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OBJECTIVE The objective of this study is to evaluate the corneal endothelium in patients with chronic obstructive pulmonary disease (COPD) using a specular microscope. METHODS The right eyes of 64 patients with a COPD diagnosis and 65 healthy individuals were evaluated. Cell density (CD) (cell/mm2 ), corneal thickness (CT) (μ), hexagonal cell ratio (%), and coefficient of variation (cell area standard deviation/mean cell area, μm2 ) were analyzed by specular microscopy (SM). RESULTS The CT was significantly reduced in the COPD group compared with the control group (P = 0.021). Moreover, a significant difference was found between the COPD group and the control group in terms of corneal endothelial CD (P = 0.011), hexagonal cell ratio (P = 0.008), and coefficient of variation (P = 0.012). CONCLUSION The corneal endothelial structure was significantly deteriorated in patients with COPD compared with the control group. SM is a valuable method that could be used in treatment and follow-up of corneal endothelium in patients with COPD.

Purpose To investigate the impact of tobacco use on corneal thickness and corneal endothelial health. Methods We searched the PubMed/MEDLINE, EMBASE, the Cochrane Central and all affiliated databases of the Web of Science on 20 July 2020. Two authors reviewed the studies and extracted the data in an independent fashion. Studies were reviewed qualitatively in the text, and central corneal thickness (CCT) and corneal endothelial characteristics (endothelial cell density, endothelial cell variability, average of endothelial cell size and endothelial cell hexagonality) were introduced for quantitative analyses. Results Eighteen studies (2077 were smokers and 6429 non-smokers) were identified, of which 17 studies provided data eligible for one or more of the quantitative analyses. When compared to non-smokers, smokers had a higher CCT (+3.3 μm, 95% CI: +0.9 to +5.7 μm, p = 0.007) and a lower endothelial cell density (-140 cells/mm2 , 95% CI: -30 to -250 cells/mm2 , p = 0.01). Other corneal endothelial measures did not differ significantly. Conclusion Tobacco use is associated with a higher CCT and lower corneal endothelium cell density, but the clinical impact of these findings is small. Further studies are warranted on patients with a priori poor corneal health, where smoking may constitute an important risk of further progression, for example upon anterior segment surgery.

Background Multipotent neural crest cells (NCC) contribute to the corneal endothelium and keratocytes during ocular development, but the molecular mechanisms that underlie this process remain poorly understood. We performed RNA-Seq analysis on periocular neural crest (pNC), corneal endothelium, and keratocytes and validated expression of candidate genes by in situ hybridization. Results RNA-Seq profiling revealed enrichment of genes between pNC and neural crest-derived corneal cells, which correspond to pathways involved in focal adhesion, ECM-receptor interaction, cell adhesion, melanogenesis, and MAPK signaling. Comparisons of candidate NCC genes to ocular gene expression revealed that majority of the NCC genes are expressed in the pNC, but they are either differentially expressed or maintained during corneal development. Several genes involved in retinoic acid, transforming growth factor-β, and Wnt signaling pathways and their modulators are also differentially expressed. We identified differentially expressed transcription factors as potential downstream candidates that may instruct expression of genes involved in establishing corneal endothelium and keratocyte identities. Conclusion Combined, our data reveal novel changes in gene expression profiles as pNC differentiate into highly specialized corneal endothelial cells and keratocytes. These data serve as platform for further analyses of the molecular networks involved in NCC differentiation into corneal cells and provide insights into genes involved in corneal dysgenesis and adult diseases.

Corneal transplantation is currently the most effective treatment to restore corneal clarity in patients with endothelial disorders. Endothelial transplantation, either by Descemet membrane endothelial keratoplasty (DMEK) or by Descemet stripping (automated) endothelial keratoplasty (DS(A)EK), is a surgical approach that replaces diseased Descemet membrane and endothelium with tissue from a healthy donor eye. Its application, however, is limited by the availability of healthy donor tissue. To increase the pool of endothelial grafts, research has focused on developing new treatment options as alternatives to conventional corneal transplantation. These treatment options can be considered as either 'surgery-based', that is tissue-efficient modifications of the current techniques (e.g. Descemet stripping only (DSO)/Descemetorhexis without endothelial keratoplasty (DWEK) and Quarter-DMEK), or 'cell-based' approaches, which rely on in vitro expansion of human corneal endothelial cells (hCEC) (i.e. cultured corneal endothelial cell sheet transplantation and cell injection). In this review, we will focus on the most recent developments in the field of the 'cell-based' approaches. Starting with the description of aspects involved in the isolation of hCEC from donor tissue, we then describe the different natural and bioengineered carriers currently used in endothelial cell sheet transplantation, and finally, we discuss the current 'state of the art' in novel therapeutic approaches such as endothelial cell injection.

OBJECTIVE To determine endothelial cell density (ECD) and morphology and morphometry of corneal endothelial cells in the tawny owl (Strix aluco), as well as to report the effects of aging on these parameters. ANIMAL STUDY AND PROCEDURES Twenty tawny owls were included in the study and classified into 2 groups according to their age: fledglings ( 1 year old). Central corneal endothelium was studied by means of noncontact specular microscopy (Specular Microscope SP-2000P; Topcon, Tokyo, Japan), and results for ECD (cells/mm2 ), mean cell area ((MCA (μm2 )), polymegathism (CV), and pleomorphism (% hexagonal cells) were obtained. Results are described by median, interquartile range (25th, 75th percentiles), and absolute range for ECD, MCA, pleomorphism, and polymegathism. In addition, inferential analyses by Mann-Whitney U test were also performed. A two-tailed Type I error of 5% was established. RESULTS Results in fledglings were as follows: ECD = 2864 cells/mm2 , MCA = 348 μm2 , % hexagonal cells = 72.75%, and CV = 21. Results in adults were as follows: ECD = 2602 cells/mm2 , MCA = 384 μm2 , % hexagonal cells = 78.83%, and CV = 16. No significant differences in ECD and MCA were seen between the groups (P > .05), although there were significant differences in % hexagonal cells and CV (P

Although various biopolymers and synthetic compounds have been proposed and tested as the vitreous substitutes, no ideal material has been identified yet. In the present study, we developed an in situ-formed hydrogel by crosslinking hydroxypropyl chitosan with alginate dialdehyde. Physical properties of the hydrogel were studied and the cytotoxicity was evaluated using L929 fibroblasts, rabbit corneal endothelial cells and retinal pigment epithelial cells. In a preliminary in vivo study, the hydrogel was employed as vitreous substitute after vitrectomy surgery on rabbits and multiple parameters indicating biosafety and biocompatibility were measured and analyzed postoperatively. Our results showed that the refractive index, transmittance, pH value and density of the hydrogel were similar to those of human vitreous. Cytotoxicity tests demonstrated the hydrogel to be nontoxic to all of the three cell lines selected. Using the rabbit model, we showed that the hydrogel could form in situ and postoperative analysis of slit-lamp observation, intraocular pressure, corneal endothelium examination, B-scan ultrasound and fundus photography showed no significant adverse reactions in the operated eyes during the 90-day follow-up. However, electroretinogram and histopathological examinations indicated minor vision decline and decrease of the densities of cones and rods in the operated rabbit eyes. Collectively, our study suggested that the in situ-formed hydrogel could potentially be used as a vitreous substitute, with its long-term safety and efficacy to be further assessed. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1997-2006, 2018.

