Treatment of corneal endothelial damage in a rabbit model with a bioengineered graft using human decellularized corneal lamina and cultured human corneal endothelium.

OBJECTIVE: We aimed to investigate the functionality of human decellularized stromal laminas seeded with cultured human corneal endothelial cells as a tissue engineered endothelial graft (TEEK) construct to perform endothelial keratoplasty in an animal model of corneal endothelial damage. METHODS: Engineered corneal endothelial grafts were constructed by seeding cultured human corneal endothelial cell (hCEC) suspensions onto decellularized human corneal stromal laminas with various coatings. The functionality and survival of these grafts with cultured hCECs was examined in a rabbit model of corneal endothelial damage after central descemetorhexis. Rabbits received laminas with and without hCECs (TEEK and control group, respectively). RESULTS: hCEC seeding over fibronectin-coated laminas provided an optimal and consistent endothelial cell count density and polygonal shape on the decellularized laminas, showing active pump fuction. Surgery was performed uneventfully as standard Descemet stripping automated endothelial keratoplasty (DSAEK). Corneal transparency gradually recovered in the TEEK group, whereas haze and edema persisted for up to 4 weeks in the controls. Histologic examination showed endothelial cells of human origin covering the posterior surface of the graft in the TEEK group. CONCLUSIONS: Grafting of decellularized stroma carriers re-surfaced with human corneal endothelial cells ex vivo can be a readily translatable method to improve visual quality in corneal endothelial diseases.

Lamina cribrosa position and Bruch's membrane opening differences between anterior ischemic optic neuropathy and open-angle glaucoma.

PURPOSE:: To compare the optic nerve head morphology among primary open-angle glaucoma, non-arteritic anterior ischemic optic neuropathy eyes, their fellow healthy eyes and control eyes, using spectral-domain optical coherence tomography with enhanced depth imaging. METHODS:: Observational cross-sectional study including 88 eyes of 68 patients. In this study, 23 non-arteritic anterior ischemic optic neuropathy eyes, 17 fellow unaffected eyes, 25 primary open-angle glaucoma eyes, and 23 age-matched control eyes were included. Peripapillary retinal nerve fiber layer thickness and optic disk area were evaluated. Bruch's membrane opening diameter, optic cup depth, anterior lamina cribrosa depth, and prelaminar tissue thickness were assessed. RESULTS:: Non-arteritic anterior ischemic optic neuropathy and primary open-angle glaucoma eyes had similar visual field mean deviation and peripapillary retinal nerve fiber layer thickness (P = 0.6 and P = 0.56, respectively). Bruch's membrane opening diameter was significantly larger in primary open-angle glaucoma eyes than in control eyes (P = 0.02). Lamina cribrosa and disk cup were deeper in eyes with primary open-angle glaucoma than both control and non-arteritic anterior ischemic optic neuropathy eyes (P < 0.001). Prelaminar tissue thickness was significantly thinner in primary open-angle glaucoma eyes than in non-arteritic anterior ischemic optic neuropathy eyes (P < 0.001). Lamina cribrosa was shallower in both non-arteritic anterior ischemic optic neuropathy and unaffected fellow eyes compared to healthy eyes (P < 0.001 and P = 0.04, respectively). No differences were found in the optic disk area. CONCLUSION:: A forward lamina cribrosa placement and not a smaller disk could be involved in the pathogenesis of non-arteritic anterior ischemic optic neuropathy. A significantly larger Bruch's membrane opening diameter was found in primary open-angle glaucoma eyes compared with control eyes. This issue has clinical implications because Bruch's membrane opening has been considered a stable reference for disk-related measures.

A comparison of two optical coherence tomography-angiography devices in pseudoexfoliation glaucoma versus primary open-angle glaucoma and healthy subjects.

