Corneal radius of curvature after anterior lamellar versus penetrating keratoplasty.

BACKGROUND: Keratoplasty may induce major spherical refractive error related to abnormal corneal radius of curvature (CRC). METHODS: Two hundred and thirty-eight consecutive eyes of 238 patients with clear graft and at least one postoperative Orbscan examination performed after suture removal (average follow-up time, 86 months) were retrospectively analyzed. Anterior lamellar keratoplasties (ALK group, n = 119) and penetrating keratoplasties (PK group, n = 119) were matched for preoperative diagnosis and lens status. RESULTS: The average postoperative, suture-out, Orbscan 3-mm CRC was 7.17 mm with a wide 95 % confidence interval [6.26 mm; 8.37 mm]. It was 7.05 mm in the ALK group and 7.31 mm in the PK group (p < 0.01). In the ALK group, this figure was 7.00 mm for oversized grafts and 7.67 mm for non-oversized grafts (p < 0.001). CRC values were significantly lower for eyes with keratoconus (7.00 mm) or stromal scar after infectious keratitis (7.06 mm) compared with stromal scar after trauma (7.74 mm) or stromal dystrophies (8.17 mm). Values were significantly lower for big-bubble ALKs (6.92 mm) and manual dissection-ALKs (7.14 mm) compared with PKs (7.31 mm) and microkeratome-assisted ALKs (7.45 mm). The average Orbscan 3-mm SimK cylinder, irregularity, and refractive power symmetry index were, respectively, 4.7 D/4.8 D/1.9 D for ALKs and 5.2 D/4.8 D/1.8 D for PKs (p = 0.99). CONCLUSIONS: The CRC is lower after ALK compared with PK, and features important variability. In eyes with ALK, non-oversized grafts result in postoperative CRC close to normal values and corneal diseases associated with stromal thinning and DALK result in lower postoperative CRC.

Long-term results of deep anterior lamellar versus penetrating keratoplasty.

OBJECTIVE: To compare deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in eyes with corneal diseases not involving the corneal endothelium (keratoconus, scars after infectious keratitis, stromal dystrophies, and trauma). DESIGN: Retrospective, comparative case series. PARTICIPANTS: One hundred forty-two consecutive DALK (DALK group; big-bubble technique or manual lamellar dissection using a slitlamp) and 142 matched PK (PK group). METHODS: Three models were used to describe the postoperative outcomes of the endothelial cell density. A joint regression model was used to predict long-term graft survival. Visual acuity, ultrasound pachymetry, specular microscopy, and optical coherence tomography (OCT) findings were recorded. MAIN OUTCOME MEASURES: Postoperative endothelial cell loss and long-term predicted graft survival. RESULTS: The average 5-year postoperative endothelial cell loss was -22.3% in the DALK group and -50.1% in the PK group (P<0.0001). The early- and late-phase annual rates of endothelial cell loss were -8.3% and -3.9% per year, respectively, in the DALK group and -15.2% and -7.8% per year in the PK group (P<0.001; biphasic linear model). The median predicted graft survival was 49.0 years in the DALK group and 17.3 years in the PK group (P<0.0001). The average visual acuity was lower in the manual dissection subgroup compared with the PK group (average difference, 1.0 to 1.8 line) and with the big-bubble subgroup (average difference, 2.2 to 2.5 lines). The average central corneal thickness at 12 months was 536 µm in the PK group, 523 µm in the big-bubble subgroup, and 562 µm in the manual dissection subgroup (P<0.001). The average thickness of the residual recipient stroma measured by OCT was 87±26 µm in the manual dissection subgroup. No correlation was found between this figure and logarithm of the minimal angle of resolution at any postoperative time point (P>0.05). CONCLUSIONS: Long-term, model-predicted graft survival and endothelial densities are higher after DALK than after PK. The big-bubble technique gives better results than manual dissection and PK. Compared with PK, manual dissection provides higher survival of both the corneal endothelium and graft, but lower visual acuity.

