Intravitreal ranibizumab (Lucentis) in the treatment of retinal angiomatous proliferation (RAP).

BACKGROUND: Retinal angiomatous proliferation (RAP) is a distinct variant of neovascular age-related macular degeneration (AMD). The aim of this study is to evaluate the functional and anatomic outcome after intravitreal ranibizumab (Lucentis) treatment in patients with RAP. METHODS: Prospective study of consecutive patients with newly diagnosed or recurrent RAP treated with intravitreal ranibizumab at the Jules Gonin Eye Hospital between March 2006 and December 2007. Baseline and monthly follow-up visits included best-corrected visual acuity (BCVA), fundus exam and optical coherence tomography. Fluorescein and indocyanine green angiography were performed at baseline and repeated at least every 3 months. RESULTS: Thirty-one eyes of 31 patients were treated with 0.5 mg of intravitreal ranibizumab for RAP between March 2006 and December 2007. The mean age of the patients was 82.6 years (SD:4.9). The mean number of intravitreal injections administered for each patient was 5 (SD: 2.4, range 3 to 12). The mean follow up was 13.4 months (SD: 3, range 10 to 22). The baseline mean logMAR BCVA was 0.72 (SD: 0.45) (decimal equivalent of 0.2). The mean logMAR BCVA was improved significantly (P < 0.0001) at the last follow-up to 0.45, SD: 0.3 (decimal equivalent 0.35). The visual acuity (VA) improved by a mean of 2.7 lines (SD 2.5). Mean baseline central macular thickness (CMT) was 376 microm, and decreased significantly to a mean of 224 microm (P < 0.001) at the last follow-up. Mean reduction of CMT was 152 microm (SD: 58). An average of 81.5% of the total visual improvement and 85% of the total CMT reduction occurred during the first post-operative month after one intravitreal injection of ranibizumab. During follow-up, an RPE tear occurred in one eye (3.2%) of the study group. No injection complications or systemic drug-related side-effects were noted during the follow-up period. CONCLUSIONS: Intravitreal ranibizumab injections appeared to be an effective and safe treatment for RAP, resulting in visual gain and reduction in macular thickness. Further long-term studies to evaluate the efficacy of intravitreal ranibizumab in RAP are warranted

Iron is neurotoxic in retinal detachment and transferrin confers neuroprotection.

In retinal detachment (RD), photoreceptor death and permanent vision loss are caused by neurosensory retina separating from the retinal pigment epithelium because of subretinal fluid (SRF), and successful surgical reattachment is not predictive of total visual recovery. As retinal iron overload exacerbates cell death in retinal diseases, we assessed iron as a predictive marker and therapeutic target for RD. In the vitreous and SRF from patients with RD, we measured increased iron and transferrin (TF) saturation that is correlated with poor visual recovery. In ex vivo and in vivo RD models, iron induces immediate necrosis and delayed apoptosis. We demonstrate that TF decreases both apoptosis and necroptosis induced by RD, and using RNA sequencing, pathways mediating the neuroprotective effects of TF are identified. Since toxic iron accumulates in RD, we propose TF supplementation as an adjunctive therapy to surgery for improving the visual outcomes of patients with RD

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Ischemic ocular syndrome as a complication of mixed central retinal vein and artery occlusion

Mixed retinal vascular occlusions are rare conditions associated with poor visual prognosis. We describe a patient pre- senting a sequential arterial and venous occlusion, leading to ischemic ocular syndrome. History and Signs A 60-year-old diabetic male patient developed unilateral visual loss (CF). Fundus exami- nation revealed a central retinal artery occlusion. After 2 months, he presented a painful eye. Biomicroscopy revealed anterior seg- ment neovascularization, and IOP was 10mmHg. Fundus exami- nation revealed moderate signs of a central retinal vein occlusion. Panretinal photocoagulation was applied. After 4 days, as pain was still present, with mild anterior segment uveitis and normal IOP, an anterior segment fluorescein angiogram was performed, revealing sectorial iris non-perfusion. Therapy and Outcome General examination revealed a severe carotid obstruction. As a previous contralateral endarteriectomy had been complicated leading to a vascular prosthesis, further ipsilateral carotid surgery was not advised. Panretinal photocoagulation led to the abolition of pain and neovascularization. Conclusions This case illustrates the con- tinuum of retinal arterial and venous occlusion with the rare com- plication of an ischemic ocular syndrome

Preretinal partial pressure of oxygen gradients before and after experimental pars plana vitrectomy.

