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Endothelial keratoplasty without Descemet's stripping in congenital hereditary endothelial dystrophy
Endothelial keratoplasty without Descemet’s stripping in congenital hereditary endothelial dystrophy Jatin N. Ashar, MD,* Muralidhar Ramappa, MD,* and Sunita Chaurasia, MD PURPOSE
METHODS RESULTS
CONCLUSIONS
To compare outcomes of non–Descemet’s stripping endothelial keratoplasty (nDSEK) with Descemet’s stripping endothelial keratoplasty (DSEK) for the surgical management of congenital hereditary endothelial dystrophy (CHED). Patients with CHED who were treated with DSEK or nDSEK were analyzed and compared with respect to graft adhesion, graft clarity, visual acuity, refraction, and complications. A total of 6 patients were included in the series. Of these, 3 (mean age, 5.6 1.52 years; 1 male) underwent DSEK and 3 (mean age, 5.6 0.57 years; 2 males) nDSEK. Preoperative best-corrected visual acuity of patients who underwent DSEK was 1.3 logMAR units compared with 1.13 logMAR units for nDSEK patients. There were no intraoperative complications. During the early postoperative period, 1 patient who had n DSEK had lenticule detachment and was successfully managed by repeat air injection. The average time for resolution of graft edema was 30 days. The postoperative best-corrected visual acuity was 0.13 0 .10 in DSEK patients and 0.13 0 .10 in nDSEK patients (P 5 1). Mean refraction was comparable in both groups of patients. The outcomes of nDSEK were similar to DSEK in CHED in this small series. The specific advantage of nDSEK is the decreased surgical time and intraocular tissue manipulation. ( J AAPOS 2013;17:22-24)
D
escemet’s stripping endothelial keratoplasty (DSEK) has been described as an alternative to penetrating keratoplasty for management of congenital hereditary endothelial dystrophy (CHED).1,2 Performing DSEK in a child with CHED, however, poses challenges: there is limited anterior chamber clearance for the proper positioning of the lenticule without impacting the crystalline lens, and visualization may be poor as the result of corneal edema. In addition, the stripping of Descemet’s membrane may be difficult and could lead to inadvertent lens trauma or pull on the posterior stromal fibers. A few modifications in surgical procedure may help in successful completion of DSEK in CHED. These include using trypan blue3 dye to stain Descemet’s membrane, using Chandelier endo illuminator4 to enhance visualization, or performing endothelial keratoplasty (EK) without stripping Descemet’s memAuthor affiliations: Cornea and Anterior Segment Services, L.V. Prasad Eye Institute, Hyderabad, India Financial Support: Hyderabad Eye Research Foundation, India. * These authors contributed equally to the present article. Submitted December 8, 2011. Revision accepted September 4, 2012. Published online January 28, 2013. Correspondence: Muralidhar Ramappa, MD, Cornea and Anterior Segment Services, Kallam Anji Reddy Campus, L. V. Prasad Eye Institute, L. V. Prasad Marg, Banjara Hills, Hyderabad 500034, India (email: [email protected]). Copyright Ó 2013 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2012.09.013
22
brane.1 EK has been successfully performed without removal of Descemet’s membrane in cases of pseudophakic bullous keratopathy,5 failed graft,6 and corneal decompensation after argon laser iridotomy7 and in few cases of CHED.1 Herein we present the comparative evaluation of outcomes of non–Descemet’s stripping endothelial keratoplasty (nDESK) with standard DSEK in patients with CHED.
