Central Graft Thickness Research Articles

Outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes with failure of primary Descemet membrane endothelial keratoplasty (DMEK)

AimTo evaluate the outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes after failure of primary Descemet membrane endothelial keratoplasty (DMEK).MethodsThis was a retrospective, non-comparative interventional case...

POSTOPERATIVE THINNING OF LAMELLAR DONOR GRAFT AFTER CONVENTIONAL DESCEMET'S STRIPPING AUTOMATED ENDOTHELIAL KERATOPLASTY.

SUMMARY – The purpose of this study was to evaluate postoperative deturgescence of lamellar donor graft after conventional Descemet’s stripping automated endothelial keratoplasty (DSAEK). It was a prospective study that included 55 eyes of patients (mean age 70.9±9.4 years; female 61.8%, male 38.2%). Preoperative thickness of lamella was compared with postoperative thickness six months after surgery. Central lamellar graft thickness decreased from 142±27 µm preoperatively to 124±20 µm 6 months postoperatively (p<0.01). After performing conventional DSAEK corneal transplantation, surgeons should expect deturgescence of corneal graft and reduction in thickness of lamellae by about 12% of initial thickness according to our results. We found this information important for better planning of surgical procedures and knowing what to expect after surgery, as well as for better cooperation with eye banks when ordering pre-cut corneal tissue.

Factors Influencing Graft Endothelial Cell Density after Descemet Stripping Automated Endothelial Keratoplasty.

Purpose:To determine the factors that influence the endothelial cell density (ECD) of donor grafts after Descemet stripping automated endothelial keratoplasty (DSAEK).Methods:This retrospective, interventional case series comprised 77 eyes of 64 patients who underwent DSAEK. Confocal microscopy was performed at the final follow-up examination to evaluate the endothelial cell count, cell morphology, and graft thickness. Univariate and multiple linear regression analyses were used to investigate recipient-, donor-, surgical-, and postoperative related variables capable of influencing graft endothelial cell counts after DSAEK.Results:The mean patient age was 62.3 ± 15.6 years; patients were followed-up for 26.2 ± 20.9 months postoperatively. Forty-six eyes (59.7%) underwent stand-alone DSAEK; 31 eyes (40.3%) underwent DSAEK combined with cataract surgery. The donor trephination size was 8.0 ± 0.21 mm. The mean donor age was 30.4 ± 11.2 years, and the mean preoperative endothelial cell density was 3127.4 ± 315.1 cells/mm2, which decreased to 1788.6 ± 716.5 cells/mm2 postoperatively (P < 0.001). The mean postoperative central graft thickness was 102.4 ± 31.6 μm. Univariate analysis revealed that postoperative ECD was significantly associated with death to preservation time (P = 0.046), graft thickness (P = 0.016), follow-up duration (P = 0.005), and graft non-attachment (P = 0.049). Multiple regression analyses identified graft thickness (β = 10.62, P = 0.003) and follow-up duration (β = -22.09, P = 0.001) as the significant characteristics influencing postoperative ECD.Conclusion:The primary predictors of ECD after DSAEK were graft thickness and duration of follow-up. Surgeons’ requests for ultrathin DSAEK donor grafts to improve visual outcomes might not have the desired postoperative outcome with respect to ECD.

Évaluation pratique de la prise en charge par DSAEK des décompensations endothéliales après kératoplasties transfixiantes