Graft rejection and graft failure after anterior lamellar versus penetrating keratoplasty.

PURPOSE: To compare anterior lamellar keratoplasty (ALK) with the reference surgical technique (penetrating keratoplasty [PK]) for risk of rejection. DESIGN: Retrospective, comparative case series. METHODS: setting: Institutional. patients: One hundred forty-nine consecutive ALK procedures (ALK group) and 149 matched PK procedures (PK group) performed for optical indication in eyes with corneal diseases not involving the corneal endothelium (ie, keratoconus, scars after infectious keratitis, stromal dystrophies, and trauma). main outcome measures: Three-year graft survival and cumulative incidence of rejection episodes. RESULTS: The 3-year overall graft survival was 98.3% in the ALK group and 94.3% in the PK group (P = .03). The 3-year cumulative incidence of irreversible rejection was 0.0% in the ALK group and 5.2% in the PK group (P = .02). The 3-year cumulative incidence of rejection episodes was 10.0% in the ALK group and 23.2% in the PK group (P = .01). The average graft-to-rejection episode time was 21.6 ± 22.0 months in the PK group and 19.4 ± 12.7 months in the ALK group (P = .76). CONCLUSIONS: ALK techniques dramatically decrease the risk of irreversible endothelial and stromal rejection after corneal transplantation. Immune-mediated rejection episodes are observed after ALK, but its lower graft failure rate compared with PK is at least partly the result of the absence of endothelial rejection. In addition, the incidence of rejection episodes after ALK was 50% less than that observed after PK.

Reproducibility of viscoelastic property and intraocular pressure measurements obtained with the Ocular Response Analyzer.

PURPOSE: To analyse the reproducibility of corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated intraocular pressure (IOPcc) obtained with the ocular response analyzer (ORA). METHODS: This is a prospective study, nonmasked, of eight successive examinations with the ORA device in 60 normal eyes. Using 30 eyes (one eye per subject), the reproducibility was assessed by comparing the first series of four examinations to the second four and by calculating the within-subject coefficient of variation. The correlation and difference with the fellow eye were analysed, respectively. RESULTS: The mean values were 10.7 ± 1.8 mmHg, CRF; 10.6 ± 1.6 mmHg, CH; 15.9 ± 3.9 mmHg, IOPg and 16.2 ± 3.7 mmHg, IOPcc. The reproducibility was significantly different for CRF (5.2 ± 5.9%), CH (7.3 ± 8.6%), IOPg (7.7 ± 6.7%) and IOPcc (10.1 ± 8.0%); p < 0.001. Considering the reproducibility, CRF correlated with CH (rs = 0.55; p < 0.001) and showed to be independent of IOPg and IOPcc. The score spread was best for CRF (2.6 ± 1.5 mmHg; 24.0%) compared to IOPg (4.3 ± 1.5 mmHg; 28.1%) and CH (3.1 ± 1.7 mmHg; 29.9%) and worst for IOPcc (5.5 ± 2.5 mmHg; 34.4%). The lowest difference with the fellow eye was observed for CRF (5.0%; p = 0.09). The correlation with the fellow eye was high, especially for IOPcc and CRF (rs > 0.9; p < 0.001) followed by IOPg and CH (rs > 0.8; p < 0.001). CONCLUSION: The ORA device provides reproducible information on viscoelastic properties of the cornea in normal eyes notably CRF and CH. IOPcc was less reproducible. Four measurements per eye were necessary to reach a 10% precision and six for 5%.

Morphometry of corneal epithelial cells on normal eyes and after anterior lamellar keratoplasty.

