Nonexudative morphologic changes of neovascularization on optical coherence tomography angiography as predictive factors for exudative recurrence in age-related macular degeneration.

PURPOSE: To evaluate morphologic changes of choroidal neovascularization (CNV) on optical coherence tomography angiography (OCTA) during the nonexudative period and to correlate the features and timing of recurrence in neovascular age-related macular degeneration. (AMD). METHODS: Two hundred thirty-eight eyes with type 1 CNV were retrospectively reviewed. For cases with exudative recurrence, OCTA images were tracked for analysis between the recurrences. Qualitative parameters of morphologic changes of CNV on OCTA, including tiny branching vessels, anastomotic loops, peripheral vascular arcade, and perilesional halo, were correlated with the features of exudative recurrence. RESULTS: Exudative recurrence was identified in 163 cases, and among them, nonexudative morphological changes in CNV were identified using OCTA in 45 cases. For the cases with nonexudative changes on OCTA, exudative recurrence eventually developed within 0.5-3.5 months (mean, 2.3 ± 2.0 months) after identifying morphologic changes OCTA. The following changes in CNV were revealed on OCTA: tiny branching vessels in 53.3% (24/45) of cases, anastomotic loops in 40.0% (18/45), peripheral vascular arcades in 44.4% (20/45), and perilesional halo in 35.6% (16/45). Among the morphologic parameters, development of tiny branching vessels was significantly associated with early exudative recurrence (1.5 ± 1.2 months, p = 0.019), higher incidence of intraretinal fluid (IRF) (p = 0.016), and subretinal or subretinal pigment epithelial hemorrhage (p = 0.023) at recurrence, compared with other morphologic changes. CONCLUSION: Development of tiny branching vessels of CNV on OCTA during the nonexudative period was associated with early exudative recurrence, including IRF or hemorrhage. Identifying the nonexudative changes of CNV on OCTA might predict exudative recurrence and provide additional parameters for monitoring neovascular AMD.

Changes in the Ocular Parameters of Patients with Graves' Disease after Antithyroid Drug Treatment.

Background and Objectives: To find the differences in ocular axial length, keratometric measurements, and intraocular lens (IOL) power in patients with Graves' disease (GD) after treatment with a thionamide antithyroid drug (ATD), methimazole. Materials and Methods: The medical charts of 28 patients (4 males and 24 females; mean age: 47.2 ± 21.2 years) were studied. Each patient was examined twice using an IOL Master Device and keratometry at the first visit (before ATD treatment) and after 1 month of ATD treatment. The IOL power was calculated for each patient using the Hoffer Q, SRK-2, and SRK/T formulas according to axial length. Results: After 1 month, the axial length increased (right and left eyes: p < 0.001 and p = 0.05, respectively). Based on keratometry, changes in the horizontal and vertical optical power [in diopters (D)] were not statistically significant. However, the IOL power changed after 1 month of ATD treatment in 64.3% of the patients. In 14 patients (50%), there was a 0.5-1.0 D IOL power decrease in single eyes; in two patients (7.1%), an IOL power decrease of 0.5-1.0 D in both eyes; and in two patients (7.1%), a 0.5 D IOL power increase in single eyes. The calculated IOL power values were lower after ATD treatment (right and left eyes, p = 0.010 and p = 0.018, respectively). Conclusions: The IOL power changed in 64.3% of GD patients after ATD treatment. Therefore, avoiding cataract surgery at the early stage of ATD treatment would be appropriate for selecting a more accurate IOL power.

Progression of macular atrophy in patients undergoing anti-vascular endothelial growth factor therapy for neovascular age-related macular degeneration.

