Endothelial Loss Research Articles

Hyaline membrane disease (HMD): the role of the perinatal pathologist

Hyaline membrane disease (HMD), the pathologic correlate of respiratory distress syndrome (RDS) of the newborn, is an acute lung disease of premature infant caused by inadequate amounts of surfactant. Decreased surfactant results in insufficient surface tension in the alveolus during expiration, leading to atelectasis, decreased gas exchange, severe hypoxia and acidosis. HMD predominantly occurs in infants younger than 32 weeks of gestation and weighing less than 1,200 g. In the interpretation of perinatal lung pathology, it is necessary to consider the development of the immature lung, particulary in the third trimester. Microscopically HMD is characterized by the occurrence of dilated terminal and respiratory bronchioles and of alveolar ducts lined by acellular eosinophilic hyaline membranes. The membranes are composed of necrotic alveolar lining cells, amniotic fluid constituents and fibrin. Retinopathy of prematurity and bronchopulmonary dysplasia are late complications of RDS that usually occur in infants who weigh less than 1,500 g and were maintained on a mechanical respiration more than 6 days. Here a pratical approach to a microscopic analysis of the lung in newborns died with the clinical setting of RDS is presented. The most important pathological findings for a complete clinical pathological diagnosis are: the evaluation of the architectural lung development; the endothelial cell lesions; the interstitial edema; the occurrence of disseminated intravascular coagulation; the presence of associated inflammatory lesions. The usefulness of some immunohistochemical stains is also underlined, including anti-surfactant, anti-smooth muscle actin and anti-CD31 to better evaluate surfactant production, pulmonary artery maturation and endothelial cell damage, respectively. Finally, the prevalent role of endothelial dysfunction and endothelial barrier loss is underlined, representing a major pathological event in the deposition of HMD. Proceedings of the International Course on Perinatal Pathology (part of the 10th International Workshop on Neonatology · October 22nd-25th, 2014) · Cagliari (Italy) · October 25th, 2014 · The role of the clinical pathological dialogue in problem solving Guest Editors: Gavino Faa, Vassilios Fanos, Peter Van Eyken

Short-term effects of extracorporeal shock waves on microcirculation

BackgroundExtracorporeal shock wave application (ESWA) has the potential to qualify as an adjuvant therapy option for soft tissue disorders such as chronic wounds. As of today, little is known about its exact mechanism of action. For a better understanding of the pathophysiology, we investigated the effect of ESWA on microcirculation and leukocyte–endothelial interaction. Materials and methodsIntravital fluorescent microscopy was used to quantify microcirculatory parameters in the ears of hairless mice (n = 30). Values were obtained just before and 10 min after the ESWA (500 shots, 1 Hz, duration 500 s). Mice were randomly divided into three groups undergoing different shock wave intensities (energy flux density: control: 0.00 mJ/mm2; low level: 0.015 mJ/mm2; and higher level (hl): 0.04 mJ/mm2; n = 10 mice per group). Histologic evaluations were taken after completion of the experiments. ResultsA significant increase in the venular diameter was observed in both the groups that underwent ESWA compared with the control group (hl: 118%, low level: 117%, and control: 96%; P < 0.004). Edema formation increased significantly in group I (P = 0.002). ESWA provoked an arteriolar constriction (hl: 93% versus control: 104%; P = 0.019) 10 min after treatment. The highest value of venular blood flow was found in group hl. Moreover, shock waves increased significantly the number of sticking leukocytes immediately after application (hl: 274%, P = 0.003). ConclusionsESWA has a significant and immediate impact on microcirculation with endothelial integrity loss and increase of adherent leukocytes as part of a proinflammatory process. Although a dilation of venules was caused, arterioles primarily show a constriction. The study shows alterations in microcirculation that could help understand the mechanism of action in the future.

Endothelial Akt1 mediates angiogenesis by phosphorylating multiple angiogenic substrates.