PURPOSE: To analyze morphometry of corneal epithelial cells in normal eyes and after anterior lamellar keratoplasty (ALK) using confocal microscopy. METHODS: This retrospective comparative case series included 29 eyes of patients who had undergone ALK (ALK group) and 29 subjects before refractive surgery with normal corneas (control group). The Heidelberg Retina Tomograph II with the Cornea Module was used. Images were recorded and analyzed with Image J software. Morphometric parameters used to analyze epithelial cells were cell area, coefficient of variation of cell area, perimeter, circularity, and Feret diameter. RESULTS: Confocal microscopy was performed between 3 and 70 months after surgery. For basal epithelial cells, no significant differences between right eyes and left eyes were found in normal eyes for all morphometric parameters (P < 0.05 and rs > 0.40). The mean epithelial cell area increased during central and vertical migration (migration of epithelial cells from the basal stratum to the outermost layer) (P < 0.001). The mean basal cell area in the central zone was significantly higher (P < 0.001) after ALK in the ALK group than that in the control group. After ALK, the mean basal cell area decreased with postoperative time (rS = -0.78; P < 0.001) and returned to normal 24 months after transplantation (P = 0.27). Comparison of both groups showed significant differences in cell perimeter, circularity, and Feret diameter of basal cells and intermediate cells (P ≤ 0.001). CONCLUSION: Morphometric analysis of the corneal basal epithelium seems to be a relevant tool to assess the epithelial condition.

Predicted long-term outcome of corneal transplantation.

OBJECTIVE: To analyze graft survival and the outcome of the corneal endothelium after corneal transplantation in a single model to predict the long-term prognosis of these grafts. DESIGN: Cohort study. Data were recorded prospectively and then analyzed retrospectively. PARTICIPANTS: One thousand one hundred forty-four consecutive eyes of 1144 patients who underwent corneal transplantation between 1992 and 2006. INTERVENTIONS: Penetrating keratoplasty and deep anterior lamellar keratoplasty. MAIN OUTCOME MEASURES: Slit-lamp examination and wide-field specular microscopy results. A joint analysis of endothelial cell loss and time to graft failure was undertaken. From midterm simultaneous analysis of graft survival and endothelial cell loss, long-term graft survival was predicted. RESULTS: The observed 5- and 10-year graft survival estimates were, respectively, 74% and 64%. The average endothelial cell density (cell loss) was 2270 cells/mm(2) before surgery, 1058 cells/mm(2) (-53%) during the sixth postoperative year, and 865 cells/mm(2) (-61%) during the 10th postoperative year. Overall, the predicted graft survival estimate was 27% at 20 years and 2% at 30 years. Both observed and predicted graft survival were higher in patients who had undergone lamellar keratoplasty than in patients who had undergone penetrating keratoplasty and had normal recipient endothelium and higher in patients who had undergone penetrating keratoplasty and had normal recipient endothelium than in patients who had undergone penetrating keratoplasty and had impaired recipient endothelium. CONCLUSIONS: For corneal diseases involving the endothelium, penetrating keratoplasty seems to be a good therapeutic approach in elderly patients because the graft life-span may be similar to the patient life expectancy. Conversely, for younger patients, penetrating keratoplasty is only a midterm therapeutic approach. For corneal diseases not involving the endothelium, deep anterior lamellar keratoplasty seems to be a promising therapeutic approach with higher long-term expected survival.

Comparison of techniques used for removing the recipient stroma in anterior lamellar keratoplasty.

OBJECTIVE: To compare 3 techniques used for removing the recipient stroma during anterior lamellar keratoplasty (ALK): the "big-bubble" technique, manual dissection using a crescent blade and slitlamp operating microscope, and microkeratome lamellar cut. DESIGN: Retrospective comparative cohort study of 69 consecutive ALKs and 69 consecutive penetrating keratoplasties (PKs). Manifest refraction, slitlamp examination, Goldmann tonometry, ultrasound pachymetry, specular microscopy, and confocal microscopy findings were recorded. RESULTS: The 12-month graft survival estimate was 98.5% in the ALK group and 94.1% in the PK group (P = .19). Higher endothelial cell density was found after ALK (P < .001). At 12 months (before suture removal), 53% of eyes that underwent ALK and 44% of eyes that underwent PK had 20/40 or better spectacle-corrected visual acuity (P = .24). In keratoconic eyes, these values were 83% and 69%, respectively (P = .18). Significant differences in visual acuity, corneal central thickness, and keratocyte density among ALK subgroups were found, with the best results obtained using the big-bubble technique and the worst results obtained using the microkeratome. In eyes that underwent ALK, visual acuity increased with keratocyte density. CONCLUSIONS: Better results were obtained after ALK vs PK, and the big-bubble technique seemed to provide the best results.