PURPOSE: To assess differences in the progression of macular atrophy (MA) between neovascular age-related macular degeneration (AMD) subtypes and to identify the risk factors associated with the foveal involvement among patients with MA undergoing long-term anti-vascular endothelial growth factor (VEGF) treatment. METHODS: Eighty eyes of 80 patients with neovascular AMD who developed incident MA following anti-VEGF therapy were retrospectively included. Macular atrophy (MA) was quantified using autofluoresence (AF) images within 24 months after the onset of MA, and the enlargement rate was compared between neovascular AMD subtypes. Regression models were constructed to explore relationships between foveal involvement in MA and baseline characteristics. RESULTS: The growth rate of MA was 0.18 mm2 /year for type 1 neovascularization (NV), 0.24 mm2 /year for type 2 NV, and 1.21 mm2 /year for type 3 NV; differences between groups were significant (p = 0.022). Multivariate logistic regression analysis revealed that thin subfoveal choroidal thickness (p = 0.028), presence of subretinal drusenoid deposit (p = 0.005), type 2 or 3 NV (p = 0.023), and geographic atrophy in the fellow eye (p = 0.035) were significant risk factors for MA with foveal involvement. The number of injections showed no significant association with the progression or the foveal involvement in MA. CONCLUSIONS: The progression of MA in patients with neovascular AMD undergoing anti-VEGF treatment differed significantly depending on the subtype of neovascularization. The risk of foveal involvement in MA was associated with the baseline factors or phenotype of neovascular AMD rather than with injection frequency of anti-VEGF.

Effects of Stuffer DNA on the Suppression of Choroidal Neovascularization by a rAAV Expressing a mTOR-Inhibiting shRNA.

Choroidal neovascularization (CNV) is the defining characteristic of the wet subtype of age-related macular degeneration (AMD), which is a rapidly growing global health problem. Previously, we had demonstrated the therapeutic potential of gene therapy against CNV using short hairpin RNA (shRNA) delivered via recombinant adeno-associated virus (rAAV), which abrogates mammalian-to-mechanistic (mTOR) activity in a novel manner by simultaneously inhibiting both mTOR complexes. Both the target and use of gene therapy represent a novel treatment modality against AMD. Here, the xenogeneic GFP gene used as a reporter in previous studies was removed from the virus vector to further develop the therapeutic for clinical trials. Instead, a stuffer DNA derived from the 3' UTR of the human UBE3A gene was used to ensure optimal viral genome size for efficient rAAV assembly. The virus vector containing the stuffer DNA, rAAV2-shmTOR-SD, positively compares to one encoding the shRNA and a GFP expression cassette in terms of reducing CNV in a laser-induced mouse model, as determined by fundus fluorescein angiography. These results were confirmed via immunohistochemistry using anti-CD31, while a TUNEL assay showed that rAAV2-shmTOR-SD possesses anti-apoptotic properties as well. The qualities exhibited by rAAV2-shmTOR-SD demonstrate its potential as a human gene therapeutic for the treatment of wet AMD.

mTORC1 and mTORC2 are differentially engaged in the development of laser-induced CNV.

BACKGROUND: The mechanistic target of rapamycin (mTOR) pathway is a potential target to inhibit pathologic processes in choroidal neovascularization. However, the exact role of mTOR signaling in the development of CNV remains obscure. In this study, we assessed the role of mTORC1 and mTORC2 as well as the effect of rapamycin (sirolimus) on choroidal neovascularization (CNV) in a laser-induced mouse model. METHODS: In experiment A, we observed the natural course of CNV development and the dynamics of mTOR-related proteins during the 12 days after the laser injury. The expression of mTOR-related proteins was evaluated using Western blot (WB). Cryosections of CNV-induced mice were immunostained for the visualization of the vascular and extravascular components of the CNV. Experiment B was performed to confirm the critical period of mTOR signaling in the development of laser-induced CNV, we administered rapamycin before and/or during the active period of mTOR complexes. WB and immunofluorescence staining was performed to evaluate the mode of action and the effect of mTOR inhibition on CNV development. RESULTS: In experiment A, we detected high levels of p-mTOR S2448 and p-mTOR S2481 from the 5th to 12th day of laser injury. Immunofluorescence imaging of cryosections of mice sacrificed on day 7 revealed greater co-immunoreactivity of p-mTOR S2448 positive cells with CD11b and F4/80, while p-mTOR S2481 positive cells showed colocalization with CD31, α-SMA, and cytokeratin. In experiment B, rapamycin injection during the active period of mTOR signaling demonstrated near-complete inhibition of CNV lesion as well as significant induction of autophagy. CONCLUSION: Our study suggests the mTOR as a critical player during CNV development in laser-induced mouse model through differentially acting with the mTORC1 and mTORC2. mTORC1 activity was high predominantly in inflammatory cells in CNV lesion, while mTORC2 activity was higher in vascular components and the RPE.

