Surgical outcomes of florid diabetic retinopathy treated with antivascular endothelial growth factor.

PURPOSE: To evaluate the effectiveness of vitreoretinal surgery combined with antivascular endothelial growth factor therapy to treat florid diabetic retinopathy, a rare and severe form of diabetic retinopathy in young patients. METHODS: Retrospective observational case series including 61 eyes of 45 patients operated on for florid diabetic retinopathy over the past 5 years, with preoperative or intraoperative intravitreal injection of bevacizumab. Cases were classified into three stages of disease severity, according to the extension of the fibrovascular membranes. Main outcome measures were mean change in visual acuity, anatomical outcome, and surgical complications. RESULTS: After a mean follow-up of 20.3 months, the mean visual acuity significantly increased from +1.7 logMAR before surgery to +0.8 logMAR after surgery (P < 0.01). The visual gain was significant in Stages I and II (P < 0.05) but not significant in Stage III. A flat retina without silicone oil was achieved in 84% of eyes. Eight eyes (13%) progressed to neovascular glaucoma and/or phthisis despite repeated surgeries. CONCLUSION: Vitrectomy combined with antivascular endothelial growth factor therapy allows both favorable visual and anatomical outcomes in this rapidly evolving disease. Prognosis remains poor in severe stages, suggesting that the earlier the surgery performed, the better is the visual prognosis.

Long-term in vivo impedance changes of subretinal microelectrodes implanted in dystrophic P23H rats.

Retinal prostheses are being developed to restore vision in blind patients with photoreceptor degeneration. Electrodes arrays were subretinally implanted in transgenic P23H rats with their photoreceptors degenerated. Electrical stability of the implants was evaluated by long-term monitoring of their impedance changes. Electrode impedances were found to increase by two log units over a three weeks period whereas no impedance increase was noted when the implants were located in the vitreous. In case of hemorrhage or major fibrous reactions, the impedance continued to increase steadily. After explantation, it recovered its initial value indicating no deterioration of the implant. Although the glial cell layer at the surface of the subretinal space was slightly larger, no major glial reaction was seen in direct contact to the implant. These results indicate that no functional testing should be considered before at least three weeks post implantation.

Simulations to study spatial extent of stimulation and effect of electrode-tissue gap in subretinal implants.

We present a finite element based simulation and analysis method to describe the spatial extent of stimulation and the effects of electrode-tissue interactions in subretinal prostheses. In particular, we estimate the threshold stimulation current needed to depolarise and evoke action potentials in the ganglion cells to be stimulated at a particular distance from the electrode. This is achieved through the application of a threshold electric field to a spherical neuronal soma model of a retinal ganglion cell under consideration. Threshold stimulation currents and the lateral extent of the stimulation zone were computed for disc microelectrodes in subretinal stimulation mode. Recent evidence indicates a decrease in threshold charge with time following subretinal implantation. Consequently, to explain the variation in threshold stimulation currents, we propose a hypothesis based on an electrode-tissue gap. Threshold stimulation currents and impedances for different electrode-tissue gaps were computed. We validate the hypothesis with our simulation results that the changes in impedance observed with time in vivo can be mainly attributed to the varying distance of the ganglion cells from electrodes due to changes in electrode-tissue gap. Our simulation framework proposes a convenient and practical method applicable for studying different electrode geometries used for retinal stimulation.

Cephalic tetanus from penetrating orbital wound.

Tetanus is a neurologic disorder caused by tetanospasmin, a protein toxin elaborated by Clostridium tetani. Cephalic tetanus is a localized form of the disease causing trismus and dysfunction of cranial nerves. We report the case of a man who presented with facial trauma, complete ophthalmoplegia, exophthalmos, areactive mydriasis, and periorbital hematoma. An orbital CT revealed air bubbles in the right orbital apex. The patient was given a tetanus toxoid booster and antibiotherapy. After extraction of a wooden foreign body, the patient developed right facial nerve palsy, disorders of swallowing, contralateral III cranial nerve palsy, and trismus. Only one case of cephalic tetanus from penetrating orbital wound has been reported in literature 20 years ago. When a patient presents with an orbital wound with ophthalmoplegia and signs of anaerobic infection, cephalic tetanus should be ruled out.

Mitoxantrone therapy for acute posterior multifocal placoid pigment epitheliopathy with cerebral vasculitis.

