Macular function following intravitreal ranibizumab for macular edema associated with branch retinal vein occlusion: 12-month results.

PURPOSE: To evaluate the 12-month effects of intravitral ranibizumab (IVR) injections on the physiology and morphology of the macula in eyes with a branch retinal vein occlusion with macular edema (BRVOME). METHODS: We studied 13 eyes of 13 patients with a BRVOME. All patients were initially treated with IVR injections at 3 consecutive monthly intervals, the initiation phase. Additional treatments were done according to the pro re nata (PRN) regimen. The physiology of the macula was assessed by the focal macular electroretinograms (fmERGs) and the best-corrected visual acuity (BCVA). The morphology of the macular area was determined by spectral-domain optical coherence tomography. The retina was assessed at the baseline, and at 3, 6, and 12 months after beginning the IVR injections. The fmERGs were elicited by a 15° circular stimulus, and also by 15° semicircular stimuli placed on the occluded or non-occluded side of the macula. The amplitudes of the a- and b-waves, photopic negative response (PhNR), and sums of the oscillatory potentials (ΣOPs) were measured. In addition, the implicit times of the a- and b-waves were measured. RESULTS: The BCVA was improved significantly relative to the baseline after the initiation phase (P < 0.01), and it was maintained with the PRN regimen for the 12-month experimental period. The foveal thickness was also significantly decreased after the initiation phase (P < 0.005) but was then worse at 12 months during the maintenance phase (P < 0.05). The fmERGs on the occluded side were significantly reduced at the baseline, and the b-waves and ΣOPs amplitudes improved after the initiation phase. However, they decreased during the PRN period. On the non-occluded side, the amplitudes and implicit times of the a- and b-waves remained unchanged after the initiation phase, the PhNR and ΣOPs amplitudes significantly increased at 3 months compared to the baseline (PhNR, P < 0.005; ΣOPs, P < 0.005), which was maintained throughout the 12 month study period. CONCLUSIONS: The deterioration of the macular function on the occluded side during the maintenance phase suggests that there is a progression of the disease process during the PRN period in eyes with BRVOME.

Macular function following intravitreal ranibizumab for macular edema associated with branch retinal vein occlusion.

PURPOSE: To determine the physiology of the macula by the focal macular electroretinograms (fmERGs) in patients with branch retinal vein occlusion with macular edema (BRVOME) treated by intravitreal injections of ranibizumab (IVR). METHODS: We studied 17 eyes of 17 patients with BRVOME. The contralateral unaffected eyes served as controls. All patients were treated with an IVR at monthly intervals for 3 consecutive months. The baseline best-corrected visual acuity (BCVA), optical coherence tomographic (OCT) findings, and fmERGs were compared to the post-treatment values. The fmERGs were elicited by a 15° circular spot or a superior or inferior semicircular spot. The center of the spot was placed on the fovea. The amplitudes of the a- and b-waves, photopic negative response (PhNR), and sum of the oscillatory potentials (ΣOPs: sum of OP1, OP2, and OP3 amplitudes) were measured. In addition, the implicit times of the a- and b-waves were also measured. RESULTS: The BCVA improved significantly from 0.39 ± 0.28 logMAR units to 0.17 ± 0.18 logMAR units after the resolution of the central macular edema (P < 0.01). All components of the fmERGs elicited by the semicircular stimulus spot placed on the occluded side were smaller than that elicited from the corresponding area of the control eyes. The b-wave amplitudes increased significantly from 0.49 ± 0.25 to 0.75 ± 0.36 µV following the IVR injections, but the amplitudes of the a-wave and PhNR remained reduced (P < 0.05). The amplitudes of the PhNR and ΣOPs elicited by stimulating the non-occluded side were reduced with relative preservation of the a- and b-waves (P < 0.05). They recovered after the treatment from 0.27 ± 0.15 to 0.50 ± 0.30 and 0.33 ± 0.15 to 0.53 ± 0.19 µV, respectively. CONCLUSIONS: IVRs improved the macular function not only on the occluded side but also on the non-occluded side. On the occluded side, the BRVOME affects the function of all retinal layers of the macula. Even after the IVR, the function of the photoreceptors and retinal ganglion cells remained abnormal. On the non-occluded side, the inner retinal function improved after the IVR.

