Endothelial Keratoplasty Research Articles

Pseudo Corneal Ectasia Due to Corneal Endothelial Disease

Purpose To describe two patients referred for presumed ectasia after laser in situ keratomileusis (LASIK) based on increasing myopia and corneal steepening years after LASIK. In both patients, further testing confirmed endothelial disease with central corneal edema as the cause of topographic changes. Methods Two patients showing symptoms similar to post-LASIK ectasia were assessed with Scheimpflug imaging (Pentacam; Oculus Optikgeräte GmbH) and subsequently treated with endothelial keratoplasty. Results Case 1 was a 66-year-old woman with increasing myopia after LASIK that was initially diagnosed as post-LASIK ectasia. Pentacam imaging revealed central corneal steep-ening with central corneal edema, and the clinical presence of guttata was consistent with Fuch's endothelial dystrophy. Case 2 was a 49-year-old man who also had increasing myopia and corneal steepening after LASIK, but no guttata. Pentacam imaging showed a similar pattern of central corneal swelling. Both patients underwent endothelial keratoplasty with reversal of corneal steepening. Conclusions Several conditions can mimic corneal ectasia, necessitating thorough clinical examination and tomography. This report describes two cases of central corneal edema resulting in myopia and corneal steepening that mimicked corneal ectasia. [ Journal of Refractive Surgery Case Reports. 2024;4(3):e24–e29.]

Descemet Membrane Endothelial Keratoplasty for Late Corneal Edema Secondary to Obstetrical Forceps–Related Tears

Purpose: The purpose of our paper is to describe the outcome of Descemet membrane endothelial keratoplasty (DMEK) in patients with a history of known obstetrical forceps–related tears who developed clinically significant corneal edema in their eighth decade of life. Methods: Case series. Results: Two patients with a known history of obstetrical forceps–related tears presented with corneal edema and vertical tears of Descemet membrane consistent with birth trauma. DMEK was performed for both cases. Case 1 underwent pseudophakic DMEK, and Case 2 underwent combined phacoemulsification and DMEK (triple-DMEK). DMEK grafts were fully attached in both cases at postoperative 1-day and 1-week appointments, as confirmed on slit-lamp examination and anterior segment optical coherence tomography. There was marked improvement in best-corrected visual acuity and corneal edema in both patients. Conclusions: We demonstrate that DMEK can afford excellent results in patients with a history of obstetrical forceps injury, who experience corneal edema later in life. In addition, we show that the triple-DMEK can be done successfully in this entity.

Evaluation for Descemet Membrane Endothelial Keratoplasty in Failed Penetrating Keratoplasty

Evaluation for Descemet Membrane Endothelial Keratoplasty in Failed Penetrating Keratoplasty

Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty for Iridocorneal Endothelial Syndrome With a Glaucoma Drainage Device.

The purpose of this study was to evaluate the feasibility and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) for treating iridocorneal endothelial (ICE) syndrome with a glaucoma drainage device (GDD). In this retrospective, interventional case series, data of ICE eyes with a GDD treated with DMEK were collected at the Zhongshan Ophthalmic Center. A total of 24 patients (24 eyes) with mild-to-moderate ocular anterior segment anomalies together with good intraocular pressure (IOP) control preoperatively were included between March 10, 2014, and November 11, 2021. Cases were performed DMEK with concomitantly procedures, such as goniosynechialysis, an entire recipient's Descemet stripping, trimming of glaucoma tubes, and an inferiorly peripheral iridotomy. Graft survival, corrected distance visual acuity (CDVA), endothelial cell loss, IOP, and surgical complications were documented. The mean length of follow-up after surgery was 30.8 ± 7.8 months. Postoperative CDVA improved significantly. At 1 and 2 years postoperatively, 10 (50%) of 20 eyes and 7 (47%) of 15 eyes achieved a CDVA of 20/32 or better, cumulative graft success rates by Kaplan-Meier survival analysis were 89% and 67%, and endothelial cell loss were (59 ± 10)% and (71 ± 7)%, respectively. Within the follow-up period, IOP elevation and progressive peripheral anterior synechiae occurred in 7 (29%) and 5 (21%) of 24 eyes, respectively. With specific technical modifications, DMEK had not increased the risk of postoperative complications and provided comparable clinical outcomes in the treatment of ICE eyes with a GDD with those observed in the treatment of ICE eyes without a GDD.