PURPOSE: To compare peripapillary vascular parameters derived from two optical coherence tomography angiography devices in pseudoexfoliation glaucoma, primary open-angle glaucoma, and healthy controls and to evaluate their diagnostic accuracy. METHODS: Observational, cross-sectional study. In total, 20 eyes with pseudoexfoliation glaucoma, 20 primary open-angle glaucoma eyes matched by peripapillary retinal nerve fiber layer thickness, and 20 control eyes were recruited. Participants underwent standard automated perimetry and peripapillary retinal nerve fiber layer analysis by Optovue and Cirrus optical coherence tomography. Vascular parameters provided by Angiovue and Angioplex optical coherence tomography angiography were compared. Their diagnostic accuracy and correlation with structural and functional parameters were assessed. RESULTS: All peripapillary optical coherence tomography angiography vascular parameters were significantly different among groups (all p < 0.05). The whole image capillary density and peripapillary capillary density by Angiovue were significantly lower in pseudoexfoliation glaucoma compared with primary open-angle glaucoma (p = 0.009 and p = 0.001, respectively). Conversely, vascular parameters by Angioplex were not statistically different between primary open-angle glaucoma and pseudoexfoliation glaucoma. A good correlation was found using Angiovue between whole image capillary density and visual field mean deviation (0.758, p < 0.001), peripapillary capillary density and visual field mean deviation (0.729, p = 0.001), and peripapillary capillary density and peripapillary retinal nerve fiber layer thickness in eyes with pseudoexfoliation glaucoma (0.716, p = 0.001). Angiovue parameters showed higher area under the receiver operating characteristic curves than Angioplex to discriminate among groups. CONCLUSION: Only Angiovue detected a significantly lower capillary density in pseudoexfoliation glaucoma compared to primary open-angle glaucoma at similar glaucoma damage. Both, Angiovue and Angioplex demonstrated a decreased capillary density in glaucoma eyes compared to healthy eyes. Furthermore, Angiovue-derived vascular parameters showed better correlation with functional and structural parameters and a higher diagnostic capacity to discriminate among groups compared to Angioplex.

Automated Evaluation of Choroidal Thickness and Minimum Rim Width Thickness in Nonarteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND: The aim of this study was to evaluate and compare peripapillary choroidal thickness (pCT) and macular choroidal thickness (CT), Bruch membrane opening-minimum rim width (BMO-MRW), retinal nerve fiber layer (RNFL) thickness, and optic disc area among nonarteritic anterior ischemic optic neuropathy (NAION) eyes, the contralateral unaffected eyes, and healthy control eyes. METHODS: Twenty-six patients diagnosed with NAION (29 affected and 21 unaffected eyes) and 29 healthy matched control individuals (29 eyes) were analyzed by swept-source optical coherence tomography. All participants underwent scanning by Spectralis optical coherence tomography to analyze BMO-MRW, RNFL thickness, and optic disc area. RESULTS: Mean pCT in the NAION eyes, unaffected fellow eyes, and the control group was 130.5 ± 72.1 µm, 149.6 ± 75.7 µm, and 103.7 ± 36.7 µm, respectively (analysis of variance [ANOVA], P = 0.04). Mean macular CT in the NAION eyes, unaffected fellow eyes, and the control group was 226.1 ± 79.8 µm, 244.6 ± 81.4 µm, and 189.9 ± 56.4 µm, respectively (ANOVA, P = 0.03). Mean and all sectorial RNFL and BMO-MRW thickness values were significantly thinner in the NAION eyes vs the unaffected fellow and control eyes (P ≤ 0.00). The unaffected fellow eyes in NAION patients showed a significantly thicker average and sectorial BMO-MRW values than control eyes (P ≤ 0.02) except for the nasal sector (P = 0.09). Mean optic disc area derived from BMO analysis was not significantly different among groups (ANOVA, P = 0.86). CONCLUSIONS: The fellow unaffected eyes in patients with NAION showed significantly thicker mean peripapillary and macular choroidal and BMO-MRW thicknesses than disease-free control eyes. No differences in the mean optic disc area were found. Both a thick peripapillary choroid and a thick neuroretinal rim might contribute to the development of NAION or possibly be a secondary phenomenon.

Pupillary Abnormalities in Descemet Membrane Endothelial Keratoplasty After Nearly Full Tamponade.

