Radiofrequency Heating of the Cornea: An Engineering Review of Electrodes and Applicators

This paper reviews the different applicators and electrodes employed to create localized heating in the cornea by means of the application of radiofrequency (RF) currents. Thermokeratoplasty (TKP) is probably the best known of these techniques and is based on the principle that heating corneal tissue (particularly the central part of the corneal tissue, i.e. the central stroma) causes collagen to shrink, and hence changes the corneal curvature. Firstly, we point out that TKP techniques are a complex challenge from the engineering point of view, due to the fact that it is necessary to create very localized heating in a precise location (central stroma), within a narrow temperature range (from 58 to 76ºC). Secondly, we describe the different applicator designs (i.e. RF electrodes) proposed and tested to date. This review is planned from a technical point of view, i.e. the technical developments are classified and described taking into consideration technical criteria, such as energy delivery mode (monopolar versus bipolar), thermal conditions (dry versus cooled electrodes), lesion pattern (focal versus circular lesions), and application placement (surface versus intrastromal)

Treatment of cytomegalovirus retinitis with intravitreal ganciclovir: a case report

A 60-year-old male on chemotherapy for multiple myeloma developed cytomegalovirus (CMV) retinitis in one eye. He was commenced on intravenous ganciclovir. This regime had to be modified, however, in view of the fact that he had bone marrow neoplasia (multiple myeloma) and was on chemotherapy. Since intravenous ganciclovir causes bone marrow aplasia, this could worsen his clinical state rapidly. He therefore had a ganciclovir implant inserted into his vitreous. This was to prevent the systemic effects of ganciclovir on the bone marrow. This paper highlights the possibility of CMV retinitis in immunocompromised non-AIDS adults, the clinical manifestation of CMV retinitis in non-AIDS immunocompromised patients, and the relative advantage of intravitreal sustained release ganciclovir implants over systemic treatment in selected patients. Nigerian Journal of Ophthalmology Vol. 13(2) 2005: 67-7

Retinal and Choroidal Biopsies

Despite clinical examination, imaging, and laboratory testing, some uveitic or malignant processes may present a diagnostic dilemma. If noninvasive testing fails to provide a diagnosis, tissue biopsy may be considered for establishing the underlying etiology and guiding therapy. Advances in surgical technique and laboratory testing have allowed for safer tissue collection and increased diagnostic yield. This chapter will address the specific surgical techniques used to obtain tissue samples from the vitreous, retina, and choroid. It will also discuss methodologies commonly utilized to evaluate ocular biopsy specimens in clinical practice

Age-specific changes in the prevalence and management of optically correctable visual impairment between 1988 and 2000: the Ponza Eye Study

To obtain age-specific data on changes in the prevalence and management of optically correctable visual impairments (OCVIs) in Ponza, Italy