To report our anatomical and functional results as well as possible complications of the first six Descemet's stripping endothelial keratoplasties (DSAEK) performed in our department for endothelial decompensation after penetrating keratoplasty (PK) METHODS: This was a retrospective and observational monocentric study of six patients with DSAEK after prior PK between January 2015and July 2016. The data collected were: demographic characteristics (age, sex), ophthalmological comorbidities, initial indication for PK, delay between PK and DSAEK. Best corrected visual acuity (BCVA) preoperatively and at 1, 3and 6months postoperatively were collected in Monoyer's and Parinaud scale and converted to log MAR for statistical analysis. The central cornea and graft thickness measured on OCT as well as postoperative complications were also collected. Mean follow-up duration was 7.2months [3-10]. The average time after PK was 7.7years. The mean age of the patients was 67.5years [32-87]. The initial indication for PK was Fuchs dystrophy (3/6), pseudophakic bullous keratopathy (1/6), corneal laceration (1/6) and other corneal dystrophy (1/6). The authors report one case a combined phaco-DSAEK surgery. The complications observed were: an early graft detachment treated by an additional air bubble injection (1/6) and cystoid macular edema in one other case. The average central corneal thickness decreased from 780μm at day7postoperatively to 656μm at 6months. The average thickness of the graft decreased from 154μm at day7to 122μm at 6months. The mean preoperative BCVA was 1.52log MAR [1.0-1.7], compared to the mean postoperative BCVA which was 1.5log MAR [1.1-2.3] at 1month, 1.15log MAR [0.5-1.7] at 3months and 1.1log MAR [0.7-1.7] at 6months (data available for 4patients at 6months). The recovery of visual acuity was limited in 2cases, despite corneal clarity restored in all our patients. Our results can be compared to those described in literature. As more penetrating keratoplasty grafts reach the end of their lives, this will allow for more powerful studies. DSAEK on eyes previously treated with PK is a good alternative to a new PK in the case of endothelial decompensation of the graft. The possibility of a posterior lamellar graft allows for faster visual recovery, with preservation of the anterior corneal power and a lower rate of complications.

Clinical evaluation of deep anterior lamellar keratoplasty using glycerol-cryopreserved corneal tissues for refractory herpetic stromal keratitis: An observational study.

The study aimed to evaluate the therapeutic effects of deep anterior lamellar keratoplasty (DALK) using glycerol-cryopreserved corneal tissues (GCCTs) in patients with refractive herpes simplex keratitis (HSK). This article was a retrospective, noncomparative, and interventional case series. Patients with HSK underwent DALK using GCCTs at Shanghai Tongji Hospital from 2012 to 2015. The best spectacle corrected visual acuity, recurrent inflammation, graft status, postoperative central graft thickness, and pre/postoperative complications were detected. The follow-up ranged from 24.4 ± 5.6 months (range: 16–38 months). Overall, the best spectacle corrected visual acuity was increased from HM/10 cm to 0.15 before surgery to 0.41 ± 0.14 (range: 0.1–0.8; P < 0.05) at 12 months postoperatively. Intraoperative microperforation occurred in 4 eyes (14.81%), and rejection episodes were encountered in 3 of 27 eyes (11.1%), and all of the eyes reversed. HSK recurred in 2 eyes (7.41%), 1 eye with repeated recurring HSK, and eventually led to perpetual corneal opacity and the patient refused a retransplantation. The mean entire corneal thickness was 0.519 ± 0.018 mm (range: 0.5–0.56 mm) and the mean graft thickness was 0.405 ± 0.033 mm (range: 0.35–0.47 mm) in the final follow-up. The DALK using GCCTs was proven to be an effective and safe therapy in treating refractory HSK.

Deep Laser-Assisted Lamellar Anterior Keratoplasty With Microkeratome-Cut Grafts.

The goals of this laboratory study were to evaluate the interface quality in laser-assisted lamellar anterior keratoplasty (LALAK) with microkeratome-cut grafts and achieve good graft-host apposition. Simulated LALAK surgeries were performed on 6 pairs of eye-bank corneoscleral discs. Anterior lamellar grafts were precut with microkeratomes. Deep femtosecond (FS) laser cuts were performed on host corneas followed by excimer laser smoothing. Different parameters of FS laser cuts and excimer laser smoothing were tested. Optical coherence tomography was used to measure corneal pachymetry and evaluate graft-host apposition. The interface quality was quantified in a masked fashion using a 5-point scale based on scanning electron microscopy images. Deep FS laser cuts at 226 to 380 μm resulted in visible ridges on the host bed. Excimer laser smoothing with a central ablation depth of 29 μm and saline as a smoothing agent did not adequately reduce ridges (score = 4.0). Deeper excimer laser ablation of 58 μm and Optisol-GS as a smoothing agent smoothed ridges to an acceptable level (score = 2.1). Same sizing of the graft and host cut diameters with an approximately 50-μm deeper host side cut relative to the central graft thickness provided the best graft-host fit. Deep excimer laser ablation with a viscous smoothing agent was needed to remove ridges after deep FS lamellar cuts. The host side cut should be deep enough to accommodate thicker graft peripheral thickness compared with the center. This LALAK design provides smooth lamellar interfaces, moderately thick grafts, and good graft-host fits.

