrane) dystrophy. Clin Ophthalmol 2012;6:1187Y90. 16. Wilson SE, Netto M, Ambrosio R, Jr. Corneal cells: chatty in development, homeostasis, wound healing, and disease. Am J Ophthalmol 2003;136:530Y6.
Gabriela Mahelkova Department of Ophthalmology for Children and Adults 2nd Faculty of Medicine of Charles University and University Hospital ´ valu 84, Prague 5, 150 06 VU Czech Republic e-mail: [email protected]; [email protected]
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
CLINICAL CASE
Corneal Confocal Microscopy for Vision Disturbance After an Epithelial Abrasion Gabriela Mahelkova*, Kvetoslava Ferrova†, Pavel Pochop*, Milan Odehnal†, and Dagmar Dotrelova*
ABSTRACT Purpose. To demonstrate the use of in vivo corneal confocal microscopy to reveal the reason for persistent disturbance of vision after a corneal abrasion. Case Report. A 49-year-old man presented with a decrease in visual acuity and monocular diplopia after a traumatic corneal abrasion. Anterior segment optical coherence tomography was not beneficial. In vivo corneal confocal microscopy showed abnormal folding in the basal epithelial layer of the cornea. Based on these findings, a therapeutic abrasion of the affected epithelium was performed. Visual acuity returned to 1.0 after therapeutic abrasion, and overall findings on the eye were within physiological limits. Control corneal confocal microscopic examination confirmed reparation of the structure of epithelial cell layers. Conclusions. The in vivo corneal confocal microscopy can reveal corneal pathologic abnormality even in cases where other methods are not beneficial. Alongside other modern methods, it may become an important tool to help locate pathologic abnormality accurately and choose the proper therapeutic strategy. (Optom Vis Sci 2014;91:e18Ye20) Key Words: corneal confocal microscopy, healing of corneal epithelium, traumatic corneal abrasion, corneal basal epithelial cells, visual disturbance
T
raumatic corneal abrasions (removal of part or all of the corneal epithelium) are one of the most common ophthalmic injuries. They generally heal rapidly within 24 to 72 hours and without scarring if Bowman’s membrane is not involved.1,2 However, because the cornea is the major refractive surface of the eye, even minor changes in its structure may result in significant visual problems. We report a case of a patient with persistent deterioration of vision after a superficial corneal abrasion. We used the corneal optical coherence tomography (OCT) and in vivo corneal microscopy to reveal the underlying pathologic abnormality. The latter seemed to be more appropriate in our case.
CASE REPORT A 49-year-old man was treated in our department for a superficial corneal abrasion of the central cornea caused by a *MD, PhD † MD Department of Ophthalmology for Children and Adults, 2nd Faculty of Medicine of Charles University and University Hospital Motol (GM, KF, PP, MO, DD); and Department of Physiology, 2nd Faculty of Medicine of Charles University (GM), Prague, Czech Republic.
child’s fingernail. Initially, he was treated with a topical antibiotic ointment (Ophthalmo-Framykoin, Zentiva, Czech Republic) and eye patching. There was no apparent pathologic abnormality of the other eye. The patient had no history of an eye disease and did not use eyeglasses. The epithelial defect had apparently healed within 3 days. However, the patient continued to suffer from disturbed vision in the affected eye. The patient’s best spectaclecorrected visual acuity was 0.8 in the affected eye (Snellen chart, 6-m distance, high contrast), and he complained about monocular diplopia. The problem did not disappear despite 2 weeks of artificial tears application. Slit lamp examination revealed only a very discrete white linear opacity in the superficial layers, just under the surface near the central cornea. Otherwise, there were no pathological findings on the anterior or posterior segment of the affected eye. We used the corneal OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Germany) and in vivo corneal confocal microscopy (scanning slit corneal microscope; Confoscan 3.0; NIDEK Technologies, Italy) to examine the central part of the cornea. Scanning with the Cirrus OCT was performed using the anterior segment five-line raster scan as well as anterior segment cube scan protocol. The corneal OCT showed no pathological finding. Corneal confocal microscopy equipped with a non-applanating 40 immersion objective lens designed for full-thickness
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
In Vivo Confocal Microscopy After Corneal AbrasionVMahelkova et al.
e19
FIGURE 1.
FIGURE 3.
