Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy.

Cochrane Database Syst Rev. 2014 Feb 14;2:CD008420. doi: 10.1002/14651858.CD008420.pub3.

Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy.

Abstract

BACKGROUND:

Fuchs endothelial dystrophy (FED) is a condition in which there is premature degeneration of corneal endothelial cells. When the number of endothelial cells is reduced to a significant degree, fluid begins to accumulate within the cornea. As a result, the cornea loses its transparency and the individual suffers a reduction in vision. The only successful surgical treatment for this condition is replacement of part or all of the cornea with healthy tissue from a donor. The established procedure, penetrating keratoplasty (PKP), has been used for many years and its safety and efficacy are well known. Endothelial keratoplasty (EK) techniques are relatively new surgical procedures and their safety and efficacy relative to PKP are uncertain.

OBJECTIVES:

The objective of this review was to compare the benefits and complications related to two surgical methods (EK and PKP) of replacing the diseased endothelial layer of the cornea with a healthy layer in people with FED.

SEARCH METHODS:

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2014, Issue 1), MEDLINE (January 1950 to January 2014), EMBASE (January 1980 to January 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to January 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 27 January 2014.

SELECTION CRITERIA:

We included all randomised controlled trials (RCTs) comparing EK versus PKP for people (of any age and gender) who had been clinically diagnosed with FED.

DATA COLLECTION AND ANALYSIS:

Two authors independently screened the search results, assessed trial quality and extracted data using the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS:

We included three RCTs that enrolled a total of 139 eyes of 136 participants and analysed 123 (88%) eyes. Two RCTs randomised eyes into either the endothelial keratoplasty (EK) group or penetrating keratoplasty (PKP) group and one RCT randomised eyes into either the femtosecond laser-assisted endothelial keratoplasty (FLEK) group or PKP group. The RCTs comparing EK with PKP did not show any significant differences between procedures with respect to best corrected visual acuity (BCVA) at two years (mean difference (MD) 0.14 logMAR; 95% confidence interval (CI) -0.08 to 0.36; P = 0.23) or at one year (MD 0.09 logMAR; 95% CI -0.05 to 0.23; P = 0.22), whereas the trial comparing FLEK with PKP showed significantly better BCVA after PKP (MD 0.20 logMAR; 95% CI 0.10 to 0.30; P = 0.0001). Only one RCT reported on irregular astigmatism (higher-order aberration), which was less with EK than PKP (MD -1.20 µm; 95% CI -1.53 to -0.87; P < 0.001). Only one RCT reported on endothelial cell counts (lower after FLEK than PKP: MD -969 cells/mm²; 95% CI -1161 to -777; P < 0.001), primary graft failure (higher after FLEK than PKP: RR 7.76; 95% CI 0.41 to 145.22; P = 0.10), and graft rejection (more after FLEK than PKP: RR 1.11; 95% CI 0.07 to 17.12; P = 0.94). Only one RCT reported that 27.8% of participants had graft dislocation, 2.8% had epithelial ingrowth and postoperative pupillary block, and 13.9% had intraocular pressure (IOP)-related problems in the FLEK group compared with the PKP group, in whom 10% had suture-related problems, 5% had wound dehiscence and 10% had suture revision to correct astigmatism. Overall, the adverse events in the FLEK group appeared to be more frequent than in the PKP group. No trials reported information about quality of life or economic data. The overall methodological quality of the three trials was not satisfactory as most did not perform allocation concealment or masking of participants and outcome assessors, and all trials had a small sample size.

AUTHORS’ CONCLUSIONS:

The rapid growth of endothelial keratoplasty as the treatment of choice for FED is based upon the belief that visual recovery is more rapid, surgically induced astigmatism (regular and irregular) is less and rates of transplant rejection are lower with EK. This change in practice also assumes that the rates of long term transplant survival are equal for the two procedures. The practical differences between the surgical procedures mean that visual recovery is inherently more rapid following EK, but this review found no strong evidence from RCTs of any difference in the final visual outcome between EK and PKP for people with FED. This review also found that higher order aberrations are fewer following EK but endothelial cell loss is greater following EK. The RCTs that we included employed different EK techniques, which may have a bearing on these findings. EK procedures have evolved over the years and can be performed using different techniques, for example deep lamellar endothelial keratoplasty, Descemets stripping endothelial keratoplasty (DSEK), Descemets stripping automated endothelial keratoplasty (DSAEK), femtosecond laser-assisted endothelial keratoplasty and Descemet membrane endothelial keratoplasty (DMEK). More RCTs are needed to compare PKP with commonly performed EK procedures such as DSEK, DSAEK and DMEK in order to determine the answers to two key questions, whether there is any difference in the final visual outcome between these techniques and whether there are differences in the rates of graft survival in the long term?

