Visual field after anti-vascular endothelial growth factor therapy and laser treatment for retinopathy of prematurity

PURPOSE

To evaluate the visual field after anti-vascular endothelial growth factor (VEGF) therapy and laser treatment for retinopathy of prematurity.

METHOD

Retrospective cohort study. Infants with retinopathy of prematurity treated by anti-VEGF therapy or laser treatment were included in the study. Degrees of visual field in eight directions examined by Goldmann perimeter (intensity, 1000 apostilb; size, V4e = 64 mm2) were compared between the anti-VEGF therapy and laser treatment groups. The visual acuity (VA) and spherical equivalent refraction were also compared between the two groups.

RESULTS

Nine eyes with anti-VEGF therapy and 12 eyes with laser treatment were enrolled in the analysis. The total, upper, nasal upper, nasal, nasal lower, temporal lower, and temporal upper visual fields were significantly wider in the eyes with anti-VEGF therapy than in those with laser treatment (496 vs 416, P = .002; 53 vs 45, P = .008; 56 vs 43, P = .003; 58 vs 39, P < .001; 55 vs 44, P = .01; 72 vs 65, P = .01; and 62 vs 56, P = .03, respectively). The logarithm of the minimum angle of resolution VA tended to be better in the eyes with anti-VEGF therapy than in those with laser treatment (0.01 vs 0.15, P = .06). Eyes with anti-VEGF therapy had significantly lower myopia than those with laser treatment (spherical equivalent refraction: -0.72 vs -5.7, P = .001).

CONCLUSION

Anti-VEGF therapy may provide a wider visual field, better VA, and less myopia compared with laser treatment.

Effects of internal limiting membrane peeling on anatomical and functional outcomes in macula-off rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy: Japan-Retinal Detachment Registry

PURPOSE

To investigate the effects of internal limiting membrane (ILM) peeling on retinal attachment after a single surgery, and on postoperative visual acuity (VA) at 6 months, in eyes with macula-off rhegmatogenous retinal detachment (RRD) complicated by proliferative vitreoretinopathy (PVR).

STUDY DESIGN

Nationwide, multicenter retrospective cohort study.

METHODS

The Japan-RD Registry database was used for analysis of patients who had undergone vitrectomy for macula-off RRD complicated by PVR. Multivariate analysis was performed to detect prognostic factors for retinal attachment after a single surgery and for VA at 6 months postoperatively. Retinal attachment after a single surgery or VA at 6 months postoperatively was the objective variable; ILM peeling, preoperative VA, PVR grade, age, and intraocular pressure were explanatory variables.

RESULTS

Eighty-nine eyes met the inclusion criteria; ILM peeling was performed in 25 eyes (28%). Preoperative VA was significantly associated with retinal attachment, but ILM peeling did not (odds ratios = 2.1 and 1.3, respectively; p = 0.009 and 0.67, respectively). Poor preoperative VA and younger patient age were significantly associated with poor postoperative VA, but ILM peeling was not (β-values = 0.37, -0.008, and 0.15, respectively; p < 0.001, p = 0.02, and p = 0.15, respectively.

CONCLUSIONS

Preoperative VA was a risk factor associated with retinal attachment. Preoperative VA and patient age were risk factors associated with postoperative poor VA. In eyes with macula-off RRD complicated by PVR, ILM peeling did not have a clear beneficial effect on anatomical and functional outcomes, suggesting that it may be unnecessary for eyes with this condition.

Association between treatment for retinopathy of prematurity and blood monocyte counts

PURPOSE

To investigate blood monocyte counts as a risk factor for retinopathy of prematurity (ROP) treatment.

DESIGN

Retrospective cohort study.

METHODS

Infants who underwent ROP screening at Shiga University of Medical Science Hospital between January, 2011 and July, 2021 were included in this study. Screening criteria were a gestational age (GA) < 32 weeks or birth weight (BW) < 1500 g. The week with the largest difference in monocyte counts between the infants with and without type 1 ROP determined based on the effect size. Multivariate logistic regression analysis was applied to investigate whether the monocyte counts constituted an independent risk factor for type 1 ROP. The objective variable was type 1 ROP, and the explanatory variables were GA, BW, infants' infection, and Apgar score at 1 min and monocyte counts in the week with the largest monocyte-counts difference between the with- and without type 1 ROP groups.

RESULTS

In total, 231 infants met the inclusion criteria. The monocyte counts in the fourth week after birth (4w MONO) exhibited the largest difference between infants with and without type 1 ROP. The analysis was performed on 198 infants, excluding 33 infants without 4w MONO data. Thirty-one infants had type 1 ROP, whereas 167 infants did not. BW and 4w MONO were significantly associated with type 1 ROP (odds ratio: 0.52 and 3.9, P < .001 and 0.004, respectively).

CONCLUSIONS

The 4w MONO was an independent risk factor for type 1 ROP and may be useful in follow-up of infants with ROP.

Blood neutrophil-to-lymphocyte ratio as a risk factor in treatment for retinopathy of prematurity

PURPOSE

To investigate the blood neutrophil-to-lymphocyte ratio (NLR) as a risk factor for retinopathy of prematurity (ROP) development or treatment.

METHODS

Retrospective cohort study. Infants who underwent ROP screening at Shiga University of Medical Science Hospital and Omihachiman Community Medical Center between April 2010 and December 2021 were included in this study. Screening criteria were gestational age (GA) < 32 weeks or birth weight (BW) < 1500 g. Multivariate logistic regression analysis was applied to investigate whether the NLR constituted an independent risk factor for ROP development or treatment. The objective variable was ROP development or treatment, and the explanatory variables were GA, BW, NLR, maternal infection or clinical chorioamnionitis and corticosteroid use by the mother. Maternal infection or clinical chorioamnionitis and corticosteroid use by the mother was included in the explanatory variables to adjust for factors affecting the NLR.

RESULTS

In total, 220 infants met the inclusion criteria, of whom 125 developed ROP, whereas 95 infants did not display ROP. GA was significantly associated with ROP development (odds ratio (OR): 0.41, p < 0.001); however, the NLR was not significantly associated with ROP development (OR: 1.0, p = 0.74). Thirty-eight infants received treatment for ROP, whereas 182 infants had no such treatment. BW and the NLR were significantly associated with ROP treatment (OR: 1.6 and 0.66, p < 0.001 and 0.003, respectively).

CONCLUSION

The NLR was not a risk factor for ROP development but was a risk factor for ROP treatment.

Assessment of mouse VEGF neutralization by ranibizumab and aflibercept

PURPOSE

To assess the interaction between ranibizumab, aflibercept, and mouse vascular endothelial growth factor (VEGF), both in vivo and in vitro.

METHODS

In vivo, the effect of intravitreal injection of ranibizumab and aflibercept on oxygen induced retinopathy (OIR) and the effect of multiple intraperitoneal injections of ranibizumab and aflibercept on neonatal mice were assessed. In vitro, the interaction of mouse VEGF-A with aflibercept or ranibizumab as the primary antibody was analyzed by Western blot.