The role of Wnt/ß-catenin signaling in the restoration of induced pluripotent stem cell-derived retinal pigment epithelium after laser photocoagulation.

To investigate the role of Wnt/ß-catenin signaling pathway in the restoration of induced pluripotent stem cell-derived retinal pigment epithelium (hiPSC-RPE) after laser photocoagulation. After differentiation of RPE cells from hiPSCs, laser photocoagulation was performed. Activation of Wnt/ß-catenin signaling at days 1 and 5 after laser photocoagulation was evaluated by expression of ß-catenin. Cell proliferation and alteration in cell-to-cell contact at day 5 after laser photocoagulation with or without Dickkopf-1 (Dkk-1) treatment were studied using ethynyl-2'-deoxyuridine (EdU) assay and zonula occludens-1 (ZO-1) expression analysis, respectively. The mRNA levels of Wnt genes at day 5 after laser photocoagulation were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Activation of Wnt/ß-catenin signaling at days 1 and 5 after laser photocoagulation was confirmed by ß-catenin accumulation in the cytoplasm and nucleus of hiPSC-RPE. Many EdU-positive cells also expressed ß-catenin, and the number of EdU-positive cells was decreased at day 5 after laser photocoagulation after Dkk-1 treatment, indicating that Wnt/ß-catenin signaling mediated hiPSC-RPE proliferation. ZO-1 expression was not decreased with Dkk-1 treatment at day 5 after laser photocoagulation, indicating that Wnt/ß-catenin signaling mediated hiPSC-RPE restoration. At day 5, after laser photocoagulation, mRNA levels of Wnt2b, Wnt3, Wnt5a, Wnt7a, and Wnt10b were increased. Wnt/ß-catenin signaling has a crucial role in restoration of hiPSC-RPE proliferation after laser photocoagulation. Manipulation of Wnt/ß-catenin signaling while elucidating the underlying mechanisms of RPE restoration might have a therapeutic potential in retinal degenerative diseases.

Transduction Patterns of Adeno-associated Viral Vectors in a Laser-Induced Choroidal Neovascularization Mouse Model.

Adeno-associated virus (AAV) vector is a promising platform technology for ocular gene therapy. Recently clinical successes to treat choroidal neovascularization (CNV) in wet type age-related macular degeneration have been reported. However, because pathologic conditions of the retina may alter the tropism of viral vectors, it is necessary to evaluate the transduction efficiency of different serotypes of AAV vectors in the retinas with CNVs. Here, we show the patterns and efficacy of transduction of AAV2, -5, and -8 vectors in a laser-induced CNV mouse model. C57BL/6J mice were subjected to unilateral laser photocoagulation on the right eye to induce CNV 5 days prior to intravitreal injection of AAV2, -5, and -8 capsids expressing EGFP. Transduction was increased around CNV lesions for all AAV capsid types, and AAV2 resulted in the highest transduction efficiency. In the absence of CNV, the AAV2 vector transduced ganglion and inner nuclear layer (INL) cells, and AAV5 and AAV8 transduced only a small proportion of cells in the retinal ganglion cell layer. CNV increased AAV2 vector expression throughout the retina and in and around CNVs; the transduced cells included retinal ganglion cells, Müller cells, cells from the INL and outer nuclear layer (ONL), photoreceptors, and retinal pigment epithelium (RPE) cells. Inflammatory cells and endothelial cells in CNVs were also transduced by AAV2. AAV5 and AAV8 were transduced in retinal ganglion, Müller, INL, ONL, and RPE cells in a localized pattern, and only endothelial cells at the surface of CNV lesions showed EGFP expression. Taken together, CNV formation resulted in enhanced transduction of AAV2, -5, and -8, and AAV2 exhibited the highest transduction efficiency in cells in CNV lesions.

