Pavel Pochop

Cytomegalovirus encephalitis/retinitis in allogeneic haematopoietic stem cell transplant recipient treated successfully with combination of cidofovir and foscarnet.

Abstract:  We report an 18‐yr‐old female patient with repeated CMV reactivations after HSCT treated by several pre‐emptive courses of virostatic therapy. Seven months after HSCT, she developed CMV encephalitis/retinitis. Initial therapy with GCV and hyperimmune globulin failed, and later on GCV‐resistant strain was detected. Continual increase of CMV DNA in peripheral blood led us to combined therapy with CDV and FCV, which was successful and free of severe renal toxicity. To our best knowlegde, this is the first reported case of successful CMV treatment with a combination of CDV and FCV.

An Adsorptive Transfer Technique Coupled with Brdicka Reaction to Reveal the Importance of Metallothionein in Chemotherapy with Platinum Based Cytostatics

The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug.

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.

Topotecan vitreous and plasma levels and retinal toxicity after transcorneal intravitreal delivery in healthy albino rabbits: Alternative retinoblastoma treatment

AIM To determine intravitreal and plasma concentrations and retinal toxicity after transcorneal intravitreal injection of 1 μg and 2 μg of topotecan (Hycamtin). METHOD Twelve healthy albino rabbits were included in this in vivo experiment. Six anesthetized albino rabbits received a single transcorneal intravitreal injection of 1 μg (group A) or 2 μg (group B) of topotecan. Vitreous and blood samples were collected until 168 h. Left eyes were treated with the same volume of saline. Plasma and vitreous levels of topotecan were determined by high-performance liquid chromatography. Area under the plasma concentration time curve (AUC) was calculated using trapezoidal rule. Clinical evidence of toxicity was classified into four grades according to anatomical structures. Electroretinograms (ERGs) were recorded. RESULTS Time to maximum concentration was observed up to 2 h after drug injection in group A whereas up to 1 h in group B. Low levels of topotecan were detected in plasma in both groups and in the vitreous humor of the contralateral eye in group B. Topotecan levels (mean vitreous AUC in group A 2.55 μg/mL.h and in group B 5.338 μg/mL.h) were detectable up to 6 h in both groups. We observed following structural changes in rabbit eyes: corneal vascularization, cataract, hemophthalmus, choroidal edema and focal retinal atrophy. Abnormal ERGs were obtained. CONCLUSION Our findings proved that transcorneal intravitreal administration of 1 μg and 2 μg of topotecan results in potentially cytotoxic intraocular concentrations. More studies are needed to establish the safety of topotecan for retinoblastoma in children.

Early detection of recurrent primary iris stromal cyst using ultrasound biomicroscopy

Primary iris stromal cyst characteristically presents as a smooth, round, translucent mass in the anterior chamber. In small children it tends to grow rapidly and may be confused with intraocular malignancy. Management is difficult, and recurrences are frequent. We report 2 cases of primary iris stromal cyst in which recurrence was detected relatively early using ultrasound biomicroscopy and successfully managed with iridectomy.

Long-term results of pars plana vitrectomy as an anti-inflammatory therapy of pediatric intermediate uveitis resistant to standard medical treatment

Purpose: To evaluate the efficacy of pars plana vitrectomy (PPV) as an anti-inflammatory therapy in pediatric recurrent intermediate uveitis. Methods: A retrospective study evaluated the long-term results of PPV indicated for intermediate uveitis with a mean observation period of 10.3 years (range 7-15.6 years) in 6 children (mean age 8 years, range 6-12 years). Pars plana vitrectomy was performed on 10 eyes in the standard manner and was initiated by vitreous sampling for laboratory examination. Data recorded were perioperative or postoperative vitrectomy complications, anatomic and functional results of PPV, and preoperative and postoperative best-corrected Snellen visual acuity. Results: No perioperative or postoperative complications were observed. Bacteriologic, virologic, mycotic, and cytologic analysis of the vitreous was negative in all tested children. Five eyes were subsequently operated on for posterior subcapsular cataracts. An average preoperative visual acuity of 0.32 improved to an average postoperative visual acuity of 0.8. Conclusions: In the case of systemic immunosuppressive treatment failure in pediatric uveitis, particularly in eyes with cystoid macular edema, we recommend PPV relatively early.

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.