RESULTS

In both experiments using intravitreal injections in OIR mice and multiple intraperitoneal injections in neonatal mice, anti-VEGF effects were observed with aflibercept, but not with ranibizumab. Western blot analysis showed immunoreactive bands for mouse VEGF-A in the aflibercept-probed blot, but not in the ranibizumab-probed blot.

CONCLUSIONS

Aflibercept but not ranibizumab interacts with mouse VEGF, both in vivo and in vitro. When conducting experiments using anti-VEGF drugs in mice, aflibercept is suitable, but ranibizumab is not.

Effect of intravitreal bevacizumab for retinopathy of prematurity on weight gain

Purpose

To evaluate the short-term effect on body weight (BW) gain after intravitreal bevacizumab (IVB) for retinopathy of prematurity (ROP).

Methods

This was a retrospective 1:1 matched case-control study. Infants with ROP treated by IVB or photocoagulation (PC) at Shiga University of Medical Science Hospital between April 2010 and December 2019 were included in the study. To match BWs at treatment between the IVB and PC groups, 1:1 matching for BWs at treatment within 100 g was performed. The BW gains for the 7 days before treatment (pre-treatment week), the 7 days after treatment (first post-treatment week), and the period from 7 to 14 days after treatment (second post-treatment week) were compared between the IVB and PC groups.

Results

Following 1:1 matching, 13 infants in both groups were enrolled in the analysis. The weekly BW gain for the first post-treatment week was significantly lower in the IVB group compared with the PC group (86 g vs. 145 g; P = 0.046), whereas the weekly BW gains for the pre-treatment week (173 g vs. 159 g; P = 0.71) and the second post-treatment week (154 g vs. 152 g; P = 0.73) were comparable between the two groups. The short-term inhibitive effect of IVB on BW gain was particularly observed in infants weighing less than 1500 g at treatment (<1500 g: 47 g vs. ≥1500 g: 132 g; P = 0.03).

Conclusion

IVB could have a short-term inhibitive effect on BW gain in infants with ROP, and this effect is more likely to occur in infants with a lower BW at the time of treatment.

Effect of internal limiting membrane peeling on postoperative visual acuity in macula-off rhegmatogenous retinal detachment

Purpose

To investigate the effects of internal limiting membrane (ILM) peeling on visual acuity (VA) after rhegmatogenous retinal detachment (RRD) surgery.

Methods

This retrospective analysis examined the medical records of patients with RRD who underwent vitrectomy at 26 institutions. To detect prognostic factors of VA at 6 months postoperatively (post-VA), multivariate linear regression was performed with post-VA as the objective variable; ILM peeling, sex, age, preoperative VA (pre-VA), intraocular pressure, axial length, duration of RRD, and cataract surgery served as explanatory variables. Recurrence of RRD and epiretinal membrane formation within 6 months postoperatively were compared between groups of patients with and without ILM peeling, among patients with macula-on and macula-off RRD.

Results

The inclusion criteria were met by 523 eyes with a macula-on RRD and 364 eyes with a macula-off RRD. ILM peeling was performed in 85 eyes with a macula-on RRD and 57 eyes with a macula-off RRD. In eyes with a macula-on RRD, ILM peeling did not affect post-VA (p = 0.72). Vitrectomy without cataract surgery and poor pre-VA were significantly associated with poor post-VA (p = 0.01 and p < 0.001, respectively). In eyes with a macula-off RRD, ILM peeling, long duration of RRD, and poor pre-VA were significantly associated with poor post-VA (p = 0.037, p = 0.007, and p < 0.001, respectively). Recurrence of RRD and epiretinal membrane formation were similar between groups of patients with and without ILM peeling, among patients with macula-on and macula-off RRD. Retina sensitivity was not evaluated by microperimetry.

Conclusion

ILM peeling did not affect post-VA in eyes with a macula-on RRD, whereas post-VA was worse in eyes with ILM peeling than in eyes without peeling, among eyes with a macula-off RRD.

The systemic antiangiogenic effect of intravitreal aflibercept injection in a mouse model of retinopathy of prematurity

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness and intravitreal anti-vascular endothelial growth factor (VEGF) injection is becoming a first-line choice for treatment of ROP. However, there is a major concern that intravitreally injected anti-VEGF agents could escape from the eye into the systemic circulation and impair systemic development. Moreover, escaped anti-VEGF agents could have an effect on the retina of the fellow eye. In this study, we investigated the hematogenous effect of a single intravitreal anti-VEGF injection in a mouse model of ROP. Here, we showed that single intravitreal aflibercept injection to one eye can affect body weight gain, the fellow eye, and renal vessels, although no apparent effect was observed in brain vessels. Furthermore, this hematogenous effect was dose-dependent. Our results provide very important insights into the clinical use of anti-VEGF agents for ROP treatment.

Evaluation of acquired color vision deficiency in retinal vein occlusion using the Rabin cone contrast test

PURPOSE

To investigate acquired color vision deficiency (CVD) using the Rabin cone contrast test (RCCT) in patients with retinal vein occlusion (RVO).

METHODS

We retrospectively evaluated 39 patients with macular edema due to RVO who were treated with intravitreal injections of anti-VEGF agents and demonstrated improvement of best-corrected visual acuity to 20/20 Snellen VA or better. The acquired CVD was evaluated by the RCCT and standard pseudo-isochromatic plates-part 2 (SPP-2).

RESULTS

Mean L, M, and S color contrast test (CCT) scores were significantly lower in RVO eyes than in the fellow eyes (L CCTs, 70.0 ± 13.3 vs. 90.0 ± 8.0, respectively, P < 0.01; M CCTs, 85.0 ± 16.6 vs. 95.0 ± 5.7, respectively, P < 0.01; S CCTs, 80.0 ± 21.5 vs. 95.0 ± 7.1, respectively, P < 0.01). Acquired CVD was diagnosed in 25 eyes of 39 patients by the RCCT and in 15 eyes of 39 patients by SPP-2. The RCCT was performed on two different days in 21 patients. It revealed acquired CVD in 17 eyes on the first day and in 10 eyes on the second day. Acquired CVD was improved in 9 eyes, unchanged in 8 eyes, and worsened in 2 eyes.

CONCLUSIONS

The RCCT revealed eyes with RVO had acquired CVD. Acquired CVD caused by RVO can be improved further in some cases even after recovery of vision to 20/20. The RCCT may be able to quantitatively diagnose acquired CVD status.

An Attachment Including a +20-D Lens to Gain Extended Field Images in Wide-Angle Optical Coherence Tomography Angiography

Purpose:

This article evaluates the clinical usefulness of an attachment involving a +20-D lens to gain extended field images on wide-angle optical coherence tomography angiography (OCTA).