The PI3K/Akt pathway is necessary for several key endothelial cell (EC) functions, including cell growth, migration, survival, and vascular tone. However, existing literature supports the idea that Akt can be either pro- or antiangiogenic, possibly due to compensation by multiple isoforms in the EC when a single isoform is deleted. Thus, biochemical, genetic, and proteomic studies were conducted to examine isoform-substrate specificity for Akt1 vs. Akt2. In vitro, Akt1 preferentially phosphorylates endothelial nitric oxide synthase (eNOS) and promotes NO release, whereas nonphysiological overexpression of Akt2 can bypass the loss of Akt1. Conditional deletion of Akt1 in the EC, in the absence or presence of Akt2, retards retinal angiogenesis, implying that Akt1 exerts a nonredundant function during physiological angiogenesis. Finally, proteomic analysis of Akt substrates isolated from Akt1- or Akt2-deficient ECs documents that phosphorylation of multiple Akt substrates regulating angiogenic signaling is reduced in Akt1-deficient, but not Akt2-deficient, ECs, including eNOS and Forkhead box proteins. Therefore, Akt1 promotes angiogenesis largely due to phosphorylation and regulation of important downstream effectors that promote aspects of angiogenic signaling.

Balancing hematopoietic cell fate and endothelial identity in hemogenic endothelium

Hematopoietic stem and progenitor cells (HP/SCs) first emerge from the embryonic endothelium during development to establish what will eventually become the adult hematopoietic system, in a process termed the endothelial to hematopoietic transition (EHT). Factors proven critical for EHT include Runx1, Sox17, and Notch1. However, early endothelial loss of either notch1 or sox17 also disrupts vascular specification, while runx1 impacts hematopoiesis without an overt vascular consequence. Here we present data that Notch1 and Sox17 are actually dispensable for hematopoietic emergence from the endothelium during EHT, and that endothelial loss after vascular specification results in augmented hematopoietic emergence.

Risk factors for donor endothelial loss in eye bank-prepared posterior lamellar corneal tissue for descemet stripping automated endothelial keratoplasty.

The aim of this study was to investigate donor, tissue, and precut procedure risk factors for endothelial cell density (ECD) loss in posterior lamellar corneal tissue preparation by an eye bank for Descemet stripping automated endothelial keratoplasty. A total of 259 corneoscleral rims precut by the Singapore Eye Bank from October 2011 to August 2013 were evaluated. Donor characteristics, tissue characteristics, and precut procedure parameters were analyzed. The mean donor age was 57.18 ± 11.35 years, and the mean cutting transition time was 4.16 ± 0.75 seconds. The mean ECD was 2826 ± 225 and 2787 ± 224 cells per square millimeter before and after precutting, respectively, with an average ECD change of -1.38% ± 3.28%. The precutting procedure failure rate was 1.2%. Mutivariate regression analysis showed that an older donor age, a higher ECD before cutting, and a slower cutting transition speed were significant factors. Corneas with an ECD >2800 cells per square millimeter before precutting, cutting transition time >5.5 seconds, and corneas with donor age >65 years were significantly more likely to have greater than 5% ECD loss after precutting (odds ratio, 6.42, 1.66, and 1.62; 95% confidence interval, 1.44-29.43, 1.45-2.72, and 1.66-5.82, respectively). Donor source, death-to-preservation time (range, 0.67-10.88 hours), death-to-precutting time (range, 0-7 days), and graft thickness (range, 43-232 μm) were not statistically significant factors. The ECD loss in the precut tissue prepared by the eye bank was very low. The risk factors identified provide better understanding of how to improve the quality and safety profiles when preparing graft tissue for Descemet stripping automated endothelial keratoplasty.