Assessment of Generative Artificial Intelligence (AI) Models in Creating Medical Illustrations for Various Corneal Transplant Procedures.

This study aimed to task and assess generative artificial intelligence (AI) models in creating medical illustrations for corneal transplant procedures such as Descemet's stripping automated endothelial keratoplasty (DSAEK), Descemet's membrane endothelial keratoplasty (DMEK), deep anterior lamellar keratoplasty (DALK), and penetrating keratoplasty (PKP). Methods: Six engineered prompts were provided to Decoder-Only Autoregressive Language and Image Synthesis 3 (DALL-E 3) and Medical Illustration Manager (MIM) to guide these generative AI models in creating a final medical illustration for each of the four corneal transplant procedures. Control illustrations were created by the authors for each transplant technique for comparison. A grading system with five categories with a maximum score of 3 points each (15 points total) was designed to objectively assess AI's performance. Four independent reviewers analyzed and scored the final images produced by DALL-E 3 and MIM as well as the control illustrations. All AI-generated images and control illustrations were then provided to Chat Generative Pre-Trained Transformer-4o (ChatGPT-4o), which was tasked with grading each image with the grading system described above. All results were then tabulated and graphically depicted. The control illustration images received significantly higher scores than produced images from DALL-E 3 and MIM in legibility, anatomical realism and accuracy, procedural step accuracy, and lack of fictitious anatomy (p<0.001). For detail and clarity, the control illustrations and images produced by DALL-E 3 and MIM received statistically similar scores of 2.75±0.29, 2.19±0.24, and 2.50±0.29, respectively (p=0.0504). With regard to mean cumulative scores for each transplant procedure image, the control illustrations received a significantly higher score than DALL-E 3 and MIM (p<0.001). Additionally, the overall mean cumulative score for the control illustrations was significantly higher than DALL-E 3 and MIM (14.56±0.51 (97.1%), 4.38±1.2 (29.2%), and 5.63±1.82 (37.5%), respectively (p<0.001)). When assessing AI's grading performance, ChatGPT-4o scored the images produced by DALL-E 3 and MIM significantly higher than the average scores of the independent reviewers (DALL-E 3: 10.0±0.0 (66.6%) vs. 4.38±1.20 (29.2%),p<0.001; MIM: 10.0±0.0 (66.6%) vs. 5.63±1.82 (37.5%), p<0.001). However, mean scores for the control illustrations between ChatGPT-4o and the independent reviewers were comparable (15.0±0.0 (100%) vs. 14.56±0.13 (97.1%); p>0.05). AI is an extremely powerful and efficient tool for many tasks, but it is currently limited in producing accurate medical illustrations for corneal transplant procedures. Further development is required for generative AI models to create medically sound and accurate illustrations for use in ophthalmology.

Assessment of Corneal Graft Outcomes in a Murine Model of Endothelial Keratoplasty.

Objectives: In this study, we establish a protocol for evaluating the outcomes of endothelial keratoplasty, including graft survival, rejection, or failure. Additionally, we also evaluate the alloimmune response in graft recipients. Methods: We performed EK using C57BL/6 (allogeneic) and BALB/c (syngeneic) as donors and BALB/c mice as recipients. Slit-lamp examination and optical coherence tomography were performed for clinical evaluations for 16 weeks post-procedure. Criteria for the assessment of corneal opacity were established and the animals were graded weekly. Additionally, we assessed corneal endothelial cell density by harvesting the corneas and staining with zonula occludens-1 (ZO-1). Lastly, lymph nodes were collected, and CD4+ T cells were MACS-sorted and co-cultured with syngeneic or allogeneic antigen-presenting cells (APCs) to assess the IFN-γ expression levels by alloreactive Th1 cells (ELISPOT) in response to the direct (donor) or indirect (host) pathways of sensitization. Results: We observed graft failure in four animals, including irreversible corneal opacity, graft detachment, and anterior synechiae in the first four weeks. The remaining animals were graded between 0 and 5 as per the established criteria. The total and graft corneal thickness and endothelial cell density progressively worsened with a higher grade of corneal opacity. The direct allosensitization of Th1 cells was significantly higher in mice with a higher grade of corneal opacity. At 16 weeks follow-up, the grafts remained stable with low opacity scores in syngeneic EK recipients; however, the opacity scores were higher and variable in allogeneic EK recipients. Conclusions: These findings establish a standardized protocol to assess the graft outcomes in a murine model of EK. Furthermore, we delineate the underlying immunological pathway that contributes to the immune-mediated rejection of grafts in this model.