Methods:

An attachment with a +20-D lens was developed to take OCTA images of anterior segments, and it was used to obtain extended field images of the posterior segment in this study. Ten eyes of 5 individuals who did not have a history of ocular or systemic disease underwent wide-angle OCTA with a 12 × 12-mm center field using the PLEX Elite 9000 with and without the attachment. The ratio of the area of the center field to the area of the extended field with the attachment was calculated.

Results:

The mean area of the center image was 125 disc areas and that of the field extended by the attachment was 210 disc areas. The mean ratio between the center field and the extended field was 1.67.

Conclusions:

The attachment involving the +20-D lens seems to be clinically useful to gain extended field images on wide-angle OCTA.

Comparison of Surgical Outcomes Between Two Types of Lamellar Macular Holes

Purpose

The classification of lamellar macular holes (LMHs) into two subtypes has recently been proposed. However, the effectiveness of vitrectomy for treatment of each type of LMH is not well established. The goal of this study was to compare functional and anatomic changes after vitrectomy between eyes with degenerative LMH and those with tractional LMH.

Patients and methods

This was a retrospective analysis of the medical records of patients with LMH who underwent vitrectomy. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were measured preoperatively (baseline), as well as at 1, 3 and 12 months postoperatively. BCVA and CMT were compared between eyes with degenerative LMH and those with tractional LMH.

Results

Thirty-two eyes met the inclusion criteria. Thirteen eyes were diagnosed with degenerative LMH and 19 eyes were diagnosed with tractional LMH. Compared with baseline BCVA, postoperative BCVA improved significantly at 12 months postoperatively: from 0.33 to 0.12 logarithm of the minimum angle of resolution (logMAR) in eyes with degenerative LMH and from 0.30 to 0.12 logMAR in eyes with tractional LMH (p < 0.05 for both comparisons). BCVA at 12 months postoperatively did not significantly differ between the two groups. CMT decreased significantly from 419.4 µm at baseline to 364.2 µm at 12 months postoperatively in eyes with tractional LMH (p < 0.05); conversely, there was no significant difference in eyes with degenerative LMH (315.5 µm baseline to 314.9 µm at 12 months postoperatively; p > 0.05).

Conclusion

Vitrectomy improved BCVA in eyes with degenerative LMH as well as in eyes with tractional LMH. BCVA at 12 months postoperatively did not differ between the two groups.

Vogt-Koyanagi-Harada Disease-Like Uveitis during Nivolumab (Anti-PD-1 Antibody) Treatment for Metastatic Cutaneous Malignant Melanoma

Nivolumab is an anti-programmed cell death protein 1 monoclonal antibody that is used to treat metastatic cutaneous malignant melanoma. Although bilateral uveitis has been reported as a side effect of nivolumab administration, there are few reports of Vogt-Koyanagi-Harada disease (VKH)-like uveitis. We report such a case. A 63-year-old woman with metastatic cutaneous malignant melanoma experienced visual loss in both eyes 10 days after her second nivolumab injection. Her decimal best-corrected visual acuity (BCVA) was 0.7 in the right eye and 0.4 in the left eye. Examination revealed bilateral granulomatous keratic precipitates and posterior synechiae in the left eye. Optical coherence tomography showed multiple sites of serous retinal detachment (SRD) in the left eye and wavy retinal pigment epithelium in both eyes. Fluorescein angiography revealed multiple pinpoint-sized areas of leakage in both eyes and active leakage from the disc in her right eye. Indocyanine green angiography (IA) showed choroidal hyperfluorescence due to choroidal vascular leakage, with hypofluorescent dark spots during the late phase. These findings supported a diagnosis of VKH-like uveitis following nivolumab injections. Nivolumab was discontinued because of headache. Anterior chamber inflammation disappeared 3 weeks after starting topical corticosteroid treatment, and the SRD disappeared within 3 months. Her decimal BCVA recovered to 1.0 in the right eye and to 0.9 in the left eye. Also, the fluorescein angiography and IA findings had improved by 4 months. We concluded that careful follow-up is required after nivolumab treatment because VKH-like panuveitis might develop.

Endophthalmitis Following Exposure of a Haptic After Sutureless Intrascleral Intraocular Lens Fixation

An 88-year-old woman who had undergone sutureless intrascleral fixation of the intraocular lens (IOL) 3 years previously was seen at an eye clinic because of ocular pain and loss of vision 2 days prior to this visit. She was diagnosed with endophthalmitis and referred to our hospital. At her first presentation here, the best-corrected visual acuity (BCVA) was 0.01 in the left eye, and conjunctival hyperemia and hypopyon were apparent. A haptic was exposed outside the conjunctiva at the nasal upper quadrant, with a white substance around the haptic. The fundus was not visible. We diagnosed endophthalmitis. That same day, we performed vitrectomy and IOL removal, immediately followed by intravitreal injection of antibiotic. The inflammation resolved gradually, and at the 1-year follow-up her BCVA had recovered to 0.6. Patients should receive careful, long-term follow-up after sutureless intrascleral IOL fixation.

Comparison between wide-angle OCT angiography and ultra-wide field fluorescein angiography for detecting non-perfusion areas and retinal neovascularization in eyes with diabetic retinopathy

PURPOSE

To compare the ability of wide-angle optical coherence tomography angiography (OCTA) with that of ultra-wide field fluorescein angiography (UWFFA) to detect non-perfusion areas (NPAs) or retinal neovascularization (NV) in eyes with diabetic retinopathy (DR).

METHODS

Patients with DR underwent UWFFA using the Optos® panoramic 200Tx imaging system and wide-angle OCTA with 12 × 12 mm fields of five visual fixations using the PLEX Elite 9000®. We compared the abilities of UWFFA and OCTA to detect NPAs and NV.

RESULTS

Fifty-eight eyes of 33 patients (mean age, 60.0 years old; female/male, 16/17) with DR were evaluated. NPAs were detected in 47 out of 58 eyes using UWFFA and in 48 eyes using OCTA. NVs were detected in 25 out of the 58 eyes using UWFFA and in 26 eyes using OCTA. The sensitivity for detection of NPA using OCTA was 0.98, and the specificity was 0.82. The sensitivity for detection of NV was 1.0, and the specificity was 0.97.

CONCLUSION

The wide-angle OCTA seems to be clinically useful for the detection of NPAs or NV.

Changes in Retinal Thickness after Vitrectomy for Epiretinal Membrane with and without Internal Limiting Membrane Peeling

PURPOSE

To investigate anatomic changes in retinal thickness (RT) and functional changes after vitrectomy for idiopathic epiretinal membranes (ERMs) with and without internal limiting membrane (ILM) peeling.

METHODS

The medical records of 100 eyes of 96 patients with ERM who underwent vitrectomy and ERM removal were reviewed retrospectively. The RT was measured by optical coherence tomography, and the area was divided into 9 sections. The best-corrected visual acuity (BCVA), 9 RT areas, and incidence rates of recurrent ERM were compared between the groups with and without ILM peeling before the operation and 12 months postoperatively.