Corneal transplant rejection rate and severity after endothelial keratoplasty.

Cornea. 2007 Oct;26(9):1039-42.

Corneal transplant rejection rate and severity after endothelial keratoplasty.

Abstract

PURPOSE:

To examine the corneal transplant rejection rate and the rate of graft failure subsequent to rejection in the first 2 years after endothelial keratoplasty (EK) and to compare this to background data for similar cases of penetrating keratoplasty (PK).

METHODS:

Anonymized data from consecutive cases of EK [deep lamellar (DLEK) or Descemet stripping (DSEK)] for Fuchs corneal endothelial dystrophy or pseudophakic bullous keratopathy operated on before August 2004 were collected in 4 participating centers. The number and timing ofrejection episodes and cases of subsequent graft failure were recorded, together with the time to cessation of topical steroid medication. Two-year postoperative findings were compared with background data for similar patients undergoing PK recorded in the Swedish Corneal Transplant Registry.

RESULTS:

Rejection episodes were less frequent after EK than PK (P = 0.035). Fifteen (7.5%) of 199 EK cases had a rejection episode in the first 2 years after surgery versus 92 (13%) of 708 PK cases. Graft failure after rejection in EK may have been less frequent than in PK (P = 0.063), with only 1 (6.7%) case of rejection after EK versus 26 (28.3%) cases of rejection after PK proceeding to graft failure. A strong trend toward continued use of low-dose topical steroid medication was observed in the EK group. Eighty percent of EK patients were still taking topical steroid medication 2 years after surgery, whereas topical steroid medication had been ceased within a year of surgery in almost all PK patients in the comparator group.

CONCLUSIONS:

Corneal transplant rejection is less frequent and may be less severe after EK than after PK. It is not yet clear whether these apparent differences are simply a product of relatively prolonged postoperative topical steroid cover in EK patients.

Structural Measurements for Monitoring Change in Glaucoma: Comparing Retinal Nerve Fiber Layer Thickness With Minimum Rim Width and Area

retinal nerve fiber, glaucoma, optic nerve, nerve fiber layer thickness
Invest Ophthalmol Vis Sci. 2015 Oct 1;56(11):6886-6891. doi: 10.1167/iovs.15-16701.

Structural Measurements for Monitoring Change in Glaucoma: Comparing Retinal Nerve Fiber Layer Thickness With Minimum Rim Width and Area.

Author information

 retinal nerve fiber, glaucoma, optic nerve, nerve fiber layer thickness

Abstract

PURPOSE:

Minimum rim width (MRW) and area (MRA) have been introduced as anatomically defensible measures of neuroretinal rim tissue observable using spectral-domain optical coherence tomography (SDOCT). They have been reported to change earlier than retinal nerve fiber layer thickness (RNFLT) in glaucoma. This study sought to determine which is better to distinguish subsequent change from variability, using the previously described longitudinal signal-to-noise ratio (LSNR).

METHODS:

Data from 157 eyes of 157 participants with high-risk ocular hypertension or non-end-stage glaucoma (mean deviation [MD] from -22 to +3 dB) were used. Participants were tested approximately every 6 months for at least six visits. For each eye, MRW, MRA, and RNFLT were regressed linearly against time. Longitudinal signal-to-noise ratio for each eye was defined as the rate of change over time (signal) divided by the standard deviation of residuals from this trend (noise). These were compared between parameters using a Wilcoxon signed rank test.

RESULTS:

The median LSNRs were -0.58y-1 for RNFLT (bootstrapped 95% confidence interval -0.69 to -0.48y-1); -0.44y-1 (-0.59 to -0.32y-1) for MRW; and -0.23y-1 (-0.32 to -0.08y-1) for MRA. Longitudinal signal-to-noise ratios were significantly more negative for RNFLT than for MRW (P = 0.025) or for MRA (P < 0.001).