A Detailed Analysis of Individuals Having Graft Failure After Corneal Transplantation

ABSTRACT Purpose To describe demographic and clinical characteristics of patients with graft failure after keratoplasty, determine the cause of graft failure and outcomes. Methods The charts of patients between 2008–2013 in the Cornea Service at Wills Eye Hospital with a history of a corneal transplant before the end of 2012 were retrospectively reviewed. Included were patients who had graft failure after corneal transplantation and had at least one year of follow-up after transplantation. Penetrating keratoplasty (PK) and Descemet’s stripping endothelial keratoplasty (DSEK) patients were analyzed separately. Results A total of 186 eyes of 170 patients with graft failure after a PK (156) or DSEK (30) procedures were identified. The baseline characteristics included 100 female and 70 male patients with an age between 0 and 90 years (median 63 years). At the time of surgery, 38% had three or more systemic diseases and 68% were using three or more systemic medicines. Mean follow up time for PK was nearly four times of DSEK. Only 2 DSEK eyes (7%) underwent a 3rd DSEK graft, while 47 (30%) PK eyes underwent a 3rd PK and 15 (10%) PK eyes underwent more than three PK procedures. Conclusions Most DSEK failures occurred in 1st year, while graft failure in PKs is scattered over years. Failure in DSEK is mostly due to graft or surgical risk factors but in PK mostly due to factors in the host. DSEK does not appear to be as affected by the patients’ demographic and clinical characteristics as much as PK.

Double-Cannula Maneuver for the Double-Roll Configuration of Donor Descemet Membrane Outside Recipient Anterior Chamber During Descemet Membrane Endothelial Keratoplasty.

The purpose of this study was to present a new surgical technique to convert a single roll of Descemet membrane (DM) into a double roll using 2 cannulas in a balanced salt solution-filled Petri dish during DM endothelial keratoplasty. A single DM roll stained with trypan blue was placed in a balanced salt solution-filled Petri dish. Two cannulas (28G) were introduced from opposite ends of the single roll, inserted into the roll, and slowly spread apart to change the single roll into a double roll. The DM was aspirated into the modified Jones tube and loaded, maintaining a double-roll configuration with endothelium-down orientation in a bevel-up position. The modified Jones tube with the bevel down was inserted into the recipient anterior chamber through the main wound. The modified Jones tube was rotated to the bevel-up orientation. After checking the graft orientation, the DM was inserted into the recipient anterior chamber. The double-roll DM was easily unfolded by tapping the center of the cornea using a cannula. A 28G cannula was inserted under the DM, and the anterior chamber was filled with air. Three months after surgery, the patient's corrected visual acuity in the right eye was 6/7.5 and the endothelial cell count was 1095/mm2. The corneal thickness was 533 μm, and the cornea was clear. The double-cannula maneuver mechanically changes the single roll of the donor DM to a double roll outside the recipient anterior chamber, making DM unfolding easier and minimizing the risk of upside-down apposition of the donor DM.

Bubble-graft coverage after Descemet Membrane Endothelial Keratoplasty depending on gaze angle.