Importance Transient corneal endothelial changes are routinely noted on slit-lamp examination immediately following selective laser trabeculoplasty (SLT). Background To determine the mechanism of transient corneal endothelial changes observed following SLT. Design University laboratory-based observational study. Samples Ten corneas from six human cadaveric donors. Methods Corneas were treated with SLT, direct laser or peroxide, or used as controls. Haematoxylin and eosin staining and immunolabelling for zonula occludens-1 (ZO-1) and beta-catenin were performed. Main outcome measures Histological appearance; ZO-1 and beta-catenin immunostaining. Results There were no differences in histological features between SLT-treated and control corneas. Corneas treated with SLT or peroxide showed reduced and less regular ZO-1 immunofluorescence along cell membranes compared with ZO-1 expression in controls. These changes were generalized across the endothelium. There was no effect on the ZO-1 immunostaining after direct laser. There was no difference in beta-catenin immunostaining patterns between control, SLT and peroxide-treated corneas. Conclusions and relevance Altered ZO-1 immunostaining may represent disassembly of tight junctions between corneal endothelial cells. The similarity of our findings between SLT-treated and peroxide-treated corneas suggests that both conditions trigger changes at the level of endothelial tight junctions, perhaps triggered by liberation of free radicals as previously proposed.

A 1-year-old, female spayed, domestic shorthair cat presented for blepharospasm of the right eye. Slit-lamp biomicroscopic examination showed focal corneal ulceration and presumptive keratomalacia of the right eye. Examination of the left eye was normal apart from a focal endothelial opacity. Within the first 24 h of medical management, the right eye developed marked corneal edema and globular anterior protrusion of the corneal surface consistent with feline acute corneal hydrops (FACH). Surgical management consisted of a bridge conjunctival graft, nictitating membrane flap, and temporary tarsorrhaphy. Resolution of corneal edema and pain occurred in the right eye within 24 days. Spectral domain optical coherence tomography (SD-OCT) of the anterior segment was performed in both eyes. Conjunctival tissue from the bridge graft precluded examination of deeper corneal structures in the right eye. The left eye displayed a focal separation of the corneal endothelium and Descemet's membrane from the overlying stroma. These SD-OCT findings are similar to the analogous syndrome found in humans and represent a potential etiology for FACH of the right eye in the case presented here. Unfortunately, the cat was lost to follow-up and the progression of this lesion to FACH in the left eye could not be determined.

BACKGROUND AND PURPOSE The purpose of this study was to investigate the subacute effects of Rose Bengal (RB) and 532 nm green light-induced photochemical crosslinking (RB-PCL) on rabbit thin corneal stability and safety in vivo. MATERIALS AND METHODS Rabbit thin corneal models with 250 μm thickness were created by photorefractive keratectomy surgery. Photochemical crosslinking with green light (wavelength 532 nm) at an illumination intensity of 0.4 W/cm2 for 250 s (100 J/cm2 ) was performed, followed by antibiotic treatment and slit lamp monitoring for four weeks. At the end of week four, corneal biomechanical stiffness, biochemical resistance to collagenase digestion, and corneal cellular morphology were assessed. The penetration depth of RB into the corneal stromal was measured by confocal microscopy. RESULTS At the end of week 4, RB-PCL had increased corneal tensile strength by an average 2.5-fold and had extended the corneal collagenase digestion time from 10.17 ± 2.93 to 15.83 ± 2.64 days. RB penetrated approximately 90 µm into the corneal stroma. RB-PCL did not alter the corneal endothelial and stromal morphology at the cellular or subcellular levels, according to electron microscopic examination. CONCLUSIONS RB and 532 nm green light irradiation effectively induced crosslinking in rabbit thin cornea, by increasing both the biomechanical stiffness and the biochemical resistance without evidence of morphological damage to the corneal endothelium or stroma. This study demonstrated the efficacy of RB-PCL in strengthening thin cornea at four weeks after the treatment, providing a potential and possibly better option for treating corneal ectasia disorders in cases where corneal thickness is less than 400 µm. Lasers Surg. Med. 50:324-332, 2018. © 2017 Wiley Periodicals, Inc.

Objective Cataracts are the most common ocular disorder in dogs. Phacoemulsification is the preferred treatment method among ophthalmologists, but the cellularity of the endothelium must be considered for its success, as endothelial lesions may produce permanent corneal decompensation. The objective of this study was to evaluate the effects of intracameral ascorbic acid, a known antioxidant, on the corneal endothelium of dogs undergoing phacoemulsification. Animal studied In all, 40 eyes from 20 dogs, males and females from 7 to 12 years of age, were assessed for mature cataracts. Procedures Two groups were formed (n = 20): Group 1 (G1) received a balanced salt solution (BSS), whereas Group 2 (G2) received sterile ascorbic acid diluted in a BSS, at a final concentration of 0.001 m ascorbic acid. The corneal endothelium was assessed via non-contact specular microscopy at multiple time points before and after phacoemulsification. Cell density (cells/mm2 ) and area (mm2 ), corneal thickness (mm), hexagonality, and the coefficient of variation of cell size were all assessed. P values equal to or less than 0.05 were considered significant. Results With respect to the density of endothelial cells, both groups showed losses, but they were less severe in G2. There were no differences in corneal thickness. Hexagonality decreased significantly in the postoperative period in G1. Also in G1, the coefficient of variation of cell size increased significantly. Conclusion According to the results obtained, ascorbic acid minimizes cellular losses in the corneal endothelium.

