BACKGROUND AND OBJECTIVE: To compare macular thickness measurements and segmentation error rates between Stratus optical coherence tomography (OCT) (Carl Zeiss Meditec, Inc., Dublin, CA), and Fourier-domain OCT (RTVue, Optovue, Inc., Fremont, CA). PATIENTS AND METHODS: A retrospective study was performed of 93 normal and pathologic eyes from 79 subjects imaged with both OCT instruments on the same day. Both the macular thickness measurement for each Early Treatment Diabetic Retinopathy Study (ETDRS) zone and the incidence of segmentation error in the central macula between the two instruments were compared. RESULTS: Macular thickness measurements for all nine ETDRS zones were higher with RTVue compared with Stratus OCT ( P < .01). Linear regression analysis showed the highest correlation in the central macula (R 2 = 0.88), with progressively lower correlation peripherally. The overall segmentation error rate was 29% with Stratus OCT versus 32% with RTVue ( P > .05). CONCLUSION: Macular thickness measurement was greater with RTVue than with Stratus OCT in all ETDRS areas, with the best correlation seen in the central macula. No difference in segmentation error rate was noted between the two instruments. [Ophthalmic Surg Lasers Imaging 2010;41:301–310.]
To investigate the safety and tolerability of ranibizumab combined with proton beam irradiation in treating exudative age-related macular degeneration.Six eyes (6 subjects) with exudative age-related macular degeneration (4 newly diagnosed; 2 previous treated with ranibizumab) were treated with 4 monthly ranibizumab and 24 GyE proton beam irradiation (2 fractions, 24 hours apart) and seen monthly thereafter and retreated with ranibizumab for decrease in best-corrected visual acuity of ≥2 lines, new macular hemorrhage or fluid noted on optical coherence tomography.Follow-up ranged from 12 months to 36 months (mean, 28 months). Baseline best-corrected visual acuity ranged from 20/40 to 20/250. Final best-corrected visual acuity ranged from 20/25 to 20/400. No radiation retinopathy was noted in any eye. Calculated radiation distribution dose curves indicate that ≤10% of retina received ≥90% of radiation dose in all eyes. Two subjects lost ≥3 lines of best-corrected visual acuity during follow-up, 1 subject in both eyes from enlarging geographic atrophy and the other from worsening fibrovascular pigment epithelial detachment, which was refractory to multiple ranibizumab treatments before enrollment. Among 4 eyes with newly diagnosed exudative age-related macular degeneration, 3 had no fluid on optical coherence tomography at month 12 without further treatment.No safety concerns were noted after 3 years in eyes with exudative age-related macular degeneration treated with ranibizumab combined with proton beam irradiation in this small pilot study. A larger randomized prospective study is under way to further evaluate this combination therapy.
Importance Retinal vein occlusion is the second most common retinal vascular disease. Bevacizumab was demonstrated in the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2) to be noninferior to aflibercept with respect to visual acuity in study participants with macular edema due to central retinal vein occlusion (CRVO) or hemiretinal vein occlusion (HRVO) following 6 months of therapy. In this study, the cost-utility of bevacizumab vs aflibercept for treatment of CRVO is evaluated. Objective To investigate the relative cost-effectiveness of bevacizumab vs aflibercept for treatment of macular edema associated with CRVO or HRVO. Design, Setting, and Participants This economic evaluation study used a microsimulation cohort of patients with clinical and demographic characteristics similar to those of SCORE2 participants and a Markov process. Parameters were estimated and validated using a split-sample approach of the SCORE2 population. The simulated cohort included 5000 patients who were evaluated 100 times, each with a different set of characteristics randomly selected based on the SCORE2 trial. SCORE2 data were collected from September 2014 October 2019, and data were analyzed from October 2019 to July 2021. Interventions Bevacizumab (followed by aflibercept among patients with a protocol-defined poor or marginal response to bevacizumab at month 6) vs aflibercept (followed by a dexamethasone implant among patients with a protocol-defined poor or marginal response to aflibercept at month 6). Main Outcomes and Measures Incremental cost-utility ratio. Results The simulation demonstrated that patients treated with aflibercept will have an expected cost $18 127 greater than those treated with bevacizumab in the year following initiation. When coupled with the lack of clinical superiority over bevacizumab (ie, patients treated with bevacizumab had a gain over aflibercept in visual acuity letter score of 4 in the treated eye and 2 in the fellow eye), these results demonstrate that first-line treatment with bevacizumab dominated aflibercept in the simulated cohort of SCORE2 participants. At current price levels, aflibercept would be considered the preferred cost-effective option only if treatment restored the patient to nearly perfect health. Conclusions and Relevance While there will be some patients with CRVO-associated or HRVO-associated macular edema who will benefit from first-line treatment with aflibercept rather than bevacizumab, given the minimal differences in visual acuity outcomes and large cost differences for bevacizumab vs aflibercept, first-line treatment with bevacizumab is cost-effective for this condition.
Normal and asymptomatic feline immunodeficiency virus (FIV)-infected adult cats were inoculated orally with Toxoplasma gondii tissue cysts to assess differences in clinical disease, T. gondii serologic test results, hematologic results, and oocyst shedding. There was no difference between FIV-naive and FIV-infected cats in terms of clinical illness and duration of oocyst shedding following primary exposure. Both groups of cats developed significant decreases in neutrophil counts following primary inoculation with T. gondii; FIV-infected cats that were neutropenic prior to inoculation with T. gondii developed the most profound decreases in neutrophil numbers. Both FIV-naive and FIV-infected cats became lymphopenic during acute T. gondii infection; however, only FIV-naive cats developed lymphocytosis in the recovery stage. FIV-infected cats had lower total CD4+ and higher total CD8+ T-lymphocyte counts than FIV-naive cats prior to inoculation with T. gondii, but changes in these lymphocyte subsets were similar between groups of cats during the first several weeks after inoculation. Toxoplasma gondii infection had neither an ameliorating nor enhancing effect on T-lymphocyte subset abnormalities in FIV-infected cats during acute or chronic infection. Both groups of cats developed comparable levels of T. gondii-specific IgM and IgG antibodies and T. gondii antigen-specific lymphocyte blastogenic responses following primary inoculation. Both groups of cats were fed T. gondii tissue cysts 66 wk following primary exposure and both groups were solidly immune as evidenced by a lack of oocyst shedding and only minor changes in IgM but not IgG antibodies.
Lozano, Virginia; Serrano, Miguel A.; Losada, Maria J.; Perera, Daniel; Armas, Karintia; Medina, Erika; Morse, Lawrence S.; Hubbard, G BakerEditor(s): McDonald, H Richard Author Information
AbstractGamma-glutamyl transpeptidase (GGTP) is a membrane bound enzyme which has an important role in regulation of glutathione and glutamate in the retina. We have used histochemical and colorimetric enzyme assays to localize GGTP in the bovine retina and choroid. Our results demonstrate that (i) GGTP is present in retinal microvessels but not choroidal microvessels. (ii) Retinal microvascular endothelium loses the ability to express GGTP in cultured cells, (iii) GGTP is present in Muller cells, (iv) Isolated and purified rod outer segments contain high levels of GGTP. (v) Retinal pigment epithelial cells (RPE) m vivo and in culture contain GGTP. The findings of this study lend support to the concept that GGTP may be a biochemical marker for cellular systems which are part of specialized diffusion barriers.