PURPOSE: To evaluate preretinal partial pressure of oxygen (PO2) gradients before and after experimental pars plana vitrectomy. METHODS: Arteriolar, venous, and intervascular preretinal PO2 gradients were recorded in 7 minipigs during slow withdrawal of oxygen-sensitive microelectrodes (10-μm tip diameter) from the vitreoretinal interface to 2 mm into the vitreous cavity. Recordings were repeated after pars plana vitrectomy and balanced salt solution (BSS) intraocular perfusion. RESULTS: Arteriolar, venous, and intervascular preretinal PO2 at the vitreoretinal interface were 62.3 ± 13.8, 22.5 ± 3.3, and 17.0 ± 7.5 mmHg, respectively, before vitrectomy; 97.7 ± 19.9, 40.0 ± 21.9, and 56.3 ± 28.4 mmHg, respectively, immediately after vitrectomy; and 59.0 ± 27.4, 25.2 ± 3.0, and 21.5 ± 4.5 mmHg, respectively, 2½ hours after interruption of BSS perfusion. PO2 2 mm from the vitreoretinal interface was 28.4 ± 3.6 mmHg before vitrectomy; 151.8 ± 4.5 mmHg immediately after vitrectomy; and 34.8 ± 4.1 mmHg 2½ hours after interruption of BSS perfusion. PO2 gradients were still present after vitrectomy, with the same patterns as before vitrectomy. CONCLUSION: Preretinal PO2 gradients are not eliminated after pars plana vitrectomy. During BSS perfusion, vitreous cavity PO2 is very high. Interruption of BSS perfusion evokes progressive equilibration of vitreous cavity PO2 with concomitant progressive return of preretinal PO2 gradients to their previtrectomy patterns. This indicates that preretinal diffusion of oxygen is not altered after vitrectomy. The beneficial effect of vitrectomy in ischemic retinal diseases or macular edema may be related to other mechanisms, such as increased oxygen convection currents or removal of growth factors and cytokines secreted in the vitreous

Effect of acetazolamide on the optic disc oxygenation in miniature pigs.

BACKGROUND: The purpose of our study was to evaluate the variations of the optic disc PO (2) during normoxia and hyperoxia (100 % O (2)), before and after intravenous administration of acetazolamide. MATERIAL AND METHODS: PO (2) measurements were obtained at intervascular areas of the optic disc in 11 anaesthetized miniature pigs using oxygen-sensitive microelectrodes introduced through the vitreous cavity by a micromanipulator. PO (2) was measured continuously during 10 minutes under systemic normoxia and systemic hyperoxia. Oxygen measurements were repeated under these conditions after intravenous injection of acetazolamide (bolus of 500 mg) in 8 animals. RESULTS: In systemic hyperoxia, the optic disc PO (2) increased moderately (DeltaPO (2) = 4.7 +/- 2.5 mmHg; p < 0.001; n = 11) in parallel with systemic PaO (2). Acetazolamide led to a slow and progressive increase in the optic disc PO (2) (DeltaPO (2) = 2.1 +/- 1.7 mmHg; p > 0.1; n = 8 after 10 min, while DeltaPO (2) = 4.3 +/- 3.2 mmHg; p < 0.05; n = 8 after 30 min), in parallel with a slow and progressive increase in systemic PaCO (2). The optic disc PO (2) increased much more significantly after injection of acetazolamide under systemic hyperoxia (DeltaPO (2) = 13.3 +/- 3.1 mmHg; p < 0.001; n = 8). CONCLUSIONS: Systemic hyperoxia alone is not sufficient to increase substantially the optic disc PO (2) in miniature pigs due to a vasoconstrictor effect. Intravenous injection of acetazolamide can increase the optic disc PO (2) progressively, due to a vasodilatory effect of elevated systemic PaCO (2). The association of acetazolamide injection with systemic hyperoxia can further improve the oxygenation of the optic disc

Effect of systemic nitric oxide synthase inhibition on optic disc oxygen partial pressure in normoxia and in hypercapnia.

PURPOSE: To investigate the effect of systemic nitric oxide synthase (NOS) inhibition on optic disc oxygen partial pressure (PO(2)) in normoxia and hypercapnia. METHODS: Intervascular optic disc PO(2) was measured in 12 anesthetized minipigs by using oxygen-sensitive microelectrodes placed 0.1), despite a 21% increase of mean arterial pressure. Optic disc PO(2) increase under hypercapnia was blunted after L-NAME injection (DeltaPO(2) = 0.6 +/- 1.1 mm Hg; 3%; P > 0.1), and this effect was reversible by L-arginine. Moreover, L-NAME reduced the response to carbogen by 29% (DeltaPO(2) = 9.1 +/- 4.4 mm Hg; 49%; P = 0.01 versus before L-NAME). The response to hyperoxia was not affected. CONCLUSIONS: Whereas systemic NOS inhibition did not affect optic disc PO(2) in normoxia, a blunting effect was noted on the CO(2)-induced optic disc PO(2) increase. Nitric oxide appears to mediate the hypercapnic optic disc PO(2) increase