Effect of Descemet Membrane Endothelial Keratoplasty Graft Storage Time on Graft Elasticity.

PURPOSE: The purpose of this study was to evaluate the effect of Descemet membrane endothelial keratoplasty (DMEK) graft storage time on its elastic properties, measured using atomic force microscopy (AFM). METHODS: Twenty human corneas (from 10 donors), unsuitable for transplantation, were obtained from the eye bank (S. Fyodorov Eye Microsurgery State Institution, Moscow). Ten DMEK grafts were prepared and stored in the corneal storage medium, Optisol-GS at 4°C after preparation, and AFM analysis was performed within 12 hours after preparation (group A). Ten paired corneas from the respective donors were stored in Optisol-GS at 4°C for 1 week after preparation before AFM analysis (group B). Data were analyzed using the Hertz model for the evaluation of the Young modulus of elasticity. RESULTS: Force-distance curve analysis showed an increase in the Young modulus of elasticity in group B in comparison with that in group A, and the mean values were 10.4 ± 1.8 kPa and 6.77 ± 2.25 kPa, respectively (P < 0.001). There was no correlation between the Young modulus of elasticity and donor age (r = 0.110, P = 0.644), endothelial cell count (r = -0.145, P = 0.541), and procurement interval (r = 0.14, P = 0.755). CONCLUSIONS: A longer graft storage time in cold storage medium was found to significantly reduce the elasticity of the DMEK graft. Clinically, this could potentially influence the unfolding of the DMEK graft within the anterior chamber during surgery and the postoperative detachment rate.

Intracorneal knot or flange depot fixation: new transscleral technique for intraocular lens fixation.

A new surgical technique of transscleral-intracorneal suture fixation of intraocular lenses with suture ends located within the transparent corneal or corneal-limbal paracentesis is reported. This new technique significantly reduces scleral and conjunctival trauma, is minimally invasive, is simple to perform, is not associated with complicated intraocular surgical maneuvers, and precludes suture knot, flange, and suture-end erosion. The internal part of the corneal stroma or corneal-limbal area serves as a secure depot for suture-end fixation with durable resistance. The technique enables visualization of the exact position of suture ends over time.

Late dislocation of the capsular bag-intraocular lens-modified capsular tension ring complex after knotless transscleral suturing using 9-0 polypropylene.

We report a case of late breakage of a 9-0 polypropylene transscleral suture used for fixation of a dislocated capsular bag-intraocular lens-modified capsular tension ring complex in a 52-year-old woman with Marfan syndrome. Breakage occurred despite use of a cow-hitch technique for external and internal fixation. We believe breakage was caused by the suture chafing on the sharp edges of the modified capsular tension ring eyelet. Cross-sectional analysis of Malyugin-modified capsular tension rings from two different manufacturers revealed a difference with respect to radius of curvature. Suturing intraocular implants with relatively sharp edges may cause suture breakage; further studies are needed to identify the critical parameters for the surface quality of sutured intraocular implants.

Five-year results of non-penetrating deep sclerectomy with demineralized cancellous bone xenogenically derived collagen glaucoma implant.

PURPOSE: To investigate the long-term effectiveness of non-penetrating deep sclerectomy (NPDS) with xenogenically derived cancellous bone collagen glaucoma implant (XCB-CGI) implantation in patients with primary open-angle glaucoma (POAG). MATERIALS AND METHODS: Retrospective chart review of patients with POAG stages 2 and 3 was treated with NPDS and XCB-CGI. Follow-up was at 6 months, 1, 2, 3, 4 and 5 years after surgery. Main outcomes were intraocular pressure (IOP) and medication burden. Secondary outcomes were visual acuity, corneal hysteresis (CH), visual field (VF) and optical coherence tomography (OCT) parameter analysis. RESULTS: Among 71 patients (71 eyes), the mean age was 72.7 ± 9.8. Average initial IOP was 27.7 ± 7.9 and average initial med load was 2.36 ± 0.99. At 6 months, 1, 2, 3, 4 and 5 years, the average IOP was 14.9 ± 3.3 mm Hg (46.2% reduction), 15.3 ± 4.0 mm Hg (44.7% reduction), 14.2 ± 3.8 mm Hg (48.7% reduction), 15.2 ± 3.3 mm Hg (45.0% reduction), 15.5 ± 3.3 mm Hg (44.0% reduction) and 14.2 ± 2.8 mm Hg (48.7% reduction), respectively. In 5 years, the success rate was 34% and 67%, without, and with medications (1.8 ± 0.8 meds required), respectively. Visual acuity was not significantly different (P > .05) at all follow-up visits from baseline. Mean CH increased by 2.1 ± 0.8 (P = .05). No glaucomatous deterioration of the VF and OCT parameters was detected in 56 eyes at the 5-year follow-up. CONCLUSION: NPDS with XCB-CGI implantation is an effective procedure to normalize the level of IOP, stabilize glaucomatous changes and decrease the number of meds needed for glaucoma control.

