TECHNIQUES
Novel Method to Avoid the Open-Sky Condition in Penetrating Keratoplasty: Covered Cornea Technique Osman S¸ . Arslan, MD,* Mustafa Ünal, MD,† Ceyhun Arici, MD,* Erdo g an Cicik, MD,* Serhat Mangan, MD,* and Eray Atalay, MD*
Purpose: The aim of this study was to present a novel technique to avoid the open-sky condition in pediatric and adult penetrating keratoplasty (PK).
Methods: Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. After trephining the recipient cornea up to a depth of 50% to 70%, the anterior chamber was entered at 1 point. Then, only a 2 clock hour segment of the recipient button was incised, and this segment was sutured to the recipient rim with a single tight suture. The procedure was repeated until the entire recipient button was excised and resutured. The donor corneal button was sutured to the recipient corneal rim. The sutures between the recipient button and the rim were then cut off, and the recipient button was drawn out. Results: None of the patients operated on with this technique developed complications related to the open-sky condition. Visual acuities, graft failure rates, and endothelial cell loss were comparable with the findings of studies performed for conventional PK. Conclusions: The technique described avoids the open-sky condition during the entire PK procedure. Endothelial cell loss rates are acceptable. Key Words: penetrating keratoplasty, pediatric, suprachoroidal hemorrhage, endothelial cell loss (Cornea 2014;33:994–998)
P
enetrating keratoplasty (PK) involves the full-thickness replacement of the cornea. Although lamellar techniques to replace damaged tissue only have been developed, PK remains one of the most commonly performed corneal transplantation procedures worldwide, especially for conditions that involve both endothelial and stromal pathologies.1 Because PK is an open-sky procedure, it carries significant intraoperative risks, including expulsive choroidal hemorrhage and vitreous loss. In infants and children, the cornea and sclera are less rigid; trephining the recipient
Received for publication February 27, 2014; revision received May 5, 2014; accepted May 15, 2014. Published online ahead of print July 9, 2014. From the *Department of Ophthalmology, Cerrahpas¸a Medical Faculty, Istanbul University, Istanbul, Turkey; and †Department of Ophthalmology, Medical Faculty, Akdeniz University, Antalya, Turkey. The authors have no funding or conflicts of interest to disclose. Reprints: Mustafa Ünal, MD, Department of Ophthalmology, Akdeniz University, Antalya, Turkey (e-mail: [email protected]). Copyright © 2014 by Lippincott Williams & Wilkins
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| www.corneajrnl.com
cornea in this population is more difficult and increases the risk of developing iridocorneal adhesions. In phakic eyes, there may be spontaneous extrusion of the lens and the vitreous.2 Recently, 2 novel methods were reported to obtain a stabilized PK procedure, in which the anterior chamber is maintained, to reduce the disadvantages associated with an open-sky procedure.3,4 This study presents the long-term results of a new technique in a large number of pediatric and adult cases, in which the globe was not exposed to the opensky condition during the entire PK procedure.
MATERIALS AND METHODS In this noncomparative interventional case series study, 116 eyes of 109 consecutive patients, who underwent PK between January 2006 and July 2013, were retrospectively evaluated. All surgeries were performed by the same surgeon (O.S¸.A.). Institutional review board approval was obtained. All infants and children (0–13 years old) and only adult patients with a high risk of suprachoroidal hemorrhage (SH) were operated on using this technique during the aforementioned period. Criteria for the increased risk of developing an SH included older age, glaucoma, tachycardia, systemic hypertension, arteriosclerosis, anticoagulant therapy, prior SH, or a combination of the above. Eyes requiring planned or unplanned additional procedures, such as lens extraction, intraocular lens implantation, glaucoma shunt implantation, and anterior vitrectomy were not operated on with this technique. In corneas allowing sufficient visualization for these additional procedures via a “closed” approach, the technique was used. Patients who were lost to follow-up were excluded from the data analysis. A complete ophthalmic examination was performed preoperatively and postoperatively, including slit-lamp examination, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), refractive error, endothelial cell density (ECD), and retinal examination. If a direct retinal examination was not possible because of corneal blurring, a B-scan ultrasonographic test was performed. The ECD was determined using a noncontact specular microscope (Topcon SP2000p; Topcon Corp, Tokyo, Japan). Endothelial cell counts of the donor buttons were measured preoperatively and repeated postoperatively at 6 and 12 months. Detailed donor information was available in all cases. Donor age ranged from 2 to 84 years. Corneoscleral buttons were stored in Optisol GS solution. Death-to-enucleation Cornea Volume 33, Number 9, September 2014
Cornea Volume 33, Number 9, September 2014
Covered Cornea Technique
FIGURE 1. Intraoperative photographs of a case. A–F, Recipient bed preparation. G and H, Donor cornea preparation. I and J, Suturing of the donor button across the recipient area. K, L, and M, Cutting of the sutures between the recipient bed and the recipient button, and drawing out of the recipient button. N and O, End of the operation.
