Candida interface keratitis after deep anterior lamellar keratoplasty: Clinical, microbiologic, histopathologic, and confocal microscopic reports

PURPOSE: To report the clinical, histopathologic, microbiologic, and confocal microscopic features of Candida keratitis after deep anterior lamellar keratoplasty (DALK). METHODS: We performed clinical, confocal scan, microbiologic and histopathologic examinations on two corneas from 2 young patients who underwent DALK for keratoconus. RESULTS: The first patient presented with asymptomatic white to cream-colored interface deposits 2 months after DALK. The confocal scan disclosed clusters of hyperreflective, fine granular deposits at the region of interface, with no evidence of inflammation or hyphaelike structures. The clinical presumption of possible "epithelial downgrowth" was suggested, and because of the progression of these lesions, irrigation of the interface was considered. Finally, penetrating keratoplasty was performed because of a rupture in the Descemet membrane. Histopathologic examination of the cornea disclosed yeastlike structures within the interface area. The microbiologic results of the irrigation fluid showed Candida glabrata. The second patient presented with a symptomatic infiltration of the inferior interface close to the suture site 2.5 months after DALK. The confocal scan showed foci of inflammation with clusters of hyperreflective round-shaped structures that resembled epithelial cells. Clinically, there was a suggestion of epithelial downgrowth, and subsequently, penetrating keratoplasty was performed because of the progression of the lesion. Histopathologic examination of the cornea disclosed an acute and chronic granulomatous keratitis caused by yeastlike structures. The microbiologic results revealed infection with Candida albicans. CONCLUSIONS: These are the first reported occurrences of interface Candida keratitis after DALK and with different confocal features. The clinical and the confocal features of interface Candida keratitis may be similar to those seen in epithelial downgrowth, which may postpone correct diagnosis and treatment. Candida keratitis should be considered in cases of interface deposits after any form of lamellar keratoplasty. © 2007 Lippincott Williams & Wilkins, Inc

Gamma irradiation of ocular melanoma and lymphoma cells in the presence of gold nanoparticles: in vitro study

The aim of this work was to determine whether conjugation of cultivated choroidal melanoma and Burkitt's lymphoma cells with gold nanoparticles (GNPs) is beneficial for these series of ocular cancer patients. GNPs are radiosensitizers and can sensitize tumors to radiotherapy.This application has been examined in several tumor types, but not in choroidal melanoma. This study shows the results of in vitro study on the choroidal melanoma and also Burkitt's lymphoma cells in the presence of GNPs during continuous gamma irradiation. Cytotoxicity of GNPs were assessed for five different concentrations then cultured melanoma and Burkitt's lymphoma cells were irradiated with a Gamma source in the presence and absence of NPs. Incubation of melanoma cells with GNP concentrations below 100 μg/ml, accompanied by gamma irradiation, increased cell death (P value = 0.016). In the absence of irradiation, GNPs at these concentrations did not affect cultured melanoma cell metabolism. Reduced cell viability resulted from a significant increase in absorbed energy by the tumor. Moreover, GNP concentrations higher than 200 μg/ml induced cytotoxicity in melanoma cells. Cytotoxicity assay in GNPs-loaded Burkitt's lymphoma cells showed a slight decrease in cell viability at 50 μg/ml and clear cytotoxicity at concentrations higher than 100 μg/ml (P value = 0.035). Concentration and proper injection doses of GNPs in sensitive tissues such as the human eye are important variables yet to be determined.This is the first report of choroidal melanoma dosimetry performed in the presence of GNPs and provides valuable insights into future therapeutic approaches. Further in vitro study with more different sizes and concentrations is needed to determine the optimum size and concentration before any clinical research in this regard. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine

Gamma irradiation of ocular melanoma and lymphoma cells in the presence of gold nanoparticles: in vitro study