RESULTS

Thirty-nine eyes that underwent vitrectomy with ILM peeling and 61 eyes that underwent vitrectomy without ILM peeling met the inclusion criteria. There were no significant differences between the groups in the BCVA and any of the RTs before the operation and 12 months postoperatively. The ERMs recurred in 8 (20.5%) of 39 eyes and 26 (42.6%) of 61 eyes in the groups with and without ILM peeling, respectively, with a difference that reached significance (p = 0.02) 12 months postoperatively.

CONCLUSIONS

Vitrectomy for ERM affects the BCVA or the RTs 12 months postoperatively. Additional ILM peeling does not affect them, but it might reduce the ERM recurrence rate.

Comparison between ranibizumab and aflibercept for macular edema associated with central retinal vein occlusion

PURPOSE

We compared the efficacy of bimonthly intravitreal injections of ranibizumab (IVR) with that of bimonthly intravitreal injections of aflibercept (IVA) in two prospective, consecutive groups of patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO).

PATIENTS AND METHODS

Eyes with ME after CRVO received either bimonthly IVR (ranibizumab group; n = 13) or IVA (aflibercept group; n = 13) injections and were followed monthly for 6 months. Three patients in the ranibizumab group and two in the aflibercept group were lost to follow-up and excluded from the study. The best-corrected visual acuity (BCVA), central foveal thickness (CFT) on optical coherence tomography, and aqueous vascular endothelial growth factor (VEGF) concentrations were evaluated before and after treatment.

RESULTS

From baseline to month 6, significant improvements occurred in mean logMAR BCVA (ranibizumab group: 0.78-0.47; p < 0.05; aflibercept group: 0.74-0.54; p < 0.05) and mean CFT (ranibizumab group: 685-311 µm; p < 0.05; aflibercept group: 695-230 µm; p < 0.05). Fluctuations in CFT were seen at months 2, 4, and 6 in the ranibizumab group. Mean aqueous VEGF concentration decreased from baseline to month 2 in the ranibizumab group (509.9-348.2 pg/ml) and aflibercept group (412.1 pg/ml to undetectable limits in eight of 11 eyes and to 13.6, 15.6, and 24.1 pg/ml in the other three eyes, respectively).

CONCLUSIONS

There was no significant improvement of visual acuity in one group compared with another; VEGF may not be completely neutralized by bimonthly injections of ranibizumab.

Ocular Behçet's disease is less complicated with allergic disorders. A nationwide survey in Japan

OBJECTIVES

Behçet's disease (BD) is a systemic inflammatory disorder polarised to the Th1 and Th17 immune systems. Allergic diseases are polarised to the Th2 immune system. The aim of the present study is to investigate the prevalence of allergic diseases in patients who have BD.

METHODS

The study involved a large-scale interview survey of Japanese patients with BD at 21 institutes of ophthalmology; 353 patients (255 males and 98 females) were recruited for this study. We analysed the history of allergic diseases such as atopic dermatitis (AD), allergic rhinitis (AR), bronchial asthma (BA) and drug/food allergies (FA).

RESULTS

Oral aphthous ulcers, ocular lesions, skin lesions, genital ulcers, arthritis, neurological lesions, intestinal lesions, deep vein thrombosis and epididymitis were reported in 95.8%, 98.6%, 72.5%, 44.8%, 13.9%, 6.8%, 6.2%, 3.7% and 1.4% of the patients, respectively. It was also reported that 73 patients (20.7%) had histories of allergic diseases: AD (5 cases, 1.4%), AR (36 cases, 10.2%), BA (19 cases, 5.4%) and FA (30 cases, 8.5%). This percentage was significantly lower than in a survey that Japan's Ministry of Health, Labour and Welfare conducted for healthy population (47.6%) (odds ratio = 0.29, 95% confidence interval = 0.22-0.38, p=4.9×10-22). Frequencies of posterior/pan-uveitis, relatively severe ocular findings, and visual prognosis were not affected by a history of allergic diseases in BD.

CONCLUSIONS

Patients with BD had fewer complications from allergic diseases than did the entire population of Japan.

Contrast Sensitivity after Pars Plana Vitrectomy: Comparison between Macula-On and Macula-Off Rhegmatogenous Retinal Detachment

PURPOSE

To evaluate the contrast sensitivity (CS) of eyes successfully repaired by vitrectomy for rhegmatogenous retinal detachment (RRD) with or without preoperative macular involvement.

METHODS

In this retrospective, consecutive, interventional case series, 109 eyes received primary vitrectomy for RRD, of which 36 with at least 12 months of follow-up and a best-corrected visual acuity (BCVA) ≥1 at 12 months postoperatively were investigated. The main outcome measurements were BCVA and CS at 12 months postoperatively. Patients with macula-on RRD preoperatively were included in the macula-on group, and patients with macula-off RRD preoperatively were included in the macula-off group. The between-group difference in CS under evening vision conditions was measured with a Takagi glare tester CGT-2000 at 6 visual angles and 13 contrast levels with and without glare.

RESULTS

CS was significantly lower in the macula-off group for targets with visual angles of 1.6, 1.0, and 0.64° with glare (p < 0.05) and for the target with a visual angle of 0.64° without glare (p < 0.05).

CONCLUSIONS

CS in the higher spatial frequency range (especially with glare) is reduced in macula-off RRD patients with good postoperative BCVA compared to macula-on RRD patients with good postoperative BCVA.

Comparison of single injection and three monthly injections of intravitreal bevacizumab for macular edema associated with branch retinal vein occlusion

Purpose

Our aim was to compare the 1 year efficacy and safety results of intravitreal bevacizumab (IVB) in two prospective, consecutive groups of patients with macular edema (ME) following branch retinal vein occlusion (BRVO).

Patients and methods

Twenty-five eyes with ME after BRVO received one IVB injection (single-injection group) and 27 eyes received three monthly IVB injections (three-injection group). Both groups were followed monthly for 12 months. The best-corrected visual acuity (BCVA) and the central foveal thickness (CFT) on optical coherence tomography were evaluated before and after treatment. Patients were eligible to receive an IVB injection if the mean CFT increased 100 μm or more or the BCVA decreased 0.1 logarithm of the minimum angle of resolution (logMAR) unit or more compared with values measured on the last visit.

Results

The mean logMAR BCVA and CFT, respectively, improved from 0.56 to 0.33 and from 598 μm to 348 μm in the single-injection group (P<0.001) and from 0.55 to 0.26 and from 514 μm to 293 μm in the three-injection group (P<0.001). During the study period, the mean total number of injections was significantly smaller in the single-injection group than in the three-injection group (2.1 and 4.3, respectively, P<0.001). No serious complications related to the IVB injections developed in either group.

Conclusion

The single-injection group achieved similar visual outcomes for ME secondary to BRVO with fewer injections compared with the three-injection group.

Anterior chamber paracentesis might prevent sustained intraocular pressure elevation after intravitreal injections of ranibizumab for age-related macular degeneration

BACKGROUND/AIMS

To evaluate the efficacy of anterior chamber paracentesis for preventing sustained intraocular pressure (IOP) elevation after intravitreal ranibizumab (IVR) injections for age-related macular degeneration (AMD).