Purpose To investigate the effect of the severity of keratoconus on the corneal endothelium using specular microscopy. Methods Seven hundred and twelve eyes from the Homburg Keratoconus Center (HKC) database were included in this retrospective study. Corneal endothelium was evaluated using the Tomey EM-3000 specular microscope. Keratoconus-related topographic and tomographic data were obtained from Scheimpflug-based tomography (Oculus Pentacam® HR). Eyes were classified into stages 0 (healthy) to 4 (severe keratoconus) according to the Topographic Keratoconus Classification (TKC). Subgroups were analysed based on contact lens (CL) type (none/rigid/soft). Results The frequencies of keratoconus stages 0/1/2/3/4 according to TKC were 169/94/206/166/77. The endothelial cell density (ECD) for the endothelial cell area for TKC 0/1/2/3/4 was 2611/2624/2557/2487/2401 cells per mm2 and the coefficient of variation (CV) was 40.9/40.0/41.6/46.2/49.0%, respectively. The more severe the keratoconus stage, the lower the endothelial cell count (p < 0.001) and the higher the CV (p < 0.001). No contact lens wearing was noted in 207 eyes (NoCL), rigid CL in 200 (RCL) and soft CL in 54 (SCL). CD for NoCL/RCL/SCL was 2523/2533/2644 per mm2 and CV was 41.8/54.1/43.1%, respectively. A significant difference in CV was found between NoCL and RCL (p = 0.02), and no significant difference in CV was found between NoCL and SCL (p = 0.07). Endothelial cell density (ECD) did not differ significantly between NoCL and RCL or SCL. Conclusion Endothelial cell density (ECD) decreases and CV increases significantly with increasing tomographic severity of keratoconus. In patients with RCL compared to eyes without CL wear, we found a statistically significantly higher CV in the endothelial cell size.

Objective To investigate the ophthalmic parameters of lowland pacas, including the anatomic features, tear production, intraocular pressure, central corneal thickness, and morphology of the corneal endothelium. Animals studied Thirteen adult, anesthetized Cuniculus paca. Procedure Eyes were evaluated using slit-lamp biomicroscopy, the Schirmer tear test I, digital applanation tonometry, binocular indirect ophthalmoscopy, and noncontact specular microscopy. Results The biomicroscopy findings showed blue/brown pigmented bulbar conjunctivae, well-developed cilia (only in the upper eyelid margin), superior and inferior lacrimal puncta, brown irides, round pupils, and vestiges of the nictitating membrane. The results of the Schirmer tear test I revealed (mean ± SD) a lacrimation rate of 4.10 ± 0.44 mm/min. The intraocular pressure was 6.34 ± 0.43 mmHg. Central corneal thickness measured by specular microscopy was 0.35 ± 0.01 mm. The mean values of density, hexagonality, and the area of the endothelial cells were 2083.15 ± 42.47 cells/mm2 , 67.07 ± 3.30%, and 486.30 ± 9.56 μm2 , respectively. Conclusions The ocular parameters defined in this study may be used for reference in future studies and might also contribute to therapeutic approaches appropriate to this species.

Purpose To verify that ocular surface irrigation with 0.025% povidone-iodine (PI) or 0.0025% polyvinyl alcohol-iodine (PAI) during cataract surgery minimizes bacterial contamination of the anterior chamber. Methods The study was a prospective, interventional case series. First, the bactericidal effect of PI or PAI against Staphylococcus aureus was evaluated in vitro. Next, in 400 eyes undergoing cataract surgery, the ocular surface was irrigated every 20 seconds during surgery with balanced salt solution (BSS; 200 eyes) or BSS containing 0.025% PI (100 eyes) or 0.0025% PAI (100 eyes). At the completion of surgery, anterior chamber fluid was cultured bacteriologically. Visual acuity (VA) and corneal endothelial cell density were measured before and 7 days after surgery. Results A marked bactericidal effect was observed when S. aureus was directly exposed for 15 seconds to 0.01% PI or 0.001% PAI diluted in BSS. When the two solutions were stored at room temperature, bactericidal effect did not attenuate after 60 min. The bacterial detection rate at the completion of surgery was significantly reduced in 0.025% PI (0%, 0/100 eyes) or 0.0025% PAI group (0%, 0/100 eyes) compared to BSS group (5%, 10/200 eyes) (p = 0.0340). No differences in postoperative visual acuity and postoperative corneal endothelial cell density were observed between three groups. Conclusion In cataract surgery, irrigation every 20 seconds of the operative field with 0.025% PI or 0.0025% PAI, both of which contain 0.0025% available iodine concentration, achieved a very low bacterial contamination rate in the anterior chamber.

Purpose Intraocular lens (IOL) fixation using a sutureless 27-gauge needle intrascleral IOL implantation technique requires six surgical wounds. We developed a modified technique using two 27-gauge trocars for vitrectomy and indwelling flanged IOL haptics to reduce the number of surgical wounds. Setting Department of Ophthalmology, Hyogo College of Medicine. Design This retrospective study enrolled 54 patients who had undergone IOL scleral fixation between January 2016 and April 2019. Methods Patients who underwent IOL scleral fixation and were observed for >12 weeks were analysed using medical record data. Before October 2017, patients underwent normal flanged IOL scleral fixation. Between November 2017 and April 2019, patients underwent the modified method (flanged IOL via 27-gauge trocars with double-needle technique). Primary end-point was superiority or non-inferiority of modified IOL scleral fixation compared with normal IOL scleral fixation for visual acuity (VA). Changes in corneal endothelium cell number, refractivity, astigmatisms and surgery-related complications, were secondary end-points. Results There were no significant differences in baseline characteristics between groups. Raw VA and best collected VA (BCVA) were significantly improved in all eyes (p-). There were no statistical significances in raw VA, BCVA and surgery-related complications between groups. Conclusions Results of the modified technique were not inferior compared with the original technique although it was less invasive. Therefore, flanged IOL fixation via trocars using a double-needle technique is a useful technique for IOL implantation.

Background: Fuchs endothelial corneal dystrophy (FECD) is a progressive and potentially a sight threatening disease, and a common indication for corneal grafting in the elderly. Aberrant thickening of Descemet's membrane, formation of microscopic excrescences (guttae) and gradual loss of corneal endothelial cells are the hallmarks of the disease. The aim of this study was to identify differentially abundant proteins between FECD-affected and unaffected Descemet's membrane. Methods: Label-free quantitative proteomics using nanoscale ultra-performance liquid chromatography-mass spectrometry (nUPLC-MSE ) was employed on affected and unaffected Descemet's membrane extracts, and interesting findings were further investigated using quantitative reverse transcription-polymerase chain reaction and immunohistochemical techniques. Results: Quantitative proteomics revealed significantly lower abundance of apolipoprotein E (APOE) and immunoglobulin heavy constant gamma 1 protein (IGHG1) in affected Descemet's membrane. The difference in the distribution of APOE between affected and unaffected Descemet's membrane and of IGHG1 detected by immunohistochemistry support their down-regulation in the disease. Comparative gene expression analysis showed significantly lower APOE mRNA levels in FECD-affected than unaffected corneal endothelium. IGHG1 gene is expressed at extremely low levels in the corneal endothelium, precluding relative expression analysis. Conclusions: This is the first study to report comparative proteomics of Descemet's membrane tissue, and implicates dysregulation of APOE and IGHG1 proteins in the pathogenesis of Fuchs endothelial corneal dystrophy.

