INTRODUCTION: In some diseases of the cornea, histopathological or microbiological evaluation of a stromal samples is essential. On the other hand one of the main aims in the therapy is to keep the cornea clear and without scars. Until now bioptic techniques were not suitable for both aims, getting a sample with minimal damage of the cornea. There was a lack of a method for corneal biopsy which is clinically easily applicable. MATERIAL: We developed a new instrument for taking corneal biopsies. It is a microtrephine with 160 microns diameter rotating with 30,000 Rpm. It takes biopsies of corneal epithelium and stroma as solid cylinders. The biopsy is non traumatic, safe and repeatable. Biopsies were taken until now on 32 alkali burnt rabbit corneas, 8 enucleated human corneas and 5 patients. RESULTS: 157 biopsies were taken until now. In 75% a sample could be gained. The perforation rate was 0.63% in rabbits. No perforation occurred until now in human corneas. Preparations of light-, scanning- and transmission electron microscopy are presented in this paper for demonstrating examples of application. Microbiological preparations of corneal infiltrates were sterile up to now, representing sterile technique with this new instrument. Herpes simplex PCR was positive in one out of six stromal biopsies from one cornea in supposed herpes keratitis. CONCLUSION: With the microtrephine samples of the corneal stroma can be taken with high precision. A wide variety of routine diagnostics including repeated measurements on stromal samples of a single cornea are possible now. Early bioptic diagnostics of corneal diseases can be achieved now.

Animals↗

PubMedDate not supplied

[Digital fluorescein angiography in follow-up of the clinical course in therapy of patients with central vein occlusion and cystoid macular edema].

BACKGROUND: Fluorescein angiography with a scanning laser ophthalmoscope allows the quantification of morphologic and dynamic changes in the retina. In two patients with central retinal vein occlusion we monitored the progression of the cystoid macular edema (CME) and changes of microcirculation with a follow up of 4 to 6 months. MATERIALS AND METHODS: Two patients with central retinal vein occlusion and CME were examined by means of digital fluorescein angiography. Arteriovenous passage times and macular capillary blood velocities in combination with quantifications of the macular angioarchitecture and the extent of the CME were evaluated. RESULTS: Hemodilution therapy improved retinal circulation, whereas macular circulation and the severity of the CME remained unchanged. With persisting CME oral acetazolamid therapy was initiated. Oral Acetazolamide led to resorption of the cystoid edema in tandem with improved macular circulation. The capillary density was altered but remained unchanged over time. CONCLUSIONS: By means of digital analysis of fluorescein angiograms a detailed monitoring and retinal and macular dynamics, macular morphology is possible. In these two cases CME improved after Acetazolamide and moreover retinal circulation returned to normal conditions.

Acetazolamide↗

PubMedDate not supplied

Interactions between ocular surface fluid and cornea related to contact lenses.

PURPOSE: To improve the quantification of damage to the ocular surface, metabolite levels, electrolyte concentrations, and enzyme activities were assayed in corneal epithelium, stroma and tears. METHODS: In rabbits, rinsing or contact lenses were used to induce microtrauma. For more severe trauma, experimental injuries were induced with 1 N NaOH. Human accidents included epithelial lesions and mild chemical burns. Enzymatic test systems and electron dispersive X-ray analyses (EDXA) were employed. Corneal hydration was assessed by wet and dry weights. Interleukins were analysed with ELISA. RESULTS: In contrast to normal eyes, in ocular surface trauma the interaction between tear fluid and cornea played an important part. After wearing contact lenses or rinsing, glucose and lactate levels in the cornea and in tears increased, and ATP and glycogen in the cornea decreased. After epithelial lesions, N-acetylglucose aminidase (NAcGA, E.C.3.2.1.50) was released into the tears. Epithelial defects alone and--much more--rinsing the denuded stromal surface produced an increase of lactate and glucose in tears and a dramatic fall in Na, Cl, and S levels in the stroma. Rinsing with phosphate induced corneal calcification. IL-1 and IL-6 were increased in human corneal buttons from patients with trauma and inflammation. CONCLUSIONS: Biochemical analyses may be useful to quantify trauma to the ocular surface.

Acetylglucosaminidase↗