Association of reduced Connexin 43 expression with retinal vascular lesions in human diabetic retinopathy.

Connexin 43 (Cx43) downregulation promotes apoptosis in retinal vascular cells of diabetic animal models; however, its relevance to human diabetic retinopathy has not been established. In this study, we investigated whether diabetes alters Cx43 expression and promotes retinal vascular lesions in human retinas. Diabetic human eyes (aged 64-94 years) and non-diabetic human eyes (aged 61-90 years) were analyzed in this study. Retinal protein samples and retinal capillary networks were assessed for Cx43 level by Western blot (WB) analysis and immunostaining. In parallel, retinal capillary networks were stained with hematoxylin and periodic acid Schiff to determine the extent of pericyte loss (PL) and acellular capillaries (AC) in these retinas. Cx43 protein expression was significantly reduced in the diabetic retinas compared to non-diabetic retinas as indicated by WB analysis (81 ± 11% of control). Additionally, a significant decrease in the number of Cx43 plaques per unit length of vessel was observed in the diabetic retinas compared to those of non-diabetic retinas (62 ± 10% of control; p < 0.005). Importantly, a strong inverse relationship was noted between Cx43 expression and the relative number of AC (r = -0.89; p < 0.0005), and between Cx43 expression and number of pericyte loss (r = -0.88; p < 0.0005). Overall, these results show that Cx43 expression is reduced in the human diabetic retinas and Cx43 reduction is associated with increased vascular cell death. These findings suggest that diabetes decreases retinal Cx43 expression and that the development of PL and AC is associated with reduced Cx43 expression in human diabetic retinopathy.

Downregulation of Connexin 43 promotes vascular cell loss and excess permeability associated with the development of vascular lesions in the diabetic retina.

PURPOSE: To determine whether downregulation of Connexin 43 (Cx43) expression promotes development of acellular capillaries (ACs), pericyte loss (PL), excess permeability, and retinal thickening in rat retinas. METHODS: Control rats, diabetic rats, and rats intravitreally injected with Cx43 siRNA or scrambled siRNA were used in this study to determine if acute downregulation of Cx43 expression contributes to retinal vascular cell death and excess permeability. Western blot (WB) analysis and Cx43 immunostaining were performed to assess Cx43 protein levels and distribution in the retinal vessels. Concurrently, retinal networks were subjected to terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL) assay and counter-stained to assess the number of apoptotic cells, ACs, and PL. Assessment of fluorescein isothiocyanate-dextran (FITC-dex) extravasation from retinal capillaries and optical coherence tomography (OCT) were performed to determine retinal vascular permeability and retinal thickness, respectively. RESULTS: WB analysis indicated a significant decrease in the Cx43 protein level in the retinas of the diabetic rats and those intravitreally injected with Cx43 siRNA compared to the retinas of the control rats. Likewise, the retinal vascular cells of the diabetic rats and the Cx43 siRNA-treated rats showed a significant decrease in Cx43 immunostaining. Importantly, the number of apoptotic cells, ACs and PL, FITC-dex extravasation, and thickness increased in the retinas of the diabetic and Cx43 siRNA-treated rats compared to those of the control rats. CONCLUSIONS: Results indicate that downregulation of Cx43 expression alone induces vascular cell death and promotes vascular permeability in the retina. These findings suggest that diabetes-induced downregulation of Cx43 participates in promoting retinal vascular lesions associated with diabetic retinopathy (DR).

Background diseases and the number of previous intravitreal aflibercept injections on immediate intraocular pressure increase and vitreous reflux rate in phakic eyes.