Subjects and Methods In this retrospective interventional case series, the surgical outcomes in patients with CHED who underwent either DSEK or nDSEK were analyzed. All children had progressive corneal edema since birth. The patients were examined on postoperative day 1, at 1 week, then monthly for 3 months. At each visit visual acuity, lenticule status, corneal clarity, and complications were recorded. All surgeries were performed under general anesthesia. Donor tissues for transplantation met the following criteria: endothelial count of .2600 cells/mm2 with a coefficient of variance \25 and hexagonality of cells .70, with an overall clinical grading of very good and preservation time\48 hours in McCarey-Kaufman medium. The donor graft dissection was performed with the Moria microkeratome (Moria/Microtek Inc, Doylestown, PA) in 2 cases; by manually using a Barron’s artificial anterior chamber (Katena, Denville, NJ) in 3 cases; and by Femtosecond laser (Visumax, Carl Zeiss Meditec Inc, Dublin, CA) in 1 case. An anterior chamber maintainer was placed inferotemporally to maintain the anterior
Journal of AAPOS
Volume 17 Number 1 / February 2013
Ashar, Ramappa, and Chaurasia
23
FIG 1. Postoperative slit-lamp photographs of the conventional DSEK: compact cornea with intact lenticule and large peripheral iridectomy (A); wellcentered lenticule with iris details seen clearly (B); cross-section through slit lamp showing well attached compact lenticule (C). Postoperative slitlamp photographs of non–DSEK: well-attached lenticule with clear cornea (D); compact cornea with greater iris details (E); well-apposed lenticule with smooth interface (F). chamber depth throughout the procedure. Descemet’s membrane was scored in DSEK patients within an 8 mm mark placed on the epithelium (see Video 1, available at jaapos.org); no tissue was removed from the eye in the nDSEK group (Video 2, available at jaapos.org). A 4 to 5 mm superior scleral or limbal incision was made, and the posterior lamellar graft was inserted using sheets IOL glide (BD Medical-Ophthalmic Systems, Franklin Lakes, NJ) and protecting the endothelium with 1% sodium hyaluronate (Healon, Abbott Laboratories Inc, Abbott Park, IL). After graft insertion, air tamponade was performed. A complete air fill was maintained for 10 minutes, followed by gentle partial release of air to maintain two-thirds air volume in the anterior chamber. All incisions were sutured using 10-0 monofilament nylon sutures (Video 2). We ensured graft centration at the end of the procedure by using tangential illumination from a Chandelier light pipe. The patient was maintained in a supine position for several hours postoperatively. Postoperatively all children were started on topical drops consisting of 1% prednisolone acetate 8-10 times and 5% moxifloxacin (Vigamox, Alcon labs, TX) 4 times daily for the first week. Antibiotic drops were discontinued after the first week, whereas steroid drops were tapered weekly to 4 times daily,
Journal of AAPOS
which was maintained for 3-4 months after surgery, and thrice daily thereafter.
Results A total of 6 eyes of 6 patients were included in this series. The DSEK group included 3 patients (1 male), with a mean age of 5.6 1.52 years. The nDSEK group included 3 patients (2 males), with a mean age of 5.6 0.57 years. The visual acuity before surgery was 1.3 logMAR in the DSEK group and 1.13 logMAR in the nDSEK group. On the first postoperative day, all grafts adhered well. The cornea was edematous, and there was a small air bubble (\1/2 to 1/3) in the anterior chamber. None of the patients had pupillary block. At 1 week postoperatively, 1 patient in the nDSEK group presented with a partially detached graft; after a repeat air injection the graft was then successfully secured. Anterior segment optical coherence tomography showed that the graft was well positioned in all other patients at the 1-week follow-up. The average time of resolution of graft edema was 30 days. Cornea
24
Ashar, Ramappa, and Chaurasia
Volume 17 Number 1 / February 2013
Table 1. Summary of results of children with congenital hereditary endothelial dystrophy undergoing endothelial keratoplasty Visual acuity, logMAR Patient 1 2 3 4 5 6
Sex
Age, years
Surgery
Preop
Postop (1 year)
Final refraction
Complications
M F M F M F
7 4 6 6 6 5
nDSEK nDSEK nDSEK DSEK DSEK DSEK
1.3 1.3 1.3 0.8 1.3 1.3
0.5 1 0.8 0.6 0.8 0.6
10.00 1 4.00 180 13.50 1 2.50 50 10.50 1 1.50 10 16.00 1 2.00 180 2.00 1 1.00 180 16.00 1 2.00 90
Lenticule dislocation: successfully rebubbled
DSEK, Descemet’s stripping endothelial keratoplasty; F, female; M, male; nDSEK, non-Descemet’s stripping endothelial keratoplasty; postop, postoperative; preop, preoperative.
clarity was restored in all eyes and continued to improve in all patients over the ensuing 3 months. Figure 1 depicts representative slit-lamp photographs at the 3-month followup examination. The visual acuity began to improve from 1 month after surgery. Table 1 summarizes the outcomes in the 6 patients at 1 year after surgery. At the final follow-up examination, the cornea was clear in all patients. Apart from the lenticular dislocation in 1 patient, successfully managed by air injection, no other complications were noted in other patients during the follow-up period: all patients showed normal crystalline lens and normal intraocular pressure.