Descemet Stripping Automated Endothelial Keratoplasty in Fuchs' Endothelial Dystrophy versus Pseudophakic Bullous Keratopathy.

Purpose:To compare clinical and confocal scan outcomes after Descemet stripping automated endothelial keratoplasty (DSAEK) performed for Fuchs’ endothelial dystrophy (FED) versus pseudophakic bullous keratopathy (PBK).Methods:This retrospective comparative study included 47 consecutive eyes of 39 patients with the diagnosis of FED (n = 29, group 1) or PBK (n = 18, group 2) that underwent DSAEK. Clinical outcomes were compared between the study groups. At the final follow-up examination, confocal microscopy was used to measure and compare central corneal and graft thickness as well as endothelial cell density and morphology between the two groups.Results:Mean age at the time of surgery was 65.2 ± 11.8 and 69.4 ± 12.5 years in groups 1 and 2, respectively (P = 0.27). Follow-up period was 23.6 ± 14.0 months in group 1 and 25.6 ± 15.7 months in group 2 (P = 0.79). Postoperative best spectacle-corrected visual acuity was significantly better in group 1 than in group 2 until postoperative month 6. Afterwards, the two study groups were comparable in this regard. At the final follow-up examination, spherical equivalent refractive error was + 0.39 ± 1.46 diopters (D) in group 1 and + 0.80 ± 1.47 D in group 2 (P = 0.45). Postoperative keratometric astigmatism was 1.02 ± 0.83 D and 2.36 ± 0.67 D, respectively (P < 0.001). Mean central graft thickness was 98.0 ± 33.3 μm in group 1 and 107.6 ± 28.0 μm in group 2 (P = 0.45). No statistically significant difference was observed between the two groups in terms of the postoperative endothelial cell density.Conclusion:The outcomes of DSAEK surgery were comparable between FED and PBK. All grafts were clear despite the lower than normal endothelial cell counts.

Use of anterior segment optical coherence tomography to predict corneal graft rejection in small animal models.

To correlate the degree of anterior chamber (AC) inflammation and corneal thickness evaluated by anterior segment optical coherence tomography (ASOCT) with corneal graft rejection status and to explore the value of ASOCT in assisting the diagnosis or prediction of graft rejection using a rat penetrating keratoplasty (PK) model. A total of 40 PKs were performed using Fisher rats (allogeneic groups) and Lewis rats (syngeneic group) as donors and Lewis rats as recipients: isograft control group (n=10), allograft untreated group (n=10), and allograft with 1% prednisolone acetate treatment group (n=20). All the grafts were evaluated for 28 days by a scoring rejection index (RI) to assess the graft opacity, edema, and neovascularization using slit lamp biomicroscopy. The AC inflammation and corneal graft thickness were assessed using ASOCT. All the allogeneic control grafts and four of the 20 allogeneic steroid-treated grafts developed rejection episodes. In the allogeneic treated group, the rejected grafts had a significantly higher mean AC inflammation grade at 1 week (grade 3.25±0.49 vs. 1.83±0.36, P<0.001), significantly thicker central graft thickness at 2 weeks (455.25±42.42 μm vs. 381.247±12.51 μm, P=0.047), and a significantly higher RI at 4 weeks (7.75±0.63 vs. 4.60±0.13, P<0.001) compared to the nonrejected grafts. Eyes with ≥grade 3 AC inflammation at 1 week, or with ≥400 μm central graft thickness at 2 weeks, were significantly associated with graft rejection (odds ratio [OR], 15.15, P=0.009, and OR, 9.75, P=0.014, respectively). The use of ASOCT to evaluate AC inflammation and corneal thickness aids in the early evaluation and diagnosis of graft rejection in animal models. Early increased AC inflammation was an early predictor of graft failure prior to definitive clinical evaluation.