Refractive outcomes following cataract combined with lamellar keratoplasty: femtosecond-DSEK versus microkeratome-DSAEK.

PURPOSE: Prediction of postoperative refraction following posterior lamellar keratoplasty is crucial for choosing proper intraocular lens power in combined surgeries. Femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS-DSEK) creates thin, planar grafts while microkeratome-assisted Descemet's stripping automated endothelial keratoplasty (DSAEK) creates non-planar, concaved grafts. We evaluated whether this fundamental difference affects the refractive outcomes in cataract surgery combined with FS-DSEK compared to cataract surgery combined with microkeratome-assisted DSAEK. METHODS: A retrospective analysis of 28 patients who underwent FS-DSEK combined with phacoemulsification and intraocular lens (IOL) implantation (group A) compared to 26 patients who underwent microkeratome-assisted DSAEK combined with phacoemulsification and IOL implantation (group B). Pre- and 1-year postoperative best-corrected visual acuity (BCVA), keratometry values, corneal thickness, central-to-peripheral graft thickness ratio (C/P ratio), and target postoperative spherical equivalent (SE) versus actual postoperative SE were analyzed. RESULTS: Target postoperative SE and actual postoperative SE significantly shifted toward hyperopia in group B, but not in group A. Postoperative hyperopic shifts were 0.14 D and 1.13 D in groups A and B, respectively (P < 0.001). BCVA improved after surgery in both groups, with no significant difference between the groups. Postoperative C/P ratio differed significantly between the groups and was negatively correlated with postoperative hyperopic shift (r = - 0.616, P < 0.001). CONCLUSION: Refractive outcomes of cataract surgery combined with FS-DSEK are relatively neutral, whereas those of cataract surgery combined with microkeratome-assisted DSAEK cause significant hyperopic shift. Clinicians should select accordingly an appropriate intraocular lens power when performing these surgeries.

Long-term myofibroblast persistence in the capsular bag contributes to the late spontaneous in-the-bag intraocular lens dislocation.

Late spontaneous in-the-bag intraocular lens (IOL) dislocation is a complication presenting 6 months or later after cataract surgery. We aimed to characterize the cells in the lens capsules (LCs) of 18 patients with spontaneous late in-the-bag IOL dislocation. Patients' average age was 82.6 ± 1.5 years (range 72-98), and most of them had pseudoexfoliation syndrome (PEX). Cells from the LCs were positive for myofibroblast (αSMA), proliferation (Ki-67, PCNA), early lens development/lens progenitor (SOX2, PAX6), chemokine receptor (CXCR4), and transmembrane (N-cadherin) markers, while negative for epithelial (E-cadherin) marker. Moreover, the cells produced abundant fibronectin, type I and type V collagen in the nearby extracellular matrix (ECM). During ex vivo cultivation of dislocated IOL-LCs in toto, the cells proliferated and likely migrated onto the IOL's anterior side. EdU proliferation assay confirmed the proliferation potential of the myofibroblasts (MFBs) in dislocated IOL-LCs. Primary cultured lens epithelial cells/MFBs isolated from the LC of dislocated IOLs could induce collagen matrix contraction and continuously proliferated, migrated, and induced ECM remodeling. Taken together, this indicates that long-lived MFBs of dislocated IOLs might contribute to the pathogenic mechanisms in late in-the-bag IOL dislocation.

Anterior vitreous detachment: risk factor for intraoperative complications during phacoemulsification.

PURPOSE: To confirm the presence of incomplete vitreolenticular adhesion via microscope-integrated intraoperative optical coherence tomography (iOCT) during cataract surgery and via diagnostic spectral-domain OCT (SD-OCT) postoperatively. SETTING: S. Fyodorov Eye Microsurgery Complex State Institution, Moscow, Russia. DESIGN: Prospective noninterventional single-center study. METHODS: Clinical characteristics and surgical videos of 27 patients (28 eyes) who had cataract surgery were documented. Real-time iOCT integrated into the surgical microscope was directed to view the retrolenticular anatomy at the end of the surgery. Postoperatively, SD-OCT was also performed. RESULTS: This study comprised 28 eyes of 27 patients. Berger space was identified in 21 cases (75%) intraoperatively via iOCT and in 23 cases (82%) postoperatively via stationary OCT. Depth dimensions varied from 33.5 ± 87.0 µm to 383.1 ± 226.3 µm. Hyperreflective dots and particles of different shapes and sizes were documented within Berger space in 16 cases (57%) intraoperatively and in 9 cases (32%) postoperatively. Capsular rupture occurred in 1 case due to excessive posterior capsular movement anteriorly. The posterior capsular rupture was converted into a posterior capsulorhexis, leaving the anterior hyaloid membrane intact. CONCLUSIONS: iOCT confirmed the penetration of crystalline lens microfragments, cellular material, or medical suspension (triamcinolone) into the space between the posterior lens capsule and the anterior hyaloid membrane. This occurs due to discontinuity of both lenticular zonules and Wieger ligament attachment. A Wieger ligament rupture can also allow excessive Berger space hydration during phacoemulsification leading to anterior displacement of the posterior lens capsule increasing the risk of instrument touch and posterior capsule rupture.