CONCLUSIONS:

Retinal nerve fiber layer thickness measured by SDOCT had a better LSNR than MRW or MRA. Although MRW and MRA may be more sensitive for early detection of glaucomatous damage, these data suggest that RNFLT may be preferable for monitoring change.

CONCLUSIONS:

Retinal nerve fiber layer thickness measured by SDOCT had a better LSNR than MRW or MRA. Although MRW and MRA may be more sensitive for early detection of glaucomatous damage, these data suggest that RNFLT may be preferable for monitoring change.

Driving with Glaucoma: Task Performance and Gaze Movements

Driving, Glaucoma, Task performance, Gaze movements
Optom Vis Sci. 2015 Nov;92(11):1037-1046.

Driving with Glaucoma: Task Performance and Gaze Movements.

Abstract

PURPOSE:

The aim of this pilot study was to assess the driving performance and the visual search behavior, that is, eye and head movements, of patients with glaucoma in comparison to healthy-sighted subjects during a simulated driving test.

METHODS:

Driving performance and gaze behavior of six glaucoma patients and eight healthy-sighted age- and sex-matched control subjects were compared in an advanced driving simulator. All subjects underwent a 40-minute driving test including nine hazardous situations on city and rural roads. Fitness to drive was assessed by a masked driving instructor according to the requirements of the official German driving test. Several driving performance measures were investigated: lane position, time to line crossing, and speed. Additionally, eye and head movements were tracked and analyzed.

RESULTS:

Three out of six glaucoma patients passed the driving test and their driving performance was indistinguishable from that of the control group. Patients who passed the test showed an increased visual exploration in comparison to patients who failed; that is, they showed increased number of head and gaze movements toward eccentric regions. Furthermore, patients who failed the test showed a rightward bias in average lane position, probably in an attempt to maximize the safety margin to oncoming traffic.

CONCLUSIONS:

Our study suggests that a considerable subgroup of subjects with binocular glaucomatous visual field loss shows a safe driving behavior in a virtual reality environment, because they adapt their viewing behavior by increasing their visual scanning. Hence, binocular visual field loss does not necessarily influence driving safety. We recommend that more individualized driving assessments, which will take into account the patient’s ability to compensate, are required.

Neovascular Glaucoma.

neovascular glaucoma, visual field loss, glaucoma, eye disease
Dev Ophthalmol. 2015 Oct 26;55:196-204. [Epub ahead of print]

Neovascular Glaucoma.

Abstract

Neovascular glaucoma (NVG) is a secondary ocular pathological condition resulting from a myriad of ocular and systemic conditions with retinal ischemia as a mediator in over 95% of cases. NVG is caused by the growth of a fibrovascular membrane secondary to a local angiogenic stimulus over the trabecular meshwork obstructing aqueous outflow. This results in an initial secondary open-angle glaucoma stage that may be amenable to intraocular pressure (IOP)-lowering medications and modulation of the underlying ischemic process, often in combination with panretinal photocoagulation and adjunctive use of vascular endothelial growth factor inhibitors. In the more advanced stages of neovascularization, connective tissue myofibroblasts associated with new vessel growth contract causing progressive synechial closure of the anterior-chamber angle. Elevation of IOP, once significant secondary angle closure is established, tends to be refractory to topical and oral IOP-lowering medications and often requiresglaucoma surgical interventions.

Dev Ophthalmol. 2015 Oct 26;55:196-204. [Epub ahead of print]

neovascular glaucoma, visual field loss, glaucoma, eye disease

Neovascular Glaucoma.

Abstract

Neovascular glaucoma (NVG) is a secondary ocular pathological condition resulting from a myriad of ocular and systemic conditions with retinal ischemia as a mediator in over 95% of cases. NVG is caused by the growth of a fibrovascular membrane secondary to a local angiogenic stimulus over the trabecular meshwork obstructing aqueous outflow. This results in an initial secondary open-angle glaucoma stage that may be amenable to intraocular pressure (IOP)-lowering medications and modulation of the underlying ischemic process, often in combination with panretinal photocoagulation and adjunctive use of vascular endothelial growth factor inhibitors. In the more advanced stages of neovascularization, connective tissue myofibroblasts associated with new vessel growth contract causing progressive synechial closure of the anterior-chamber angle. Elevation of IOP, once significant secondary angle closure is established, tends to be refractory to topical and oral IOP-lowering medications and often requiresglaucoma surgical interventions.