Anterior-Segment Optical Coherence Tomography Investigation of Corneal Deturgescence and Epithelial Remodeling After DSAEK

The aim of this study was to evaluate via Fourier-domain anterior-segment optical coherence tomography 3-dimensional corneal, epithelial, and graft thickness changes after Descemet stripping automated endothelial keratoplasty (DSAEK). Sixteen eyes were investigated preoperatively and up to 6 months postoperatively for preoperative and postoperative central corneal thickness (CCT), minimum corneal thickness, central graft thickness (CGT), and for epithelial topographic thickness variability. An age-matched and gender-matched control group of 32 healthy eyes was used for comparison. In the DSAEK group, the preoperative CCT was 582.32 ± 45.24 (550-615) μm. One-month postoperatively, the CCT was 736.26 ± 34.52 (713-771) μm, and the CGT was 210.42 ± 34.52 (145-243) μm. Three months postoperatively, the CCT was 641.39 ± 38.75 (569-684) μm, and the CGT was 171.23 ± 27.54 (119-185) μm. The preoperative center epithelial thickness was 55.74 ± 9.29 (45-74) μm, the minimum was 32.53 ± 14.30 (13-53) μm, the maximum was 76.00 ± 11.32 (64-105) μm, and the topographic thickness variability was 10.84 ± 4.09 (5.90-18.80) μm. Three months postoperatively, the center epithelial thickness was 47.21 ± 5.45 (43-56) μm, the minimum was 35.11 ± 4.70 (30-41) μm, the maximum was 58.11 ± 6.51 (49-65) μm, and the topographic variability was 4.77 ± 1.48 (2.90-6.50) μm. The average differences were -8.53, +4.53, and -17.89 μm for the center, minimum, and maximum (P < 0.001, <0.001, and <0.001). Similar results were obtained 3 and 6 months postoperatively. We present a near-term postoperative investigation of the corneal and epithelial thickness changes after DSAEK for bullous keratopathy, by in vivo, clinical anterior-segment optical coherence tomography. Epithelial thickness recovery and normalization and corneal deturgescence were noted as early as in the first postoperative month.

Comparison of organ cultured precut corneas versus surgeon-cut corneas for Descemet’s stripping automated endothelial keratoplasty

To compare precut and surgeon-cut organ cultured donor corneas for DSAEK. A total of 119 consecutive eyes treated with DSAEK were retrospectically identified. 65 grafts were cut by the surgeon (Moria, ALTK System) prior to DSAEK and 54 grafts were precut by laboratory technicians from the Danish Eye Bank (Horizon single-use system). 1year after surgery, tomographic images were obtained with the Pentacam HR. Endothelial cell density (ECD) and best-corrected visual acuity (BCVA) was determined. Graft thickness and graft asymmetry was evaluated in the centre and 1mm from the edge of the graft in 6 semi-meridians. 1year after surgery, the ECD loss was similar in the two groups, averaging 25.9±14% in surgeon-cut, and 22.9±17% in precut group (p=0.33). Mean central graft thickness was 172±6μm in surgeon-cut grafts and 182±6μm in precut grafts (p=0.30). BCVA was similar in surgeon-cut and precut corneas; being 0.25±0.02 logMAR and 0.24±0.02 logMAR, respectively (p=0.59). The graft asymmetry index was 1.48±0.02 for surgeon-cut and 1.44±0.02 for precut grafts. There were no significant differences in complications rate in both groups. No correlations between BCVA and central graft thickness or graft asymmetry index in both groups were observed. Organ cultured precut donor corneas are comparable with surgeon-cut grafts with respect to ECD, graft thickness and asymmetry, and postoperative complication rate.