time ranged from 50 minutes to 6 hours, and use time ranged from 0 to 4 days. The main outcome measures were intraoperative and postoperative complications and visual acuities, refractive data, and ECDs.
Surgical Technique All surgeries were performed under general or retrobulbar anesthesia (Figs. 1, 2). A lid speculum was used in all cases with or without a Flieringa ring. The ring was used when the globe and sclera were soft and easily distensible in pediatric cases and in the case of prior multiple surgeries and aphakia in the adult group. The recipient cornea was trephined to a depth of 50% to 70% by using a disposable stainless steel trephine (Figs. 1A, B, 2A, B). The incision was deepened with a blade, and the anterior chamber was entered (Fig. 1C). The anterior chamber was formed with a viscoelastic material (Viscoat; Alcon) to protect the iris and lens from damage while excising the recipient button with scissors. At this stage, maneuvers, such as synechiotomy, iridoplasty, or intraocular lens manipulation, can be performed. Only a 2 clock hour segment of the recipient button (;60 degrees) was incised from the recipient rim, and this segment was Ó 2014 Lippincott Williams & Wilkins
sutured with a tight single interrupted suture to the recipient rim again (Figs. 1D, 2C). The incision was then continued for another 2-o’clock segment, and this area was also sutured again (Figs. 1E, 2D). The procedure was repeated until all the recipient buttons were incised and resutured to the recipient rim (Fig. 2E). Upon completion, there was a completely excised recipient button left in its place sutured to the recipient rim with 6 to 8 interrupted sutures. The donor cornea was prepared at this stage (Figs. 1F, 2E). The donor cornea was trephined from the endothelial side by using a corneal punch (Fig. 1G). A host–graft disparity of 0.25 to 0.5 mm (0.5–1.0 mm in pediatric cases) was used. The epithelial side of the recipient button was coated with viscoelastic material (Fig. 2F). The donor corneal button, also coated with viscoelastic material on the endothelial side, was sutured to the recipient corneal rim with 6 to 8 interrupted sutures (Figs. 1H, 1I, 2G, 2H). A 2- to 3 clock hour segment of the donor button was left without suturing the corneal rim. A safety suture was passed through only the donor button without passing through the rim at this segment. Sutures between the recipient button and recipient rim were then cut off (Figs. 1J, 2I), a high amount of viscoelastic material was injected again between the donor and recipient buttons, and www.corneajrnl.com |
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FIGURE 2. Illustration of the covered corneal technique.
the recipient button was removed through the unsutured segment (Figs. 1K, 1L, 1M, 2J, 2K). Immediately after removing the button, the safety suture that was previously inserted to the donor button was passed to the recipient rim and tied (Figs. 1N, 1O, 2L).