An abnormal folding in the layer of basal epithelial cells.
Activated keratocytes presented in the anterior stroma.
examination of the cornea, with a working distance of 1.92 mm (Achroplan; Zeiss, Oberkochen, Germany), was used to scan the corneal tissue. The objective lens of the confocal microscope was disinfected (isopropyl alcohol 70% vol/vol, swabs), and one drop of viscous isotonic gel (Vidisic gel; Bausch and Lomb) was applied to the tip of the lens and advanced forward until the gel touched the cornea, allowing optical but not physical contact between the objective lens and corneal epithelium. Using in vivo corneal confocal microscopy, we found an abnormal folding in the layer of basal epithelial cells (Fig. 1). The more superficial epithelial layers showed irregular morphology and increased reflectivity (Fig. 2). We found only a couple of activated keratocytes in the anterior stroma (Fig. 3). These findings suggested that a therapeutic abrasion of the epithelial layers in the affected area was warranted. After the abrasion, a contact lens was applied, and antibiotic drops were recommended. After another 4 days, the epithelial defect had healed, and the visual problems had resolved. The final visual acuity was 1.0. After 14 days, the control corneal
confocal microscopic examination revealed lower basal epithelial cell density in the affected eye (4663 cells/mm2) relative to the other healthy eye (6580 cells/mm2) and activated keratocytes presented in the anterior stroma. Otherwise, the findings were normal within the corneal layers.
FIGURE 2. The increased reflectivity and irregular morphology is apparent within the more superficial epithelial layers of the affected eye prior to the therapeutic abrasion.
DISCUSSION Traumatic corneal abrasions result from cutting, scratching, or abrading of the corneal surface. Simple corneal abrasions rarely become complicated, and in most cases, a complete recovery occurs in few days. However, potential complications include infection and, especially in the case of deeper scratches, corneal scarring. The centrally located scars may affect visual acuity significantly.1,2 Modern imaging methods used in corneal refractive surgery can often show irregularities in the structure of the cornea (e.g., corneal topography, aberrometry). However, they have limited value for accurate localization of pathologic abnormality in the individual layers of the cornea. This is essential for eventual treatment planning. The possible use of anterior segment OCT to evaluate the corneal changes in patients with recurrent epithelial erosions and to monitor the changes caused by the wound-healing response in patients receiving phototherapeutic keratectomy was reported.3Y6 Given the exact height and depth of the affected tissue, the ablation of the appropriate amount of tissue may be planned. Optical coherence tomography is a high-resolution technology that can create precise cross-sectional images of the cornea. The variations in the corneal and epithelial thickness and the tissue reflectivity could be evaluated. However, bright central flare caused by the very strong specular reflection at the corneal vertex may worsen the detailed evaluation of this area. We were not able to depict the pathological changes in the corneal structure using the OCT in our patient. In vivo corneal confocal microscopy allows noninvasive realtime spatial sectioning of living corneal tissue at the cellular level. It is capable of examining changes in the corneal cells layer by layer and of identifying corneal microstructural changes in
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
e20 In Vivo Confocal Microscopy After Corneal AbrasionVMahelkova et al.
different corneal pathologies (e.g., corneal dystrophies) as well as after refractive surgery.7Y15 The cornea must be totally transparent to refract light properly. The exact organization of all the structural elements is necessary at all the layers. Using in vivo corneal confocal microscopy, we were able to see abnormal folding in the basal epithelial layer and signs of epithelial cell hyperplasia in the affected eye. We found no scarring in the Bowman’s layer or in the stroma. This may be the reason why the OCT failed to display the pathology. The therapeutic abrasion of the affected epithelium led to satisfactory healing and resolved the visual problem. The lower basal epithelial cell density remaining on the affected eye and the activated keratocytes presented in the anterior stroma corresponded to previously published works on the stages of epithelium healing and stromal-epithelial interaction after corneal injury observable by corneal confocal microscopy.14,16 Thus, in vivo corneal confocal microscopy may reveal the underlying pathologic abnormality even in cases where the corneal OCT is not beneficial. The main limitation of this method is that it has only limited ability to precisely target a desired area, and only a very small area is examined with each scan. However, with improvement of this limitation in a new device generation, corneal confocal microscopy, in addition to the other modern methods, may become an important tool to help us locate a pathologic abnormality accurately and choose the proper therapeutic strategy (e.g., simple epithelial abrasion vs. removal of the scar using PTK).