Purpose: To evaluate the effects of 2% Dorzolamide, 0.5% Timolol and 0.005% Latano- prost on the biometrics of the anterior segment in normotensive cats. Material/Methods: Three groups of 15 clinically healthy randomly selected cats received one single molecule on the right eye during 7 days (Group 1: 2% Dorzolamide BID, Group 2: 0.5% Timolol BID, Group 3: 0.005% Latanoprost SID). Left eyes received no treatment and were used as con- trols. Complete ophthalmic examination, IOP measurement and anterior segment assessment by Ultrasound Biomicroscopy (UBM) were performed in the same conditions at day 1 and day 7, on both eyes. Eight anatomical parameters of the anterior segment were evaluated: the geometric iridocorneal angle (ICA) – formed by the plane of the iris root and the inter- nal corneoscleral limbus – the width of the opening of the ciliary cleft (CC), the width of the mid-CC, the length of the CC, the anterior chamber (AC) depth (distance between the corneal endothelium and the anterior lens capsule), the central and peripheral corneal thick- nesses, then the distance between the anterior lens capsule and the internal corneoscleral limbus. Results: The use of the controlateral eye as control was statistically validated, as well as the representativeness of fifteen-cat cohorts. A significant decrease of IOP was observed only for dorzolamide (5.3%). None of the eight anatomical parameters were statistically modified by the topical instillation of the three drugs. Discussion: The use of the three first-line antiglaucomatous agents does not significantly alter the anterior segment architecture in normotensive cats.

Basement membranes are protein-rich extracellular matrices (ECM) that are essential for epithelial and endothelial tissue structure and function. Aging and disease cause changes in the physical properties and ECM composition of basement membranes, which has spurred research to develop methods to repair and/or regenerate these tissues. An area of critical clinical need is the cornea, where failure of the endothelium leads to stromal edema and vision loss. Here we developed an engineered basement membrane (EBM) that consists of a dense layer of collagen IV and/or laminin approximately 5–10nm thick, created using surface-initiated assembly, conformally attached to a collagen I film. These EBMs were used to engineer a corneal endothelium (CE) that mimicked the structure of Descemet’s membrane with a thin stromal layer, towards use as a graft for lamellar keratoplasty. Results showed that bovine and human CE cells formed confluent monolayers on the EBM, expressed ZO-1 at the cell-cell borders and achieved a density of ~1600 cells mm−2 for 28 and 14 days, respectively. These results demonstrated that our technique was capable of fabricating EBMs with structural and compositional properties that mimic native basement membranes and that our EBM may be a suitable carrier for engineering transplant quality CE grafts.

A common indication for corneal transplantation, which is the most transplanted tissue, is a dysfunctional corneal endothelium due to Fuchs' endothelial dystrophy (FED). FED is diagnosed by the presence of in vivo pathological microtopography on the Descemet membrane, which is called corneal guttata. Minimally invasive corneal endothelial cell regenerative procedures such as endothelial cell injection therapy and Rho kinase inhibitor pharmacotherapy have been proposed as alternatives to conventional corneal transplantation for FED patients. However, the effect of guttata on monolayer reformation following such therapies is unknown and there is no equivalent in vitro or animal model to study monolayer reformation. Using a synthetic guttata FED disease model, the formation of the monolayer is investigated to evaluate the efficacy of both therapies. Results obtained suggest that guttata dimensions, density, and spacing greatly affect the fate of corneal endothelial cells in terms of migratory behavior and monolayer reformation. Densely packed synthetic guttata mimicking late-stage FED hinders monolayer reformation, while synthetic guttata of lower height and density show improved monolayer formation. These results suggest that severity of the FED, as determined by height and density of existing guttata, can potentially attenuate corneal endothelial monolayer formation of corneal cell injection therapy and pharmacotherapy.

Background Corneal endothelial transplantation has become the gold standard for the treatment of corneal endothelial dysfunctions, replacing full thickness transplantation, known as penetrating keratoplasty. Corneal endothelial transplantation has been described using two different techniques: Descemet’s membrane endothelial keratoplasty (DMEK) and Descemet’s stripping automated endothelial keratoplasty (DSAEK). Both are still performed worldwide. Objectives To compare the effectiveness and safety of Descemet's membrane endothelial keratoplasty (DMEK) versus Descemet's stripping automated endothelial keratoplasty (DSAEK) for the treatment of corneal endothelial failure in people with Fuch’s endothelial dystropy (FED) and pseudophakic bullous keratopathy (PBK). Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 7); MEDLINE Ovid; Embase Ovid; LILACS BIREME; the ISRCTN registry; ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The date of the search was 11 August 2017. Selection criteria We included randomised controlled trials (RCTs) and non-randomised paired, contralateral-eye studies in any setting where DMEK was compared with DSAEK to treat people with corneal endothelial failure. Data collection and analysis Two review authors independently screened the search results, assessed trial quality and extracted data using the standard methodological procedures expected by Cochrane. Our primary outcome was best corrected visual acuity (BCVA) measured in logarithm of the Minimum Angle of Resolution (logMAR). Secondary outcomes were endothelial cell count, graft rejection, primary graft failure and graft dislocation. We graded the risk of bias of non-randomised studies (NRSs) using ROBINS-I. Main results We did not identify any RCTs but found four non-randomised studies (NRSs) including 72 participants (144 eyes), who had received DSAEK in the first eye followed by DMEK in the fellow eye. All the studies included adult participants where there was evidence of FED and endothelial failure requiring a corneal transplant for the treatment of visual impairment. We did not find any studies that included PBK. The trials were published between 2011 and 2015, and we assessed them as high risk of bias due to potential unknown confounding factors since DSAEK preceded DMEK in all participants. Two studies reported results at 12 months, one at 6 months, and one between 6 and 24 months. At one year, using DMEK in cases of endothelial failure may result in better BCVA compared with DSAEK (mean difference (MD) -0.14, 95% confidence interval (CI) -0.18 to -0.10 logMAR, 4 studies, 140 eyes, low-certainty evidence). None of the participants had severe visual loss (BCVA of 1.0 logMAR or more; very low-certainty evidence). Regarding endothelial cell count data (4 studies, 134 eyes) it is hard to draw any conclusions since two studies suggested no difference and the other two reported that DMEK provides a higher cell density at one year (very low-certainty evidence). No primary graft failure and only one graft rejection were recorded over four studies (144 eyes) (very low-certainty evidence). The most common complications reported were graft dislocations, which were recorded in one or two out of 100 participants with DSAEK but were more common using DMEK, although this difference could not be precisely estimated (risk ratio (RR) 5.40, 95% CI 1.51 to 19.3; 4 studies, 144 eyes, very low-certainty evidence). Authors' conclusions This review included studies conducted on people with corneal endothelium failure due to FED for whom both DMEK and DSAEK can be considered, and found low-certainty evidence that DMEK provides some advantage in terms of final BCVA, at the cost of more graft dislocations needing 're-bubbling' (very low-certainty of evidence).