The aim of this work was to determine whether conjugation of cultivated choroidal melanoma and Burkitt's lymphoma cells with gold nanoparticles (GNPs) is beneficial for these series of ocular cancer patients. GNPs are radiosensitizers and can sensitize tumors to radiotherapy.This application has been examined in several tumor types, but not in choroidal melanoma. This study shows the results of in vitro study on the choroidal melanoma and also Burkitt's lymphoma cells in the presence of GNPs during continuous gamma irradiation. Cytotoxicity of GNPs were assessed for five different concentrations then cultured melanoma and Burkitt's lymphoma cells were irradiated with a Gamma source in the presence and absence of NPs. Incubation of melanoma cells with GNP concentrations below 100 μg/ml, accompanied by gamma irradiation, increased cell death (P value = 0.016). In the absence of irradiation, GNPs at these concentrations did not affect cultured melanoma cell metabolism. Reduced cell viability resulted from a significant increase in absorbed energy by the tumor. Moreover, GNP concentrations higher than 200 μg/ml induced cytotoxicity in melanoma cells. Cytotoxicity assay in GNPs-loaded Burkitt's lymphoma cells showed a slight decrease in cell viability at 50 μg/ml and clear cytotoxicity at concentrations higher than 100 μg/ml (P value = 0.035). Concentration and proper injection doses of GNPs in sensitive tissues such as the human eye are important variables yet to be determined.This is the first report of choroidal melanoma dosimetry performed in the presence of GNPs and provides valuable insights into future therapeutic approaches. Further in vitro study with more different sizes and concentrations is needed to determine the optimum size and concentration before any clinical research in this regard. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine

Ahram mineral water-induced sulfate keratopathy: Histopathologic, electron microscopic, and confocal scan features

Purpose: To characterize histopathologic, electron microscopic, and confocal scan features of Ahram mineral water (AMW)-induced keratopathy in cadaver corneas. Methods: Seven cadaver globes were examined, 5 of which were exposed to AMW from the corneal side for different durations (30 seconds and 3, 15, 30, and 60 minutes) and the other 2 were considered as control. After performing confocal scan on each cornea, we excised the corneoscleral rim and sent it for histopathologic evaluation. Scanning electron microscopic and transmission electron microscopic examinations were performed on the cornea exposed to AMW for 60 minutes. Results: Depending on the time of exposure, the confocal scan features varied from intraepithelial high-contrast deposits to subepithelial bulla formation. The histopathologic features ranged from diffuse intracytoplasmic sulfur deposits to subepithelial bulla formation. Scanning electron microscopic examination disclosed rather diffuse irregular bright deposits of high sulfur content over the surface epithelium and together with focal cellular destruction and micro-hole formation in the case with 60-minute exposure. On transmission electron microscopy, electron-lucent bulky deposits were found underneath the basal epithelial cells and between their basement membrane and Bowman layer. Confocal scan of the control corneas disclosed nonspecific anterior stromal haze and Descemet folds, with no evidence of intraepithelial deposits. No pathologic finding was noted on histopathologic examination of the control corneas. Conclusions: AMW induces sulfate keratopathy of mainly anterior corneal involvement and with various histopathologic, confocal microscopic, and electron microscopic features even with short-time exposure. © 2008 by Lippincott Williams & Wilkins

Comparison of toluidine blue 1 staining patterns in cytopathologically confirmed ocular surface squamous neoplasias and in non-neoplastic lesions

Purpose: To evaluate the role of toluidine blue (TB) staining patterns in diagnosis of ocular surface squamous neoplasia (OSSN) in comparison to that of impression cytology. Methods: TB 1 dye was applied to different ocular surface lesions, followed by impression cytology (IC). Dye distribution, intensity, and pattern of uptake by the lesion were scored and total score �5 was considered �positive TB staining�. The TB results were then compared with those using IC to determine the presence of cellular atypia. Results: The study enrolled 88 eyes of 82 patients. IC demonstrated cellular atypia in 50 (56.8) cases. Forty-three of 45 �TB-positive� eyes (95.51) had cellular atypia on IC (p < 0.001). Sensitivity and specificity of TB in identifying OSSN were 86 and 94.74, respectively, with positive and negative predictive values of 95.56 and 83.72. TB staining intensity of dark blue and/or mixed types and stippled pattern of TB staining were strongly correlated with dysplastic changes in IC (P � 0.001). TB staining distribution whether in form of diffuse, patchy or scattered eyes with atypia did not significantly differ from those without atypia in IC (P = 0.172). Conclusion: The sensitivity and specificity of TB vital dye in diagnosing OSSN can be increased by focusing on color intensity and a stippled pattern. © 201

