PurposeRetinal photocoagulation and nondamaging laser therapy are used for treatment of macular disorders, without understanding of the response mechanism and with no rationale for dosimetry. To establish a proper titration algorithm, we measured the range of tissue response and damage threshold. We then evaluated safety and efficacy of nondamaging retinal therapy (NRT) based on this algorithm for chronic central serous chorioretinopathy (CSCR) and macular telangiectasia (MacTel).MethodsRetinal response to laser treatment below damage threshold was assessed in pigmented rabbits by expression of the heat shock protein HSP70 and glial fibrillary acidic protein (GFAP). Energy was adjusted relative to visible titration using the Endpoint Management (EpM) algorithm. In clinical studies, 21 eyes with CSCR and 10 eyes with MacTel were treated at 30% EpM energy with high spot density (0.25-diameter spacing). Visual acuity, retinal and choroidal thickness, and subretinal fluid were monitored for 1 year.ResultsAt 25% EpM energy and higher, HSP70 was expressed acutely in RPE, and GFAP upregulation in Müller cells was observed at 1 month. Damage appeared starting at 40% setting. Subretinal fluid resolved completely in 81% and partially in 19% of the CSCR patients, and visual acuity improved by 12 ± 3 letters. Lacunae in the majority of MacTel patients decreased while preserving the retinal thickness, and vision improved by 10 letters.ConclusionsHeat shock protein expression in response to hyperthermia helps define the therapeutic window for NRT. Lack of tissue damage enables high-density treatment to boost clinical efficacy, therapy in the fovea, and retreatments to manage chronic diseases.

Upon degeneration of photoreceptors in the adult retina, interneurons, including bipolar cells, exhibit a plastic response leading to their aberrant rewiring. Photoreceptor reintroduction has been suggested as a potential approach to sight restoration, but the ability of deafferented bipolar cells to establish functional synapses with photoreceptors is poorly understood. Here we use photocoagulation to selectively destroy photoreceptors in adult rabbits while preserving the inner retina. We find that rods and cones shift into the ablation zone over several weeks, reducing the blind spot at scotopic and photopic luminances.

Purpose To evaluate the efficacy and safety of a pars plana Ahmed valve implantation combined with 23-gauge sutureless vitrectomy in the treatment of patients with medically uncontrolled neovascular glaucoma (NVG) in proliferative diabetic retinopathy (PDR). Methods The authors retrospectively reviewed the records of 11 consecutive patients with refractory NVG in PDR who underwent a 23-gauge sutureless vitrectomy combined with pars plana placement of an Ahmed valve implant. Control of intraocular pressure (IOP), pre- and postoperative best-corrected visual acuity and the development of intra- and postoperative complications were evaluated during the follow-up. Results The mean follow-up was 12.2 months (range, 8 to 25 months). Mean preoperative IOP was 35.9 ± 6.3 mmHg and mean postoperative IOP at the last visit was 13.3 ± 3.2 mmHg. Control of IOP (8 to 18 mmHg) was achieved in all patients, but 91% (10 of 11 patients) needed antiglaucoma medication (mean number of medications, 1.2 ± 0.6). Postoperative visual acuity improved in 11 eyes, and the logarithmically to the minimum angle of resolution mean visual acuity in these eyes improved from 1.67 ± 0.61 to 0.96 ± 0.67. The complications that occurred were transient hypotony in one case, transitory hypertension in two cases, and postoperative vitreous hemorrhage which spontaneously cleared in two cases. Conclusions We suggest the combination of 23-gauge pars plana vitrectomy and Ahmed valve implantation is safe and effective in PDR patients with refractory NVG.

ABSTRACT.Purpose: To investigate the changes in the aqueous levels of various cytokines after intravitreal triamcinolone or bevacizumab for branch retinal vein occlusion (BRVO). Methods: Twenty-four eyes with macular oedema associated with BRVO and six eyes of six patients undergoing cataract surgery participated in this study. Each patient with BRVO randomly received an intravitreal injection of either 4 mg triamcinolone or 1.25 mg bevacizumab. Aqueous samples were obtained before and 4 weeks after the intravitreal injection in the BRVO group and before surgery in the control group. Aqueous concentrations of 16 cytokines were measured via multiplex bead assay. Results: Prior to the administration of the drugs, aqueous levels of interleukin (IL)-6, IL-8, IL-17 and vascular endothelial growth factor (VEGF) were significantly higher in the BRVO group than in the control group (p = 0.044, p = 0.013, p < 0.001, and p = 0.008, respectively). Between the control group and the BRVO group, no significant differences were noted between pre-and postinjection best-corrected visual acuity (p = 0.60, p = 0.54) and central foveal thickness (p = 0.47, p = 0.82). In the triamcinolone group, levels of IL-6, IL-17, IP-10, platelet-derived growth factor (PDGF)-AA and VEGF were reduced significantly (p = 0.012, p < 0.001, p < 0.001, p = 0.015, and p < 0.001, respectively). But in bevacizumab group, only VEGF was significantly reduced (p < 0.001). Between the IVTA group and the IVBe group, no significant differences in the changes in VEGF levels were noted (p = 0.06). Conclusion: Triamcinolone injection reduces plural inflammatory cytokines in BRVO, while bevacizumab has no influence on other cytokines as selective anti-VEGF therapy. No differences in the therapeutic effect were noted between an inhibition of plural inflammatory cytokines and an inhibition of VEGF only.

Combined 23-gauge sutureless vitrectomy and clear corneal phacoemulsification in patients with proliferative diabetic retinopathy was safe and effective. It may have not only the known advantages of conventional combined surgery but also additionally those such as faster visual rehabilitation and less conjunctival fibrosis.

Subretinal implantation of multiple photovoltaic arrays via a single retinotomy, followed by their tiling, minimizes the scleral and retinal incisions and provides better fit to the spherical shape of the eye ball, compared to a single, larger module. Such minimally traumatic procedure can be performed with 20-gauge intraocular instruments.

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Intravitreal bevacizumab and subtenon triamcinolone injection reduces the VEGF, MCP-1 and PDGF-AA levels and increases the IL-8 level in the plural cytokine profiles of patients with DME, which might explain the limited therapeutic effect of combination therapy.