Summary This presentation highlights non-viral and viral vector strategies to modify corneal endothelial cells. Functional data will be presented.

This study aims to systemically review the effect of laser iridotomy on the corneal endothelium. Searches were performed for studies that either compared corneal endothelial cell density/count, corneal thickness and morphology pre- and postiridotomy, or evaluated the postiridotomy development of corneal decompensation. There were 26 eligible studies. Our review shows that the effect of laser iridotomy on the corneal endothelium has been investigated with varying results. Although it has been demonstrated to be a relatively safe procedure, there is still the potential long-term risk of corneal decompensation, for which a corneal transplantation may be indicated eventually. The longest interval between laser iridotomy and corneal decompensation reported was 8 years. Mechanisms proposed for endothelial damage include direct focal injury, thermal damage, mechanical shock waves, iris pigment dispersion, transient rise in intraocular pressure, inflammation, turbulent aqueous flow, time-dependent shear stress on endothelium, chronic breakdown of blood-aqueous barrier and damage from bubbles that settled onto the endothelium. Inherent risk factors identified were iridotrabecular contact, current or prior acute angle closure, pigmented irides, small iris-to-endothelium distance, pre-existing endothelial disease and diabetes. Intervention-related risk factors include laser type, delivery and quantity. The significance of the risk factors and their direct association with the development of corneal decompensation remain to be determined. Understanding these risk factors may allow physicians to counsel their patients better. They may offer opportunities for preventive strategies, allowing us to ensure that a procedure performed to prevent disease progression and visual loss does not cause further morbidity.

Purpose: The purpose of this study was to assess the incidence of intraoperative floppy iris syndrome (IFIS) and the morphology of the corneal endothelium after cataract extraction in Caucasian male patients exposed to the α-1a adrenergic receptor antagonist tamsulosin. Methods: In a clinical prospective study, 23 male patients (23 eyes) treated with tamsulosin due to benign prostatic hyperplasia and 25 male patients (25 eyes) with no tamsulosin treatment had cataract surgery. The divide-and-conquer technique was used with the Infinity OZil® machine. A combination of Healon and Healon5 was used in all patients, but the use of additional Vision Blue, iris retractors or intracameral phenylephrine in the tamsulosin group was at the discretion of the surgeon. The endothelial cell density, variation in endothelial cell size (CV), percentage of hexagonal cells and central corneal thickness (CCT) were recorded at baseline and at 3 months postoperatively. Results: In the tamsulosin-treated group, 19 of 23 eyes (83%) developed IFIS, compared with no IFIS in the control group. Compared with the control group, the tamsulosin group showed significantly less dilatation at the start of the operation, significant miosis during surgery and significantly greater corneal endothelial cell loss 3 months postoperatively (12% versus 3%; p

Background Whitish spots are sometimes noted in the corneal endothelium after selective laser trabeculoplasty. To evaluate the corneal endothelium after selective laser trabeculoplasty, corneal specular microscopy was performed. Design Prospective observational study in a private practice. Participants Fifteen consecutive patients with open-angle glaucoma undergoing selective laser trabeculoplasty in February 2012 had their corneal endothelium examined with specular microscopy before and after treatment. Methods Selective laser trabeculoplasty was done with 50 ± 5 shots to 180 degrees of meshwork using 0.3–0.9 mJ of power to achieve the reaction of a hint of microbubbles in 80% of laser shots. Main Outcome Measures Corneal specular microscopy photographs (0.25 × 0.54 mm) were taken prior to, immediately after and 1 month after selective laser trabeculoplasty. These photographs were assessed and graded. Results Of the 15 patients, three showed numerous, four showed few and eight showed no increase of dark spots after selective laser trabeculoplasty. All the dark spots resolved by 1 month. Conclusion The effect of selective laser trabeculoplasty on the corneal endothelium may be transient, and long-term effects are probably negligible in normal corneas. However, in compromised corneas and corneas with pigment deposits on endothelium, there may be a risk of corneal endothelial compromise, especially after repeated selective laser trabeculoplasty. Larger and longer term studies with histopathological evaluation would be useful to evaluate the effect of selective laser trabeculoplasty on normal and subnormal corneal endothelium. Until further studies are done, it would be wise to minimize the number and energy of laser shots.

ummary The anatomical and biological properties of stem cells in the eye have been the topic of indepth research over the last few decades. Enormous advances in the cell and tissue isolation and cultivation techniques, as well as molecular characterization of the different cell populations have been achieved, next to the major advances made in the bioscaffolds’ engineering for cell delivery and treatment of eye diseases. Advances in the cell and gene therapy have reached culmination with the human cornea being at the top and holding great promise in treating eye disorders. The eye is indeed a golden mine for stem cells. This session will include lectures from European experts in the field with high international recognition and large collaborative networks. Challenges in the clinical applications of cornea limbal stem cells will be described, along with advances in corneal endothelium engineering for future transplantation applications. In addition, examples of regulating the gene expression towards solving ocular surface diseases will be shown, as well as future directions hallmarking stem cell and cell therapy in ophthalmology.