Contact Lens-Assisted Collagen Cross-Linking (CACXL): A New Technique for Cross-Linking Thin Corneas

To report a novel method of contact lens-assisted corneal cross-linking (CACXL) in eyes with thin corneas. Patients diagnosed as having progressive keratectasia with a minimum corneal thickness less than 400 and greater than 350 μm after epithelial abrasion were included. After epithelial abrasion, the iso-osmolar riboflavin 0.1% in dextran was applied every 3 minutes for 30 minutes. An ultraviolet barrier-free soft contact lens (0.09-mm thickness, 14-mm diameter) soaked in iso-osmolar riboflavin 0.1% for 30 minutes was placed on the cornea. Once the minimum corneal thickness value was confirmed to be greater than 400 μm, the ultraviolet-A irradiance was started along with instillation of iso-osmolar riboflavin 0.1% in the pre-corneal and pre-contact lens region. Intraoperative minimum corneal thickness changes were recorded with ultrasound pachymetry and optical coherence tomography. Postoperative visual acuity, corneal topography (Orbscan; Bausch & Lomb, Rochester, NY), endothelial cell loss (EM-3000; Tomey, Nagoya, Japan), and stromal demarcation line (Visante; Carl Zeiss Meditec, Jena, Germany) were measured. Fourteen eyes underwent the procedure. Mean preoperative minimum corneal thickness after epithelial abrasion was 377.2 ± 14.5 μm (range: 350 to 398 μm). There was a significant difference in minimum functional corneal thickness (Friedman test, P = .000) intraoperatively, before epithelial abrasion, after epithelial abrasion, and with contact lens and riboflavin film. Mean minimum functional corneal thickness after the contact lens was 485.1 ± 15.8 μm (range: 458 to 511 μm). Mean absolute increase in the minimum corneal thickness along with the contact lens and pre-corneal riboflavin film was 107.9 ± 9.4 μm (range: 90 to 124 μm). Mean depth of stromal demarcation line was 252.9 ± 40.8 μm (range: 208 to 360 μm). There was no significant endothelial loss (P = .063) and the corneal topography was stable at the last follow-up (P = .505). CACXL technique was effective and safe in performing cross-linking in corneas less than 400 μm after epithelial abrasion and appeared effective based on stromal demarcation line depth.

Traumatic dislocation of implanted collamer phakic lens: a case report and review of the literature.

Purpose : Present a case of dislocation of an Implantable Collamer Lens (ICL) that occurs after blunt trauma and review the published literature on this topic.Methods : Case report and literature review using PubMed.Results : A 44 year-old male presented to the emergency department with sudden onset of blurry vision after blunt trauma to the left eye. Three years prior, he had undergone bilateral ICL placement for high myopia. On examination, the superotemporal haptic was noted to be dislocated into the anterior chamber, but there was no endothelial touch by the dislocated lens. The patient had an associated hyphema that was medically managed, and 2 weeks after the injury, the patient underwent ICL repositioning. A review of the literature was performed and five previous cases of ICL dislocation were identified. Three of these occurred after blunt trauma. One of these cases was associated with endothelial touch and decompensation and eventually required a descement’s stripping endothelial keratoplasty (DSAEK).Conclusion : Dislocation of ICLs after blunt trauma is a rare but important potential sequela of the procedure and can lead to corneal decompensation if there is lens-endothelial touch. All patients who suffer blunt dislocation of ICL should be followed long-term after repositioning for signs of endothelial loss and dysfunction.

Amantadine-related corneal edema and endothelial cell loss: Four case reports

Amantadine is widely used in treating influenza A, hepatitis, Parkinson's disease, and fatigue in multiple sclerosis. In the past, only a few case reports have demonstrated that amantadine is associated with corneal edema, endothelial dysfunction, and other corneal comorbidity. We herein present four cases with reversible corneal edema and endothelial loss after taking amantadine, including two cases with delayed presentation of corneal edema after use of amantadine for 18 months and 12 months.

