Artificial vision by direct optic nerve electrode (AV-DONE) implantation in a blind patient with retinitis pigmentosa.

The purpose of this study was to evaluate the efficacy and safety of artificial vision by using a direct optic nerve electrode (AV-DONE) in a blind patient with retinitis pigmentosa (RP). This device, comprising three wire electrodes (0.05 mm in diameter), was implanted into the optic disc of a patient with RP with no light perception vision and the device was left implanted. Six months later, visual sensations were elicited by electrical stimulation through each electrode and the thresholds for the phosphene perception elicited by pulses of 0.25-ms duration/phase and a pulse frequency of 320 Hz were 30, 5, and 70 microA for each electrode. The phosphenes, which ranged in size from that of a match head to an apple, were round, oval, or linear, primarily yellow, and focally distributed. The area of the phosphenes changed when the electrical stimulation was supplied from different electrodes. No complications arose during the follow-up period. Localized visual sensations were produced in a blind patient with advanced RP, suggesting that our system could lead to the development of a useful visual prosthesis system.

Our experience after 1765 intravitreal injections of bevacizumab: the importance of being part of a developing story.

This retrospective report describes our 20 months'experience using intravitreal injections of bevacizumab for the treatment of several retinal diseases. We describe our experience after 1765 intravitreal injections of bevacizumab in the treatment of different proliferative retinopathies - retinopathy of prematurity, choroidal neovascularization, diabetic retinopathy, among others. We believe that the findings reported in this study move us closer to a better treatment for different pathologies. However, further studies need to be performed in order to determine the safety and long-term efficacy of intravitreal bevacizumab either as first line therapy, after failure of conventional therapy, or in combination with conventional therapy.

Intraocular pressure rise during 25-gauge vitrectomy trocar placement.

PURPOSE: Small-gauge vitrectomy has been used to treat various vitreous and macular pathologies. Trocar/cannula insertion may raise intraocular pressure (IOP) to the point it might become detrimental to the eye, especially in the setting of open-globe trauma and eyes with severe vascular compromise. We propose to determine the magnitude of this IOP rise and its possible implications. METHODS: Three different settings were designed to measure IOP rise during trocar placement for 25 ga vitrectomy (TSV); water-column manometry was performed during trocar placement in pig eyes. Electronic applanation tonometry was recorded in human eyes undergoing 25-ga vitrectomy for macular pathology during trocar placement, and wound behavior was recorded during trocar placement in harvested dog eyes with a previously sutured corneal wound. RESULTS: The pressure recorded during trocar placement was 57.5 mmHg in pig eyes and 63.7 mmHg in human eyes. Sutured corneal wounds in dog eyes showed wound leakage and tissue incarceration during trocar insertion. CONCLUSIONS: The 25-ga vitrectomy system may have limited usefulness in the setting of open-eye trauma and compromised bloodflow, due to the elevated pressures reached during trocar placement.

Perfluorocarbon-perfused vitrectomy using a transconjunctival 25-gauge system.

PURPOSE: To describe the feasibility of perfluorocarbon-perfused vitrectomy (PCPV) using a 25-gauge system in complicated retinal detachment cases. METHODS: Thirteen nonconsecutive patients with complicated retinal detachment (either tractional secondary to proliferative diabetic retinopathy or rhegmatogenous) who would not normally be selected for 25-gauge vitrectomy were included in the study. Vitrectomy using 25-gauge ports and perfluorocarbon perfusion was performed. Real vitrectomy time, amount of perfluorocarbon liquid (PCL) used, instrument bending, feasibility of surgical maneuvers using an arbitrary scale, and anatomical and visual results were evaluated. RESULTS: Real vitrectomy time ranged from 6.2 minutes to 17.1 minutes (mean, 10.3 minutes). Amount of PCL ranged from 8 mL to 40 mL (mean, 24.38 mL). Instruments never bent even when using a wide-angle sutured contact lens. All desired maneuvers could be performed and were facilitated by PCL. All retinas were reattached, with two cases of mild recurrent vitreous hemorrhage. Visual acuity improved in 76.9% of eyes. CONCLUSIONS: PCPV using a 25-gauge system can be performed, even in complicated cases.