Comparison of Descemet-On Versus Descemet-Off Deep Anterior Lamellar Keratoplasty

To determine the effect of retained donor Descemet membrane (DMs) on visual outcomes, contrast sensitivity (CS), higher-order aberrations (HOAs), and central graft thickness after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique. In this retrospective comparative study, keratoconic eyes undergoing a DALK using the big-bubble technique were enrolled. A bared DM was achieved in all cases. A donor cornea without (group 1; 48 eyes) or with (group 2; 22 eyes) DM was sutured to the recipient bed. The 2 groups were compared in terms of best spectacle-corrected visual acuity, keratometric astigmatism, refractive error, CS, HOAs, and central graft thickness at least 3 months after complete suture removal. Additionally, the rate of postoperative pseudoanterior chamber formation was compared between the study groups. The mean follow-up duration was 23.2 ± 6.9 months in group 1 and 26.5 ± 6.5 months in group 2 (P = 0.61). The postoperative best spectacle-corrected visual acuity was 0.18 ± 0.08 logMAR and 0.24 ± 0.30 logMAR, respectively (P = 0.36). The 2 groups had comparable postoperative keratometric astigmatism, spherical equivalent refraction, and HOAs. In terms of CS, however, group 1 demonstrated better results at a low spatial frequency. The mean postoperative central graft thickness was greater in group 2 (589.8 ± 34.5 μm) than in group 1 (523.6 ± 63.0 μm; P < 0.001). A pseudoanterior chamber developed in 3 eyes of group 1 and in 2 eyes of group 2 (P = 0.23). All cases were successfully managed by giving an intracameral air injection. DALK performed using the big-bubble technique for keratoconus may give better results in terms of CS if a donor cornea without DM is transplanted.

Morphology of Graft–Host Junction in Cases With Postkeratoplasty Corneal Ectasia

We analyzed the central corneal and graft-host junction (GHJ) thickness profiles in cases with signs of corneal ectasia after penetrating keratoplasty for keratoconus. Anterior segment optical coherence tomography (ASOCT) was performed in cases with clinical or topographic signs of ectasia after complete suture removal. Corneal thickness was measured on the GHJ and at 1 mm on either side of the GHJ. Corneal thickness maps using Scheimpflug imaging were obtained. Eight patients (11 eyes) with an average age of 52.55 ± 10.13 years were included. Mean age of the corneal grafts was 25.83 ± 12.37 years. Mean central corneal thickness was 577.45 ± 78.52 (range, 486-704) μm. Mean thickness 1 mm inside the GHJ, at the GHJ, and 1 mm outside the GHJ was 511.81 ± 66.15 (range, 380-600), 438.18 ± 86.35 (range, 260-550), and 465.45 ± 110.93 (range, 320-690) μm, respectively. Thinning of the graft, GHJ, or the host cornea was seen on ASOCT in all eyes. The central graft thickness was significantly higher compared with the graft thickness at and around the GHJ (P < 0.05 for all). The inferonasal quadrant was the thinnest in 7 eyes (63.63%). Corneal thinning beyond the GHJ and subsequent ectasia can occur many years after initial keratoplasty in cases with keratoconus. Long-term follow-up of these cases may be desirable after corneal transplantation surgery. ASOCT is a useful tool for monitoring corneal thickness at and around the GHJ.

Evaluating DSAEK Graft Deturgescence in Preservation Medium After Microkeratome Cut With Optical Coherence Tomography

To evaluate the Descemet stripping automated endothelial keratoplasty (DSAEK) graft deturgescence in preservation medium after microkeratome cut using Fourier domain optical coherence tomography. The central and peripheral thickness of DSAEK grafts was measured by Fourier domain optical coherence tomography immediately after microkeratome cuts and 1, 2, 3, and 4 hours afterward. All measurements were taken when the grafts were stored in 4°C preservation medium. The hourly change in central graft thickness and graft shape (peripheral graft thicknes - central graft thickness) was calculated and tracked over time. Five DSAEK grafts were measured. The average central graft thickness was 188.7 ± 44.4 μm (range, 146-255 µm) immediately after microkeratome cuts. The average central graft thickness was 147.5 ± 33.0 μm (range, 116-190 µm) after 4 hours in preservation medium (P < 0.001). The average hourly change in central graft thickness was -30.5 μm (P = 0.0051), -8.6 μm (P = 0.055), -2.0 μm (P = 0.42), and 0.0 μm (P = 0.93) at 1, 2, 3, and 4 hours, respectively, after microkeratome cuts. The average hourly change in graft shape was insignificant. DSAEK grafts become thinner after microkeratome cut and stabilize at approximately 2 hours. Therefore, DSAEK graft thickness should be measured at 1.5 to 3 hours after microkeratome cut.