In Descemet Membrane Endothelial Keratoplasty (DMEK) a gas bubble is usually used to attach the graft to the host cornea. In this study, we observed the bubble size and bubble-graft coverage at different gaze angles following DMEK. This observational prospective study analyzed 465 images of patients who underwent an uneventful DMEK. Intraoperatively, the anterior chamber was filled up to 90% of its volume with a 20% Sulfur Hexafluoride (SF6) gas-air mixture. Postoperatively, the bubble was photographed daily in different gaze angles ranging from a supine position (0°) to an upright position (90°) and a slightly inclined position (105°). The primary outcomes were bubble-graft coverage and bubble diameters depending on the gaze angle and time after DMEK. The highest bubble-graft coverage was achieved at a 0° gaze angle at all times of measurement. In the first 48 h after DMEK, the mean bubble-graft coverage was over 85% at a gaze angle between 0° and 45°. Starting 72 h after DMEK, the graft coverage declined at all gaze angles. The graft coverage at a 0° gaze angle was 88.61 ± 10.90% after 96 postoperative hours, while the graft coverage was below 85% at all other gaze angles. Our clinical results provide novel insight into variation in bubble-graft coverage as a function of gaze angle and may be used to aid in patient counselling for appropriate body positioning following DMEK to prevent early graft detachment. Maintaining supine positioning seems to be most advantageous starting 48 h after DMEK.

Blocking Air in the Filtering Bleb: Effects on Graft Adhesion After Descemet's Stripping Automated Endothelial Keratoplasty.

To evaluate the outcome of Descemet's stripping automated endothelial keratoplasty (DSAEK) with "blocking air" in the filtering bleb in patients with previous trabeculectomy. In total, 299 eyes in 283 patients who underwent DSAEK were retrospectively reviewed. Endothelial graft adhesion, intraocular pressure (IOP), and air volume in the anterior chamber with (group A) or without (group B) a filtering bleb were compared between the groups. Group A was divided into two subgroups according to the presence (group A1) or absence (group A2) of air in the filtering bleb; the same three factors were compared between the subgroups. The graft detachment rate was significantly higher in group A (14.3%) than in group B (6.5%) (p = 0.04). IOP was significantly lower in group A than in group B before surgery (p = 0.01), at the end of surgery (p = 0.04), at three hours (p < 0.001), and one week postoperatively (p = 0.02). The graft detachment rate did not significantly differ between groups A1 and A2. There were no differences in IOP at each follow-up time, whereas there was a statistically significant increase in IOP from the preoperative measurement to the end of surgery in group A1 (21.0±7.0 mmHg) compared with group A2 (14.2±8.6 mmHg) (p = 0.02). The presence of blocking air in the filtering bleb helps ensure increased IOP during the early postoperative period but had no significant effect on graft detachment rates.

Determining Risk Factors for Detachment After Endothelial Keratoplasties: Nine-Year Review of a Single Institution.

To determine roles of patient history, donor tissue characteristics, tissue preparation methods, and surgeon technique for graft detachment requiring rebubbling after Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) procedures. Retrospective analysis of all eyes undergoing first-time DSAEK or DMEK at the study institution between 2013 and 2022. Data were collected regarding recipients' history, donors' medical history, tissue preparation methods, intraoperative details, and postoperative clinical outcomes. Multivariate statistical analysis was conducted to identify risk factors for graft detachment necessitating rebubbling. Of 1240 eyes meeting inclusion criteria, 746 (60.2%) underwent DSAEK, and 494 (39.8%) underwent DMEK. DSAEK procedures had 12.5% rebubbling rate, whereas DMEK procedures had 18.4% rebubbling rate (P = 0.005). Sub50-DSAEK (<50 μm) grafts had 16.0% rebubble rate, whereas sub100-DSAEK (51-99 μm) and >100 μm DSAEKs had rebubble rate of 9.9% and 9.5%, respectively (P = 0.006). Significant risk factors for DSAEK graft detachment included history of retinal surgery (OR = 2.59), preloaded tissue (OR = 2.70), forceps insertion (OR = 2.33), use of sub50-DSAEK lenticules versus sub100-DSAEK (OR = 2.44) and >100 μm DSAEK (OR = 2.38) lenticules, and donor history of noninsulin-dependent diabetes mellitus (OR = 4.18). DMEK risk factors included recipient history of cancer (OR = 2.51) and use of higher SF6 gas concentration (OR = 1.09). Although rebubbled DMEK eyes had comparable refractive outcomes to nonrebubbled eyes (P >0.05), rebubbled DSAEK eyes had worse refractive outcomes at all time points (P < 0.05). Graft detachments in DSAEK and DMEK are influenced by various factors, including donor tissue characteristics, tissue preparation, and surgical technique. Identifying and understanding these factors can potentially improve postoperative outcomes.