AIM: To evaluate the effect of background diseases and number of previous intravitreal aflibercept injections (IVAIs) on immediate intraocular pressure (IOP) increase and vitreous reflux (VR) rate and to evaluate the correlation of both age and axial length with immediate IOP increase and VR rate. METHODS: This study included 105 patients with cystoid macular edema secondary to retinal vein occlusion, 35 patients with diabetic macular edema, 69 patients with neovascular age-related macular degeneration (nAMD), and 12 patients with myopic choroidal neovascularization, which underwent first-time IVAI. The correlation of immediate IOP increase and VR rates with the four background diseases was investigated. Moreover, the correlation of age with immediate IOP increase and VR rate as well as correlation of axial length with immediate IOP increase and VR rate were evaluated. Further, 54 patients with nAMD were treated with IVAI>10 times (multiple IVAIs). Moreover, the correlation of immediate IOP increase and VR rates with first-time and multiple IVAIs in nAMD was determined. RESULTS: The immediate IOP increase (P=0.16) and VR rates (P=0.50) were almost similar among the four background diseases. The immediate postinjection IOP and age, VR rate and age, immediate postinjection IOP and axial length, or VR rate and axial length were not correlated in the four background diseases. The immediate IOP increase (P=0.66) and VR rates (P=0.28) did not significantly differ between first-time and multiple IVAIs in nAMD. CONCLUSION: Background diseases and number of previous IVAIs have no effect on immediate IOP increase and VR rate. Further, age and axial length have no correlation on immediate IOP increase and VR rate.

Reactivation of previously controlled Vogt-Koyanagi-Harada disease more than 46 years following COVID-19 vaccination: a case study.

We report a case of Vogt-Koyanagi-Harada (VKH) disease that recurred 46 years after initial treatment. A 59-year-old woman presented with a 2-month history of bilateral vision blurring. She had received her third dose of coronavirus disease 2019 (COVID-19) vaccination 4 months before the onset of blurring. The best-corrected visual acuity (BCVA) was 1.0 in the right eye and 0.15 in the left eye at the initial visit. Iritis and synechia were observed between the lens and iris bilaterally. A sunset glow fundus was found in both eyes with no serous retinal detachments or disc hyperemia. The patient had a history of VKH disease and had been treated with whole-body corticosteroid administration at another hospital when she was 13 years old. The patient was diagnosed with VKH disease recurrence, and oral corticosteroid therapy and corticosteroid eyedrop treatment were initiated. The treatment response was good. At the time of this writing, recurrence had not been observed for 14 months, and the BCVA was 1.0 in both eyes. To our knowledge, this case represents the longest recorded interval of VKH disease recurrence in the literature to date. COVID-19 vaccination might be the cause of long-term well-controlled disease recurrence.

Effect of the COVID-19 pandemic on Vogt-Koyanagi-Harada disease.

To determine the disease prevalence rate and clinical characteristics of Vogt-Koyanagi-Harada (VKH) disease among new patients before and after the declaration of a state of emergency (April 7, 2020) in Japan. New patients and patients with newly diagnosed VKH disease were categorized into "Before" and "After" groups based on the initial visit. The prevalence rate, sex ratio, and age of patients newly diagnosed with VKH were compared between the groups. Best-corrected visual acuity (BCVA) and recurrence rates were compared among 59 patients observed for > 12 months after receiving pulse steroid therapy. For reference, we also examined the prevalence rate of patients newly diagnosed with acute angle closure (AAC) in the Before and After groups. The prevalence rates of VKH disease among newly diagnosed patients (P < 0.05) or patients with AAC (P < 0.001) were significantly higher in the After group. No significant differences in sex ratio or age of VKH disease were observed in both groups. BCVA and recurrence rates showed no significant differences. The COVID-19 pandemic increased the prevalence of VKH disease among new patients compared with that of AAC. However, the clinical features of VKH disease were unlikely affected by the COVID-19 pandemic.

Possible association between vaccination against SARS-CoV-2 and recurrence of macular edema due to branch retinal vein occlusion: a case report.

We herein describe a patient who developed recurrence of macular edema (ME) due to branch retinal vein occlusion (BRVO) 3 days after administration of the BNT162b2 vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A man in his early 50s visited our hospital because of vision loss in his right eye. His logarithmic best-corrected visual acuity (BCVA) was -0.79 in both eyes. ME due to superior temporal BRVO was observed in his right eye, and the central foveal thickness (CFT) was 486 µm. The patient was treated with an intravitreal aflibercept injection with logarithmic BCVA of -0.79, leading to resolution of the ME with a CFT of 299 µm. Three months after the initial visit, he received a fourth dose of an mRNA vaccine. Three days later, he developed vision loss in his right eye. Although the logarithmic BCVA was maintained at -0.79, ME recurred with a CFT of 507 µm. The patient was treated with an additional dose of intravitreal aflibercept injection. The ME resolved and the logarithmic BCVA in the right eye was maintained at -0.79. This case indicates a possible association between vaccination against SARS-CoV-2 and recurrence of ME due to BRVO.

