Systemic Rho-kinase inhibition using fasudil in mice with oxygen-induced retinopathy.

PURPOSE: To investigate the influence of the selective Rho-kinase (ROCK) inhibitor, fasudil, on the mRNA level of proinflammatory factors and the retinal vascular development in mice with oxygen-induced retinopathy (OIR). METHODS: C57BL/6J mice underwent standard protocol for OIR induction from postnatal days 7 to 12. Subsequently, they received a daily intraperitoneal injection of fasudil or sodium chloride from P12 to P16. Analyses were performed using vascular staining on retinal flat mounts, RNA expression by qPCR, and immunohistochemistry on paraffin sections. RESULTS: On retinal flat mounts, the proportion of avascular area and tuft formation did not differ between the fasudil and NaCl group. Immunohistochemical staining revealed a less intense staining with inflammatory markers after fasudil. Nevertheless, there were no differences on RNA level between the two groups. CONCLUSIONS: In conclusion, our findings support that daily systemic application of fasudil does not decrease retinal neovascularization in rodents with oxygen-induced retinopathy. The results of our study together with the controversial results on the effects of different ROCK inhibitors from the literature makes it apparent that effects of ROCK inhibition are more complex, and further studies are necessary to analyze its potential therapeutic effects.

Inhibition of Placenta Growth Factor Reduces Subretinal Mononuclear Phagocyte Accumulation in Choroidal Neovascularization.

Purpose: The cellular immune response driven by mononuclear phagocytes (MPs) is crucial for choroidal neovascularization (CNV) progression. Case reports show that a switch from pure anti-vascular endothelial growth factor-A (VEGF-A) intravitreal treatment to aflibercept, a drug with combined anti-VEGF-A and anti-placenta growth factor (PlGF) activity, can be beneficial for patients who do not respond to anti-VEGF-A alone. Since MPs harbor VEGFR1, we hypothesize that the interplay of P1GF/vascular endothelial growth factor receptor 1 (VEGFR1) in immune cells plays a pivotal role for CNV. Methods: CNV was induced with laser, and immune cells and neovascularization were analyzed in vivo and ex vivo. Immunohistochemistry was employed for protein detection. Differential expression of angiogenic factors and macrophage polarization markers were assessed by quantitative PCR (qPCR). One day after laser, intravitreal injection of aflibercept or anti-PlGF was performed. Results: In the early inflammatory phase after laser, Plgf but not Vegfa was significantly upregulated. VEGF-A upregulation is limited to the scar, whereas PlGF shows a wider distribution. M1 (proinflammatory) macrophage markers were upregulated in the early phase of CNV. However, M2 (proangiogenic) markers showed more inconsistent dynamics. We demonstrated that both aflibercept and anti-PlGF treatments decrease the overall amount of activated subretinal MPs, and especially of those expressing PlGF. These data correlated with a reduction in leakage associated to CNV. Aflibercept showed a stronger reduction in both parameters. Conclusions: The results hint at an interplay between PlGF/VEGFR1 and MPs that is important in the early phase of CNV. A combined inhibition of VEGF-A and PlGF is superior to a specific anti-PlGF treatment in terms of subretinal MP recruitment.

Intraocular Pressure Measurements After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: Intraocular pressure (IOP) elevation occurs regularly after Descemet membrane endothelial keratoplasty (DMEK). This study evaluated the effect of central corneal thickness (CCT) on the IOP after DMEK. PATIENTS AND METHODS: This prospective study recorded the IOP of 46 eyes from 46 patients preoperatively, and then 1 and 3 months after DMEK. IOP measurement was performed by noncontact pneumatic tonometry (NCT), iCare, Goldmann applanation tonometry (GAT), and dynamic contour tonometry (DCT). CCT was analyzed by anterior-segment optical coherence tomography. RESULTS: Mean IOPs as measured by NCT, iCare, GAT, and DCT, respectively, were 14.3, 11.6, 12.7, and 16.0 mm Hg preoperatively; 13.1, 12.6, 12.7, and 16.0 mm Hg after 1 month; and 14.7, 14.5, 12.9, and 17.7 mm Hg after 3 months. There was a correlation of IOP measurements between GAT and NCT (P=0.119), GAT and iCare (P=0.892), and iCare and NCT (P=0.081) after 1 month and between iCare and NCT (P=0.702) after 3 months. Although GAT recorded approximately stable IOP values, NCT, iCare, and DCT tended to measure a higher IOP postoperatively than preoperatively. Preoperatively, correlations between IOP and CCT were not statistically significant for any measurement technique. After 3 months, the IOP measured by NCT and iCare correlated significantly with CCT (P=0.003, 0.041). CONCLUSIONS: Correlation between the different measurement techniques was poor and showed a broad distribution of limits of agreement. Therefore, a change between the 4 techniques during follow-up is not recommended. Nevertheless, all techniques detected the IOP elevation during follow-up, requiring therapy.

PREDICTORS OF TREATMENT RESPONSE OF VASOPROLIFERATIVE RETINAL TUMORS TO RUTHENIUM-106 BRACHYTHERAPY.

PURPOSE: To identify predictors of treatment response by evaluating long-term outcomes of vasoproliferative retinal tumors after ruthenium-106 brachytherapy. METHODS: In a retrospective case series, 39 eyes of 38 patients with vasoproliferative retinal tumors received ruthenium-106 brachytherapy between 2001 and 2013. Baseline clinical and morphologic parameters were analyzed regarding posttreatment tumor activity status. RESULTS: Within a median follow-up period of 2.9 ± 2.9 years, overall, a tumor inactivation was achieved in 72% of cases and visual acuity remained stable in 69%. The mean apex dose was 90 ± 23 Gy (range, 51-140 Gy). Mean tumor thickness decreased significantly, from 2.9 ± 0.9 mm to 1.5 ± 1.0 mm (P < 0.001; paired t-test). Persistence or recurrence of tumor activity occurred in 28% of cases, requiring secondary intervention with intravitreal drug injections, vitrectomy, cryotherapy, or repeated brachytherapy. Comparison of inactive and active vasoproliferative retinal tumors revealed significant correlation between both initial basal tumour diameter and area and subsequent tumour activity status. In particular, a diameter >7.5 mm was associated with an 8-fold risk of persistent or recurrent activity, whereas basal area >40 mm demonstrated a 6-fold risk (P = 0.009 and 0.021, respectively; Fisher's exact-test). In contrast, tumor thickness was not found to be of prognostic relevance. CONCLUSION: Ruthenium-106 brachytherapy is an effective and safe therapeutic option for vasoproliferative retinal tumors. Additionally, tumor diameter and area are efficient predictors of persistence or recurrence of tumor activity.

Selective spatial attention modulates bottom-up informational masking of speech.

To hear out a conversation against other talkers listeners overcome energetic and informational masking. Largely attributed to top-down processes, information masking has also been demonstrated using unintelligible speech and amplitude-modulated maskers suggesting bottom-up processes. We examined the role of speech-like amplitude modulations in information masking using a spatial masking release paradigm. Separating a target talker from two masker talkers produced a 20 dB improvement in speech reception threshold; 40% of which was attributed to a release from informational masking. When across frequency temporal modulations in the masker talkers are decorrelated the speech is unintelligible, although the within frequency modulation characteristics remains identical. Used as a masker as above, the information masking accounted for 37% of the spatial unmasking seen with this masker. This unintelligible and highly differentiable masker is unlikely to involve top-down processes. These data provides strong evidence of bottom-up masking involving speech-like, within-frequency modulations and that this, presumably low level process, can be modulated by selective spatial attention.