Background To assess the surgical procedure, safety and stability of a next generation injectable telescope prosthesis in a rabbit model. Methods After removal of the crystalline lenses of eight New Zealand White rabbits, the next generation device was randomly implanted in one eye, and the available telescope prosthesis (Normal device) was implanted in the fellow eye. Operative parameters (incision, capsulorrhexis size and operative time), intraoperative and postoperative complications rates, endothelial cell density changes and the distance between the corneal endothelium and the telescope (central clearance distance) were measured and compared between the groups. Results Incision size and capsulorrhexis size were smaller, and operative time was shorter in the next generation group in comparison with the Normal group. No difference was found in the intraoperative and postoperative complication rates between the groups. Endothelial cell density loss observed in the next generation group was less than the loss in the Normal group, but the difference was not significant statistically. The central clearance distance was significantly larger in the next generation group in comparison with the Normal group (P = 0.001). Conclusions The next generation telescope was implanted through a smaller incision, with a shorter surgical time and a larger central clearance distance in the rabbit eyes, in comparison with the Normal group. The next generation device may allow reduced trauma to the corneal endothelium, better control during surgery and induce less astigmatism while preserving the optical advantages of the Food and Drug Administration-approved telescope prosthesis.

Purpose To describe the gross and histopathological ocular findings in a horse following suspected lightning injury. Methods The eyes of a 2-year-old thoroughbred gelding were clinically and histopathologically evaluated following a severe lightning storm following euthanasia because of visual impairment. Results Severe corneal edema and hydrops were noted clinically oculus dexter. Indirect ophthalmoscopy revealed bilateral symmetrical raised hyporeflective peripapillary geographic lesions. Histopathologic evaluation revealed corneal edema in the right eye with normal corneal endothelium. Posterior segment evaluation revealed localized, pericentral choroidal lesions characterized by the presence of hemorrhage, early fibrosis, and minimal lymphoplasmacytic, neutrophilic, and histiocytic inflammation with spindle cell proliferation. The retinas overlying the choroidal lesions were necrotic and mostly absent. Peripheral to the focal lesion, the retina abruptly returned to normal architecture peripheral to a zone of apoptotic photoreceptors. Centrally, swollen axons extended into the optic disc. Conclusions There have been few descriptions of ocular lesions in animals following suspected lightning injury. We believe these findings to be unique because of the type of thermal injury that may be characteristic of lightening injury. We do not know whether these lesions would have progressed over time.

Background: To compare the clinical outcomes in Marfan's with subluxated lens having phaco-emulsification with simultaneous scleral-fixated posterior chamber intraocular lens or iris-fixated anterior chamber intraocular lens implantation. Design: Randomized case series in the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Participants: Seventy-one eyes of 49 patients with Marfan syndrome with subluxated lens. Methods: This is a randomized case series of patients with Marfan syndrome and subluxated lenses who underwent phaco-emulsification combined with scleral-fixated posterior chamber intraocular lens or iris-fixated anterior chamber intraocular lens implantation. Main Outcome Measures: The evaluation indexes included the surgery time, best corrected visual acuity, intraocular pressure, aqueous flare and cells counts, corneal endothelium counts and complications. Results: Increase in best corrected visual acuity in both groups was not significant. The aqueous flare and cells rose in both groups postoperatively. Significant difference between the two groups at 1 week postoperatively was found, whereas no statistically significant difference was found later. The loss rate of corneal endothelium cells in the scleral-fixated posterior chamber intraocular lens group was 13.2% and 19.5% at 3 months and 1 year postoperatively, which in the iris-fixated anterior chamber intraocular lens group was 13.3% and 19.3% (P > 0.05). Prolapse of vitreous was found in 21 cases intraoperatively. The posterior capsule opacification rate was 32% and 15%, respectively. The decentration of the intraocular lens was found in 19 eyes (48.7%) in the scleral-fixated posterior chamber intraocular lens group 1 year postoperatively, whereas none was found in the iris-fixated anterior chamber intraocular lens group. Conclusions: Iris-fixated anterior chamber intraocular lens after phaco-emulsification presented a safe, simple and efficient approach for managing subluxated lens in Marfan syndrome.

Objective To determine the effect of 0.5% tropicamide and the resultant mydriasis on the anterior segment in normotensive dogs using ultrasound biomicroscopy. Procedure Twenty-four dogs without ocular disease underwent ultrasound biomicroscopic examination of both the eyes under general anesthesia. Pharmacologic mydriasis was induced in the right eye of each dog by the topical instillation of 0.5% tropicamide. Ultrasound biomicroscopic examinations were performed and the anatomical parameters of the anterior segment were evaluated including the geometric iridocorneal angle (ICA) - formed by the plane of the iris root and the internal corneoscleral limbus - the width of the opening of the ciliary cleft (CC), the width of the mid-CC, the length of the CC, and the anterior chamber (AC) depth (distance between the corneal endothelium and the anterior lens capsule). Results Mydriasis resulting from the topical use of 0.5% tropicamide is associated with an increase in the geometric ICA and a decrease in the opening of the CC, without any effect on the width of the mid-CC, or on the length of the CC, or on the AC depth. Conclusions Mydriasis induced by topical 0.5% tropicamide results in modification of the anterior segment which may influence the drainage of aqueous humor.

Purpose: We aimed at developing simulation software capable of producing images of corneal endothelium close to identical to images captured by clinical specular microscopy with defined morphometrical characteristics. It was further planned to demonstrate the usefulness of the simulator by analysing measurement errors associated with a trained operator using a commercially available semi-automatic algorithm for analysis of simulated images. Methods: Software was developed that allows creation of unique images of the corneal endothelium expressing morphology close to identical with that seen in images of corneal specular microscopy. Several hundred unique images of the corneal endothelium were generated with randomization, spanning a physiological range of endothelial cell density. As an example of the usefulness of the simulator for analysis of measurement errors in corneal specular microscopy, a total of 12 of all the images generated were randomly selected such that the endothelial cell density expressed was evenly distributed over the physiological range of endothelial cell density. The images were transferred to a personal computer. The imagenet-640 software was used to analyse endothelial cell size variation, percentage of hexagonal endothelial cells, and endothelial cell density. Results: The simulator developed allows randomized generation of corneal specular microscopy images with a preset expected average and variation of cell structure. Calculated morphometric information of each cell is stored in the simulator. The image quality can secondarily be varied with a toolbox of filters to approximate a large spectrum of clinically captured images. As an example of the use of the simulator, measurement errors associated with one trained operator using the imagenet-640 software, and focusing on endothelial cell density, were examined. The functional dependence between morphometric information estimated with the imagenet-640 software algorithm and real morphometric information as provided by the simulator was analysed with regression. It was demonstrated that that the estimations of endothelial cell size variation was associated with a scaling error and that the random error was strongly dependent on the operator. Conclusion: The newly developed simulator for randomized generation of morphometrically defined corneal specular microscopy images for the first time makes it possible to estimate a spatial scaling error of an available semi-automatic algorithm and to determine the random measurement error of important morphometric estimates in a defined reference sample of images. It is anticipated that the simulator will be a valuable tool for the generation of a large set of morphometrically well-characterized corneal specular microscopy images that can be used for calibration among research centres, for minimization of random errors and for measurement of quality control. Simulated images will be useful for the development of fully automatic analysis of corneal endothelial cell morphometry.