Evaluation of a Toric Implantable Collamer Lens After Corneal Collagen Crosslinking in Treatment of Early-Stage Keratoconus

The aim of this study was to assess the predictability, efficacy, safety, and stability in patients who received a toric implantable collamer lens (TICL) after collagen crosslinking in early-stage keratoconus. This prospective interventional case series study was conducted at the Alexandria Main University hospitals, University of Alexandria, Egypt. Sixteen eyes underwent implantation of a TICL (STAAR Surgical Inc) after crosslinking. The mean spherical refraction was -5.98 ± 4.39 diopters (D) (range, -0.50 to -14.50 D), and the mean cylinder was -4.91 ± 1.51 D (range, -2.50 to -7.75 D). Uncorrected distance visual acuity (UDVA), manifest and cycloplegic refraction, corrected distance visual acuity (CDVA), vault, intraocular pressure, and endothelial cell count (using specular microscopy) were evaluated during a 3-year follow-up. The mean Snellen decimal CDVA improved from 0.56 ± 0.13 (range, 0.40-0.80) preoperatively to 0.89 ± 0.17 (range, 0.60-1.20) at 3 years of the follow-up (P < 0.0001). The mean UDVA also improved significantly from 0.63 ± 0.14 before ICL implantation to 0.88 ± 0.18 after 3 years of the follow-up (P < 0.001). At 3 years, the mean spherical and cylindrical manifest refractions were 0.00 ± 0.18 D and -0.05 ± 0.14 D, respectively. At the end of the follow-up, the vault was 509.75 ± 141.47 μm (range, 320-900) and the intraocular pressure was 11.94 ± 1.12 mm Hg. No complications occurred during the surgical procedures. No eye needed explantation or repositioning of the TICL. The endothelial cell count loss after 3 years was -8.98%. Correction of spherical and cylindrical refractive errors in keratoconic eyes by TICL implantation 12 months after crosslinking gave significantly promising outcomes, particularly in the astigmatic component of refraction.

Molecular analysis of blood–retinal barrier loss in the Akimba mouse, a model of advanced diabetic retinopathy

The molecular mechanisms of vascular leakage in diabetic macular edema and proliferative retinopathy are poorly understood, mainly due to the lack of reliable in vivo models. The Akimba (Ins2AkitaVEGF+/−) mouse model combines retinal neovascularization with hyperglycemia, and in contrast to other models, displays the majority of signs of advanced clinical diabetic retinopathy (DR). To study the molecular mechanism that underlies the breakdown of the blood-retinal barrier (BRB) in diabetic macular edema and proliferative diabetic retinopathy, we investigated the retinal vasculature of Akimba and its parental mice Kimba (trVEGF029) and Akita (Ins2Akita). Quantitative PCR, immunohistochemistry and fluorescein angiography were used to characterize the retinal vasculature with special reference to the inner BRB. Correlations between the degree of fluorescein leakage and retinal gene expression were tested by calculating the Spearman's correlation coefficient. Fluorescein leakage demonstrating BRB loss was observed in Kimba and Akimba, but not in Akita or wild type mice. In Kimba and Akimba mice fluorescein leakage was associated with focal angiogenesis and correlated significantly with Plvap gene expression. PLVAP is an endothelial cell-specific protein that is absent in intact blood-retinal barrier, but its expression significantly increases in pathological conditions such as DR. Furthermore, in Akimba mice BRB disruption was linked to decreased expression of endothelial junction proteins, pericyte dropout and vessel loss. Despite fluorescein leakage, no alteration in BRB protein levels or pericyte coverage was detected in retinas of Kimba mice. In summary, our data not only demonstrate that hyperglycemia sensitizes retinal vasculature to the effects of VEGF, leading to more severe microvascular changes, but also confirm an important role of PLVAP in the regulation of BRB permeability.