Mechanized astigmatic arcuate keratotomy with the Hanna arcitome for astigmatism after keratoplasty.

PURPOSE: To report the results of correction of post-keratoplasty astigmatism by arcuate keratotomy performed with the Hanna arcitome (Moria). SETTING: Service 5, Hôpital des 15-20, Paris VI University, Paris, France. METHODS: Forty eyes operated on for post-keratoplasty astigmatism using the Hanna arcitome were retrospectively studied. Paired symmetrical arcuate keratotomies were performed on the graft button. Mean follow-up was 10.8 months +/- 11.2 (SD). Outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and subjective refraction. For statistical analysis, visual acuity data were transformed into logMAR units. The refractive data were analyzed using the Alpins method. RESULTS: By a mean of 10.8 +/- 11.2 months after surgery, the UCVA had improved a mean of 0.28 +/- 0.46 lines, which was significant (P = .013). The BSCVA remained stable. The mean subjective cylinder was 8.84 +/- 3.00 diopters (D) preoperatively and 4.88 +/- 2.50 D postoperatively (P<.001). The changes in postoperative subjective cylinder values correlated with preoperative cylinder values (r(s) = 0.584; P<.0001). The subjective axis was modified by 20 degrees or less in 27 eyes (67.5%). The mean surgically induced astigmatism was 8.07 +/- 3.83 D and the mean correction index, 0.96 +/- 0.46. One microperforation occurred and required suturing. Incisions were off center in 1 case, and 2 patients had an allograft rejection after the procedure. CONCLUSIONS: Arcuate keratotomy performed with the Hanna arcitome was effective in reducing post-keratoplasty astigmatism. The device enabled safer, easier arcuate incisions than with manual techniques. However, predictability and efficacy could be improved by a more accurate nomogram.

Comparison of optical low-coherence reflectometry and ultrasound pachymetry in measuring corneal graft thickness.

PURPOSE: To compare optical low-coherence reflectometry (OLCR) and ultrasound pachymetry in measuring corneal graft thickness in patients after keratoplasty. METHODS: We retrospectively measured the central graft thickness in 41 eyes of 41 patients with the OLCR pachymeter (Haag Streit, Koeniz, Switzerland) and the SP-2000 contact ultrasound pachymeter (Tomey, Nagoya, Japan). Five separate measurements were performed on each eye with both methods. Mean, SD, repeatability, and coefficient of variation of measurements were calculated, and the correlation between the 2 methods was studied with Spearman regression. RESULTS: Mean central graft thickness was 546 +/- 51 (SD) microm with the contact ultrasound pachymeter and 546 +/- 47 microm with the OLCR pachymeter. The correlation between both methods was strong (rs = 0.96). No significant differences in mean SD of measurements were observed between OLCR pachymetry (mean SD = 4.66 microm) and contact ultrasound pachymetry (mean SD = 4.88 microm). The repeatability of both methods was comparable (P = 0.06) and high (the average coefficient of variation of the central corneal graft thickness was 0.9% with both pachymeters). The postoperative time did not affect the correlation between both pachymeters (P > 0.05). CONCLUSIONS: Central corneal graft thickness values obtained with the OLCR pachymeter were similar to those obtained with a contact ultrasound pachymeter. In some cases of lamellar keratoplasty, the corneal refractive index could change at the interface level that could affect OLCR measurements.

Graft reepithelialization after penetrating keratoplasty using organ-cultured donor tissue.