RESULTS Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. Preoperative diagnoses, ages, and genders of the patients are shown in Tables 1 and 2. All the operations were completed without any complications; the technique itself was easy to perform. None of the infant patients developed intractable postoperative inflammation or synechia formation. The follow-up period ranged between 5 months and 7 years. Permanent rejection or graft failure was recorded in 4 adult eyes (9.1%) and in 22 pediatric eyes (30.5%). The mean ECD in donor buttons was 2479 6 242 in the pediatric group and 2450 6 225 in the adult group. Although
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postoperative ECD was possible in all eyes in the adult group, it could be measured reliably in 23 eyes in the pediatric group. The mean ECD was 1962 6 223 at 6 months and 1885 6 223 in 12 months in the pediatric group (endothelial cell loss of 20.9% and 24% at 6 and 12 months, respectively). The mean ECDs in the adult group were 1902 6 221 at 6 months and 1809 6 211 at 12 months (endothelial cell loss of 22.4% and 26.2 at 6 and 12 months, respectively). The postoperative BSCVA in the pediatric group, which was measurable in 25 eyes, was 20/400 or better in 14 eyes (56%) and 20/40 or better in 9 eyes (36%). The BSCVA was 20/40 or better in 35 eyes in the adult group (79.5%). The main causes for a BSCVA worse than 20/40 were amblyopia, high postoperative astigmatism, lenticular opacity, and retinal pathology in the pediatric group; and agerelated macular changes, diabetic retinopathy, and high postoperative astigmatism in the adult group. The maximum keratometry (mean 6 SD) was 46.19 6 4.24 diopters in the adult group and 47.72 6 5.12 diopters in the pediatric group. Spherical equivalent (mean 6 SD) Ó 2014 Lippincott Williams & Wilkins
Cornea Volume 33, Number 9, September 2014
Covered Cornea Technique
TABLE 1. Demographic Data of the Patients No. Patients Infants–children Adults
65 44
Mean Age (yrs) and Sex M/F Mean Follow-up (mos) 3.2; 31/34 67.5; 24/20
38.6 (5 mos–8 yrs) 48.6 (5 mos–8 yrs)
(range) was 20.70 6 1.95 (25.50 to +2.0) and 22.12 6 1.90 (2650 to +3.50). The pediatric group had steeper keratometric values and was more myopic than was the adult group because of high graft–host disparity.
DISCUSSION The technique presented here has important advantages in both pediatric and adult PK-operated patients. The opensky condition was avoided during the entire procedure, and the surgeon worked under a closed system. The follow-up time was relatively long, and none of the patients operated on with this technique developed complications related to the open-sky condition. PK in children is a high-risk procedure. The decreased rigidity and increased elasticity of the infant cornea and sclera make transplantation technically more difficult. Difficulties in achieving proper wound closure and predisposition to forward movement of the lens–iris diaphragm led to a higher rate of complications, such as intraoperative scleral collapse, iris prolapse, lenticular extrusion, and SH. Iridocorneal adhesions, fibrin formation, and postoperative inflammation may be prominent.2 Avoiding the open-sky condition would prevent many of the difficulties encountered during pediatric PK. Massive SH is a well-known, possibly serious complication of many surgical procedures, including cataract extraction, glaucoma-filtering procedures, PK, retinal detachment surgery, and pars plana vitrectomy. Factors that predispose the patient to experiencing SH include hypertension, atherosclerosis, glaucoma, and patient coughing or straining during surgery. Incidence may be higher in PK than in other types of intraocular surgeries.5–7 The risk of hemorrhage may
TABLE 2. Preoperative Diagnoses Patients Pediatric group Sclerocornea and associated pathologies Anterior cleavage syndrome including Peters anomaly Other congenital anomalies including congenital hereditary endothelial dystrophy and macular dystrophy Congenital glaucoma Traumatic Other Adult group Bullous keratopathy Traumatic Postinfectious leucoma Other
Ó 2014 Lippincott Williams & Wilkins
No. Eyes 13 12 9
8 8 15 16 12 10 6