Discussion EK allows for selective replacement of the dysfunctional endothelium with a healthy donor endothelium. Descemet’s membrane stripping was considered to be an essential step while we performed EK.8 However; in several recent studies authors have shown that Descemet’s membrane may be left intact when no structural damage or abnormalities are present. It may be essential to remove the Descemet’s membrane in cases in which there is an underlying pathology, as in cases of Fuchs’ endothelial dystrophy. Some authors believe that the removal of Descemet’s membrane is an important step for the graft adhesion to the posterior cornea stroma and believe that retention of the membrane may lead to an increased risk of graft detachment8; however, there is no direct evidence to support this belief. In patients with CHED, it has been shown that although the corneal endothelium has a normal endothelial cell density, it has abnormal endothelial cell morphology, with thickening of Descemet’s membrane.9 Although the Descemet’s membrane shows thickening, it is regular and homogenous. Busin and collegues1 performed DSEK without Descemet’s membrane stripping with good visual outcomes in 6 eyes of 3 infants with CHED. We deferred Descemet’s stripping in the 3 cases primarily because of corneal clouding, which hampered adequate visualization of Descemet’s membrane. A forceful attempt to strip the Descemet’s membrane risks inadvertent injury to the lens
and trabecular meshwork. Moreover, we believed that a forcible attempt made at stripping the Descemet’s membrane could lead to an irregularity in the interface, possibly affecting the visual outcome. The postoperative visual acuity was comparable in the DSEK and nDSEK patients in this series. As seen in other indications of EK without Descemet’s membrane stripping, the graft interface in the CHED patients with and without Descemet’s membrane stripping appeared similar on slit-lamp examination. Our case series suggest that the short-term outcomes after nDSEK and DSEK are comparable for patients with CHED. Longer follow-up and more patients undergoing nDSEK are crucial requirements in determining the ultimate usefulness of this approach for these patients. References 1. Busin M, Beltz J, Scorcia V. Descemet-stripping automated endothelial keratoplasty for congenital hereditary endothelial dystrophy. Arch Ophthalmol 2011;129:1140-46. 2. Mittal V, Mittal R, Sangwan VS. Successful Descemet stripping endothelial keratoplasty in congenital hereditary endothelial dystrophy. Cornea 2011;30:354-6. 3. John T, Shah AA. Use of trypan blue stain in endothelial keratoplasty. Ann Ophthalmol 2009;41:10-15. 4. Inoue T, Oshima Y, Shima C, Hori Y, Maeda N, Tano Y. Chandelier illumination to complete Descemet stripping through severe hazy cornea during Descemet-stripping automated endothelial keratoplasty. J Cataract Refract Surg 2008;34:892-6. 5. Chaurasia S, Ramappa M, Murthy SI, Garg P, Sangwan VS. Endothelial keratoplasty without stripping the Descemet’s membrane. Br J Ophthalmol 2011;95:1473-4. 6. Price FW Jr, Price MO. Endothelial keratoplasty to restore clarity to a failed penetrating graft. Cornea 2006;25:895-9. 7. Kobayashi A, Yokogawa H, Sugiyama K. Non-Descemet stripping automated endothelial keratoplasty for endothelial dysfunction secondary to argon laser iridotomy. Am J Ophthalmol 2008;146:543-9. 8. Terry MA, Shamie N, Chen ES, Hoar KL, Friend DJ. Endothelial keratoplasty a simplified technique to minimize graft dislocation, iatrogenic graft failure, and pupillary block. Ophthalmology 2008;115: 1179-86. 9. Ehlers N, M odis L, Møller-Pedersen T. A morphological and functional study of congenital hereditary endothelial dystrophy. Acta Ophthalmol Scand 1998;76:314-18.