A Region-of-Interest Approach for Detecting Progression of Glaucomatous Damage With Optical Coherence Tomography

JAMA Ophthalmol. 2015 Oct 22:1-7. doi: 10.1001/jamaophthalmol.2015.3871. [Epub ahead of print]

A Region-of-Interest Approach for Detecting Progression of Glaucomatous Damage With Optical Coherence Tomography.

Abstract

IMPORTANCE:

Detecting progression of glaucomatous damage is often challenging.

OBJECTIVE:

To test the feasibility of using frequency-domain optical coherence tomography (FD-OCT) and a region-of-interest (ROI) approach to measure progressive changes in glaucomatous damage.

DESIGN, SETTING, AND PARTICIPANTS:

Among a group of patients in an institutional glaucoma practice who were likely to show glaucomaprogression, eyes with a history of an optic disc hemorrhage (DH) confirmed by stereophotography were followed up with FD-OCT cube scans of the optic disc. All patients underwent FD-OCT scans on at least 2 occasions separated by at least 1 year (mean, 3.45 years; range, 1.42-6.39 years). Because we were not studying the effects of an optic DH, no constraint was placed on the time between the documentation of an optic DH and the first scan used in the analysis.

MAIN OUTCOMES AND MEASURES:

After en face images of the FD-OCT scan were aligned based on the blood vessels, circumpapillary images were derived for an annulus 100 µm in width, and the retinal nerve fiber layer (RNFL) thickness profiles were plotted for the first and last visits. The ROI width associated with the optic DH was defined as the region of the RNFL profile below the 1% CI based on healthy norms. The change in the ROI width was compared with the change in the global RNFL thickness, which was obtained by averaging the circumpapillary RNFL thickness.

RESULTS:

The change in the ROI width (mean [SD], 8.0° [6.4°]; 95% CI, 4.9° to 11.1°; range, -0.7° to 19.3°) was significant (P < .001, 2-tailed t test) while the change in the global thickness (mean [SD], 2.40 [5.87] μm; 95% CI, -0.48 to 5.28 μm) was not significant (P > .12, 2-tailed t test). Although 15 of the 16 ROIs increased in width between visits, only 11 showed a decrease in the global RNFL thickness.

CONCLUSIONS AND RELEVANCE:

For detecting progression of local RNFL damage in patients with glaucoma, an OCT ROI approach appears superior to the OCT global RNFL thickness measure typically used.

Clinical Features and Outcomes of Retained Lens Fragments in the Anterior Chamber After Phacoemulsification

Am J Ophthalmol. 2015 Aug 20. pii: S0002-9394(15)00513-9. doi: 10.1016/j.ajo.2015.08.019. [Epub ahead of print]

Clinical Features and Outcomes of Retained Lens Fragments in the Anterior Chamber After Phacoemulsification.

Abstract

PURPOSE:

To review the clinical features, treatments, and outcomes of patients with retained lens fragments in the anterior chamber after phacoemulsification with an intact posterior capsule.

DESIGN:

Retrospective, interventional case series.

METHODS:

setting: Duke University Eye Center.

STUDY POPULATION:

Fifty-four eyes of 54 patients with a diagnosis of retained lens fragment in the anterior chamber following otherwise uncomplicated phacoemulsification cataract surgery. Patient demographics, clinical examination findings, ocular biometry measurements, treatment received, and pre- and post-lens fragment removal visual acuity were recorded.

MAIN OUTCOME MEASURES:

Corneal edema, time to surgical extraction of lens fragment, and visual acuity.

RESULTS:

All lens fragments were located in the inferior angle or the inferior anterior chamber, with 13% of cases requiring gonioscopy for diagnosis. Fifty-six percent of eyes had associated corneal edema, most often located inferiorly. Forty-four percent of patients were initially managed medically, but in all 54 cases the lens fragment was eventually removed surgically. The mean time to removal of the lens fragment from the date of cataract surgery was 70 days (range 1 day – 30 months). Five patients had corneal edema that did not resolve following fragment extraction and 3 eventually received an endothelial keratoplasty. Best-corrected visual acuity improved from an average of 20/51 before lens fragment removal to 20/28 after surgical extraction (P < .00001).