Intravitreal Fasudil for Treatment of Diabetic Macular Edema with an Unfavorable Response.

PURPOSE: This study evaluates the effect of intravitreal injection of a Rho-associated protein kinase (ROCK) inhibitor, fasudil, on diabetic macular edema (DME) with an unfavorable response. METHODS: This study included 14 eyes of 13 patients (mean age: 65.7 ± 5.2 years) with DME, and eligible eyes underwent single intravitreal injection of 0.025 mg fasudil. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), and central macular thickness (CMT) were evaluated before and 1, 2, and 3 months after treatment. The standard automated perimetry (SAP) results and maximal response of the electroretinogram (ERG) were recorded before and 3 months after treatment. RESULTS: The BCVA, IOP, and CMT remained unchanged during the study period. Similarly, the mean deviation obtained by SAP and each ERG parameter did not show significant changes after the treatment. CONCLUSIONS: Although single intravitreal fasudil injection failed to show therapeutic benefits in DME, it seemed to have no negative effect on the retina.

Chronological changes of the anterior chamber structure, axial length, and refraction in patients with Vogt-Koyanagi-Harada disease.

PURPOSE: To clarify the chronological changes in the anterior chamber structure and identify the spherical equivalent and axial length to assess the effects of steroid pulse treatment in patients with Vogt-Koyanagi-Harada disease with active uveitis. METHODS: The anterior chamber condition, including anterior chamber volume, central anterior chamber depth, peripheral anterior chamber depth, anterior chamber angle, and pupil diameter, was measured using Pentacam, and axial length was measured using IOLMaster in patients with Vogt-Koyanagi-Harada disease between June 2015 and February 2018. Furthermore, the best-corrected visual acuity, spherical equivalent, and retinal foveola thickness were also analyzed. All patients were treated with steroid pulse. All these factors were compared before and at 1 and 6 months of treatment. RESULTS: Significant changes were observed in the anterior chamber volume, central anterior chamber depth, peripheral anterior chamber depth, anterior chamber angle, axial length, best-corrected visual acuity, spherical equivalent, and retinal foveal thickness before and at 1 and 6 months of steroid pulse treatment (P < 0.001, P < 0.001, P < 0.001, P = 0.0015, P = 0.027, P < 0.001, P = 0.0043, and P < 0.001, respectively). No significant difference was observed in the pupil diameter before and at 1 month and 6 months of steroid pulse treatment (P = 0.11). CONCLUSION: The anterior chamber structure, axial length, best-corrected visual acuity, spherical equivalent, and retinal foveal thickness were dramatically changed by steroid pulse treatment in patients with Vogt-Koyanagi-Harada disease who develop active uveitis. These changes were completed within 1 month.

Vitreous Reflux Frequency and Intraocular Pressure After First-Time Intravitreal Aflibercept Injections: Comparison of 30- and 32-Gauge Needles.

PURPOSE: To compare the effects of 30-gauge versus 32-gauge needles on vitreous reflux (VR) frequency and intraocular pressure (IOP) following first-time intravitreal aflibercept injections. MATERIALS AND METHODS: Overall, 116 patients (116 eyes) who received intravitreal injections using 30-gauge needles and 104 patients (104 eyes) who received the same injection using 32-gauge needles were reviewed. The medical records of 116 patients who each received an intravitreal injection using a 30-gauge needle (median age: 67.5 ± 13.9 years) and 104 patients who each received the same injection using a 32-gauge needle (median age: 66. 3 ± 10.6 years) from January 2015 to June 2019 were compared. RESULTS: No significant difference in the frequency of VR was observed between patients injected using 30-gauge needles (38/116) and patients injected using 32-gauge needles (31/104, P = 0.64). There were no significant differences in the VR rates of patients with phakic and pseudophakic eyes between those injected using 30-gauge (P = 0.94) or 32-gauge needles (P = 0.77). Axial length did not significantly differ between patients with and without VR when injected using 30-gauge (P = 0.89) and with 32-gauge needles (P = 0.69). IOP immediately after injection was significantly higher in patients injected using 30-gauge needles than in patients injected using 32-gauge needles (P < 0.01). CONCLUSION: VR frequency was not correlated with needle size, lens status, or axial length. Patients receiving injections using 30-gauge needles had higher IOP immediately after intravitreal injection.