increase in surgeries performed under retrobulbar anesthesia.8 If a hemorrhage occurs during PK, the intraocular contents may extrude without resistance because of open-sky condition. With the current technique, the risk of developing a hemorrhage may be decreased. Even if a hemorrhage develops, it may be less catastrophic and limited. Another advantage of the technique is easier bleeding control. Vascularized recipient beds may result in profuse bleeding in the operating field, and bleeding control may be challenging to the surgeon. With the described technique, the mechanical closure of the recipient button and recipient rim aid in controlling the hemorrhage and also prevent leaking into the anterior chamber. However, placing sutures can sometimes trigger bleeding in a vascularized recipient bed. Donor button endothelial damage may be a concern in these techniques because of temporary contact of the donor endothelium and recipient button. Injecting an abundant amount of viscoelastic material into the potential space between the recipient and donor corneas just before removing the recipient button pushes back the recipient button and prevents possible contact between the buttons, thus preventing endothelial cell damage. Flattening of the recipient button by tight suturing to the recipient rim and preferring a host–graft disparity of 0.5 to 1.0 mm in pediatric patients also increase the potential space between the buttons. There was no serious endothelial cell loss during the procedure. The rate of endothelial cell loss in this study was comparable with that of previous PK studies, which reported an endothelial cell loss that can be as high as 43% within the first 12 months postoperatively.9–11 Recently, 2 new techniques were reported to avoid the open-sky condition during PK.3,4 In the protected PK technique of Lopez-Plandolit et al,3 which is similar to the current method, the authors create 2 incisions in the trephination groove, and the incisions are widened to opposite sides, and then sutured again to the recipient bed. After the viscoelasticcoated graft is sutured to the recipient bed, the recipient button is drawn out. In the anterior chamber–secured technique of Chen et al,4 first a deep anterior corneal lamella is excised. Then, a small puncture is created in each quadrant along the groove of the stromal bed, and the viscoelastic-coated graft is sutured near the 4 puncture sites. After sequential cutting of the stromal bed and suturing of the graft, the residual stromal bed is excised and drawn out before the last suture is placed. Both techniques are promising, although they are new and the number of patients is relatively low. Additionally, Loden and Price12 reported a technique that is very similar to the current method, in which the graft is sutured across the trephined host cornea to manage positive pressure. It maintained the anterior chamber that formed during PK. However, postoperative ECD and visual and refractive results were not known, and the patients were adults. The current technique is very easy to perform, and the learning period is very short. The authors have been using the technique for .8 years without any complications on a large number of patients. It has many advantages, especially in pediatric PK-operated patients, and also in adults who are at a risk of developing an SH. www.corneajrnl.com |
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REFERENCES 1. Tan DT, Mehta JS. Future directions in lamellar corneal transplantation. Cornea. 2007;26:S21–S28. 2. Vanathi M, Panda A, Vengayil S, et al. Pediatric keratoplasty. Surv Ophthalmol. 2009;54:245–271. 3. López-Plandolit S, Etxebarría J, Acera A, et al. Protected penetrating keratoplasty: surgical technique and endothelial response [in Spanish]. Arch Soc Esp Oftalmol. 2008;83:231–236. 4. Chen W, Ren Y, Zheng Q, et al. Securing the anterior chamber in penetrating keratoplasty: an innovative surgical technique. Cornea. 2013;32:1291–1295. 5. Häring G, Behrendt S, Wiechens B, et al. Severe intra- and postoperative supra-choroid hemorrhage. Risk factors, therapy, results [in German]. Ophthalmologe. 1999;96:822–828. 6. Price FW Jr, Whitson WE, Ahad KA, et al. Suprachoroidal hemorrhage in penetrating keratoplasty. Ophthalmic Surg. 1994;25:521– 525.
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| www.corneajrnl.com
7. Gloor B, Kalman A. Choroidal effusion and expulsive hemorrhage in penetrating interventions—lesson from 26 patients [in German]. Klin Monbl Augenheilkd. 1993;202:224–237. 8. Ingraham HJ, Donnenfeld ED, Perry HD. Massive suprachoroidal hemorrhage in penetrating keratoplasty. Am J Ophthalmol. 1989;108:670–675. 9. Bahar I, Kaiserman I, Srinivasan S, et al. Comparison of three different techniques of corneal transplantation for keratoconus. Am J Ophthalmol. 2008;146:905–912.e1. 10. Cornea Donor Study Investigator Group. The effect of donor age on corneal transplantation outcome results of the cornea donor study. Ophthalmology. 2008;115:620–626.e6. 11. Patel SV, Hodge DO, Bourne WM. Corneal endothelium and postoperative outcomes 15 years after penetrating keratoplasty. Am J Ophthalmol. 2005;139:311–319. 12. Loden JC, Price FW Jr. Price graft-over-host technique to manage positive pressure during penetrating keratoplasty. J Cataract Refract Surg. 1998;24:736–738.