Genetic association studies of endothelial nitric oxide synthase gene polymorphisms in women with unexplained recurrent pregnancy loss: a systematic and meta-analysis

Recurrent pregnancy loss (RPL) is a multifactorial disorder, both genetic and environmental factors contribute to the development of RPL. Recently, the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and unexplained recurrent pregnancy loss (URPL) has been reported, and the results were inconsistent. Hence, we performed the meta-analysis to drive a more precise estimation of association between eNOS polymorphisms and URPL. Odds ratio (OR) and its 95% confidence interval were calculated under co-dominant (AA vs. BB, TT vs. GG) and additive (A vs. B, T vs. G) genetic models. Studies of eNOS intron 4 VNTR and Glu298Asp were separated by ethnicities. 13 studies included 1,769 URPL cases and 1,376 healthy controls on eNOS intron 4 VNTR polymorphism, and 11 studies were involved in Glu298Asp polymorphism with 1,498 URPL cases and 1,123 healthy controls. The integrated results showed that eNOS Glu298Asp polymorphism was associated with URPL [ORs were 1.91 (1.42-2.56), P < 0.001; 1.67 (1.36-2.04), P < 0.001, respectively]. When analyses were separated by ethnic subgroups, the association between eNOS Glu298Asp polymorphism and URPL was only observed in East Asians [OR = 1.88 (1.52-2.33), P < 0.001 under additive model], and there was no association between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians. The results indicated a significant association between eNOS Glu298Asp polymorphism and URPL in East Asians. No association was observed between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians.

CORNEAL ENDOTHELIAL CELL DENSITY AFTER VITRECTOMY WITH SILICONE OIL FOR COMPLEX RETINAL DETACHMENTS

To evaluate the endothelial cell density changes in eyes with silicone oil tamponade after vitrectomy for complex rhegmatogenous retinal detachment. A prospective controlled study with 81 eyes with complex rhegmatogenous retinal detachment undergoing vitrectomy and silicone oil tamponade. Fellow eyes that fulfilled specific inclusion criteria served as controls. Endothelial cell density (in cells per square millimeter), coefficient of variance (standard deviation per mean cell area × 100), percentage of hexagonal cells, and corneal thickness were documented preoperatively and compared with values obtained at 3, 6, and 12 months postoperatively. For the purpose of the study analysis, all study eyes were divided into 5 groups, according to their lens status during the follow-up. High endothelial cell density loss was found in Group 3, (eyes that underwent an additional phacoemulsification procedure) and Group 4 (eyes that underwent lens and/or intraocular lens removal during the follow-up) at 12 months with a mean cell loss of 19% and 39%, respectively (P < 0.001). An intact natural or artificial lens-iris diaphragm may provide a protective barrier against corneal endothelial cell damage from long-term silicone oil tamponade.

Corneal changes in diabetic patients after manual small incision cataract surgery.

Diabetics have abnormal corneal morphology along with higher rate of corneal endothelial cell loss and decreased corneal endothelial cell density and early onset of cataract. To evaluate the changes in corneal endothelium and corneal thickness in patients with diabetes mellitus after Manual Small Incision Cataract Surgery (MSICS) in eyes with brunescent Cataract. Sixty eyes of 60 patients with Type 2 diabetes mellitus and 60 eyes of 60 age matched healthy patients of advanced brunescent cataract underwent MSICS were evaluated. All the patients underwent specular microscopy for the corneal endothelial cell count of cornea and central corneal thickness pre-operatively, at one week, six weeks and 12 weeks post-operatively. The morphology, variation in the endothelial size and shape and percentage of hexagonal cells were assessed. The mean pre-operative endothelial count in the control was higher than the diabetic group (p<0.001). The post-operative endothelial count loss in both the groups were statistically significant (one-way ANOVA p<0.001). On comparing post-operative endothelial loss in non diabetics (8.05%) to diabetic group, the diabetic group had significantly higher endothelial loss (14.19% p<0.001). There was also a significant increase in central corneal thickness in diabetics as compared to control (p = 0.004). The change in percentage hexagon cells in diabetic group was significantly higher than in non diabetic group (p = 0.005). Inter group change in coefficient of variance was not statistically significant (p=0.144). Compared to non-diabetic patients, diabetic patients have more endothelial cells damage after MSICS. Corneal endothelial evaluation of diabetic patients is recommended before any intraocular surgery.

