Dagmar Dotrelova

Intravitreal carboplatin concentration and area under concentration versus time curve after intravitreal and periocular delivery.

Purpose. To determine platinum (Pt) concentrations and area under the concentration versus time curve (AUC) of the vitreous humor after periocular or transcorneal intravitreal administration of carboplatin in rabbits. Methods. Eighteen albino rabbits were included in an in vivo experiment. Each animal received a single dose of either 30 mg of carboplatin by periocular injection (POI30 group: n=6) or 15 mg by periocular injection (POI15 group: n=6), or 0.05 mg by transcorneal intravitreal injection (TII group: n=6), respectively, into the right eye. Vitreous humor from the right eyes and plasma samples were collected post dose at 1, 2, 6, 24, 48, 168, and 336 hours or 448 hours, respectively. Flameless atomic absorption spectroscopy was employed to analyze total platinum concentrations in blood and vitreous humor. AUC was calculated using the trapezoidal rule. Results. Pt concentration was mostly <1 mg/L (0–3.15 mg/L) in the vitreous humor samples and ≥2 mg/L (2.33–7.3 mg/L) in the blood samples 1 hour after administration in POI groups. Markedly higher Pt concentrations were found 1 hour after intravitreal (TII) administration (10.285–66.759 mg/L) and decreased below 1 mg/L no less than 168 hours after administration. The mean AUC for Pt in vitreous humor was significantly lower (p=0.0001) after both POI30 and P0I15 administration compared to TII route (8.955 ± 2.464 mg/L/min). Conclusions. These findings proved that intravitreal carboplatin delivery enables the achievement of relatively stable concentrations and AUC of platinum in the rabbit vitreous humor. This moreover suggests that transcorneal intravitreal delivery of carboplatin aiming to treat retinoblastoma vitreous seeding is a promising mode of chemotherapy.

Bilateral retinal detachment in Marfan's syndrome

Purpose Bilateral retinal detachment (RD) in Marfans syndrome (MS) has a typical preoperative, operative, and post-operative course. This study describes symmetry of retinal tears and bilateral RD surgery in five MS patients over a period of 15 years. Methods Six eyes with uncomplicated RD were operated on using the scleral buckling procedure, and four eyes with complicated RD were operated using a pars plana vitrectomy (PPV) and inner retinal tamponade with silicon oil. Results Complete retinal reattachment was achieved in seven eyes. Partial anatomical success with attached macula was achieved in one eye. The surgery failed in two eyes. Final visual acuity was between 0.66 and 0.33 in three eyes, and between 0.25 and 0.1 in five; two eyes had no light perception. Conclusions The course of the bilateral retinal disease highly correlated with the symmetry of retinal defects.

Using corneal confocal microscopy to track changes in the corneal layers of dry eye patients after autologous serum treatment

In vivo corneal confocal microscopy allows the examination of each layer of the cornea in detail and the identification of pathological changes at the cellular level. The purpose of this study was to identify the possible effects of a three‐month treatment with autologous serum eye‐drops in different corneal layers of patients with severe dry eye disease using corneal confocal microscopy.

Nd:YAG laser membranotomy treatment of premacular hemorrhage in two children with hematologic disease.

Purpose Nd:YAG laser membranotomy is considered a safe treatment of premacular hemorrhage (PMH) in adult patients, enabling rapid enhancement of visual functions. For children, however, pars plana vitrectomy (PPV) performed under general anesthesia has been the accepted treatment. In this report, the authors describe Nd:YAG laser membranotomy (LM) in two children with PMH complicated by hematologic disease. Methods Size of lesions was measured in optic disc diameters (DD). The authors performed three openings in the anterior surface of PMH with immediate intravitreal drainage of blood in both patients. Results Rapid enhancement of visual functions was followed. The authors observed no complications in 1 year of follow-up. Conclusions LM may be a safe method of treatment of PMH in children in selected cases.

Higher Total Insulin Dose Has Positive Effect on Corneal Nerve Fibers in DM1 Patients

Purpose Neuropathies are among the most common long-term complications of diabetes mellitus (DM) and good glycemic control is essential in prevention of this complication. DM patients with similar mean glucose levels or HbA1c levels often exhibit differences in glucose variability. We tested for possible associations between parameters of glycemia compensation and corneal sub-basal nerve fiber status. Methods The study included 20 patients with DM type 1 treated using an intensified insulin regimen. The corneas of both eyes were examined using in vivo corneal confocal microscopy. Corneal nerve fiber density (NFD), nerve fiber length (NFL), and nerve branch density (NBD) were evaluated. Possible associations between parameters of glycemia compensation (HbA1c, glycemia SD, and insulin dose), and other clinical factors were analyzed. Results NBD was the highest in those with higher glycemic variability (P = 0.023). HbA1c had a negligible effect on corneal nerve parameters. NFD, NFL, and NBD were statistically significantly higher in those with higher total insulin per kilogram (P = 0.02, P = 0.01, and P = 0.012, respectively). Among other factors, a positive correlation between free thyroxine (fT4) levels and NFD and NBD was also found (P = 0.041 and P = 0.015, respectively). Conclusions Total insulin dose per kilogram may be an important factor influencing nerve fiber status and needs to be considered in future studies of diabetic neuropathy pathophysiology and its progression. Also, more attention must be paid to other possible factors when elucidating the development of diabetic complications.

Treatment of retinal capillary hemangioma using 810 nm infrared laser

AIM Presentation of the efficacy of infrared laser for the treatment of retinal capillary hemangioma (RCH). METHODS The treatment and follow-up of nine eyes (fourteen tumors of different sizes and localizations) in seven patients (five children) with RCH. Infrared diode laser (810 nm) was used for modified transpupillary thermotherapy (TTT) in long exposition mode and power between 200 and 1200 mW with a beam diameter of 2 mm (indirect ophthalmoscope, +28 D or +40 D lens) or 0.5 mm-3 mm (slit-lamp) depending on the diameter and localisation of the hemangioma. RESULTS We achieved complete destruction of the tumor with flat chorioretinal atrophic scar in all cases. Only one tumor regrowth was observed and re-treatment in this case was necessary. Treatment was combined with brachytherapy in a one case. There was one serious complication- total exudative retinal detachment, causing permanent deterioration in visual acuity despite pars plana vitrectomy (PPV). Other complications such as haze and vitreal hemorrhage were transient. The final best corrected visual acuity (BCVA) ranged from 20/20 to counting fingers at 2 feet. CONCLUSION Infrared laser can be considered an acceptable therapeutic option for RCH especially for centrally localized lesions. We believe that the role of this therapy will increase in the future.

Corneal confocal microscopy for vision disturbance after an epithelial abrasion.

Purpose To demonstrate the use of in vivo corneal confocal microscopy to reveal the reason for persistent disturbance of vision after a corneal abrasion. Case Report A 49-year-old man presented with a decrease in visual acuity and monocular diplopia after a traumatic corneal abrasion. Anterior segment optical coherence tomography was not beneficial. In vivo corneal confocal microscopy showed abnormal folding in the basal epithelial layer of the cornea. Based on these findings, a therapeutic abrasion of the affected epithelium was performed. Visual acuity returned to 1.0 after therapeutic abrasion, and overall findings on the eye were within physiological limits. Control corneal confocal microscopic examination confirmed reparation of the structure of epithelial cell layers. Conclusions The in vivo corneal confocal microscopy can reveal corneal pathologic abnormality even in cases where other methods are not beneficial. Alongside other modern methods, it may become an important tool to help locate pathologic abnormality accurately and choose the proper therapeutic strategy.