Femtosecond laser and microkeratome-assisted Descemet stripping endothelial keratoplasty: first clinical results

AimTo perform Descemet stripping automated endothelial keratoplasty (DSAEK) using a novel technique to obtain very thin (<100 µm) posterior corneal disks.MethodsTwenty five DSAEK grafts were prepared with two sequential cuts:...

Correlation of Corneal Parameters and Visual Acuity Outcomes after Descemet Stripping Endothelial Keratoplasty

Purpose: To assess a potential relationship between visual acuity and corneal haze and thickness after Descemet Stripping Endothelial Keratoplasty (DSEK). Methods: Retrospective review of patients who underwent DSEK surgery with at least 3 months of post-operative follow up. Best-spectacle corrected visual acuity (BSCVA) and ultrasonic pachymetry were measured, and a Pentacam scan was performed for each study eye. Pentacam images were analyzed to determine the surface, host stromal, interface, and graft light scattering levels, which were used as markers of corneal haze. The central donor graft and overall central thicknesses were also measured from the Pentacam. Pearson correlation coefficients were calculated for each of the parameters and post-operative BSCVA to identify any potential associations. A multivariate analysis was performed using a linear regression model predicting visual acuity for each of the significant parameters from the univariate analysis adjusting for patient age and pre-operative acuity. Results: Results are reported for 41 eyes of 36 patients. Pearson correlation coefficients showed a statistically significant positive correlation between post-operative BSCVA and age (r=0.36, P=0.020), interface-stromal scattering (r=0.44, P=0.004), and interface-graft scattering (r=0.36, P=0.022). No correlation was found between BSCVA and surface scattering (r=0.04, P=0.78), host stromal scattering (r=-0.15, P=0.35), mean interface scattering (r=0.18, P=0.25), or graft scattering (r=-0.14, P=0.38). A trend towards a positive correlation between BSCVA and central donor graft thickness was noted on the exploratory scatter plot but this was not statistically significant (r=0.27, P=0.085). A linear regression analysis controlling for age and pre-operative acuity was performed for the above parameters and the correlation between BSCVA and the difference between interface and host stromal scattering remained statistically significant (β=0.00375, P=0.0195). Conclusion: Eyes with better BSCVA after DSEK tend to have lower differences between interface and stromal light scattering. However, no relationship was found between BSCVA and the other measures of corneal light scattering or corneal thickness. Additional prospective studies using techniques such as in vivo confocal microscopy to supplement the present methods could be performed to validate the relative impact of regional differences in corneal haze on visual acuity outcomes after DSEK.