Corneal High-Order Aberrations in Fuchs Endothelial Corneal Dystrophy and Subclinical Corneal Edema.

High-order aberrations (HOAs) are known to be increased in corneas with Fuchs endothelial dystrophy (FECD) and are associated with visual impairment. This case series aimed to analyze whether tomographic changes in FECD affect the HOA in the early period of the disease. In this retrospective single-center case series, 144 eyes of 85 patients were included, of which 78 eyes of 47 patients with FECD with slit-lamp biomicroscopically visible guttae but no visible corneal edema served as the study-cohort. According to Sun et al, included eyes were divided into 2 groups: group 0 (n = 28; no subclinical corneal edema) and group 1 (n = 50; subclinical corneal edema). A total of 66 healthy eyes of 38 patients served as control group. Mean values and standard deviations were calculated for the root mean square (RMS), coma, trefoil and spherical aberrations (SA) of the cornea (C), the anterior surface (CF), and the posterior surface (CB). Statistically significant differences (P < 0.001) in the RMS HOA (group 0: 0.209 ± 0.044 μm, group 1: 0.372 ± 0.122 μm) and in coma (group 0: 0.082 ± 0.054 μm, group 1: 0.214 ± 0.101 μm) and SA (group 0: -0.130 ± 0.038 μm, group 1: -0.176 ± 0.074 μm) of the CB were found in eyes in group 1 versus those in group 0. There were no statistically significant differences in HOA between the control group and eyes in group 0. FECD eyes with subclinical corneal edema demonstrated significant increase in RMS, coma, and SA of the CB. Tomographic analysis, therefore, helps in visual impairment assessment, disease progression, and decision-making for early endothelial keratoplasty in patients with FECD.

Intraocular Lens Opacification After Descemet's Membrane Endothelial Keratoplasty-Risk Factors and Outcomes After Intraocular Lens Exchange.

To determine risk factors for intraocular lens opacification (IOLop) after Descemet membrane endothelial keratoplasty (DMEK) and to analyze clinical outcomes after IOL exchange. Cross-Sectional Study: Analysis of all cases of IOL exchange because of post-DMEK IOLop with a minimum of 6-month postoperative follow-up observed in clinic between November 2021 and April 2022. Main outcomes analyzed at the study visit were change in logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity after IOL exchange, endothelial cell loss (ECL), and graft survival. An historical cohort of 232 pseudophakic DMEK eyes was retrospectively analyzed to determine risk factors for post-DMEK IOLop. Cross-Sectional Study: Four eyes were observed (median follow-up = 45 (35.5-86.8) months). IOL materials were hydrophilic acrylic IOLs in 2 eyes and hydrophobic-hydrophilic in the other 2. At the study visit, improvement in median best-corrected visual acuity after IOL exchange was statistically significant (0.25 (0.19-0.41) logMAR to 0.00 (0-0.10) logMAR; P = 0.041). ECL ranged between 57.7% and 85.3%, without cases of graft failure. In the historical cohort, 21 eyes (9.05%) had some IOLop. In multivariate logistic regression model (105 eyes where IOL material data was available), IOLs with high water content material (odds ratio = 65.5, P = 0.0005) and rebubbling (odds ratio = 9.51, P = 0.0138) were independent risk factors for post-DMEK IOLop. Post-DMEK IOLop is infrequent, but a non-neglectable proportion of cases may require IOL explantation. IOL exchange is safe and effective in these eyes but may pose a risk for increased ECL. This study confirms that IOL material and number of rebubblings are major risk factors for post-DMEK IOLop.

Simple Modification of a DSAEK Carrier Enables Graft Insertion by Injection Without Compromising Endothelial Cell Viability.