Ó 2014 Lippincott Williams & Wilkins
Novel Method to Avoid the Open-Sky Condition in Penetrating Keratoplasty: Covered Cornea Technique Osman S¸ . Arslan, MD,* Mustafa Ünal, MD,† Ceyhun Arici, MD,* Erdo g an Cicik, MD,* Serhat Mangan, MD,* and Eray Atalay, MD*
Purpose: The aim of this study was to present a novel technique to avoid the open-sky condition in pediatric and adult penetrating keratoplasty (PK).
Methods: Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. After trephining the recipient cornea up to a depth of 50% to 70%, the anterior chamber was entered at 1 point. Then, only a 2 clock hour segment of the recipient button was incised, and this segment was sutured to the recipient rim with a single tight suture. The procedure was repeated until the entire recipient button was excised and resutured. The donor corneal button was sutured to the recipient corneal rim. The sutures between the recipient button and the rim were then cut off, and the recipient button was drawn out. Results: None of the patients operated on with this technique developed complications related to the open-sky condition. Visual acuities, graft failure rates, and endothelial cell loss were comparable with the findings of studies performed for conventional PK. Conclusions: The technique described avoids the open-sky condition during the entire PK procedure. Endothelial cell loss rates are acceptable. Key Words: penetrating keratoplasty, pediatric, suprachoroidal hemorrhage, endothelial cell loss (Cornea 2014;33:994–998)
P
enetrating keratoplasty (PK) involves the full-thickness replacement of the cornea. Although lamellar techniques to replace damaged tissue only have been developed, PK remains one of the most commonly performed corneal transplantation procedures worldwide, especially for conditions that involve both endothelial and stromal pathologies.1 Because PK is an open-sky procedure, it carries significant intraoperative risks, including expulsive choroidal hemorrhage and vitreous loss. In infants and children, the cornea and sclera are less rigid; trephining the recipient
Received for publication February 27, 2014; revision received May 5, 2014; accepted May 15, 2014. Published online ahead of print July 9, 2014. From the *Department of Ophthalmology, Cerrahpas¸a Medical Faculty, Istanbul University, Istanbul, Turkey; and †Department of Ophthalmology, Medical Faculty, Akdeniz University, Antalya, Turkey. The authors have no funding or conflicts of interest to disclose. Reprints: Mustafa Ünal, MD, Department of Ophthalmology, Akdeniz University, Antalya, Turkey (e-mail: [email protected]). Copyright © 2014 by Lippincott Williams & Wilkins
994
| www.corneajrnl.com
cornea in this population is more difficult and increases the risk of developing iridocorneal adhesions. In phakic eyes, there may be spontaneous extrusion of the lens and the vitreous.2 Recently, 2 novel methods were reported to obtain a stabilized PK procedure, in which the anterior chamber is maintained, to reduce the disadvantages associated with an open-sky procedure.3,4 This study presents the long-term results of a new technique in a large number of pediatric and adult cases, in which the globe was not exposed to the opensky condition during the entire PK procedure.