Journal of AAPOS
METHODS RESULTS
CONCLUSIONS
To compare outcomes of non–Descemet’s stripping endothelial keratoplasty (nDSEK) with Descemet’s stripping endothelial keratoplasty (DSEK) for the surgical management of congenital hereditary endothelial dystrophy (CHED). Patients with CHED who were treated with DSEK or nDSEK were analyzed and compared with respect to graft adhesion, graft clarity, visual acuity, refraction, and complications. A total of 6 patients were included in the series. Of these, 3 (mean age, 5.6 1.52 years; 1 male) underwent DSEK and 3 (mean age, 5.6 0.57 years; 2 males) nDSEK. Preoperative best-corrected visual acuity of patients who underwent DSEK was 1.3 logMAR units compared with 1.13 logMAR units for nDSEK patients. There were no intraoperative complications. During the early postoperative period, 1 patient who had n DSEK had lenticule detachment and was successfully managed by repeat air injection. The average time for resolution of graft edema was 30 days. The postoperative best-corrected visual acuity was 0.13 0 .10 in DSEK patients and 0.13 0 .10 in nDSEK patients (P 5 1). Mean refraction was comparable in both groups of patients. The outcomes of nDSEK were similar to DSEK in CHED in this small series. The specific advantage of nDSEK is the decreased surgical time and intraocular tissue manipulation. ( J AAPOS 2013;17:22-24)
D
escemet’s stripping endothelial keratoplasty (DSEK) has been described as an alternative to penetrating keratoplasty for management of congenital hereditary endothelial dystrophy (CHED).1,2 Performing DSEK in a child with CHED, however, poses challenges: there is limited anterior chamber clearance for the proper positioning of the lenticule without impacting the crystalline lens, and visualization may be poor as the result of corneal edema. In addition, the stripping of Descemet’s membrane may be difficult and could lead to inadvertent lens trauma or pull on the posterior stromal fibers. A few modifications in surgical procedure may help in successful completion of DSEK in CHED. These include using trypan blue3 dye to stain Descemet’s membrane, using Chandelier endo illuminator4 to enhance visualization, or performing endothelial keratoplasty (EK) without stripping Descemet’s memAuthor affiliations: Cornea and Anterior Segment Services, L.V. Prasad Eye Institute, Hyderabad, India Financial Support: Hyderabad Eye Research Foundation, India. * These authors contributed equally to the present article. Submitted December 8, 2011. Revision accepted September 4, 2012. Published online January 28, 2013. Correspondence: Muralidhar Ramappa, MD, Cornea and Anterior Segment Services, Kallam Anji Reddy Campus, L. V. Prasad Eye Institute, L. V. Prasad Marg, Banjara Hills, Hyderabad 500034, India (email: [email protected]). Copyright Ó 2013 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2012.09.013
22
brane.1 EK has been successfully performed without removal of Descemet’s membrane in cases of pseudophakic bullous keratopathy,5 failed graft,6 and corneal decompensation after argon laser iridotomy7 and in few cases of CHED.1 Herein we present the comparative evaluation of outcomes of non–Descemet’s stripping endothelial keratoplasty (nDESK) with standard DSEK in patients with CHED.