CONCLUSIONS:

Corneal edema is common in the setting of retained lens fragments and can evolve to corneal decompensation requiringtransplantation. Inferior corneal edema, in particular, should alert the practitioner to possible retained lens fragment. Surgical removal of retained lens fragments should be considered at the time of diagnosis.

CONCLUSIONS:

Corneal edema is common in the setting of retained lens fragments and can evolve to corneal decompensation requiringtransplantation. Inferior corneal edema, in particular, should alert the practitioner to possible retained lens fragment. Surgical removal of retained lens fragments should be considered at the time of diagnosis.

Factors influencing big-bubble formation during deep anterior lamellar keratoplasty in keratoconus

Br J Ophthalmol. 2015 Aug 26. pii: bjophthalmol-2015-307111. doi: 10.1136/bjophthalmol-2015-307111. [Epub ahead of print]

Factors influencing big-bubble formation during deep anterior lamellar keratoplasty in keratoconus.

Abstract

PURPOSE:

To investigate recipient and operative factors that can influence the rate of achieving a bare Descemet’s membrane (DM) during deepanterior lamellar keratoplasty (DALK) for keratoconus.

MATERIALS:

In this retrospective comparative study, a total of 290 (153 right) consecutive eyes from 257 (179 male) keratoconus-affected patients who underwent DALK with the big-bubble technique were enrolled. Univariate analyses and multiple logistic regressions were used to investigate factors including patient age and sex, family history of keratoconus, history of contact lens wear or vernal keratoconjunctivitis, the presence of Vogt’s striae or superficial stromal opacities, keratometric readings, corneal diameter, central and peripheral corneal thickness, anterior chamber depth, vitreous length, and trephination size, which could predict achievement of a bare DM.

RESULTS:

The surgery was completed as a DALK in 289 of 290 eyes, and a bare DM was successfully achieved in 229 (79.2%) eyes. The recipient sex and trephination size significantly influenced the success rate of big-bubble formation. Females had decreased odds of achieving a bare DM by 0.44 times (p=0.02). For each 0.1 mm increase in the trephination size, the odds of a successful big-bubble formation increased by 1.36 times (p=0.03). Other investigated factors did not significantly influence the rate of achieving a bare DM.

CONCLUSIONS:

The rate of successful big-bubble formation was 79.2% in keratoconus. Among the different factors, recipient sex and trephination size significantly influenced this rate. Females had a lower probability of big-bubble formation, and a large trephination size was associated with an increase in the probability of achieving a bare DM.

CONCLUSIONS:

The rate of successful big-bubble formation was 79.2% in keratoconus. Among the different factors, recipient sex and trephination size significantly influenced this rate. Females had a lower probability of big-bubble formation, and a large trephination size was associated with an increase in the probability of achieving a bare DM.

Small Incision Lenticule Extraction After Deep Anterior Lamellar Keratoplasty.

J Refract Surg. 2015 Sep 1;31(9):634-7. doi: 10.3928/1081597X-20150820-10.

Small Incision Lenticule Extraction After Deep Anterior Lamellar Keratoplasty.

Abstract

PURPOSE:

Femtosecond laser-assisted small incision lenticule extraction (SMILE) was performed to correct myopic astigmatism in a 39-year-old patient who had previously undergone deep anterior lamellar keratoplasty (DALK) for keratoconus, with clinically significant anisometropia and contact lens intolerance.

METHODS:

Case report.

RESULTS:

SMILE was planned in the right eye to reduce the refractive error and to allow spectacle correction. The surgical procedure was centered on the visual axis, a 5.20-mm optical zone was used, and the refractive lenticule was extracted through a 3.25-mm incision located inside the graft edge. The refractive target was achieved 1 week after surgery and remained stable until the 3-month follow-up visit, while the corrected distance visual acuity improved from 20/100 to 20/40. Complications were not observed and the graft remained clear. In vivo confocal microscopy and anteriorsegment optical coherence tomography highlighted a regular wound healing and refractive interface profile.