MATERIALS AND METHODS In this noncomparative interventional case series study, 116 eyes of 109 consecutive patients, who underwent PK between January 2006 and July 2013, were retrospectively evaluated. All surgeries were performed by the same surgeon (O.S¸.A.). Institutional review board approval was obtained. All infants and children (0–13 years old) and only adult patients with a high risk of suprachoroidal hemorrhage (SH) were operated on using this technique during the aforementioned period. Criteria for the increased risk of developing an SH included older age, glaucoma, tachycardia, systemic hypertension, arteriosclerosis, anticoagulant therapy, prior SH, or a combination of the above. Eyes requiring planned or unplanned additional procedures, such as lens extraction, intraocular lens implantation, glaucoma shunt implantation, and anterior vitrectomy were not operated on with this technique. In corneas allowing sufficient visualization for these additional procedures via a “closed” approach, the technique was used. Patients who were lost to follow-up were excluded from the data analysis. A complete ophthalmic examination was performed preoperatively and postoperatively, including slit-lamp examination, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), refractive error, endothelial cell density (ECD), and retinal examination. If a direct retinal examination was not possible because of corneal blurring, a B-scan ultrasonographic test was performed. The ECD was determined using a noncontact specular microscope (Topcon SP2000p; Topcon Corp, Tokyo, Japan). Endothelial cell counts of the donor buttons were measured preoperatively and repeated postoperatively at 6 and 12 months. Detailed donor information was available in all cases. Donor age ranged from 2 to 84 years. Corneoscleral buttons were stored in Optisol GS solution. Death-to-enucleation Cornea Volume 33, Number 9, September 2014
Cornea Volume 33, Number 9, September 2014
Covered Cornea Technique
FIGURE 1. Intraoperative photographs of a case. A–F, Recipient bed preparation. G and H, Donor cornea preparation. I and J, Suturing of the donor button across the recipient area. K, L, and M, Cutting of the sutures between the recipient bed and the recipient button, and drawing out of the recipient button. N and O, End of the operation.
time ranged from 50 minutes to 6 hours, and use time ranged from 0 to 4 days. The main outcome measures were intraoperative and postoperative complications and visual acuities, refractive data, and ECDs.
Surgical Technique All surgeries were performed under general or retrobulbar anesthesia (Figs. 1, 2). A lid speculum was used in all cases with or without a Flieringa ring. The ring was used when the globe and sclera were soft and easily distensible in pediatric cases and in the case of prior multiple surgeries and aphakia in the adult group. The recipient cornea was trephined to a depth of 50% to 70% by using a disposable stainless steel trephine (Figs. 1A, B, 2A, B). The incision was deepened with a blade, and the anterior chamber was entered (Fig. 1C). The anterior chamber was formed with a viscoelastic material (Viscoat; Alcon) to protect the iris and lens from damage while excising the recipient button with scissors. At this stage, maneuvers, such as synechiotomy, iridoplasty, or intraocular lens manipulation, can be performed. Only a 2 clock hour segment of the recipient button (;60 degrees) was incised from the recipient rim, and this segment was Ó 2014 Lippincott Williams & Wilkins
sutured with a tight single interrupted suture to the recipient rim again (Figs. 1D, 2C). The incision was then continued for another 2-o’clock segment, and this area was also sutured again (Figs. 1E, 2D). The procedure was repeated until all the recipient buttons were incised and resutured to the recipient rim (Fig. 2E). Upon completion, there was a completely excised recipient button left in its place sutured to the recipient rim with 6 to 8 interrupted sutures. The donor cornea was prepared at this stage (Figs. 1F, 2E). The donor cornea was trephined from the endothelial side by using a corneal punch (Fig. 1G). A host–graft disparity of 0.25 to 0.5 mm (0.5–1.0 mm in pediatric cases) was used. The epithelial side of the recipient button was coated with viscoelastic material (Fig. 2F). The donor corneal button, also coated with viscoelastic material on the endothelial side, was sutured to the recipient corneal rim with 6 to 8 interrupted sutures (Figs. 1H, 1I, 2G, 2H). A 2- to 3 clock hour segment of the donor button was left without suturing the corneal rim. A safety suture was passed through only the donor button without passing through the rim at this segment. Sutures between the recipient button and recipient rim were then cut off (Figs. 1J, 2I), a high amount of viscoelastic material was injected again between the donor and recipient buttons, and www.corneajrnl.com |
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Cornea Volume 33, Number 9, September 2014
Arslan et al
FIGURE 2. Illustration of the covered corneal technique.
the recipient button was removed through the unsutured segment (Figs. 1K, 1L, 1M, 2J, 2K). Immediately after removing the button, the safety suture that was previously inserted to the donor button was passed to the recipient rim and tied (Figs. 1N, 1O, 2L).