We evaluate the quality and feasibility of preloading Descemet stripping automated endothelial keratoplasty (DSAEK) grafts into a modified EndoGlide Ultrathin system for graft injection. DSAEK grafts were prepared by experienced processing technicians at 2 separate locations, loaded into a modified EndoGlide Ultrathin, and placed in storage media. Grafts processed at one location were shipped cross-country overnight to the other location and were examined on arrival for positioning within the modified EndoGlide Ultrathin. All grafts were ejected and analyzed for endothelial cell loss (ECL) with calcein acetoxymethyl staining and FIJI segmentation. A subset of grafts was measured by optical coherence tomography for graft thickness 1 hour after cut, 1 hour after loading, and 1 day after loading. No grafts were displaced from the modified carrier over 3 shipping events (n = 9), and all grafts (n = 18) were successfully ejected. Grafts loaded into the modified carrier and ejected exhibited no more cell loss than grafts loaded into the standard carrier and removed by pull-through (14.0% ± 2.8% vs. 12.2% ± 3.4%, respectively, P = 0.24). Carrier modification skills can be successfully transferred as grafts loaded by a processing technician new to carrier modification were within the acceptable limit of 25% ECL for transplant DSAEK grafts. Graft thickness increased significantly (P < 0.05) between the postcut and 1-hour postload measurement and the postcut and 24-hour postload measurement. The EndoGlide Ultrathin can be modified to enable its use for graft injection while not compromising the ability to use the pull-through method for graft delivery. Preloaded DSAEK grafts swell significantly during the 24-hour storage period, and patterns of ECL may be linked to swelling.

Nanotopography by chromatic confocal microscopy of the endothelium in Fuchs endothelial corneal dystrophy, pseudophakic bullous keratopathy and healthy corneas

AimTo investigate the interest of chromatic confocal microscopy (CCM) to characterise guttae in Fuchs endothelial corneal dystrophy (FECD).MethodsDescemet’s membranes (DM) were obtained during endothelial keratoplasty in patients with FECD and...

Comparison of rebubbling rate between preloaded endothelium-in and preloaded no-touch endothelium-out Descemet membrane endothelial keratoplasty transplantation

BackgroundTo compare the difference in rebubbling rates between patients undergoing Descemet membrane endothelial keratoplasty (DMEK) with endothelium-in using a standard IOL cartridge and those with endothelium-out DMEK utilizing a no-touch technique with borosilicate glass cartridge transplantation.MethodsThis retrospective study included all eyes that underwent preloaded endothelium-in or endothelium-out DMEK transplantation from June 2019 to December 2023 at the Hanusch Hospital, Vienna, Austria. All DMEKs were harvested, prepared and preloaded at the European Eye Bank of Venice, Italy. DMEK surgeries were done by one experienced surgeon and the procedure was completed by air tamponade of the anterior chamber.ResultsOverall, 32 eyes each of 31 endothelium-out patients and of 29 endothelium-in patients were included. 32 preloaded endothelium-in procedures were followed by 32 preloaded endothelium-out procedures. Rebubbling rate for endothelium-in was 15/32 (47%) and for endothelium-out was 7/25 (28%) (p = 0.035, Pearson’s chi-squared test). Donor age was the most important variable for rebubbling in a random forest algorithm model (ROC: 0.69).ConclusionsRebubbling rate in endothelium-out DMEK was less than two-thirds compared to endothelium-in DMEK favoring no-touch endothelium-out DMEK as the preferred technique of DMEK transplantation.

Descemet Membrane Endothelial Keratoplasty in Aphakic, Aniridic, and Vitrectomized Eyes: A Review.

