Deep Anterior Lamellar Keratoplasty After Descemet Stripping Automated Endothelial Keratoplasty Massimo Busin, MD and Jacqueline Beltz, MBBS, FRANZCO
Purpose: To report, using 2 illustrative cases, a new technique in which deep anterior lamellar keratoplasty (DALK) is performed after Descemet stripping automated endothelial keratoplasty (DSAEK) for cases of residual stromal opacity after the resolution of corneal endothelial failure.
Method: DSAEK was performed in 2 eyes with endothelial failure and stromal opacities of uncertain visual significance. After surgery, visual acuity failed to adequately improve. Residual stromal opacities were present in each case. Best-corrected visual acuity after DSAEK was 20/100 in case 1 and 20/200 in case 2. Subsequently, both cases underwent DALK.
Results: Surgeries and postoperative courses were uneventful in each case. After DALK, best-corrected visual acuity improved to 20/30 (21.0/24.0 3 90 degrees) at 9 months in case 1 and remained stable during a total of 24 months. In case 2, best-corrected visual acuity increased to 20/40 at 6 months (+2.00/26.00 3 40 degrees).
Conclusions: A new approach has been used to preserve the healthy DSAEK graft in these eyes with significant residual corneal opacities after the resolution of endothelial failure. Corneal clarity was reestablished by substituting the host central corneal stroma in its entire thickness with donor tissue, thus performing a DALK in addition to a DSAEK and avoiding a second intraocular surgery. Key Words: Descemet stripping automated endothelial keratoplasty, deep anterior lamellar keratoplasty (Cornea 2011;30:1048–1050)
ver the past decade, Descemet stripping automated endothelial keratoplasty (DSAEK) has become the preferred procedure for the treatment of corneal endothelial failure. This is largely because of the reduced intraoperative risk and excellent visual outcome associated with DSAEK.1 Penetrating keratoplasty (PK) is presently reserved for patients with fullthickness corneal disease, that is, endothelial failure and stromal opacities. However, it is not always possible to properly evaluate Received for publication September 10, 2010; revision received November 15, 2010; accepted November 19, 2010. From the ‘‘Villa Serena’’ Hospital, Department of Ophthalmology, Forlı`, Italy. M. Busin has received travel expenses reimbursement and royalties from Moria (Antony, France) since 2007. Reprints: Prof Massimo Busin, ‘‘Villa Serena’’ Hospital, Department of Ophthalmology, Via del Camaldolino 8, 47100 Forlı` FC, Italy (e-mail: [email protected]
). Copyright Ó 2011 by Lippincott Williams & Wilkins
the significance of stromal opacities on final visual acuity and, therefore, decide which type of procedure is indicated. We report 2 cases of endothelial failure and stromal opacity that did not experience a substantial visual improvement after DSAEK. These patients were managed by replacement of the entire host stroma while leaving in place the endothelial graft. In this way, the second surgery constituted a deep anterior lamellar keratoplasty (DALK) after DSAEK.
PATIENTS AND METHODS Case 1 An 82-year-old man with a history of glaucoma and phacoemulsification with implantation of intraocular lens presented to our clinic in 2007 with pseudophakic bullous keratopathy and central posterior shagreen. At that time, best spectacle–corrected visual acuity (BSCVA) was 20/400 (+1.5/24.0 3 100). Because posterior shagreen is normally expected to be visually insignificant, DSAEK was performed by means of our previously published technique.2 Postoperatively, BSCVA improved to 20/100 at 3 months (+1.0/24.0 3 100). No other pathology was identified, in particular, a macular ocular coherence tomography showed normal posterior pole condition. The presence of the stromal opacities therefore was presumed to be limiting the patient’s visual outcome. To remove the residual corneal opacity, 6 months after the DSAEK surgery, the patient underwent DALK, as described in detail. DALK was performed under peribulbar anesthesia (50% mixture of 2% lidocaine and 0.5% bupivacaine). The surgical steps are illustrated in Figure 1. A partial-thickness trephination, 7.0 mm in diameter, was performed in the host cornea, advancing the blade of a Hessburg–Barron trephine to approximately 300 mm (5 quarters of revolution from the point where the blade engaged the corneal surface). Maximal care was taken to align the trephination with the edge of the DSAEK graft. The incision was then deepened manually with a 15degree blade until the stromal surface of the DSAEK tissue, that is, the interface, was reached. As expected,3 no adhesion was found between the host and the DSAEK graft in this area, which was well within the peripheral annular DSAEK scar. The anterior stroma was excised using corneal scissors, the inferior branch of which was carefully inserted into the interface, whereas the superior one guided the cut after the trephination. As a result, the stromal surface of the endothelial graft was exposed in its central 7.0 mm, whereas a peripheral annular area approximately 1 mm in width, including the peripheral DSAEK scar, maintained the globe sealed throughout the procedure. Next, an anterior stromal lamella was dissected from the donor cornea with a microkeratome (Moria, Antony, France) using the 300-mm head to restore the normal central thickness of the cornea. The donor tissue was then punched to size with a 7.0-mm Barron punch and sutured in place with two 10-0 nylon continuous sutures. Because the procedure was extraocular, the wound did not have to be water-tight; therefore, the sutures were tied with relatively low tension. Cornea Volume 30, Number 9, September 2011
Cornea Volume 30, Number 9, September 2011
DALK After DSAEK
FIGURE 1. Surgical steps (case 1). A, Appearance after partial-thickness trephination. B, A 15-degree blade is used to deepen the trephination, down to the level of the DSAEK graft. C, Appearance after removal of the host corneal stroma. D, Final appearance.