Effect of intravitreal aflibercept on corneal endothelial cells: a 6-month follow-up study.

PURPOSE: To determine the effect of intravitreal aflibercept injection on the corneal endothelium in patients with diabetic or cystoid macular edema caused by retinal vein occlusion. MATERIAL AND METHODS: Forty-six eyes of 44 consecutive patients (27 men, 17 women; age range: 55-88 years) were evaluated. All participants initially received a single intravitreal injection of aflibercept (2 mg in 0.05 mL), followed by pro re nata use and underwent central corneal specular microscopy before the injection and at 1, 3 and 6 months after the first injection during a 6-month follow-up period. The endothelial cell density (ECD), average cell size (AVG), standard deviation of cell size (SD), coefficient of variation of cell size (CoV), maximum of cell size (MAX), minimum of cell size (MIN) and percentage of hexagonal cells (Hex%) were analyzed and the central corneal thickness (CCT) was measured. RESULTS: No significant differences in the ECD, AVG, SD, CoV, MIN, Hex% and CCT were observed between measurements obtained before and 1, 3 and 6 months after the first injection. However, the MAX measured before injection differed significantly from the values measured at 1, 3 and 6 months after the first injection (P=0.033). An average of 1.43±0.58 intravitreal aflibercept injections were administered per patient. CONCLUSION: These study findings indicate that the intravitreal administration of aflibercept (2 mg) might very slightly alter the corneal endothelium within 6 months of the first injection.

Identification of eyes at risk of acute primary angle-closure in elderly Japanese patients.

Purpose: To identify from the anterior segment the structural variables of the eyes that can be used to distinguish acute primary angle-closure (APAC) eyes or primary angle-closure suspect (PACS) eyes from normal eyes. Patients and methods: We used a Pentacam scanner to measure participants' anterior eye segments. We assessed each anterior segment structure variable on the basis of receiver operating characteristic curves using the area under the curve (AUC). Results: AUCs for eyes in men with APAC were 1.000 for central anterior chamber depth (ACD), 0.982 for peripheral ACD, 0.916 for anterior chamber angle (ACA), and 0.992 for anterior chamber volume (ACV). AUCs for eyes in women with APAC were 0.997 for central ACD, 0.942 for peripheral ACD, 0.922 for ACA, and 0.946 for ACV. AUCs for eyes in men with PACS were 0.933 for central ACD, 0.930 for peripheral ACD, 0.887 for ACA, and 0.937 for ACV. AUCs for eyes in women with PACS were 0.960 for central ACD, 0.957 for peripheral ACD, 0.937 for ACA, and 0.937 for ACV. The negative predictive values (%) in men with APAC were 100 for all the four variables (central ACD, peripheral ACD, ACA, and ACV). The negative predictive values (%) in women with APAC were 100 for central ACD, 98.7 for peripheral ACD, 97.1 for ACA, and 97.9 for ACV. The negative predictive values (%) in men with PACS were 98.6 for central ACD, 100 for peripheral ACD, 98.5 for ACA, and 99.4 for ACV. The negative predictive values (%) in women with PACS were 100 for central ACD, 98.7 for peripheral ACD, 97.1 for ACA, and 97.9 for ACV. Conclusions: The central ACD, peripheral ACD, ACA, and ACV measurements seem to be excellent markers to identify eyes without APAC or PACS.

Wasp sting of the cornea.

PURPOSE: Many treatments, such as conservative management or penetrating keratoplasty, exist for corneal wasp sting. Here, we report a case of paper wasp sting of the cornea treated by anterior chamber wash immediately following admission, which soon resolved the inflammation. CASE: A healthy 9-year-old boy who had been stung by a paper wasp on his left eye 2 days prior to presentation at Dokkyo Medical University Saitama Medical Center was found to have corneal opacity accompanied by ciliary injection. The boy had difficulty opening his left eye due to pain. His left corneal endothelial cell density was 2,789 cells/mm2, which was relatively lesser than that in the right eye. We diagnosed a paper wasp sting of the cornea based on both the patient's clinical findings and sting history. The anterior chamber was promptly irrigated using a balanced salt solution; the inflammation resolved in a few hours, and the patient could open his left eye easily the following day. One day after the operation, the visual acuity improved to 1.2, and only slight corneal opacity remained at the original wasp sting site. CONCLUSION: The positive outcome of the current case suggested that anterior chamber irrigation leads to rapid resolution of the inflammation.