Long-term results of non-valved glaucoma drainage implant surgery and glaucoma drainage implant combined with trabeculectomy.

Purpose:The purpose was to investigate the efficacy and complications of nonvalved glaucoma drainage implant (GDI) surgery and GDI combined with trabeculectomy.Subjects and Methods:Serial Japanese patients who received GDI were retrospectively investigated. The survival rate of eyes was analyzed using the Kaplan-Meier method, defining death as: (1) Intraocular pressure (IOP) <6 mmHg, or ≥22 mmHg, and <20% reduction of preoperative IOP, (2) additional glaucoma surgery, (3) loss of light perception. Prognostic factors of age, sex, previous surgery, type of glaucoma, synechial closure, preoperative IOP, type of GDI (single-, double-plate Molteno, Baerveldt 350) and GDI combined with trabeculectomy were investigated employing proportional hazards analysis.Results:One hundred and twenty-four eyes of 109 patients aged 53.3 ± 7.8 years old were analyzed. Types of GDI were single-plate (15.3%), double-plate Molteno (71.8%), and Baerveldt 350 (12.9%). The results of survival rate analysis were 86.1, 71.1, 71.1, and 64.6% for 1, 3, 5, and 10 years respectively. Thirty-four eyes (27.4%) died because of uncontrolled IOP (19.4%), loss of light perception (5.6%), and additional glaucoma surgery (2.4%). Single-plate Molteno was the only risk factor for failure. Persistent unphysiological hypotony (0.8%) and bullous keratopathy (5.6%) were observed.Conclusion:Nonvalved GDI surgery and GDI combined with trabeculectomy using nonabsorbable tube ligature proved to be an excellent device for any type of glaucoma in Japanese patients. Hypotony and corneal endothelial loss are the most serious complication in the long-term results of our patients.

New trends in anterior segment diseases of the eye.

Disorders of the anterior segment of the eye are leading causes of ocular morbidity. Such conditions include dry eye conditions, infections, traumas of various types, inflammatory reactions, hereditary disorders, and cataract. For a number of these patients, the rule is a continuous progression and aggravation of symptoms. The end stage is varying degrees of visual loss with or without pain. Despite continuous advances in ophthalmology, a number of these patients represent a challenge even in highly specialized clinics in western countries. On a worldwide basis, such conditions represent a significant public health problem. Cataract and loss of corneal transparency are still two of the most common causes of blindness worldwide [1]. While cataract is a disorder of the adult and aged population, blindness due to corneal opacities is observed in all age groups. In children, loss of corneal transparency represents the third most common cause of blindness. During the past two decades, translational research has increased our ability to understand the pathogenesis of, and also to treat, selected disorders of the ocular surface and cornea. Although still in their shaping and improved by continuous translational and clinical research, procedures for ex vivo production of corneal and conjunctival epithelial tissue allow treatment of patients with previously untreatable corneal disorders [2, 3]. Refinement of corneal transplant procedures permits targeted intervention and replacement of opaque and nonfunctioning tissues with lamellar donor tissue [4, 5]. By such techniques, the volume of foreign tissue with a potential for stimulation of immunoreactions is reduced as is the trauma induced by the surgical intervention. However, there is a pronounced lack of donor corneas. In western countries, one main indication for corneal transplantation is loss of endothelial function. Ongoing research within the field of tissue engineering will provide procedures for production of transplantable layers of corneal endothelium and thereby add a new and significant tool to our treatment options [6]. Procedures for cataract surgery are continuously being advanced, accompanied by a decline in the rate of complications such as astigmatism and corneal endothelial loss with subsequent corneal hydration [7, 8]. Due to the complexity of challenges within these areas, further progress relies to a significant extent on interaction between clinical and basic research environments. In translational research projects, extraction of information is facilitated by cooperation between clinical and basic research environments [9, 10]. The intent is to warrant that advances in basic and clinical knowledge may serve a purpose: a better understanding of the disease pathophysiology to ensure a better disease prevention, new diagnostic procedures, and novel types of treatment including drugs, whose final end point may be preclinical or clinical testing. Francisco Javier Romero Bjorn Nicolaissen Cristina Peris-Martinez