OBJECTIVE: To analyze graft reepithelialization after penetrating keratoplasty using organ-cultured donor tissue. DESIGN: Retrospective observational cohort study. PARTICIPANTS: One thousand one hundred thirty-eight consecutive penetrating keratoplasties (1003 patients) performed between 1992 and 2004 were analyzed, and 1003 were included (1 graft per patient was included). METHODS: Slit-lamp examination after fluorescein staining. MAIN OUTCOME MEASURE: Graft reepithelialization time was recorded. RESULTS: The average graft reepithelialization time was 4.6+/-13.2 days (range, 1-210 days; median, 2.5 days). Complete corneal epithelial healing was obtained in 1 day in 28.5% of patients, in 3 days in 65.8%, in 7 days in 93.6%, and in 14 days in 97.0%. Postoperative chronic epithelial defects occurred in 3.0% of patients. In univariate analysis, death-to-storage time, storage time, deswelling time, rejection risk, trephination size, suture method, use of dexamethasone ointment during surgery, use of sodium hyaluronate during surgery, and use of high postoperative steroid regimen significantly influenced the graft reepithelialization time (P<0.05). In multiple regression, only the rejection risk (beta = 0.07; P = 0.045), use of sodium hyaluronate at the end of surgery (beta = -0.17; P = 0.001), and steroid regimen (beta = 0.09; P = 0.022) significantly influenced the graft reepithelialization time. CONCLUSIONS: The use of sodium hyaluronate at the end of surgery to coat the ocular surface shortened graft reepithelialization time after penetrating keratoplasty using organ-cultured donor tissue. Graft reepithelialization time was longer in high-risk recipients, and it increased with high dexamethasone eyedrops regimen.

Late changes in refraction, pachymetry, visual acuity, and corneal topography after penetrating keratoplasty.

PURPOSE: To analyze the late changes in refraction, corneal topography, and pachymetry after penetrating keratoplasty. METHODS: We have retrospectively analyzed data of 64 eyes of 56 patients with a clear corneal graft and no other ocular diseases. The eyes were examined soon and several years after all sutures were removed, at 19.5 +/- 3.1 months and 76.8 +/- 25.2 months, respectively, after keratoplasty. All eyes were examined using the EyeSys 2000 videokeratograph and the Tomey SP2000 ultrasonic pachymeter. Corneal surface regularity was studied using the indices provided by the Holladay Diagnostic Summary (ie, asphericity coefficient Q; corneal uniformity index CU; predicted corneal acuity PCA). Irregular astigmatism was quantified using semimeridian data from videokeratographs (refractive power symmetry index). RESULTS: Visual acuity increased by an average of 0.35 +/- 0.93 lines (P = 0.002) between the 2 examinations, whereas no significant changes in refraction and videokeratoscopy (ie, power, indices, and irregular astigmatism) were observed (P > or = 0.08). Central corneal thickness significantly increased from 542 +/- 31 microm to 572 +/- 38 microm (P < 0.001). Change in BSCVA did not significantly correlate with the change in refraction, in topographic indices, or in irregular astigmatism (rs < or = 0.13; P > or = 0.16). CONCLUSION: Late after penetrating keratoplasty, best corrected visual acuity shows a small but statistically significant improvement, whereas refraction and corneal surface regularity are stable. This late improvement in visual acuity is not explained by current techniques.

Outcome of graft central thickness after penetrating keratoplasty.