CONCLUSIONS:

This case report highlights the feasibility of using SMILE as an alternative procedure for correcting refractive errors afterkeratoplasty, but further prospective studies are needed to prove the long-term refractive outcomes and safety of this technique. [J Refract Surg. 2015:31(9):634-637.].

Small Incision Lenticule Extraction After Deep Anterior Lamellar Keratoplasty.

Abstract

PURPOSE:

Femtosecond laser-assisted small incision lenticule extraction (SMILE) was performed to correct myopic astigmatism in a 39-year-old patient who had previously undergone deep anterior lamellar keratoplasty (DALK) for keratoconus, with clinically significant anisometropia and contact lens intolerance.

METHODS:

Case report.

RESULTS:

SMILE was planned in the right eye to reduce the refractive error and to allow spectacle correction. The surgical procedure was centered on the visual axis, a 5.20-mm optical zone was used, and the refractive lenticule was extracted through a 3.25-mm incision located inside the graft edge. The refractive target was achieved 1 week after surgery and remained stable until the 3-month follow-up visit, while the corrected distance visual acuity improved from 20/100 to 20/40. Complications were not observed and the graft remained clear. In vivo confocal microscopy and anteriorsegment optical coherence tomography highlighted a regular wound healing and refractive interface profile.

CONCLUSIONS:

This case report highlights the feasibility of using SMILE as an alternative procedure for correcting refractive errors afterkeratoplasty, but further prospective studies are needed to prove the long-term refractive outcomes and safety of this technique. [J Refract Surg. 2015:31(9):634-637.].

Postoperative Graft Thickness Obtained With Single-Pass Microkeratome-Assisted Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

Postoperative Graft Thickness Obtained With Single-Pass Microkeratome-Assisted Ultrathin Descemet Stripping Automated Endothelial Keratoplasty.

Abstract

PURPOSE:

To evaluate the results of microkeratome-assisted ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) using a nomogram developed for the single-pass technique.

METHODS:

A retrospective study of eyes operated between September 2014 and March 2015 at Villa Serena-Villa Igea Private Hospitals (Forlì, Italy) by a single surgeon (M.B.). Study eyes underwent UT-DSAEK performed using a linear microkeratome-assisted lamellar dissection with disposable heads of different sizes (Moria ALTK system; Moria SA) chosen according to a pachymetry-based nomogram developed at our department. The main outcome measure was the graft thickness as assessed by means of anterior segment optical coherence tomography, measured between 1 and 3 months postoperatively.

RESULTS:

Forty-two eyes were included in this study. Mean follow-up time was 5.0 ± 1.8 months (range 1.2-6.9 months). No perforation or other complication occurred during graft preparation. Mean postoperative central thickness of donor grafts was 63 ± 29 μm. Thickness ranged between 23 and 177 μm, and the second thickest graft measured 116 μm. By 3 months postoperatively, 41/42 (97%) of the grafts were of thickness ≤130 μm and 38/42 (90%) of the grafts were of central thickness ≤100 μm. The mean nasal-to-temporal absolute thickness difference at the graft’s central 3-mm zone was 5 ± 7 μm at the last available measurement.

CONCLUSIONS:

The nomogram developed at our institution allowed reliable single-pass microkeratome-assisted dissection of donor tissue, creating consistently thin and symmetric grafts without loss of tissue. The results obtained compare favorably with those reported in the past for double-pass microkeratome-assisted dissection of UT-DSAEK.

RESULTS:

Forty-two eyes were included in this study. Mean follow-up time was 5.0 ± 1.8 months (range 1.2-6.9 months). No perforation or other complication occurred during graft preparation. Mean postoperative central thickness of donor grafts was 63 ± 29 μm. Thickness ranged between 23 and 177 μm, and the second thickest graft measured 116 μm. By 3 months postoperatively, 41/42 (97%) of the grafts were of thickness ≤130 μm and 38/42 (90%) of the grafts were of central thickness ≤100 μm. The mean nasal-to-temporal absolute thickness difference at the graft’s central 3-mm zone was 5 ± 7 μm at the last available measurement.

CONCLUSIONS:

The nomogram developed at our institution allowed reliable single-pass microkeratome-assisted dissection of donor tissue, creating consistently thin and symmetric grafts without loss of tissue. The results obtained compare favorably with those reported in the past for double-pass microkeratome-assisted dissection of UT-DSAEK.