The purpose of this study was to investigate the effect of age on endothelial morphology and morphometry in cats. The corneal endothelium was studied using a contact specular microscope. A total of 18 cats (Felis catus Linnaeus, 1758) were evaluated in this study. The subjects were divided into three groups of six cats each in function of age: G1 (1 to 3 months old), G2 (5 to 12 months old), and G3 (24 to 40 months old). The examination presented data as endothelial cell density (ECD), average cell area, corneal thickness, polymegathism, and pleomorphism. Results revealed ECD decrease in corneas of normal cats with age, as well as a corresponding increase in endothelial cell area and pleomorphism. The present work suggests that the endothelial parameters evaluated change with advancing age.

Background: The characteristics of the corneal endothelium in patients with/without pseudoexfoliation syndrome (PEX) with senile cataract in Paraguay are unknown. Methods: Endothelial density, mean coefficient of variation (%) in cell size and mean cell hexagonality (%) were measured using automated specular microscopy. Multivariate general linear model analysis was used to determine the effect of age, gender and PEX on endothelial characteristics. Analysis of variance tests analysed the effect of age on endothelial variables without regard to PEX status. Categories of

Purpose: To evaluate the reparative capacity of the mechanically injured endothelium of corneas stored under organ culture (OC) or hypothermic conditions. Methods: The central endothelium of 12 pairs of human corneas with similar endothelial parameters was damaged to create a 1 mm2 lesion. One cornea from each pair was stored under OC and one under hypothermic conditions. The endothelial cell density (ECD), coefficient of variation, hexagonality and percentage of dead cells were assessed before and after damage and on days 7, 14, 21 and 28 of storage. Results: The mean ECD of corneas subsequently stored under OC or hypothermic conditions was 2764/mm2. Immediately after damage, a denuded Descemet’s membrane with a few remaining dead cells was observed at the injured area. After 7 days of storage under OC conditions, almost no dead cells were observed at the place of injury. A non-significant worsening of the qualitative parameters (polymegatism and pleomorphism) was found. After 14 days, ECD was 1933/mm2 and 2478/mm2 centrally and pericentrally, respectively. Similar values were found after 21 and 28 days of storage. The lesions with remnant dead cells persisted throughout hypothermic preservation. From day 14 the corneas became cloudy and in poor condition, while the pericentral ECD was 2523/mm2. Conclusion: The reparative capacity of the cornea is maintained under OC but not under hypothermic conditions. For corneas containing dead endothelial cells, OC is therefore the method of choice because it may improve the quality of the stored tissue.

The innate immune system provides the immediate defense against pathogens. NOD1 and NOD2 proteins are intracytoplasmic signaling receptors of the innate immune system and recognize conserved microbial molecular structures. The aim of this study was to analyze the expression of NOD1 and NOD2 proteins in healthy mouse and dog eyes using immunohistochemistry on formalin-fixed, paraffin-embedded globes. In both the mouse and dog globes, a strong immunosignal for NOD1 and NOD2 was present within corneal epithelium, corneal endothelium and conjunctival epithelium. Scattered cells in the conjunctival substantia propria displayed moderate immunopositivity for NOD1 and NOD2. Additionally, in dog eyes, nonpigmented iridal epithelium was immunopositive for NOD1 and NOD2. No other examined ocular tissues were immunopositive for NOD1 or NOD2. To the best of the authors' knowledge, this is the first description of an immunohistochemical study on NOD1 and NOD2 expression in healthy mouse and dog eyes. Since signaling molecules of the innate immune system mediate pro-inflammatory responses in numerous organs, they likely also contribute to the pathogenesis of ocular inflammation.

Acta Ophthalmol. 2010: 88: 700–704 Abstract. Purpose: This case report describes serious postoperative complications and markedly elevated intraocular pressure (IOP) associated with the NewColorIris cosmetic implant. Methods: We report an interventional case series of two patients who suffered multiple complications after NewColorIris implantation carried out in Panama. Assessment included visual acuity, photography, endothelial cell count and anterior segment optical coherence tomography (OCT) when possible. Results: Both patients presented with endothelial cell loss, uveitis, pigment dispersion and elevated IOP. Anterior segment OCT demonstrated irregularities in the position and configuration of the implants within the anterior chamber with resultant areas of implant–iris and implant–endothelial contact. One patient had acute postoperative hyphaema that resolved with anterior chamber tissue plasminogen activator injection. Both patients required explantation OU, one eye has required trabeculectomy, and one eye with bullous keratopathy is being evaluated for Descemet’s stripping endothelial keratoplasty. Conclusions: Implantation of the NewColorIris cosmetic implant can lead to serious complications including hyphaema, uncontrolled IOP, severe endothelial cell loss, bullous keratopathy and anterior uveitis. Explantation may lead to improvement, but permanent damage to the trabecular meshwork and corneal endothelium persists.

The effects of corneal incisions of different types on the corneal endothelium in cadaver eyes was studied by scanning electron microscopy. In all cases the perforations were made with a diamond knife, but in case 1) the opening was enlarged in both directions with scissors, in case 2) a partly perforating groove was made on one side, and an enlargment only with sciccors on the other, and in case 3) a long full thickness incision with diamond knife only was made. The greatest damage to the endothelium was induced by the scissors, the damage was less when partial thinning was performed before the opening with scissors, and the least trauma was seen when a diamond knife only was used. The cell loss was maximally calculted to be about 8% of the endothelial cell population when incision with scissors was performed compared with 2–3% with diamond knife incision.

Protective effect on corneal endothelium from surface modification of PMMA intraocular lenses were evaluated. Sodium hyaluronate, heparin or both were covalently bound to the PMMA surface rendering it hydrophilic. Endothelial damage was evaluated by placing the intraocular lens optics on the endothelial surface of excised rabbit corneas. The type and extent of endothelial cell damage was evaluated by light microscopy after alizarine red/trypan blue staining and by scanning electron microscopy. The number of endothelial cells attached to the intraocular lens surface was counted in the light microscope after staining with haematoxylin--eosine. Significantly less damage (p less than 0.05) to the endothelium was caused by the surface modified hydrophilic intraocular lenses. There was no difference between the various types of surface coatings studied in this investigation.