Purpose. To report favorable outcome of a case of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) associated with cerebral vasculitis after treatment with immunosuppressive therapy by mitoxantrone. Design. Single case report. Method. A 22-year-old man presented with acute isolated bilateral loss of vision revealing APMPPE. Corticosteroid therapy was initiated and visual acuity gradually improved. Seventeen days later, visual function deteriorated again, associated with flu-like syndrome and severe headaches. A relapse of APMPPE was diagnosed, complicated with lymphocytic meningitis and cerebral ischemia. Intravenous therapy with mitoxantrone was performed in combination with methylprednisolone. Results. Headaches disappeared in a few days whereas visual acuity gradually improved and stabilized at 20/40 in the right eye and 20/32 in the left eye. No adverse event was observed. Clinical improvement was confirmed by magnetic resonance imaging. Conclusion. Cerebral vasculitis is the most severe complication of the extraocular manifestations of APMPEE. This diagnosis should be evoked when severe headaches or behavior disorder are associated with APMPEE.

A low-cost and simple imaging technique of the anterior and posterior segments: eye fundus, ciliary bodies, iridocorneal angle.

PURPOSE: The authors recently used topical endoscopy to image the mouse eye fundus. Here, they widened the field of application for this ophthalmologic tool, imaging both the posterior and the anterior eye segments in larger animals commonly encountered in research laboratories and veterinary clinics. METHODS: Pupils were dilated, and local anesthetic and gel were applied to the animal cornea. The endoscopic probe was placed in contact with the cornea of conscious rats, sedated cats and dogs, anesthetized sheep, and nonhuman primates. RESULTS: High-resolution digital images of the eye fundus were obtained in all investigated animals using the endoscopic probe along the eye axis. Arteriovenous filling time was monitored with fluorescein angiography in pigmented rats. The retinal periphery and ciliary bodies could be visualized with the probe placed at an oblique angle. The probe was inclined further to observe the iridocorneal angle such that the pectinate ligaments could be seen at high resolution in cats. The authors used the probe on eyes with retinal detachment, luxation of a cataractous lens, and pigment infiltration in the iridocorneal angle, demonstrating its potential use in eye diseases. CONCLUSIONS: This topical endoscopic technique provides a unique tool for single eye examinations. The authors obtained a circular view of the anterior (iridocorneal angle) and the posterior (fundus) eye segments from all animal species studied. This technique is inexpensive and easy to use. It can be easily moved to the eye of the patient who cannot move to stand in front of classic apparatus, offering new opportunities in ophthalmology.

Panretinal, high-resolution color photography of the mouse fundus.

PURPOSE: To analyze high-resolution color photographs of the mouse fundus. METHODS: A contact fundus camera based on topical endoscopy fundus imaging (TEFI) was built. Fundus photographs of C57 and Balb/c mice obtained by TEFI were qualitatively analyzed. RESULTS: High-resolution digital imaging of the fundus, including the ciliary body, was routinely obtained. The reflectance and contrast of retinal vessels varied significantly with the amount of incident and reflected light and, thus, with the degree of fundus pigmentation. The combination of chromatic and spherical aberration favored blue light imaging, in term of both field and contrast. CONCLUSIONS: TEFI is a small, low-cost system that allows high-resolution color fundus imaging and fluorescein angiography in conscious mice. Panretinal imaging is facilitated by the presence of the large rounded lens. TEFI significantly improves the quality of in vivo photography of retina and ciliary process of mice. Resolution is, however, affected by chromatic aberration, and should be improved by monochromatic imaging.

Fourteen novel OPA1 mutations in autosomal dominant optic atrophy including two de novo mutations in sporadic optic atrophy.

The OPA1 gene, encoding a dynamin-related GTPase that plays a role in mitochondrial biogenesis, is implicated in most cases of autosomal dominant optic atrophy (ADOA). Sixty-nine pathogenic OPA1 mutations have been reported so far. Most of these are truncating mutations located in the GTPase domain coding region (exons 8-16) and at the 3'-end (exons 27-28). We screened 44 patients with typical ADOA using PCR-sequencing. We also tested 20 sporadic cases of bilateral optic atrophy compatible with ADOA. Of the 18 OPA1 mutations found, 14 have never been previously reported. The novel mutations include one nonsense mutation, 3 missense mutations, 6 deletions, one insertion and 3 exon-skipping mutations. Two of these are de novo mutations, which were found in 2 patients with sporadic optic atrophy. The recurrent c.2708_2711delTTAG mutation was found in 2 patients with a severe congenital presentation of the disease. These results suggest that screening for OPA1 gene mutations may be useful for patients with optic atrophy who have no affected relatives, or when the presentation of the disease is atypical as in the case of early onset optic atrophy.