METHODS

The medical records for all cases of exudative AMD treated with IVR injections and followed monthly for 12 months or longer were reviewed retrospectively. Anterior chamber paracentesis was performed just before IVR injections. A sustained IOP elevation was defined as 22 mm Hg or higher during 2 consecutive visits with an increase exceeding 6 mm Hg from baseline.

RESULTS

One hundred and eleven eyes met the inclusion criteria, and none of these eyes had a sustained IOP elevation.

CONCLUSIONS

Anterior chamber paracentesis before IVR injections may prevent sustained IOP elevations.

[One year outcomes of pars plana vitrectomy in proliferative diabetic retinopathy]

PURPOSE

To evaluate the 1-year results of pars plana vitrectomy for proliferative diabetic retinopathy.

PATIENTS AND METHODS

Two hundred thirty six patients with proliferative diabetic retinopathy received primary vitreous surgery at Shiga University of Medical Science Hospital and had at least 1 year follow-up period. The indications for pars plana vitrectomy included vitreous hemorrhage in 140 eyes, extramacular tractional retinal detachment in 60 eyes, macular tractional retinal detachment in 24 eyes and combined tractional retinal detachment in 12 eyes. The visual acuity and changes in visual acuity at 1-year postoperatively were evaluated. Preoperative bevacizumab injection and postoperative visual outcomes were compared between patients treated with 20 gauge (20 G) surgery and with micro incision vitrectomy surgery (MIVS).

RESULTS

The visual acuity improved by 3 lines or more in 166 eyes (70%) and remained unchanged in 56 eyes (24%); it decreased by 3 lines or more in 14 eyes (6%). Tractional retinal detachment in MIVS received more bevacizumab injections. MIVS systems achieved better visual results in the combined tractional retinal detachment group than 20 G system.

CONCLUSION

Successful visual improvement at 1-year postoperatively was observed in eyes with proliferative diabetic retinopathy after pars plana vitrectomy. Results of this study may suggest the superior performance of MIVS for pars plana vitrectomy in proliferative diabetic retinopathy.

Bimonthly injections of ranibizumab for age-related macular degeneration

PURPOSE

To evaluate the efficacy of bimonthly intravitreal injections of ranibizumab for age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) in a pilot study.

METHODS

This study was a prospective, interventional case series. Thirty eyes of 30 patients received prospectively at least three bimonthly intravitreal injections of ranibizumab (0.5 mg/0.05 ml) without loading doses. The best-corrected visual acuity (BCVA) and the central retinal subfield thickness (CRST) were measured before and monthly after the injections.

RESULTS

Twenty-eight patients received the three planned injections; one patient refused the third injection, one patient did not receive the third injection because blood pressure was raised, and one patient received a rescue injection at month 5 because of increased retinal thickness. The mean logarithm of the minimum angle of resolution (logMAR) BCVA was 0.44 ± 0.37 before treatment and significantly improved to 0.25 ± 0.34 at month 6 (p < 0.001). The mean CRST was 335 ± 85.9 μm before treatment and decreased significantly to 261 ± 78.1 μm at month 6 (p < 0.001). Nine of 30 patients received six planned injections for 12 months. The mean logMAR BCVA was 0.38 ± 0.39 before treatment and significantly improved to 0.18 ± 0.33 at month 12 (p = 0.005). The mean CRST was 360 ± 110.8 μm before treatment and decreased significantly to 249 ± 57.0 μm at month 12 (p = 0.025).

CONCLUSIONS

Bimonthly injections of ranibizumab may be effective for treating AMD and PCV.

Effect of vitrectomy on aqueous VEGF concentration and pharmacokinetics of bevacizumab in macaque monkeys

PURPOSE

To evaluate the effect of vitrectomy on the concentration of vascular endothelial growth factor (VEGF) and the pharmacokinetics of intravitreally injected bevacizumab in the aqueous humor in cynomolgus macaques.

METHODS

Pars plana lensectomy and a standard three-port vitrectomy were performed in one eye each of six macaques. After a minimal 12-week healing period, the vitrectomized eyes received an intravitreal injection of bevacizumab (1.25 mg/50 μL). Aqueous humor and venous blood samples were obtained from the macaques just before vitrectomy, just before injection of bevacizumab, on days 1, 3, and 7, and during weeks 2, 4, 6, and 8 after the injection. The bevacizumab and VEGF concentrations were measured by using enzyme-linked immunosorbent assay.

RESULTS

The VEGF concentrations in the aqueous humor ranged from 52.6 to 113.9 pg/mL (mean ± standard deviation [SD], 81.7 ± 27.0 pg/mL) before vitrectomy and 20.7 to 72.7 pg/mL (mean ± SD, 51.4 ± 20.5 pg/mL) 3 months after vitrectomy, a difference that reached significance (P = 0.03). The aqueous VEGF concentrations decreased to less than 9.0 pg/mL, the lower limit of detection, in all eyes between 1 and 7 days after injection of bevacizumab. The mean half-life of 1.25 mg intravitreally injected bevacizumab was 1.5 ± 0.6 days (range, 1.0-2.4 days) in the aqueous humor.

CONCLUSIONS

The VEGF concentration in the aqueous humor decreased and the half-life of the intravitreally injected bevacizumab was shorter in vitrectomized eyes.

[Prevalence of sleep-disordered breathing in patients with retinal vein occlusion]

PURPOSE

To investigate the prevalence of sleep-disordered breathing (SDB) in retinal vein occlusion (RVO) patients.

SUBJECT AND METHOD

Forty RVO patients who had undergone either vitreous surgery or anti-coagulation therapy were included in this study. Pulse oximetry was conducted during the night and 4% oxygen desaturation index (4% ODI times/hour) and mean SpO2 (%) were calculated. If 4% ODI > or = 5, SDB was diagnosed. The results were compared between branch retinal vein occlusion (BRVO), and central retinal vein occlusion (CRVO). In addition, simple linear regression analyses were conducted to investigate whether 4% ODI related to systemic factors for RVO patients, i.e., incidences of hypertension and diabetes and body mass index(BMI kg/m2).

RESULTS

Forty two percent of the men, 33% of the women and 37% of all the RVO patients were diagnosed as having SDB. The prevalence of SDB and 4% ODI, and the mean SpO2 were not significantly different between the BRVO and CRVO cases. The incidences of diabetes tended to correlate to the 4% ODI, however, neither proved significant. The BMI had a statistic correlation with the 4% ODI.

CONCLUSION

The results of our study suggested that RVO cases have a high frequency of SDB. We believe that at the time of ophthalmic medical examinations or during the treatment of RVO, ophthalmologists should be aware of the possibility of SDB.