Graft thickness and visual acuity after automated endothelial keratoplasty

AbstractPurpose Endothelial keratoplasty has become the standard of care for endothelial disease. Descemet Membrane Endothelial Keratoplasty (DMEK) gives superior visual results but poses several surgical challenges, compared to Descemet Stripping Automated Endothelial Keratoplasty (DSAEK). Graft thickness was advanced as a reason for this difference. Ultrathin‐DSAEK, with a double microkeratome pass has been proposed to maintain the advantages of both DSAEK and DMEK. The purpose of this study was to evaluate the possible correlation between visual acuity (VA) and central graft thickness in DSAEK.Methods A preliminary retrospective study was conducted on 42 patients who underwent DSAEK: 26 operated on with a single microkeratome pass with a 350 microns (µm) head, and 16 with a double pass using a 200 µm head. Pre‐ and post‐operative VA, and post‐operative central corneal graft thickness measured by OCT and Scheimpflug imaging were collected with at least 6 months follow‐up.Results The overall mean of graft thickness was 127.25 ± 40µm. The overall mean VA was 0.16logMAR. 38% of patients had at least 0.1logMAR VA. Graft thickness was 136.8 ± 43.4µm with a single microkeratome pass compared to 111 ± 30µm with a double pass (p&lt;0.05). Considering the overall cohort, we had a correlation between graft thickness and VA (p&lt;0.05), but also between the pre and post‐operative VA (p&lt;0.05). We had no correlation between graft thickness and VA in the double pass subgroup. No difference was found between the single and the double pass subgroups for VA.Conclusion There is no clear correlation between graft thickness and visual acuity. Other factors may come into account such as scarring of the interface, or the stage of endothelial failure.Preoperative VA could be a prognosis factor.

Femtosecond laser and microkeratome preparation of ultrathin (UT) DSAEK Grafts, the six months clinical results

AbstractPurpose To evaluate the use of a femtosecond laser and a mechanical microkeratome to prepare ultrathin posterior corneal disks for Descemet stripping automated endothelial keratoplasty (DSAEK) and to assess associated visual results, disk thickness and endothelial cell loss.Methods This clinical study involved ultrathin DSAEK tissue preparation used in 28 patients with endothelial dysfunction. The first cut was performed with an Intralase FS60 laser and the second cut with a Moria CBm 300‐ microkeratome. The thickness of the first cut was modified for each cornea to obtain a final graft thickness of 120 µm. Post‐op central graft thickness was performed with corneal laser tomography (Spectralis). Central endothelial cell density (ECD) was calculated before, 3 and 6 months after surgery.Results Final graft thickness was 92.9+28.5 µm, 83.1+23.6 µm, 77.2+16.9 µm and 74.3+27.5 µm at one week, one three and six months post‐op, respectively. No loss of corneas due to irregular cuts or perforation during preparation. The mean BSCVA was 0.4, 0.5, 0.7 and 0.7(0.39, 0.35, 0.16 and 0.17 LogMAR) after one week, one, three and six months post‐op, respectively. A 26.3% and 31.2% endothelial cell loss was observed after 3 and 6 months of the surgery, respectively. Significant positive correlation between BCVA (logMAR) and central graft thickness at 1 and 3 months was observed (r=0.76,p=0.01; r=0.73,p=0.01) as well as between BCVA (logMAR) at 3 months and preoperative central graft thickness (r=0.82,p=0.007; Spearman correlation). Patients without bullous keratopathy achieved better visual outcome at 3 months (p=0.04, Mann‐Whitney test).Conclusion Femtosecond laser and microkeratome can be used sequentially to prepare custom ultrathin DSAEK grafts with no loss of corneas. This procedure minimizes the variability inherent to microkeratomes and allows very quick recovery of visual acuity after posterior lamellar keratoplasty.

Three year visual outcomes and correlation with graft thickness in eyes following descemet stripping automated endothelial keratoplasty (dsaek)

AbstractPurpose To describe 3 year visual outcomes and correlation with graft thickness in eyes following Descemet Stripping Automated Endothelial Keratoplasty (DSAEK).Methods Retrospective case series of 106 consecutive eyes that underwent DSAEK. We recorded clinical characteristics , best‐corrected visual acuity (BCVA) and serial measurements of central graft thickness and total central corneal thickness using anterior segment optical coherence tomography over a 3‐year follow‐up. Correlation analysis of preoperative and postoperative graft thickness with BCVA at 1, 2 and 3 years were performed.Results Mean age of recipients was 64.5 years (± 11.8) years. The median preoperative logarithm of the minimal angle of resolution (logMAR) BCVA was 0.71. There was significant improvement in post‐operative BCVA at 1‐year (median improvement in BCVA 0.41, P&lt;0.001), but no significant improvement in BCVA after 2 year post operatively (P=0.563). Likewise, median central graft thickness significantly decreased post‐operatively over the first year (190um vs 166 um, P&lt;0.001), but no significant reduction of graft thickness after 2 years post‐operatively (P=0.17). There were no correlations between preoperative graft thickness and BCVA logMAR at 1 year (Spearman=‐0.187; p= 0.069), 2 year (Spearman= ‐0.049; p= 0.650) or at 3 year (Spearman=‐0.068; p= 0.614). There were also no significant correlations of logMAR BCVA with post‐operative graft thickness by AS‐OCT at any time point.Conclusion Visual acuity significantly improves after DSAEK over the first year postoperatively. However, no correlation can be found between both preoperative and postoperative graft thickness and BCVA over 3 year follow up.