Immediate Endothelial Cell Loss After Penetrating Keratoplasty

To report the pattern and the extent of corneal endothelial cell loss immediately after a penetrating keratoplasty (PK) is performed. Ten donor corneal-scleral tissues with healthy endothelium were used to perform 10 PK surgeries on cadaver eyes. An 8.25-mm donor graft was placed into an 8.00-mm trephinated recipient bed of the cadaver eye. A 10-0 nylon suture was used with a 16-interrupted suture closure technique to secure each donor button. Viscoelastic was used to protect the endothelium in every case. The corneal donor buttons were removed and stained using trypan blue and alizarin red dyes. Digital high-definition photographs were obtained to record the pattern and quantity of stain resulting from endothelial damage and cell loss. Percent endothelial loss was calculated using the digital planimetry of our previously described Adobe Photoshop technique. The immediate mean percent cell loss across the whole graft was 25.7% ± 7.5% (Range, 18-39). There was a distinct pattern of loss, with 58.3% of the loss in the peripheral 0.75 mm, and 12.4% of the loss in the central 3.00 mm. The immediate total endothelial cell loss after the PK was performed was about 25%. The immediate cell loss after the PK was consistent with areas of trephination and suture placement.

P158 Endothelial progenitor cells form biological exclusion barriers similar to that of mature endothelial cells- A therapeutic potential in systemic sclerosis?

Vascular complications associated with systemic sclerosis (SSc) including pulmonary arterial hypertension (PAH-SSc), result from endothelial damage and loss of barrier function. Endothelial progenitor cells (EPCs) express endothelial (VEGFR2+, CD31+ )...

Keratoplasty Postoperative Treatment Update

Immunosuppressive therapy is the main postoperative treatment for keratoplasty, but there are considerable differences in protocols for the use of steroids and other immunosuppressants. Therefore, we conducted 2 prospective randomized clinical trials and 1 prospective nonrandomized clinical trial on keratoplasty postoperative treatment. One study evaluated the efficacy and safety of long-term topical corticosteroids after a penetrating keratoplasty was performed. Patients who underwent keratoplasty and maintained graft clarity for >1 year were randomly assigned to either a steroid or a no-steroid group. At the 12-month follow-up, the no-steroid group developed significantly more endothelial rejection than did the steroid group. A second study elucidated the effectiveness and safety of systemic cyclosporine in high-risk corneal transplantation. The patients were assigned to a systemic cyclosporine or control group. At a mean follow-up of 42.7 months, no difference was observed in the endothelial rejection rates and graft clarity loss between the 2 groups. A third study elucidated the effectiveness and the safety of systemic tacrolimus in high-risk corneal transplantation. Of 11 consecutive eyes decompensated despite systemic cyclosporine treatment, there was no irreversible rejection in eyes treated with tacrolimus, which was significantly better than in previous penetrating keratoplasty with systemic cyclosporine treatment. Prognosis after keratoplasty in patients with keratoconus is relatively good, but special attention is required for patients with atopic dermatitis. Postkeratoplasty atopic sclerokeratitis (PKAS) is a severe form of sclerokeratitis after keratoplasty in atopic patients. Our retrospective study showed that 35 eyes of 29 patients from a total of 247 keratoconus eyes undergoing keratoplasty were associated with atopic dermatitis, of which 6 eyes of 5 patients developed PKAS. Eyes with PKAS had a significantly higher incidence of atopic blepharitis and preoperative corneal neovascularization, and therefore, we suggest systemic corticosteroids or cyclosporine to prevent PKAS in such high-risk cases.