Refractive changes after lens-sparing vitrectomy for macular hole and epiretinal membrane.

PURPOSE: Cataract progression after lens-sparing vitrectomy might differ according to original posterior segment diseases. Our objective was to analyze the refractive values after lens-sparing vitrectomy for macular hole (MH) and epiretinal membrane (ERM). MATERIALS AND METHODS: We reviewed the medical records of 25 MH patients (25 eyes) and 23 ERM patients (23 eyes) who underwent lens-sparing vitrectomy. Refractive changes in both groups were compared. All patients underwent 20-gauge three-port pars plana vitrectomy. Fluid-air exchange was performed during vitrectomy only in the MH group. The results were analyzed using the unpaired t-test, chi-square test, or Fisher exact probability test, and multivariate analysis. RESULTS: There were no significant differences in the patient's age (P=0.45). The myopia progression rate (D/month) was higher in the MH group after surgery than that in the ERM group (P=0.035). MH group had more females (P=0.043), longer surgical time (P<0.001), and higher frequencies of surgical adjuvants use (triamcinolone acetonide, P=0.019; brilliant blue G, P<0.001). The myopia progression rate in the MH group (R=0.568, P<0.001) correlated with female gender. However, no correlation was observed between longer surgical time and the use of surgical adjuvants. CONCLUSION: The rate of myopia progression was higher in the MH group. Fluid-air exchange and gender may affect the rate of myopia progression.

High Glucose Induces Mitochondrial Dysfunction in Retinal Müller Cells: Implications for Diabetic Retinopathy.

Purpose: To investigate whether high glucose (HG) induces mitochondrial dysfunction and promotes apoptosis in retinal Müller cells. Methods: Rat retinal Müller cells (rMC-1) grown in normal (N) or HG (30 mM glucose) medium for 7 days were subjected to MitoTracker Red staining to identify the mitochondrial network. Digital images of mitochondria were captured in live cells under confocal microscopy and analyzed for mitochondrial morphology changes based on form factor (FF) and aspect ratio (AR) values. Mitochondrial metabolic function was assessed by measuring oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using a bioenergetic analyzer. Cells undergoing apoptosis were identified by differential dye staining and TUNEL assay, and cytochrome c levels were assessed by Western blot analysis. Results: Cells grown in HG exhibited significantly increased mitochondrial fragmentation compared to those grown in N medium (FF = 1.7 ± 0.1 vs. 2.3 ± 0.1; AR = 2.1 ± 0.1 vs. 2.5 ± 0.2; P < 0.01). OCR and ECAR were significantly reduced in cells grown in HG medium compared to those grown in N medium (steady state: 75% ± 20% of control, P < 0.02; 64% ± 22% of control, P < 0.02, respectively). These cells also exhibited a significant increase (∼2-fold) in the number of apoptotic cells compared to those grown in N medium (P < 0.01), with a concomitant increase in cytochrome c levels (247% ± 94% of control, P < 0.05). Conclusions: Findings indicate that HG-induced mitochondrial morphology changes and subsequent mitochondrial dysfunction may contribute to retinal Müller cell loss associated with diabetic retinopathy.

Vitrectomy in patients over 90 years of age.

PURPOSE: The aim of this study was to evaluate vitrectomy procedures performed in patients over 90 years of age at the Dokkyo Medical University Koshigaya Hospital (Koshigaya, Japan). PATIENTS AND METHODS: Vitrectomies were performed in nine eyes of nine patients who were over 90 years of age between May 2010 and March 2015. Factors such as the underlying vitreoretinal disease, preoperative and postoperative best-corrected visual acuity (BCVA), surgical time, postoperative body position, need for a second surgery, systemic disease, and intraoperative changes in systemic conditions have been evaluated. RESULTS: The most common cause of the underlying vitreoretinal disease was vitreous hemorrhage derived from age-related macular degeneration and posterior dislocation of the lens secondary to a posterior capsular rupture (two cases each). The mean values for the logarithm of the minimum angle of resolution BCVA were 2.15 preoperatively and 1.46 postoperatively (P=0.020, Wilcoxon signed-rank test). The mean surgical time was 109 minutes. Prone position was needed in two cases, and no second surgeries were needed. The most common cause of systemic disease was hypertension, which was found in six cases. Transient hypertension was found in two cases during surgery, and these patients were treated using intravenous calcium blocker injections. CONCLUSION: Patients over 90 years of age who underwent vitrectomy procedures did not have serious problems, except transient hypertension during surgery. The BCVA significantly improved. These results indicated that vitrectomies could be performed successfully in patients over 90 years of age.