Adeno-Associated Viral Vector-Mediated mTOR Inhibition by Short Hairpin RNA Suppresses Laser-Induced Choroidal Neovascularization.

Choroidal neovascularization (CNV) is the defining characteristic feature of the wet subtype of age-related macular degeneration (AMD) and may result in irreversible blindness. Based on anti-vascular endothelial growth factor (anti-VEGF), the current therapeutic approaches to CNV are fraught with difficulties, and mammalian target of rapamycin (mTOR) has recently been proposed as a possible therapeutic target, although few studies have been conducted. Here, we show that a recombinant adeno-associated virus-delivered mTOR-inhibiting short hairpin RNA (rAAV-mTOR shRNA), which blocks the activity of both mTOR complex 1 and 2, represents a promising therapeutic approach for the treatment of CNV. Eight-week-old male C57/B6 mice were treated with the short hairpin RNA (shRNA) after generating CNV lesions in the eyes via laser photocoagulation. The recombinant adeno-associated virus (rAAV) delivery vehicle was able to effectively transduce cells in the inner retina, and significantly fewer inflammatory cells and less extensive CNV were observed in the animals treated with rAAV-mTOR shRNA when compared with control- and rAAV-scrambled shRNA-treated groups. Presumably related to the reduction of CNV, increased autophagy was detected in CNV lesions treated with rAAV-mTOR shRNA, whereas significantly fewer apoptotic cells detected in the outer nuclear layer around the CNV indicate that mTOR inhibition may also have neuroprotective effects. Taken together, these results demonstrate the therapeutic potential of mTOR inhibition, resulting from rAAV-mTOR shRNA activity, in the treatment of AMD-related CNV.

A Prospective, Comparative Study of the Pain of Local Anesthesia Using 2% Lidocaine, 2% Lidocaine With Epinephrine, and 2% Lidocaine With Epinephrine-Bupivicaine Mixture for Eyelid Surgery.

PURPOSE: A mixture of 2% lidocaine with epinephrine and bupivacaine was developed to achieve the fast-onset anesthetic effect of lidocaine and the long-lasting effect of bupivacaine. The authors compared pain scores between 2% lidocaine, 2% lidocaine with epinephrine, and 2% lidocaine with epinephrine-bupivicaine mixture during local anesthesia for eyelid surgeries. METHODS: This was a double-blind, randomized, prospective, comparative study. In total, 120 consecutive patients (43 males, 77 females, mean age = 47.2 ± 21.2) who underwent bilateral eyelid surgery under subcutaneous anesthesia were asked to report pain scores for each eye during the first injection of anesthesia. Each patient was randomly assigned to receive 1 of the 3 anesthetic agents in 1 eyelid, and 1 of the remaining 2 agents in the other. RESULTS: The pH values of the 2% lidocaine, 2% lidocaine with epinephrine, and 2% lidocaine with epinephrine-bupivicaine mixture were 6.23 ± 0.21, 4.21 ± 0.37, and 3.87 ± 0.19, respectively. The pain scores of each were 4.3 ± 1.8, 5.1 ± 1.8, and 5.7 ± 1.9, respectively. The 2% lidocaine with epinephrine produced a statistically significantly higher pain score than 2% lidocaine (p = 0.044, generalized estimating equation method). The mixture also showed a significantly higher pain score than 2% lidocaine (p = 0.003, generalized estimating equation method). CONCLUSIONS: Epinephrine seemed to increase subjective pain scores. Compared with 2% lidocaine with epinephrine, 2% lidocaine with epinephrine-bupivicaine mixture was not significantly different in terms of subjective symptoms or pH.