Subjects and Methods In this retrospective interventional case series, the surgical outcomes in patients with CHED who underwent either DSEK or nDSEK were analyzed. All children had progressive corneal edema since birth. The patients were examined on postoperative day 1, at 1 week, then monthly for 3 months. At each visit visual acuity, lenticule status, corneal clarity, and complications were recorded. All surgeries were performed under general anesthesia. Donor tissues for transplantation met the following criteria: endothelial count of .2600 cells/mm2 with a coefficient of variance \25 and hexagonality of cells .70, with an overall clinical grading of very good and preservation time\48 hours in McCarey-Kaufman medium. The donor graft dissection was performed with the Moria microkeratome (Moria/Microtek Inc, Doylestown, PA) in 2 cases; by manually using a Barron’s artificial anterior chamber (Katena, Denville, NJ) in 3 cases; and by Femtosecond laser (Visumax, Carl Zeiss Meditec Inc, Dublin, CA) in 1 case. An anterior chamber maintainer was placed inferotemporally to maintain the anterior
Journal of AAPOS
Volume 17 Number 1 / February 2013
Ashar, Ramappa, and Chaurasia
23
FIG 1. Postoperative slit-lamp photographs of the conventional DSEK: compact cornea with intact lenticule and large peripheral iridectomy (A); wellcentered lenticule with iris details seen clearly (B); cross-section through slit lamp showing well attached compact lenticule (C). Postoperative slitlamp photographs of non–DSEK: well-attached lenticule with clear cornea (D); compact cornea with greater iris details (E); well-apposed lenticule with smooth interface (F). chamber depth throughout the procedure. Descemet’s membrane was scored in DSEK patients within an 8 mm mark placed on the epithelium (see Video 1, available at jaapos.org); no tissue was removed from the eye in the nDSEK group (Video 2, available at jaapos.org). A 4 to 5 mm superior scleral or limbal incision was made, and the posterior lamellar graft was inserted using sheets IOL glide (BD Medical-Ophthalmic Systems, Franklin Lakes, NJ) and protecting the endothelium with 1% sodium hyaluronate (Healon, Abbott Laboratories Inc, Abbott Park, IL). After graft insertion, air tamponade was performed. A complete air fill was maintained for 10 minutes, followed by gentle partial release of air to maintain two-thirds air volume in the anterior chamber. All incisions were sutured using 10-0 monofilament nylon sutures (Video 2). We ensured graft centration at the end of the procedure by using tangential illumination from a Chandelier light pipe. The patient was maintained in a supine position for several hours postoperatively. Postoperatively all children were started on topical drops consisting of 1% prednisolone acetate 8-10 times and 5% moxifloxacin (Vigamox, Alcon labs, TX) 4 times daily for the first week. Antibiotic drops were discontinued after the first week, whereas steroid drops were tapered weekly to 4 times daily,
Journal of AAPOS
which was maintained for 3-4 months after surgery, and thrice daily thereafter.
Results A total of 6 eyes of 6 patients were included in this series. The DSEK group included 3 patients (1 male), with a mean age of 5.6 1.52 years. The nDSEK group included 3 patients (2 males), with a mean age of 5.6 0.57 years. The visual acuity before surgery was 1.3 logMAR in the DSEK group and 1.13 logMAR in the nDSEK group. On the first postoperative day, all grafts adhered well. The cornea was edematous, and there was a small air bubble (\1/2 to 1/3) in the anterior chamber. None of the patients had pupillary block. At 1 week postoperatively, 1 patient in the nDSEK group presented with a partially detached graft; after a repeat air injection the graft was then successfully secured. Anterior segment optical coherence tomography showed that the graft was well positioned in all other patients at the 1-week follow-up. The average time of resolution of graft edema was 30 days. Cornea
24
Ashar, Ramappa, and Chaurasia
Volume 17 Number 1 / February 2013
Table 1. Summary of results of children with congenital hereditary endothelial dystrophy undergoing endothelial keratoplasty Visual acuity, logMAR Patient 1 2 3 4 5 6
Sex
Age, years
Surgery
Preop
Postop (1 year)
Final refraction
Complications
M F M F M F
7 4 6 6 6 5
nDSEK nDSEK nDSEK DSEK DSEK DSEK
1.3 1.3 1.3 0.8 1.3 1.3
0.5 1 0.8 0.6 0.8 0.6
10.00 1 4.00 180 13.50 1 2.50 50 10.50 1 1.50 10 16.00 1 2.00 180 2.00 1 1.00 180 16.00 1 2.00 90
Lenticule dislocation: successfully rebubbled
DSEK, Descemet’s stripping endothelial keratoplasty; F, female; M, male; nDSEK, non-Descemet’s stripping endothelial keratoplasty; postop, postoperative; preop, preoperative.
clarity was restored in all eyes and continued to improve in all patients over the ensuing 3 months. Figure 1 depicts representative slit-lamp photographs at the 3-month followup examination. The visual acuity began to improve from 1 month after surgery. Table 1 summarizes the outcomes in the 6 patients at 1 year after surgery. At the final follow-up examination, the cornea was clear in all patients. Apart from the lenticular dislocation in 1 patient, successfully managed by air injection, no other complications were noted in other patients during the follow-up period: all patients showed normal crystalline lens and normal intraocular pressure.