Beneficial effects of melatonin and atorvastatin on retinopathy in streptozocin-induced diabetic rats

Objective: The present study was designed to evaluate the effects of Atorvastatin (ATO) plus melatonin (MEL) on streptozocin-induced diabetic retinopathy (DR) in rats. Method: Diabetes was induced in Wistar rats with an intraperitoneal injection of streptozocin (50 mg/kg). Animals were randomly assigned to one of the following groups (8 rats/group): Control group, Diabetic group, Diabetic + MEL group (20 mg/kg/day), Diabetic + ATO group (10 mg/kg/day), Diabetic + MEL + ATO group (as above). Treatments were started one week after induction of diabetes and continued for 7 weeks. At the end of the experiment, angiography was performed and the rats were killed and retinas were harvested for pathological and molecular ex-aminations. Results: Administration of MEL reduced the fluorescein leakage, MDA and ROS levels compared to diabetic group. Treatment with ATO only reduced ROS levels compared to diabetic group. In addition, administration of ATO plus MEL decreased these indices compared to the diabetic and ATO groups. Histologically, retinal vascular congestion was not observed in the combined ATO and MEL group as compared to the diabetic, ATO, and MEL groups. Conclusion: These data provide evidence for the therapeutic value of MEL in combination with ATO in clinical practice for prevention of DR. © 2020 Bentham Science Publishers

Preparation and in vivo evaluation of nanoliposomes containing melphalan after intravitreal injection in albino rabbits

The aim of present study was to evaluate the stability and toxicity of different doses of liposomal melphalan in rabbit eyes and to investigate the pathological and electrophysiological changes after administration of different doses of free form of melphalan. Liposomes containing melphalan were prepared by solvent evaporation method and mean size of these liposomes and encapsulation efficacy of nanoliposomes were determined. In albino rabbits, intravitreal injections of 10, 20, and 40 µg doses of liposomal melphalan and Alkeran® as the commercial product was performed. The rabbits were euthanized at days 2, 7, 14, and 28, and the eyes were enucleated. Vitreous and aqueous samples and electrophysiological recordings were obtained before euthanization. Histological examination was performed after enucleation. Particle size of prepared liposomes was 143.6 ± 3.2 nm. Liposomes have protected melphalan completely from any undesirable release or hydrolysis for 48 h. In a histopathological study, signs of retinal toxicity were found in all doses in the liposomal group at least at one time point during the study. In melphalan injected eyes, histopathological toxicity was found in the 40 µg dose. Extensive variability was found in electrophysiological recordings, and significant waveform changes were found in all injected eyes at least on one occasion during the study. Intraocular administration of liposomal melphalan cannot prolong the drug clearance time of this drug in the vitreous humor. In the 40 µg injected eyes, significant retinal atrophic changes were detected in all eyes throughout the study, and electrophysiological results were consistent with histopathological findings. © 2016, The Korean Society of Pharmaceutical Sciences and Technology

Midterm outcomes of autologous cultivated limbal stem cell transplantation with or without penetrating keratoplasty

Purpose: To report the midterm outcomes of autologous limbal stem cell transplantation cultivated on amniotic membrane (AM) with or without subsequent penetrating keratoplasty (PKP) in patients with total unilateral limbal stem cell deficiency (Lscd). Methods: Eight eyes of 8 consecutive patients with unilateral total LSCD underwent autologous limbal stem cell transplantation cultivated on AM. Four eyes underwent subsequent optical PKP. Main outcome measures were corneal vascularization and transparency. Results: The patients were followed for 34.0 ± 13.5 months (6-48 months). Seven cases had a stable corneal epithelium with marked decrease in opacification and vascularization. Progressive sectorial conjunctivalization was evident in all cases with subsequent PKP at the last follow-up. Primary failure was observed in one case because of exposure. Conclusions: Transplantation of autologous stem cells cultivated on AM with or without subsequent PKP seems to be an effective way for visual rehabilitation in total LSCD. More work with more cases and longer follow-up are needed to optimize this procedure to provide and maintain an adequate supply of limbal stem cells in these patients. Copyright © 2010 by Lippincott Williams & Wilkins