OBJECTIVE: To analyze the outcome of graft central thickness after penetrating keratoplasty. DESIGN: Retrospective observational cohort study. PARTICIPANTS: Eight hundred fifty-six consecutive penetrating keratoplasties (772 patients) performed between 1992 and 2001 were analyzed and 772 were included (1 graft per patient was included). METHODS: Slit-lamp examination and ultrasound pachymetry. MAIN OUTCOME MEASURES: Slit-lamp findings, intraocular pressure, and graft central thickness were recorded. RESULTS: Patients were observed for an average of 55 months. The 36- and 60-month graft survival estimates were, respectively, 77.2% and 71.0%. The average graft central thickness in successful transplants was 655 microm at 1 week, 558 microm at 1 month, 533 microm at 6 months, 538 microm at 12 months, 558 microm at 24 months, 561 microm at 36 months, and 568 microm at 5 years. At each postoperative time point, the percentage of eyes with decreased, normal, and increased graft central thickness was significantly different according to slit-lamp findings. Of the patients with increased graft thickness, 46.2% had a simple outcome (normal intraocular pressure and normal slit-lamp findings), 28.6% experienced rejection, 15.8% experienced a graft nonimmunological event, and 9.4% experienced increased intraocular pressure. At each postoperative follow-up, subsequent graft survival was significantly lower in patients with increased graft thickness as compared with patients with normal or decreased graft thickness. When analyzing only patients with simple outcome, the relative risk of graft failure was 3.3 if graft thickness was increased at 1 month (P<0.0001). CONCLUSIONS: In conclusion, graft central thickness assessed by ultrasound pachymetry is a useful method for observing patients who have undergone penetrating keratoplasty. Even when slit-lamp examination reveals no complications, patients with an increase in graft thickness above the upper limit of normal for the postoperative time point under consideration are at greater risk of failure.

Culture-proven herpetic keratitis after penetrating keratoplasty in patients with no previous history of herpes disease.

OBJECTIVE: To report three cases of herpetic infection in recipients of organ-cultured donor corneas among 586 consecutive corneal transplantation procedures. METHODS: Three patients with no history of symptomatic herpes infection underwent corneal transplantation for keratoconus (2 patients) and Fuchs dystrophy (1 patient). Two patients developed keratouveitis and primary graft failure. The third patient developed dendritic keratitis in the graft. Culture of corneal scrapings and the patient's bandage contact lens were positive for herpes simplex virus type 1 (HSV-1). Donor and recipient sera were tested for HSV serology by EIA. Recipient corneal buttons were studied by means of transmission electron microscopy and immunohistochemistry. The three HSV-1 strains were genotyped by sequencing part of a variable antigenic domain of glycoprotein B (gB). RESULTS: None of the donor corneas showed endothelial cell necrosis after organ culture. All keratoplasties performed with the three mate donor corneas had an uncomplicated course. All three donor sera were positive for HSV. Preoperative recipient sera were positive for HSV. Analysis of the recipient corneal buttons showed no evidence of herpetic infection. Sequence analysis revealed three different gB genotypes. CONCLUSION: Ascertaining that a postoperative herpetic infection in a corneal transplant originates from the donor tissue is still difficult. Although some features of the reported cases suggest donor-to-host transmission of herpes simplex virus, the recipients could have been the source of the virus.

Candida parapsilosis keratitis.

PURPOSE: To present clinical, microbiologic, and histopathologic features of keratitis due to Candida parapsilosis. METHODS: Clinicomicrobiologic evaluation of four patients (four eyes) with culture-proven C. parapsilosis keratitis. The patients were evaluated for symptoms, visual acuity, clinical observations, microbiologic examination of corneal scrapings, and pathologic examination of corneal buttons. RESULTS: Three cases were observed after penetrating keratoplasty, and one case occurred after inhalation of corticosteroids. Clinical presentation of C. parapsilosis keratitis showed a great diversity. There was one case of crystalline keratopathy and three cases of suppurative corneal infiltrate. Histopathology of corneal buttons showed interlamellar accumulations of yeast. Medical treatment included topical amphotericin B and systemic triazoles. Penetrating keratoplasty was required in three patients. CONCLUSION: Risk factors for C. parapsilosis keratitis may include corticosteroid use and prior corneal transplantation. The prognosis of C. parapsilosis keratitis with antifungal and surgical therapy may vary from good visual outcome to intraocular extension with phthisis bulbi.