High glucose alters Cx43 expression and gap junction intercellular communication in retinal Müller cells: promotes Müller cell and pericyte apoptosis.

PURPOSE: To investigate whether high glucose (HG) alters connexin 43 (Cx43) expression and gap junction intercellular communication (GJIC) activity in retinal Müller cells, and promotes Müller cell and pericyte loss. METHODS: Retinal Müller cells (rMC-1) and cocultures of rMC-1 and retinal pericytes were grown in normal (N) or HG (30 mM glucose) medium. Additionally, rMC-1 transfected with Cx43 small interfering RNA (siRNA) were grown as cocultures with pericytes, and rMC-1 transfected with Cx43 plasmid were grown in HG. Expression of Cx43 was determined by Western blotting and immunostaining and GJIC was assessed by scrape-loading dye transfer (SLDT) technique. Apoptosis was analyzed by TUNEL or differential staining assay, and Akt activation by assessing Akt phosphorylation. RESULTS: In monocultures of rMC-1 and cocultures of rMC-1 and pericytes, Cx43 protein level, number of Cx43 plaques, GJIC, and Akt phosphorylation were significantly reduced in HG medium. Number of TUNEL-positive cells was also significantly increased in rMC-1 monocultures and in rMC-1 and pericyte cocultures grown in HG medium. Importantly, when rMC-1 transfected with Cx43 siRNA were grown as cocultures with pericytes, a significant decrease in GJIC, and increase in TUNEL-positive cells was observed, concomitant with decreased Akt phosphorylation. Upregulation of Cx43 rescued rMC-1 from HG-induced apoptosis. CONCLUSIONS: Gap junction communication between Müller cells and pericytes is essential for their survival. Downregulation of Cx43 that is HG induced and impairment of GJIC activity in Müller cells contributes to loss of glial and vascular cells associated with the pathogenesis of diabetic retinopathy.

Downregulation of mitochondrial connexin 43 by high glucose triggers mitochondrial shape change and cytochrome C release in retinal endothelial cells.

PURPOSE: To determine connexin 43 (Cx43) localization in mitochondria and investigate the effects of high glucose (HG) on mitochondrial Cx43 (mtCx43) expression and whether altered mtCx43 channel activity is involved in promoting apoptosis in retinal endothelial cells. METHODS: MtCx43 localization was determined using immunostaining, green fluorescent protein (GFP)-tagged Cx43 followed by confocal imaging, and Western blot analysis using protein isolated from mitochondria of rat retinal endothelial cells (RRECs). To assess HG effects on mtCx43 expression, RRECs were grown in normal (5 mM) or HG (30 mM) medium for 7 days, and mtCx43 protein level assessed by Western blot analysis. To determine if mtCx43 channel inhibition affected mitochondrial morphology, RRECs grown sparsely were left untreated or treated with ß-glycerrhetinic acid (ß-GA), an inhibitor of connexin channels, and imaged using confocal microscopy. Additionally, mitochondria isolated from RRECs were treated with ß-GA, and cytochrome c release assessed by Western blot. RESULTS: Cx43 localization on the mitochondria of RRECs was confirmed with immunofluorescence staining using Cx43 antibody and GFP-tagged Cx43 imaged in live cells. Western blot analysis indicated that Cx43 was located primarily on the inner mitochondrial membrane, and mtCx43 protein level was significantly reduced in RRECs grown in HG condition. Treatment of RRECs with ß-GA significantly decreased mtCx43 phosphorylation, induced mitochondrial fragmentation, and isolated mitochondria treated with ß-GA showed increased cytochrome c release. CONCLUSIONS: HG-induced downregulation of mtCx43 protein resulting in decreased channel activity may promote mitochondrial morphology changes and cytochrome c release, suggesting a novel mechanism for hyperglycemia-induced apoptosis in diabetic retinopathy.