Discussion EK allows for selective replacement of the dysfunctional endothelium with a healthy donor endothelium. Descemet’s membrane stripping was considered to be an essential step while we performed EK.8 However; in several recent studies authors have shown that Descemet’s membrane may be left intact when no structural damage or abnormalities are present. It may be essential to remove the Descemet’s membrane in cases in which there is an underlying pathology, as in cases of Fuchs’ endothelial dystrophy. Some authors believe that the removal of Descemet’s membrane is an important step for the graft adhesion to the posterior cornea stroma and believe that retention of the membrane may lead to an increased risk of graft detachment8; however, there is no direct evidence to support this belief. In patients with CHED, it has been shown that although the corneal endothelium has a normal endothelial cell density, it has abnormal endothelial cell morphology, with thickening of Descemet’s membrane.9 Although the Descemet’s membrane shows thickening, it is regular and homogenous. Busin and collegues1 performed DSEK without Descemet’s membrane stripping with good visual outcomes in 6 eyes of 3 infants with CHED. We deferred Descemet’s stripping in the 3 cases primarily because of corneal clouding, which hampered adequate visualization of Descemet’s membrane. A forceful attempt to strip the Descemet’s membrane risks inadvertent injury to the lens
and trabecular meshwork. Moreover, we believed that a forcible attempt made at stripping the Descemet’s membrane could lead to an irregularity in the interface, possibly affecting the visual outcome. The postoperative visual acuity was comparable in the DSEK and nDSEK patients in this series. As seen in other indications of EK without Descemet’s membrane stripping, the graft interface in the CHED patients with and without Descemet’s membrane stripping appeared similar on slit-lamp examination. Our case series suggest that the short-term outcomes after nDSEK and DSEK are comparable for patients with CHED. Longer follow-up and more patients undergoing nDSEK are crucial requirements in determining the ultimate usefulness of this approach for these patients. References 1. Busin M, Beltz J, Scorcia V. Descemet-stripping automated endothelial keratoplasty for congenital hereditary endothelial dystrophy. Arch Ophthalmol 2011;129:1140-46. 2. Mittal V, Mittal R, Sangwan VS. Successful Descemet stripping endothelial keratoplasty in congenital hereditary endothelial dystrophy. Cornea 2011;30:354-6. 3. John T, Shah AA. Use of trypan blue stain in endothelial keratoplasty. Ann Ophthalmol 2009;41:10-15. 4. Inoue T, Oshima Y, Shima C, Hori Y, Maeda N, Tano Y. Chandelier illumination to complete Descemet stripping through severe hazy cornea during Descemet-stripping automated endothelial keratoplasty. J Cataract Refract Surg 2008;34:892-6. 5. Chaurasia S, Ramappa M, Murthy SI, Garg P, Sangwan VS. Endothelial keratoplasty without stripping the Descemet’s membrane. Br J Ophthalmol 2011;95:1473-4. 6. Price FW Jr, Price MO. Endothelial keratoplasty to restore clarity to a failed penetrating graft. Cornea 2006;25:895-9. 7. Kobayashi A, Yokogawa H, Sugiyama K. Non-Descemet stripping automated endothelial keratoplasty for endothelial dysfunction secondary to argon laser iridotomy. Am J Ophthalmol 2008;146:543-9. 8. Terry MA, Shamie N, Chen ES, Hoar KL, Friend DJ. Endothelial keratoplasty a simplified technique to minimize graft dislocation, iatrogenic graft failure, and pupillary block. Ophthalmology 2008;115: 1179-86. 9. Ehlers N, M odis L, Møller-Pedersen T. A morphological and functional study of congenital hereditary endothelial dystrophy. Acta Ophthalmol Scand 1998;76:314-18.
Journal of AAPOS