RESULTS Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. Preoperative diagnoses, ages, and genders of the patients are shown in Tables 1 and 2. All the operations were completed without any complications; the technique itself was easy to perform. None of the infant patients developed intractable postoperative inflammation or synechia formation. The follow-up period ranged between 5 months and 7 years. Permanent rejection or graft failure was recorded in 4 adult eyes (9.1%) and in 22 pediatric eyes (30.5%). The mean ECD in donor buttons was 2479 6 242 in the pediatric group and 2450 6 225 in the adult group. Although
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| www.corneajrnl.com
postoperative ECD was possible in all eyes in the adult group, it could be measured reliably in 23 eyes in the pediatric group. The mean ECD was 1962 6 223 at 6 months and 1885 6 223 in 12 months in the pediatric group (endothelial cell loss of 20.9% and 24% at 6 and 12 months, respectively). The mean ECDs in the adult group were 1902 6 221 at 6 months and 1809 6 211 at 12 months (endothelial cell loss of 22.4% and 26.2 at 6 and 12 months, respectively). The postoperative BSCVA in the pediatric group, which was measurable in 25 eyes, was 20/400 or better in 14 eyes (56%) and 20/40 or better in 9 eyes (36%). The BSCVA was 20/40 or better in 35 eyes in the adult group (79.5%). The main causes for a BSCVA worse than 20/40 were amblyopia, high postoperative astigmatism, lenticular opacity, and retinal pathology in the pediatric group; and agerelated macular changes, diabetic retinopathy, and high postoperative astigmatism in the adult group. The maximum keratometry (mean 6 SD) was 46.19 6 4.24 diopters in the adult group and 47.72 6 5.12 diopters in the pediatric group. Spherical equivalent (mean 6 SD) Ó 2014 Lippincott Williams & Wilkins
Cornea Volume 33, Number 9, September 2014
Covered Cornea Technique
TABLE 1. Demographic Data of the Patients No. Patients Infants–children Adults
65 44
Mean Age (yrs) and Sex M/F Mean Follow-up (mos) 3.2; 31/34 67.5; 24/20
38.6 (5 mos–8 yrs) 48.6 (5 mos–8 yrs)
(range) was 20.70 6 1.95 (25.50 to +2.0) and 22.12 6 1.90 (2650 to +3.50). The pediatric group had steeper keratometric values and was more myopic than was the adult group because of high graft–host disparity.
DISCUSSION The technique presented here has important advantages in both pediatric and adult PK-operated patients. The opensky condition was avoided during the entire procedure, and the surgeon worked under a closed system. The follow-up time was relatively long, and none of the patients operated on with this technique developed complications related to the open-sky condition. PK in children is a high-risk procedure. The decreased rigidity and increased elasticity of the infant cornea and sclera make transplantation technically more difficult. Difficulties in achieving proper wound closure and predisposition to forward movement of the lens–iris diaphragm led to a higher rate of complications, such as intraoperative scleral collapse, iris prolapse, lenticular extrusion, and SH. Iridocorneal adhesions, fibrin formation, and postoperative inflammation may be prominent.2 Avoiding the open-sky condition would prevent many of the difficulties encountered during pediatric PK. Massive SH is a well-known, possibly serious complication of many surgical procedures, including cataract extraction, glaucoma-filtering procedures, PK, retinal detachment surgery, and pars plana vitrectomy. Factors that predispose the patient to experiencing SH include hypertension, atherosclerosis, glaucoma, and patient coughing or straining during surgery. Incidence may be higher in PK than in other types of intraocular surgeries.5–7 The risk of hemorrhage may
TABLE 2. Preoperative Diagnoses Patients Pediatric group Sclerocornea and associated pathologies Anterior cleavage syndrome including Peters anomaly Other congenital anomalies including congenital hereditary endothelial dystrophy and macular dystrophy Congenital glaucoma Traumatic Other Adult group Bullous keratopathy Traumatic Postinfectious leucoma Other
Ó 2014 Lippincott Williams & Wilkins
No. Eyes 13 12 9
8 8 15 16 12 10 6