The aim of this review is to examine the techniques, complications, and outcomes of Descemet membrane endothelial keratoplasty (DMEK) in aphakic, aniridic, and vitrectomized eyes. A literature search was conducted in the MEDLINE database (via PubMed), using as keywords "(DMEK) AND (aphakia OR aniridia OR vitrectomy OR vitrectomized)." The research was limited to 10 years (January 2014-March 2024), in view of lack of literature before 2014. Articles, including case reports and case series, were included. Twenty articles were included. No randomized controlled trials were found nor comparative studies with more than 1 technique used. Mean rebubbling rate in complex eyes was 29%, whereas mean endothelial cell loss at 6 months was 37%. The mean postoperative visual acuity improved from 1.47 logarithm of the minimal angle of resolution to 0.7 logarithm of the minimal angle of resolution. Despite being more challenging, compared with the techniques reported in literature, DMEK can be considered a valid option for the management of endothelial decompensation in complex eyes, with rebubbling rate and endothelial cell loss at 6 months, which are similar to non-complex eyes.

Outcomes of Donor Corneas of Different Thicknesses From Endothelial Keratoplasty in Deep Anterior Lamellar Keratoplasty for Keratoconus.

To evaluate the outcomes of divided residual donor corneas obtained from endothelial keratoplasty in keratoconus with deep anterior lamellar keratoplasty (DALK). In this retrospective, comparative, clinical study, 103 keratoconic eyes that underwent DALK were enrolled; 67 eyes received thin grafts from Descemet stripping automated endothelial keratoplasty, and 36 received thick grafts from Descemet membrane endothelial keratoplasty. Baseline and postoperative central corneal thickness (CCT), inferior corneal thickness, uncorrected distance visual acuity, corrected distance visual acuity, corneal astigmatism, mean keratometry, biomechanical properties, and complication rates were measured. Six months after transplantation, the group receiving thin grafts had a CCT of only 455.1 ± 43.0 μm, whereas that of the group receiving thick grafts was 546.7 ± 44.2 μm. Both CCT and inferior corneal thickness in the thin group were significantly lower than those in the thick group (measured with Pentacam at 36 months, P < 0.001) and remained throughout the 5-year follow-up period. Both procedures had comparable postoperative logarithm of the minimum angle of resolution UDVAs, logarithm of the minimum angle of resolution corrected distance visual acuity, astigmatism, and mean keratometry values (36 months; P = 0.335, 0.286, 0.680, and 0.365, respectively). Corneal biomechanical analysis revealed that the thin group had a significantly higher stiffness parameter at the first applanation than the thick group at the 2-year follow-up (P = 0.036) while other parameters were equivalent. The outcomes of keratoplasty with donor tissue are comparable regardless of the thickness of the graft, which suggests that transplantation with either type of the split corneal procedure for DALK in patients with keratoconus is feasible.

Accuracy of formulas for intraocular lens power for eyes undergoing descemet stripping automated endothelial keratoplasty and cataract surgery.

To compare accuracy in intraocular lens (IOL) power calculation in eyes undergoing combined cataract and Descemet stripping and automated endothelial keratoplasty (C-DSAEK) surgery of the following formulas: Barrett Universal II, EVO, Haigis, Hoffer Q, Holladay 2, Kane and SRK/T. 72 eyes from 72 patients (38 males, (53%)) with a mean age 68.08 ± 8.69 years (from 44 to 88 years old) underwent combined C-DSAEK were included. The IOL powers to implant were calculated with Barrett Universal II formula targeting -1 D refraction. Preoperative and postoperative data were used to obtain the median of absolute prediction errors (MAE) targeting emmetropia with every tested formula. Means of MAE calculated were +1.45 D for Barrett Universal II, +1.37 D for EVO, +1.48 D for Haigis, +1.38 D for Hoffer Q, +1.37 D for Holladay 2, +1.39 D for Kane and +1.31 D for SRK/T. SRK/T MAE showed major significant (p < 0.01) differences compared to the other formulas. Even if tested formulas are not able to accurately target emmetropia, SRK/T seems to be able to provide closer results in eyes undergoing C-DSAEK.

Letter Regarding: Outcomes of Secondary Intraocular Lens Implantation and Descemet Stripping Endothelial Keratoplasty- Comparing Staged Versus Combined Surgical Approach.

Letter Regarding: Outcomes of Secondary Intraocular Lens Implantation and Descemet Stripping Endothelial Keratoplasty- Comparing Staged Versus Combined Surgical Approach.