A new biconcave contact lens for vitrectomy in eyes with intraocular lens implantation

The authors report a new biconcave contact lens capable of providing superior surgical views of eyes during vitrectomy and intraocular lens implantation under both fluid-filled and air-filled conditions. The new biconcave lens is made of a glass with a high refractive index (nd = 1.883). The lens is placed on the cornea using a regular lens ring for the floating vitrectomy lens system. During vitrectomy, the new biconcave lens provides a view as clear as that of the commercially available flat-concave lens when the vitreous cavity is filled with fluid. The lens also provides a more magnified view than the commercially sold biconcave lens during fluid-air exchange, with no need for replacement. The new biconcave vitrectomy lens spares the surgeon the trouble of replacing different refractive lenses during the fluid-air exchange procedure in an eye undergoing intraocular lens implantation, and may be helpful for vitreous surgery.

Evaluation of the relationship between background factors and sleep-disordered breathing in patients with proliferative diabetic retinopathy

PURPOSE

To clarify the relationship between sleep-disordered breathing (SDB) and background factors in patients with proliferative diabetic retinopathy (PDR).

PARTICIPANTS AND METHODS

One hundred fifty-one consecutive PDR patients were included in this study. These patients' SDB parameters, including the mean and lowest SpO(2), sleeping 4% oxygen desaturation index (ODI), and cumulative percentage of time spent at SpO(2) < 90% (CT90%), were measured. Simple linear regression analyses were conducted to investigate whether the SDB parameters correlated with systemic factors for PDR, including age, duration of diabetes, HbA1c value, incidence of hypertension, estimated glomerular filtration rate (eGFR), body mass index (BMI), and insulin therapy. Logistic regression analysis was also conducted to investigate whether the SDB evaluation items were factors independently associated with the incidence of hypertension.

RESULTS

Hypertension and BMI were statistically correlated with all of the parameters. The eGFR was statistically correlated with 4% ODI and insulin therapy with the lowest SpO(2). Logistic regression analysis revealed 4% ODI and eGFR as factors independently contributing to the incidence of hypertension.

CONCLUSION

The results of our study confirmed the relationship between SDB and background factors reported to be risk factors for diabetic retinopathy progression in patients with PDR.

Relationship between sleep-disordered breathing and iris and/or angle neovascularization in proliferative diabetic retinopathy cases

PURPOSE

To investigate whether sleep-disordered breathing is a risk factor for iris and/or angle neovascularization in patients with proliferative diabetic retinopathy (PDR).

DESIGN

Cross-sectional comparative case series.

SUBJECTS AND METHODS

One hundred fifty-one consecutive patients with PDR who underwent surgery in our hospital were divided based on the presence of iris and/or angle neovascularization (NV group, 37 patients) or absence of NV (non-NV group, 114 patients). Pulse oximetry was conducted during the night and the mean SpO(2), 4% oxygen desaturation index (4% ODI times/hour), the lowest SpO(2)% during sleep (lowest SpO(2)), and the cumulative percentage of time at SpO(2) <90% in analysis times (CT90%) were calculated. When the 4% ODI exceeded 5 times/hour, sleep-disordered breathing was diagnosed. The results were compared between the 2 groups. Preoperative systemic parameters also were analyzed by logistic regression to clarify risk factors for the NV group.

RESULTS

A mean total of 50% (62% of the NV group and 46% of the non-NV group) was diagnosed with sleep-disordered breathing. The mean SpO(2) and lowest SpO(2) did not differ significantly between the 2 groups; the 4% ODI (12.3 vs 6.6) and CT90% (3.8 vs 1.7) were significantly higher in the NV group (P=.02, for both comparisons). Logistic regression analysis identified insulin therapy (odds ratio [OR], 3.01; 95% confidence interval [CI], 1.26∼7.20; P=.01); and 4% ODI (OR, 1.09; CI, 1.01∼1.16; P=.02) as risk factors for the NV group.

CONCLUSIONS

In patients with PDR, nocturnal intermittent hypoxia/reoxygenation resulting from sleep-disordered breathing may be a risk factor for iris and/or angle neovascularization.

Suppression and regression of choroidal neovascularization by the multitargeted kinase inhibitor pazopanib

OBJECTIVE

To investigate pazopanib hydrochloride, a multitargeted kinase inhibitor, for treatment of choroidal neovascularization (CNV).

METHODS

Choroidal neovascularization was induced in mice by rupture of Bruch membrane with laser photocoagulation. Mice were treated with pazopanib by gavage or periocular injection, and the area of CNV was measured.

RESULTS

Twice-daily gavage of pazopanib, 100 mg/kg, suppressed the development of CNV by 93%. Treatment of established CNV between days 7 and 14 with 8, 40, or 200 mg/kg per day reduced CNV by 0%, 58%, and 71%, respectively. Substantial regression (40%) of CNV was also achieved after periocular injection of pazopanib. A single oral dose of 4 or 100 mg/kg resulted in an area under the curve from time 0 to the last quantifiable concentration of 129.6 and 752.0 microg x h/mL, respectively. After 7 days of 4, 20, or 100 mg/kg twice a day by gavage, plasma levels were 1300, 4900, and 5800 ng/mL and levels in the retina/choroid were 4800, 28 800, and 38 000 ng/g of tissue.

CONCLUSIONS

Orally administered pazopanib has good bioavailability to the retina/choroid and strongly suppresses CNV in mice. Treatment with pazopanib after CNV is established causes dose-dependent regression of CNV.

CLINICAL RELEVANCE

Pazopanib may be useful for treatment of CNV in humans.

Treatment of primary intraocular lymphoma with intravitreal methotrexate

PURPOSE

To report the efficacy of intravitreal chemotherapy for primary intraocular lymphoma (PIOL).

METHODS

Retrospective, noncomparative interventional case reports are presented for six patients (ten eyes; mean age, 58.8 years) with pathologically confirmed PIOL who participated in this study and were treated at our hospital with intravitreal injections of methotrexate (MTX) between January 2004 and February 2007. Intravitreal injections of MTX (400 microg MTX/50 microl Opeguard-MA) were administered once or twice weekly for 1 month followed by ten monthly injections. Interleukin-10 (IL-10) and IL-6 were measured in the vitreous before and after injections to determine tumor activity.

RESULTS

All eyes were clinically cleared of malignant cells. One eye lost vision. After intravitreal chemotherapy, the vitreous IL-10 concentration reached barely detectable levels.

CONCLUSIONS

Intravitreal chemotherapy achieves clinical remission and preserves vision in patients with PIOL.