We studied the corneal endothelial cells in 14 patients (6 men and 8 women, ranging in age from 15 to 70 years) with unilateral Fuchs' heterochromic cyclitis (FHC) by means of specular microscopy. The healthy fellow eyes of the patients served as control material. Two affected eyes had undergone an intracapsular cataract extraction before specular microscopy. In one patient, the cyclitic eye also had glaucoma. Changes of the endothelium characterized by intra-and intercellular dark bodies, larger dark defects spanning several endothelial cells and bright irregular patchy areas crossing cell borders on the specular reflex were found in all eyes with FHC. Individual cell analysis did not reveal any significant differences in the endothelial cell density, cell area, coefficient of variation for cell area, cell perimeter, cell shape and in the number of endothelial cell apices between unoperated cyclitic and healthy fellow eyes. The mean cell density was 4.9% lower in the unoperated eyes with FHC than in the control eyes. A significant negative correlation was observed between the patients' age and the cell density both in the healthy and the cyclitic eyes. On the other hand, the correlation between follow-up period and cell density was not statistically significant in the cyclitic eyes. Although FHC does not seem to accelerate significantly the age-related cell density reduction, the magnitude of the cell loss found in the two operated eyes (45.5% and 49.8%) and in the eye with glaucoma (45.2%) may indicate altered tolerance against endothelial traumas in this disease.

Further evaluation of a method suitable for investigation of toxic drug effect was performed. Rabbit corneas kept in organ culture were exposed to gentamicin for 24 h, and their weights were recorded. The weight increase observed in all specimens was significantly higher (p < 0.0001) in the corneas exposed to gentamicin 0.6 mg/ml (n = 7) than in the controls (n = 14). This was not the case for the corneas exposed to 0.3 mg/ml and 0.1 mg/ml. The accuracy of each weight recording was tested by repeated recordings. The standard deviation (SD) was less than 1%, and there was no significant difference between series performed by two different recorders. The reproducibility of the test was focused upon by calculating the SD of the control group, and by comparing the present results with the results of a control group in a recently published study (Medin 1992). The SD was approximately 2.8%, and no significant difference was found.

The intercellular junctions of the corneal endothelium has been studied in rabbit, monkey and human eyes. A union of apposing outer leaflets (tight junction) is usually found near the apical end of the intercellular clefts. However, evidence from lanthanum tracer studies indicates that the tight junctions do not seal the intercellular clefts completely. In addition to tight junctions, the presence of gap junctions or nexuses is demonstrated in all three species studied.

The anterior chambers of rabbit, monkey and human eyes were perfused with horseradish peroxidase. The perfusion was started immediately after enucleation of the monkey and human eyes, while the rabbit eyes were perfused in situ after the animals had been killed. Comparative results were obtained after 1 h of perfusion and were mainly based on frozen sections. Intensive staining was found in the Descemet's membrane, the sclera and the iridial stroma, considerably more than in the corneal stroma and in the ciliary body base. In the vervet monkey and human eyes only traces of peroxidase reaction products were seen in the stroma of the ciliary body base. The movement of the protein tracer from the anterior chamber into the corneal stroma is probably dependent upon vesicular transport across the corneal endothelium. The Descemet's membrane was interpreted to be more porous than the corneal stroma. A trans-corneal and a corneo-scleral movement appeared to be more efficient than the uveo-scleral one, at least in the vervet monkey and the human eyes.

Nine corneas from 5 human adult donors were obtained 11 to 31 h post mortem. In 4 corneas the endothelium was wounded by freezing and in 1 cornea by mechanical means. Care was taken to minimize endothelial damage in the remaining 4 corneas. The corneas were incubated at 31 degrees C for 6 days in a tissue culture medium containing 3H thymidine. Autoradiographs were made of the flat preparations of the endothelium. All corneas contained radioactive endothelial cell nuclei, with the highest concentration of labelled nuclei being in the wound areas. The greatest number of labelled cells was found in the cornea from the youngest donor, 19 years of age, but thymidine uptake also occurred in the oldest cornea, 89-years-old, which additionally had signs of endothelial dystrophy.

The apical edges of corneal endothelial cells have been separated along lines forming a crisscross pattern, by the help of a special method of preparation. The visualization by SEM of the lateral faces of the cells is thereby made possible. The separation leads to the formation of thin strands spanning the gap between the apical edges of adjoining cells. They are formed by stretching of the normal apical flaps. This stretching demonstrates that the main intercellular adherence is located at the tips of the apical flaps. The basal edges of the endothelial cells can be inspected, and it can be seen that the basal face of the cells has and irregular form. Threadlike processes extend from the basal cell edges. They ascend in the intercellular space and make contact with the lateral face of the neighbouring cell at varying levels. These processes are presumed to mediate intercellular transfer.

In a group of 10 patients (12 eyes) undergoing intracapsular cataract extraction, corneal endothelial cell loss was serially investigated by means of regional specular microscopy. Prevoperatively there were no significant regional differences in the endothelial cell density. Two weeks after sugery, the superior endothelium alone showed a significant cell loss (15.6%). Whereas, a definite endothelial cell loss occurred in each region of the cornea one month after surgery. The cell loss was greater in the superior (22.8%) and lower in the inferior (4.7%), respectively, when compared to that seen in the central cornea (9.6%). In each region, cell loss continued 3 months postsoperatively, but no significant cell loss occurred thereafter. These results suggest that the entire endothelial cell population may participate in the healing of the damage associated with intracapsular cataract extraction and that regional specular microscopy can be of help for detailed evaluation of such a damage.

The endothelium of 15 human corneas was studied with specular and electron microscopy after exposure to a thick, low water content, soft contact lens (SCL). Five control corneas (no lens wear) were studied using the same methods. SCL wear produced obvious changes in endothelial morphology in 12 of the 15 eyes. With specular microscopy, the changes consisted of an apparent increase in separation of cells and development of areas of loss of membrane reflectivity (blebs). When viewed with electron microscopy, the changes in the same corneas consisted of oedema in the nuclear area of the cells and bulging of the posterior endothelial surface, in some cases over an area of several cells. In 4 cases, the cellular oedema was marked showing both intracellular and intercellular vacuoles. It was concluded that the transient endothelial changes seen with specular microscopy following SCL lens wear were produced by alterations in the contour of the posterior endothelial surface resulting from disturbance to the endothelial environment.