ACKNOWLEDGMENTS The study was supported by the project (Ministry of Health, Czech Republic) for conceptual development of research organization 00064203 (University Hospital Motol, Prague, Czech Republic) and CZ.2.16/3.1.00/24022. The study was performed following all the guidelines required by the Institutional Ethics Committee. The authors declare no financial conflict of interest. The work was presented at XII Congress of Czech Vitreoretinal Society, November 23 to 24, 2012, in Pruhonice, Czech Republic (in Czech language). Received June 5, 2013; accepted September 17, 2013.
REFERENCES 1. Fraser S. Corneal abrasion. Clin Ophthalmol 2010;4:387Y90. 2. Wilson SA, Last A. Management of corneal abrasions. Am Fam Physician 2004;70:123Y8. 3. Ma JJ, Tseng SS, Yarascavitch BA. Anterior segment optical coherence tomography for transepithelial phototherapeutic keratectomy in central corneal stromal scarring. Cornea 2009;28:927Y9.
4. Wirbelauer C, Pham DT. Monitoring corneal structures with slitlamp-adapted optical coherence tomography in laser in situ keratomileusis. J Cataract Refract Surg 2004;30:1851Y60. 5. Wirbelauer C, Scholz C, Haberle H, Laqua H, Pham DT. Corneal optical coherence tomography before and after phototherapeutic keratectomy for recurrent epithelial erosions(2). J Cataract Refract Surg 2002;28:1629Y35. 6. Sayegh RR, Pineda R, 2nd. Practical applications of anterior segment optical coherence tomography imaging following corneal surgery. Semin Ophthalmol 2012;27:125Y32. 7. Mustonen RK, McDonald MB, Srivannaboon S, Tan AL, Doubrava MW, Kim CK. Normal human corneal cell populations evaluated by in vivo scanning slit confocal microscopy. Cornea 1998;17:485Y92. 8. Jalbert I, Stapleton F, Papas E, Sweeney DF, Coroneo M. In vivo confocal microscopy of the human cornea. Br J Ophthalmol 2003;87: 225Y36. 9. Chiou AG, Kaufman SC, Kaufman HE, Beuerman RW. Clinical corneal confocal microscopy. Surv Ophthalmol 2006;51:482Y500. 10. Dhaliwal JS, Kaufman SC, Chiou AG. Current applications of clinical confocal microscopy. Curr Opin Ophthalmol 2007;18:300Y7. 11. Patel DV, McGhee CN. Contemporary in vivo confocal microscopy of the living human cornea using white light and laser scanning techniques: a major review. Clin Exp Ophthalmol 2007;35:71Y88. 12. Pirnerova´ L, Hora´cˇkova´ M, Vlkova´ E, Hlinomazova´ Z, Trnkova´ V, Strmenova´ E. [The use of confocal corneal microscopy in the clinical practice]. Cesk Slov Oftalmol 2010;66:239Y47. 13. Chikama T, Takahashi N, Wakuta M, Morishige N, Nishida T. In vivo biopsy by laser confocal microscopy for evaluation of traumatic recurrent corneal erosion. Mol Vis 2008;14:2333Y9. 14. Chen WL, Shen EP, Hsieh YT, Yeh PT, Wang TJ, Hu FR. Comparison of in vivo confocal microscopic findings between epi-LASIK procedures with different management of the epithelial flaps. Invest Ophthalmol Vis Sci 2011;52:3640Y7. 15. Kobayashi A, Yokogawa H, Sugiyama K. In vivo laser confocal microscopy findings in patients with map-dot-fingerprint (epithelial basement membrane) dystrophy. Clin Ophthalmol 2012;6:1187Y90. 16. Wilson SE, Netto M, Ambrosio R, Jr. Corneal cells: chatty in development, homeostasis, wound healing, and disease. Am J Ophthalmol 2003;136:530Y6.
Gabriela Mahelkova Department of Ophthalmology for Children and Adults 2nd Faculty of Medicine of Charles University and University Hospital ´ valu 84, Prague 5, 150 06 VU Czech Republic e-mail: [email protected]; [email protected]
Optometry and Vision Science, Vol. 91, No. 1, January 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