Suppression of ocular neovascularization with siRNA targeting VEGF receptor 1

In this study, we used small interfering RNA (siRNA) directed against vascular endothelial growth factor receptor 1 (vegfr1) mRNA to investigate the role of VEGFR1 in ocular neovascularization (NV). After evaluating many siRNAs, Sirna-027 was identified; it cleaved vegfr1 mRNA at the predicted site and reduced its levels in cultured endothelial cells and in mouse models of retinal and choroidal neovascularization (CNV). Compared to injection of an inverted control sequence, quantitative reverse transcriptase-PCR demonstrated statistically significant reductions of 57 and 40% in vegfr1 mRNA after intravitreous or periocular injection of Sirna-027, respectively. Staining showed uptake of 5-bromodeoxyuridine-labeled Sirna-027 in retinal cells that lasted between 3 and 5 days after intravitreous injection and was still present 5 days after periocular injection. In a CNV model, intravitreous or periocular injections of Sirna-027 resulted in significant reductions in the area of NV ranging from 45 to 66%. In mice with ischemic retinopathy, intravitreous injection of 1.0 mug of Sirna-027 reduced retinal NV by 32% compared to fellow eyes treated with 1.0 mug of inverted control siRNA. These data suggest that VEGFR1 plays an important role in the development of retinal and CNV and that targeting vegfr1 mRNA with siRNA has therapeutic potential.

Repeated intravitreal triamcinolone injections in Behçet disease that is resistant to conventional therapy: one-year results

PURPOSE

To determine whether repeated intravitreal triamcinolone (IVTA) injections in patients with Behçet disease that is resistant to conventional therapy will prevent recurrences of uveitis.

DESIGN

Prospective preliminary clinical trial.

METHODS

Nine eyes of five patients with Behçet disease with sight-threatening uveitis that was resistant to conventional therapy received repeated IVTA injections. Each patient was examined monthly, and IVTA was given when the TA particles that remained in the vitreous were judged to be gone before the next visit.

RESULTS

Repeated IVTA completely prevented the recurrence of uveitis in eight eyes, and the one eye that had an attack experienced the uveitis when the TA particles disappeared quicker than expected. It was possible to stop systemic corticosteroid and/or immunosuppressive agents within 1 year after IVTA in three patients.

CONCLUSION

These results indicate that repeated IVTA will prevent the recurrence of uveitis in patients with Behçet disease with frequent ocular attacks that is resistant to conventional therapy.

Suppression and regression of choroidal neovascularization by polyamine analogues

PURPOSE

Polyamine analogues inhibit tumor growth in vitro and in vivo, and oligoamines with a chain length of 10, 12, or 14 are particularly potent. This study was conducted to investigate the effect of the decamines CGC-11144 and CGC-11150 in a mouse model of choroidal neovascularization (CNV).

METHODS

Mice with laser-induced rupture of Bruch's membrane were given intraperitoneal, intravitreous, or periocular injection of CGC-11144, CGC-11150, or vehicle, and after 14 days, they were perfused with fluorescein-labeled dextran, and the area of CNV was measured on choroidal flatmounts by image analysis. In some groups of mice, treatments were started 7 days after rupture of Bruch's membrane to determine the effect of the agent on established CNV. Electroretinograms (ERGs) were performed to assess the effects on retinal function, and histopathology was used to evaluate retinal structure.

RESULTS

Intraperitoneal injection of 10 or 20 mg/kg CGC-11144 or CGC-11150 resulted in small but significant reductions in the area of CNV. Intravitreous injection of 20 microg CGC-11144 or CGC-11150 on days 0 and 7 after rupture of Bruch's membrane resulted in a approximately 40% reduction in the area of CNV, with a similar reduction after periocular injections of 0.2 mg CGC-11144 three times a week for 2 weeks. Both intravitreous and periocular delivery of CGC-11144 also caused significant regression of established CNV. Within 2 days of periocular injection of CGC-11144, there was apoptosis in CNV lesions, but not in normal blood vessels or other retinal cells. Periocular injections of d,l-alpha-difluoromethyl-ornithine (DFMO), which decreases polyamine levels by a different mechanism, also inhibited CNV. There was no decline in ERG amplitudes or abnormal retinal morphology after daily injections of 0.2 mg CGC-11144 for 2 weeks, but a single intravitreous injection compromised retinal structure and function.

CONCLUSIONS

Periocular delivery of the polyamine analogues may be a useful approach for the treatment of CNV.

Periocular Gene Transfer of Pigment Epithelium-Derived Factor Inhibits Choroidal Neovascularization in a Human-Sized Eye

Gene transfer provides a potential way to achieve sustained delivery of therapeutic proteins to the eye. Studies in rodents have suggested that periocular injection of adenoviral vectors containing expression cassettes for antiangiogenic proteins results in high intraocular levels of the proteins and suppression of choroidal neovascularization (CNV). However, the differences in size and scleral thickness between mouse and human eyes make it difficult to ascertain if periocular gene transfer is a feasible approach for treating human choroidal diseases. To address this issue, we tested the effect of periocular injection of an expression cassette for pigment epithelium-derived factor (PEDF) packaged in adenoviral vector (AdPEDF.11) in a CNV model in pigs, which have eyes that are very similar to humans in size and scleral thickness. Periocular injection of beta-galactosidase (AdLacZ.11) resulted in prominent transduction of periocular tissues, as was seen in mice. Periocular injection of AdPEDF.11 caused increased levels of PEDF in the choroid and significantly reduced the amount of CNV at rupture sites in Bruch's membrane. These data suggest that periocular gene transfer may be feasible for treatment of human choroidal diseases.

Intraocular gutless adenoviral-vectored VEGF stimulates anterior segment but not retinal neovascularization

Vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) have been implicated as important stimulatory factors for retinal neovascularization. In this study, we used intraocular gene transfer with gutless adenoviral (AGV) vectors to determine the effect of increased intraocular expression of VEGF, IGF-1, or sphingosine kinase (SPK), which produces sphingosine-1-phosphate, another angiogenic factor. Retinal neovascularization did not occur from intravitreous AGV-vectored VEGF, IGF-1, SPK, or combined VEGF and IGF-1, except occasionally adjacent to the retinal penetration site from the injection. However, corneal and iris neovascularization occurred after 2 weeks in all eyes injected with AGV.VEGF, but not those injected with only AGV.IGF-1 or AGV.SPK. These data suggest that the superficial capillary bed of the retina is relatively insensitive to VEGF, IGF-1, or SPK in adult mice, except when combined with retinal trauma. However, AGV-vectored VEGF is sufficient to consistently cause severe corneal and iris neovascularization. This provides a model for anterior segment neovascularization, which unlike previous models is relatively inexpensive and is not plagued by spontaneous regression, and therefore, may be useful for identification of new treatments.

Periocular Injection of Microspheres Containing PKC412 Inhibits Choroidal Neovascularization in a Porcine Model

PURPOSE

Oral administration of PKC412, a kinase inhibitor that blocks several isoforms of protein kinase C (PKC) and receptors for vascular endothelial growth factor (VEGF), platelet-derived growth factor, and stem cell factor, inhibits ocular neovascularization in a murine model. The purpose of this study was to determine whether sustained local delivery of PKC412 in a human-sized eye inhibits choroidal neovascularization (CNV).

METHODS

Laser photocoagulation was used to rupture Bruch's membrane in young domestic pigs, and then a periocular injection of control microspheres or microspheres containing 25% or 50% PKC412 was given. After 10 days the integrated area of CNV at Bruch's membrane rupture sites was measured by image analysis. The levels of PKC412 in choroid, retina, and vitreous were measured either 10 or 20 days after periocular injection of 50% PKC microspheres or at 20 days after injection of 25% PKC412 microspheres.