Femtosecond laser and microkeratome preparation of ultrathin (UT) DSAEK grafts

AbstractAn important limitation of DSAEK is that some eyes do not achieve good visual acuity despite a clear cornea and minimal residual astigmatism. The thickness of the stromal lamella may influence the final visual acuity and better results may be achieved with thinner grafts. We describe a new technique that combines a femtosecond laser with a microkeratome to obtain consistently thin grafts, with no loss of corneas. This clinical study involves ultrathin DSAEK tissue preparation used in 28 patients with endothelial dysfunction. The first cut was performed with an Intralase FS60 laser and the second cut with a Moria CBm 300‐µm microkeratome. The thickness of the first cut was modified for each cornea to obtain a final graft thickness of 120 µm. Post‐op central graft thickness was performed with corneal laser tomography (Spectralis). Associated visual results, disk thickness and endothelial cell loss before and after surgery were evaluated. Final graft thickness was 88.3+27.6 µm, 77.2+26.6 µm and 74.3+27.5 µm at one week, one and three months post‐op, respectively. No loss of corneas due to irregular cuts or perforation during preparation. The mean BSCVA was 0.41, 0.52, and 0.72(0.39, 0.28 and 0.14 LogMAR) after one week, one and three months post‐op, respectively. Precut and post‐op (3 months) ECDs averaged 2553 cells/mm2 and 1882 cells/mm2, respectively, representing 26.3% endothelial cell loss after 3 months of the surgery. Femtosecond laser and microkeratome can be used sequentially to prepare custom ultrathin DSAEK grafts with no loss of corneas. This procedure minimizes the variability inherent to microkeratomes and allows very quick recovery of visual acuity after posterior lamellar keratoplasty.

Graft Biomechanical Properties After Penetrating Keratoplasty in Keratoconus

To measure corneal graft biomechanical properties after penetrating keratoplasty (PKP) in a group of keratoconic eyes using the ocular response analyzer (ORA) and to evaluate the relationship between donor size, donor-recipient disparity and central graft thickness (CGT), and ORA parameters. This cross-sectional study was conducted on 34 eyes of 34 keratoconus patients who had undergone PKP. Corneal hysteresis (CH), corneal resistance factor (CRF), and cornea-compensated intraocular pressure were measured at least 6 months after complete suture removal. Two groups of donor-recipient disparity (0.25 vs. 0.50 mm) were compared using the independent t test. Multivariate regression analysis was used to investigate the correlation of donor trephine size and CGT with ORA parameters. Factors influencing intraocular pressure measured with the Goldmann applanation tonometer (IOP GAT) after PKP were determined using multiple regression analysis. Mean patient age and follow-up period were 29.6 ± 6.2 years and 82.4 ± 59.6 months, respectively. Mean CGT, CH, and CRF were 564.7 ± 36.9 μm, 10.1 ± 2.1 mm Hg, and 10.0 ± 2.3 mm Hg, respectively. CH and CRF had a significant positive correlation with donor trephine size and CGT. Significantly greater values of CH and CRF were observed in the 0.5-mm disparity group compared with the 0.25-mm disparity group. Among the studied parameters, only CH, CRF, and cornea-compensated intraocular pressure had a significant positive correlation with IOP GAT. Graft biomechanics seem to be closer to normal values with larger grafts and greater donor-recipient disparity. These metrics had a significant correlation with IOP GAT after PKP.