In 2008, a 69-year-old man was referred to our clinic because of endothelial decompensation after phacoemulsification complicated by traumatic injury of the phaco tip against the posterior corneal surface. On presentation, he was noted to have, inside the edematous cornea, a central area of increased opacity believed to be caused by the focal absence of endothelium. Uncorrected visual acuity on presentation was less than 20/400 and could not be improved by any type of correction. DSAEK was performed using our standard technique,2 and 3 months later the BSCVA improved to 20/200 but remained stable thereafter. The cornea had resumed its transparency as a whole, but the central area did not clear up. No other ocular pathology was identified to explain the reduced BSCVA. Therefore, DALK was performed with the same technique as described for case 1.
RESULTS In case 1, BSCVA (21.0 sph 24.0 cyl at 90 degrees) was 20/30 at 9 months after DALK and remained unchanged 12 and 24 months postoperatively (Figs. 2A and 2B). For case 2, BSCVA (+2.00 sph 26.00 cyl at 40 degrees) increased to 20/40 at 6 months, and the final suture is yet to be removed (Figs. 2C and 2D). Endothelial cell density could not be evaluated after DSAEK because of insufficient corneal transparency. PostDALK endothelial cell density was 1223 cells per square millimeter in case 1 (24 months after DALK) and 1965 cells per square millimeter in case 2 (6 months after DALK); cumulative endothelial cell loss resulting from the 2 procedures was therefore 51.0% and 24.4%, respectively. q 2011 Lippincott Williams & Wilkins
It is clear from experience with laser refractive surgery that postoperative stromal haze, even of pronounced entity, may be compatible with good vision up to 20/20, showing that a clear correlation between the clinical appearance of stromal opacities and visual acuity has not yet been determined. The visual significance of stromal opacities is even more difficult to evaluate in the presence of endothelial failure, and it is a common experience that DSAEK alone may provide excellent visual recovery in most of these cases. To date, PK has been the only treatment for those patients with stromal opacities whose vision did not improve substantially after DSAEK, provided that all other possible causes for poor vision had been ruled out. We have used a different approach in the attempt to preserve the healthy DSAEK graft. Corneal clarity is reestablished by substituting the central corneal stroma in its entire thickness with tissue from a new donor, thus performing a DALK in addition to a DSAEK. We have previously shown that secondary surgery is possible after DSAEK, as early as 1 week after the original surgery.4 The presence of the 1-mm circumferential difference in the size of the anterior and posterior donor tissues in these cases allows for adequate maintenance of the peripheral attachment of the DSAEK tissue to the host cornea, thus preventing detachment of the posterior disk. This peripheral annular attachment also confines the DALK to an extraocular surgery, whereas PK would expose the eye to the risks of an intraocular procedure. The microkeratome-prepared interface between the 2 donor tissues is smooth and should not substantially affect the final BSCVA. In our 2 cases, BSCVA compares favorably with visual results www.corneajrnl.com |
Busin and Beltz
Cornea Volume 30, Number 9, September 2011
FIGURE 2. A, Case 1. Stromal shagreen after DSAEK. B, Appearance of case 1 after DALK (small arrows indicate DALK edge, large arrows indicate DSAEK edge). C, Case 2. Clear DSAEK graft with residual central corneal opacity. D, Appearance of case 2 after DALK (small arrows indicate DALK edge, large arrows indicate DSAEK edge).
of DSAEK performed both in unoperated corneas1 and in corneas with failed PK grafts.5 Also, the final endothelial cell density recorded in both our cases is compatible with longterm survival of the grafts, although in the first case, most likely, inexperience with the surgical technique caused a substantially greater loss of donor endothelial cells. The resulting full-thickness graft therefore takes the form of a 2-piece ‘‘top-hat,’’ similar to the 1-piece ‘‘top-hat’’ graft previously described, with all the advantages related to this type of ‘‘self-sealing’’ wound configuration.6 In particular, safety against trauma is increased and correction of postoperative astigmatism is easily achieved by opening the wound itself for a limited extension in correspondence of the steep meridian. Although larger studies would be required to analyze the outcomes of this technique, we believe that DALK provides a viable alternative to PK for patients in whom
DSAEK fails to improve their vision because of the persistence of central stromal opacity. REFERENCES 1. Lee BW, Jacobs MD, Musch DC, et al. Descemet’s stripping endothelial keratoplasty: safety and outcomes: a report by the American Academy of Ophthalmology. Ophthalmology. 2009;116:1818–1830. 2. Busin M, Bhatt P, Scorcia V. A modified technique for Descemet membrane stripping automated endothelial keratoplasty to minimize endothelial cell loss. Arch Ophthalmol. 2008;126:1133–1137. 3. Zhang Q, Randleman JB, Stulting RD, et al. Clinicopathologic findings in failed Descemet stripping automated endothelial keratoplasty. Arch Ophthalmol. 2010;128:973–980. 4. Lapenna L, Kadyan A, Busin M. Intraocular lens exchange 1 week after Descemet stripping automated endothelial keratoplasty. Cornea. 2010;29:207–209. 5. Price FW Jr., Price MO. Endothelial keratoplasty to restore clarity to a failed penetrating graft. Cornea. 2006;25:895–899. 6. Busin M. A new lamellar wound configuration for penetrating keratoplasty surgery. Arch Ophthalmol. 2003;121:260–265.
q 2011 Lippincott Williams & Wilkins