PURPOSE: To describe the incidence, risk factors, and management of pupillary abnormalities after anterior chamber (AC) full air or gas tamponade in Descemet membrane endothelial keratoplasty (DMEK) without pupillary block. METHODS: In this retrospective case series, clinical records of 25 patients (32 eyes) who underwent DMEK were reviewed for pupillary abnormalities and iris morphology. All patients had nearly full intracameral tamponade with air or 20% SF6 at the end of surgery without default air release postoperatively. RESULTS: Pupillary abnormalities ranging from mild ovalization to mid-mydriasis were seen in 56% of the cases. These abnormalities were not related to morphometric changes in the iris volume, or in the iris dilator or iris sphincter muscle, but were probably due to posterior synechiae. Combining DMEK and cataract surgery increases by 5-fold the odds of developing this complication. Surgical revision of the posterior surface of the iris and synechiolysis reversed these pupillary abnormalities. CONCLUSIONS: Nonischemic pupillary abnormalities can be seen in patients with DMEK using a nearly full air/gas tamponade in the AC after surgery despite patent iridectomy especially when combined with cataract surgery. Ensuring complete mydriasis in the immediate postoperative period and a free-floating bubble in the AC above the inferior pupillary margin may reduce its incidence.

Differences in Corneal Biomechanics in Nonpenetrating Deep Sclerectomy and Deep Sclerectomy Reconverted into Trabeculectomy.

PURPOSE: To evaluate the differences in intraocular pressure (IOP) and in corneal biomechanics in eyes with uneventful nonpenetrating deep sclerectomy (NPDS) in 1 eye and with intended deep sclerectomy reconverted into trabeculectomy (RIT) in the fellow eye of the same patient. PARTICIPANTS: Forty eyes of 20 patients with both types of glaucoma surgery and more than 6 months of follow-up, and 31 eyes of 50 controls. METHODS: IOP was assessed with Goldmann applanation tonometry (GAT), ocular response analizer (ORA), and dynamic contour tonometer (DCT). Student t test for independent samples and a univariate generalized estimating equations model were used to analyze the results. MAIN OUTCOME MEASURES: Overall, no significant differences were found between IOP of NPDS and RIT eyes when measured with 3 tonometers. RESULTS: Although NPDS showed lower values of IOP measured with GAT and ORA, RIT presented lower IOP if DCT is the chosen tonometry. Biomechanically, NPDS eyes had higher corneal hysteresis (CH) and corneal resistance factor (CRF). When compared with control patients, eyes that underwent glaucoma surgery had lower IOP using GAT, DCT and ORA (P<0.001, 0.315, and 0.260, respectively), and lower CRF (P<0.001). CONCLUSIONS: Eyes with NPDS tended to have higher values of CH and CRF and lower IOP than RIT eyes, as measured with 3 of 4 tonometry methods; these differences did not reach statistical significance.

Impact of Introducing 2 Simple Technique Modifications on the Descemet Membrane Endothelial Keratoplasty Learning Curve.

Purpose To analyze the impact of performing premarking of the Descemet roll and using SF6 20% on a surgeon's Descemet membrane endothelial keratoplasty (DMEK) learning process. Methods A total of 30 consecutive eyes with endothelial dysfunction undergoing DMEK during the learning curve of a surgeon were retrospectively analyzed. Prior to the study, the surgeon had already performed 10 DMEKs. The first 15 consecutive patients were included in group 1 (no premarking and air tamponade) and the other 15 consecutive patients were included in group 2 (premarking and SF6 tamponade). Main outcome parameters were best-corrected visual acuity (BCVA), endothelial cell density (ECD) loss at 6 months, and intraoperative and postoperative complications. Results Among the 2 groups, BCVA and ECD loss at 6 months were similar. However, there was a statistically significant reduction in primary graft failure (40% vs 0%) and need of rebubbling due to complete or partial graft detachment (40% vs 6%) when comparing group 1 versus group 2. In group 1, half of the patients needing rebubbling had primary graft failure. Conclusions Based on our personal experience, premarking the graft to assess orientation and using a SF6 gas tamponade dramatically reduces the risk of primary graft failure and the need for rebubbling even during the first stages of the learning curve. These findings should encourage surgeons to safely change from Descemet stripping automated endothelial keratoplasty to DMEK.