Clinical trial evaluating Viscoat and Visthesia ophthalmic viscosurgical devices in corneal endothelial loss after cataract extraction and intraocular lens implantation

Purpose: To assess and compare the safety and the efficacy of VisThesia™ and Viscoat® in cataract surgery.Methods: This prospective randomized clinical trial included 44 eyes of 44 patients that were assigned randomly to undergo phacoemulsification either with VisThesia™ or with Viscoat®. Preoperative data included age, gender, visual acuity, IOP and mean endothelial cell density. Postoperative, best corrected visual acuity (BCVA), IOP, mean endothelial cell density and painful sensation during surgery were recorded.Results: BCVA, evaluated with Snellen chart in decimal fraction, was statistically improved in both groups. Specifically, mean BCVA in VisThesia group was increased from 0.28 ± 1.8 SD preoperatively to 0.83 ± 1.4 SD postoperatively, whereas, in the Viscoat group, BCVA was increased from 0.31 ± 2.1 SD preoperatively, to 0.85 ± 1.2 SD after surgery (p > 0.1). The mean postoperative IOP was lower in the VisThesia group, but the difference was not statistically significant (p > 0.1). Preoperatively, the mean endothelial cell count was 2322.3 ± 161.1 SD cells/mm2 in Viscoat group and 2304.8 ± 142.8 SD cells/mm2 in the VisThesia group, similar between groups (p > 0.1). At day 15 after cataract surgery the postoperative endothelial cell count was 2102.9 ± 182.8 SD cells/mm2 in Viscoat group and 2032.6 ± 160.4 SD cells/mm2 in the VisThesia group (p > 0.1). The mean endothelial cell decrease was 212 cells/mm2 (9.1%) in the Viscoat group and 272 cells/mm2 (11.8%) in the VisThesia group. The difference was not statistically significant between the two groups (t-test = 0.18, p > 0.1). This value is within standard normal endothelial cell decrease after a cataract surgery. Painful sensation was not reported during any stage of the procedure.Conclusions: Topical-intracameral anesthesia with VisThesia™ allows cataract surgery without any painful sensation in the majority of patients. Both Viscoat® and VisThesia™ have similar safety profile during intra- and post-operative period and identical endothelial protection, as endothelial cell loss is within normal limits.

Aqualase® Revisited: Endothelial Cell Loss Strongly Depends on Lens Density

Purpose: To analyze the dependence between corneal endothelial cell loss by Aqualase® cataract surgery and the nuclear opalescence grade of the lens. Patients and Methods: A total of 100 eyes of 92 patients were enrolled in this prospective, single-center study. Patients were randomly assigned to the Aqualase (50 eyes) or the phacoemulsification group (50 eyes). The nuclear density was classified with the Lens Opacities Classification System III. All procedures were performed by the same surgeon. Preoperatively and 1 week postoperatively, endothelial cell counts were obtained using a noncontact specular microscope (Konan, Japan). Results: (1) Aqualase group: the group of patients with a nuclear density of 1-2 (17 patients) showed no significant endothelial cell loss (4.1%, p = 0.163). The endothelial cell loss in grade 3 cataracts (28 eyes) was 13.9% (p = 0.004) and in grade 4 cataracts (5 eyes) 69.1% (p = 0.043), being statistically significant in both groups. (2) Phacoemulsification group: in nuclear density groups 1 and 2, endothelial cell loss was 6.3% (p = 0.41), in group 3 it was 17.6% (p = 0.001) and in group 4 it was 14.9% (p = 0.08). Only in nuclear opalescence grade 4 there was a significant difference between the Aqualase and the phacoemulsification procedure (p = 0.008). Conclusion: Endothelial cell loss by Aqualase technology depends strongly on the nuclear opalescence grade. In low- and medium-density cataracts, Aqualase does not seem to provoke significant endothelial cell loss. Due to very high endothelial loss in hard nuclei, Aqualase is unsuitable for these cataracts.