increase in surgeries performed under retrobulbar anesthesia.8 If a hemorrhage occurs during PK, the intraocular contents may extrude without resistance because of open-sky condition. With the current technique, the risk of developing a hemorrhage may be decreased. Even if a hemorrhage develops, it may be less catastrophic and limited. Another advantage of the technique is easier bleeding control. Vascularized recipient beds may result in profuse bleeding in the operating field, and bleeding control may be challenging to the surgeon. With the described technique, the mechanical closure of the recipient button and recipient rim aid in controlling the hemorrhage and also prevent leaking into the anterior chamber. However, placing sutures can sometimes trigger bleeding in a vascularized recipient bed. Donor button endothelial damage may be a concern in these techniques because of temporary contact of the donor endothelium and recipient button. Injecting an abundant amount of viscoelastic material into the potential space between the recipient and donor corneas just before removing the recipient button pushes back the recipient button and prevents possible contact between the buttons, thus preventing endothelial cell damage. Flattening of the recipient button by tight suturing to the recipient rim and preferring a host–graft disparity of 0.5 to 1.0 mm in pediatric patients also increase the potential space between the buttons. There was no serious endothelial cell loss during the procedure. The rate of endothelial cell loss in this study was comparable with that of previous PK studies, which reported an endothelial cell loss that can be as high as 43% within the first 12 months postoperatively.9–11 Recently, 2 new techniques were reported to avoid the open-sky condition during PK.3,4 In the protected PK technique of Lopez-Plandolit et al,3 which is similar to the current method, the authors create 2 incisions in the trephination groove, and the incisions are widened to opposite sides, and then sutured again to the recipient bed. After the viscoelasticcoated graft is sutured to the recipient bed, the recipient button is drawn out. In the anterior chamber–secured technique of Chen et al,4 first a deep anterior corneal lamella is excised. Then, a small puncture is created in each quadrant along the groove of the stromal bed, and the viscoelastic-coated graft is sutured near the 4 puncture sites. After sequential cutting of the stromal bed and suturing of the graft, the residual stromal bed is excised and drawn out before the last suture is placed. Both techniques are promising, although they are new and the number of patients is relatively low. Additionally, Loden and Price12 reported a technique that is very similar to the current method, in which the graft is sutured across the trephined host cornea to manage positive pressure. It maintained the anterior chamber that formed during PK. However, postoperative ECD and visual and refractive results were not known, and the patients were adults. The current technique is very easy to perform, and the learning period is very short. The authors have been using the technique for .8 years without any complications on a large number of patients. It has many advantages, especially in pediatric PK-operated patients, and also in adults who are at a risk of developing an SH. www.corneajrnl.com |
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Cornea Volume 33, Number 9, September 2014
Arslan et al
REFERENCES 1. Tan DT, Mehta JS. Future directions in lamellar corneal transplantation. Cornea. 2007;26:S21–S28. 2. Vanathi M, Panda A, Vengayil S, et al. Pediatric keratoplasty. Surv Ophthalmol. 2009;54:245–271. 3. López-Plandolit S, Etxebarría J, Acera A, et al. Protected penetrating keratoplasty: surgical technique and endothelial response [in Spanish]. Arch Soc Esp Oftalmol. 2008;83:231–236. 4. Chen W, Ren Y, Zheng Q, et al. Securing the anterior chamber in penetrating keratoplasty: an innovative surgical technique. Cornea. 2013;32:1291–1295. 5. Häring G, Behrendt S, Wiechens B, et al. Severe intra- and postoperative supra-choroid hemorrhage. Risk factors, therapy, results [in German]. Ophthalmologe. 1999;96:822–828. 6. Price FW Jr, Whitson WE, Ahad KA, et al. Suprachoroidal hemorrhage in penetrating keratoplasty. Ophthalmic Surg. 1994;25:521– 525.
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