Comparative analysis of biomechanical parameters of the corneas following Descemet membrane endothelial keratoplasty and contralateral healthy corneas.

PURPOSE: To compare the biomechanical properties of the unilateral operated corneas in patients who had undergone Descemet membrane endothelial keratoplasty (DMEK) for pseudophakic bullous keratopathy (PBK) with those of the contralateral normal corneas. METHODS: This was a retrospective cohort study conducted at university hospitals (Department of Ophthalmology, Rabin Medical Center, Petach Tikva, Israel, and S. Fyodorov Eye Microsurgery State Institution, Moscow, Russia). Forty eyes of 20 patients who underwent DMEK for unilateral PBK 3.5 to 36 months ago and with normal fellow eyes were included in the study. An ocular response analyzer was used to measure the corneal biomechanical properties in the operated and normal fellow eyes. The main outcome measures were corneal hysteresis (CH) and corneal resistance factor (CRF). RESULTS: The mean CH (8.4 ± 1.5 mmHg vs. 8.2 ± 1.5 mmHg, P = 0.707) and the mean CRF (8.7 ± 1.6 mmHg vs. 8.3 ± 1.6 mmHg, P = 0.419) values did not show any statistically significant difference between the operated and the normal fellow eyes. CONCLUSIONS: In our study, the corneas that underwent DMEK for PBK showed normal values for biomechanical parameters. These findings support the previous studies that have reported near complete visual, functional, and ultra-structural rehabilitation of the corneas following DMEK.

Effect of NSAIDs on Pupil Diameter and Expression of Aqueous Humor Cytokines in FLACS Versus Conventional Phacoemulsification.

PURPOSE: To compare the concentrations of interleukin (IL) (IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70), interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and TNF-ß in the aqueous humor of patients undergoing femtosecond laser-assisted cataract surgery (FLACS) and corneal mechanical paracentesis treated with two different topical nonsteroidal anti-inflammatory drugs (NSAIDs): bromfenac and indomethacin. METHODS: In this prospective, randomized controlled, single-center study, aqueous humor samples were obtained immediately after performing the femtosecond laser procedure or at the start of conventional phacoemulsification. Preoperatively, the FLACS groups were administered (once daily and four times daily, respectively) either topical bromfenac 0.09% (12 eyes) or indomethacin 0.1% (12 eyes). The corneal paracentesis bromfenac and indomethacin groups received the same regimen of instillation of NSAIDs, respectively. Quantitative analysis of the expressed cytokines in the aqueous humor was performed using FlowCytomix FC 500 Pro 3.0 Software (Bender MedSystems GmbH, Vienna, Austria). RESULTS: The intraoperative pupil diameter was correlated with the expression of IL-6 after the femtosecond laser procedure in the FLACS indomethacin group (r = -0.53; P = .07). A significant difference in mean pupillary size was detected between the FLACS bromfenac and indomethacin groups at the aspiration/irrigation time point (0.53 ± 0.26 mm) and at the end of surgery (0.68 ± 0.37 mm). Progressive pupillary constriction was observed in the indomethacin and bromfenac groups. CONCLUSIONS: A smaller expression of IL-6 to the overall cytokine network value was observed in cases receiving preoperative bromfenac 0.09%, explaining improved maintenance of intraoperative mydriasis. [J Refract Surg. 2018;34(10):646-652.].

Femtosecond Laser-Assisted Intraocular Lens Fragmentation: Low Energy Transection.

PURPOSE: To describe a case of femtosecond laser-assisted hydrophobic intraocular lens transection. METHODS: Case report. RESULTS: Femtosecond laser-assisted transection of a one-piece acrylic hydrophobic intraocular lens for explantation via a small surgical incision was successfully performed with low energy parameters. CONCLUSIONS: This case illustrates a novel and effective clinical application of the femtosecond laser. [J Refract Surg. 2017;33(9):646-648.].