RESULTS

The areas of CNV at Bruch's membrane rupture sites were significantly smaller in eyes that received a periocular injection of microspheres containing 25% (P=0.0042) or 50% (P=0.0012) PKC412 than those in eyes injected with control microspheres. Ten days after periocular injection of 50% PKC412 microspheres, PKC412 was detected in the choroid, but not in the retina or vitreous. Twenty days after periocular injection of 50% PKC412, high levels of PKC412 were measured in the choroid, vitreous, and retina. Levels were lower but still substantial in all three compartments 20 days after periocular injection of 25% microspheres.

CONCLUSIONS

Sustained local delivery of PKC412 provides a promising approach for treatment of CNV.

The kinase inhibitor PKC412 suppresses epiretinal membrane formation and retinal detachment in mice with proliferative retinopathies

PURPOSE

Platelet-derived growth factor (PDGF) is an important stimulatory factor for proliferative retinopathies. Expression of PDGF-B in the retinas of transgenic mice (hemizygous rho/PDGF-B mice) results in rapid-onset retinal detachment caused by proliferation of glial cells, endothelial cells, and pericytes, whereas expression of PDGF-AA (homozygous rho/PDGF-A or PDGF-AA mice) causes slowly progressive retinal detachment from proliferation of glial cells. In this study, we investigated the effect in rho/PDGF-B and rho/PDGF-AA mice of several different receptor kinase inhibitors.

METHODS

Hemizygous rhoPDGF-B or homozygous rho/PDGF-A mice were treated orally with PKC412 (an inhibitor of PDGF, VEGF, and c-kit receptor kinases and several isoforms of PKC), PTK787 (an inhibitor of PDGF, VEGF, and c-kit receptor kinases), SU1498 (an inhibitor of VEGF receptor kinases), imatinib mesylate (an inhibitor of PDGF, c-kit, and v-abl receptor kinases), or vehicle, and at appropriate time points epiretinal membrane (ERM) formation and retinal detachment were quantified.

RESULTS

In either rho/PDGF-B or rho/PDGF-A mice, oral administration of PKC412 or PTK787, but not SU1498 or imatinib mesylate, significantly reduced ERM formation. PKC412 reduced the incidence of severe retinal detachments in both models and PTK787 did so in homozygous rho/PDGF-A mice.

CONCLUSIONS

These data indicate that PKC412 (and possibly PTK787) has appropriate activity and sufficient intraocular bioavailability after oral administration to prevent retinal detachment in models of proliferative retinopathy. PKC412 should be considered for treatment of vascular and nonvascular proliferative retinopathies in humans.

Inhibition of protein kinase C decreases prostaglandin-induced breakdown of the blood-retinal barrier

Breakdown of the blood-retinal barrier (BRB) occurs in several retinal diseases and is a major cause of visual loss. Vascular endothelial growth factor (VEGF) has been implicated as a cause of BRB breakdown in diabetic retinopathy and other ischemic retinopathies, and there is evidence to suggest that other vasopermeability factors may act indirectly through VEGF. In this study, we investigated the effect of several receptor kinase inhibitors on BRB breakdown resulting from VEGF, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), insulin-like growth factor-1 (IGF-1), prostaglandin E1 (PGE(1)), or PGE(2). Inhibitors of VEGF receptor kinase, including PKC412, PTK787, and SU1498, decreased VEGF-induced breakdown of the BRB. None of the inhibitors blocked leakage caused by TNF-alpha, IL-1beta, or IGF-1 and only PKC412, an inhibitor of protein kinase C (PKC) as well as VEGF and platelet-derived growth factor (PDGF) receptor kinases, decreased leakage caused by prostaglandins. Since the other inhibitors of VEGF and/or PDGF receptor kinases that do not also inhibit PKC had no effect on prostaglandin-induced breakdown of the BRB, these data implicate PKC in retinal vascular leakage caused by prostaglandins. PKC412 may be useful for treatment of post-operative and inflammatory macular edema, in which prostaglandins play a role, as well as macular edema associated with ischemic retinopathies.

VEGF-TRAP(R1R2) suppresses choroidal neovascularization and VEGF-induced breakdown of the blood-retinal barrier

Vascular endothelial growth factor (VEGF) plays a central role in the development of retinal neovascularization and diabetic macular edema. There is also evidence suggesting that VEGF is an important stimulator for choroidal neovascularization. In this study, we investigated the effect of a specific inhibitor of VEGF, VEGF-TRAP(R1R2), in models for these disease processes. VEGF-TRAP(R1R2) is a fusion protein, which combines ligand binding elements taken from the extracellular domains of VEGF receptors 1 and 2 fused to the Fc portion of IgG1. Subcutaneous injections or a single intravitreous injection of VEGF-TRAP(R1R2) strongly suppressed choroidal neovascularization in mice with laser-induced rupture of Bruch's membrane. Subcutaneous injection of VEGF-TRAP(R1R2) also significantly inhibited subretinal neovascularization in transgenic mice that express VEGF in photoreceptors. In two models of VEGF-induced breakdown of the blood-retinal barrier (BRB), one in which recombinant VEGF is injected into the vitreous cavity and one in which VEGF expression is induced in the retina in transgenic mice, VEGF-TRAP(R1R2) significantly reduced breakdown of the BRB. These data confirm that VEGF is a critical stimulus for the development of choroidal neovascularization and indicate that VEGF-TRAP(R1R2) may provide a new agent for consideration for treatment of patients with choroidal neovascularization and diabetic macular edema.

Intraocular expression of endostatin reduces VEGF-induced retinal vascular permeability, neovascularization, and retinal detachment

Endostatin, a proteolytic fragment of collagen XVIII, is an endogenous inhibitor of tumor angiogenesis that also inhibits choroidal neovascularization. In this study, we assessed the effects of increased intraocular expression of endostatin on vascular endothelial growth factor (VEGF)-induced changes in the retina. After subretinal injection of a pair of gutless adenoviral vectors (AGV) designed to provide tamoxifen-inducible expression of endostatin, diffuse endostatin immunoreactivity was induced thoroughout the retina by administration of tamoxifen. Induction of endostatin in double transgenic mice with doxycycline-induced expression of VEGF in the retina resulted in significant suppression of leakage of intravascular [3H]mannitol into the retina. The ability of endostatin to reduce VEGF-induced retinal vascular permeability was confirmed by using [3H]mannitol leakage and two other parameters, fluorescein leakage and retinal thickness, after subretinal injection of a bovine immunodeficiency lentiviral vector coding for endostatin (BIV-vectored endostatin, or BIVendostatin). Subretinal injection of BIVendostatin resulted in more discrete, less intense staining for endostatin in the retina than that seen with the inducible AGV system, which suggested lower levels and allowed visualization of sites where endostatin was concentrated. Endostatin staining outlined retinal blood vessels, which suggested endostatin binding to a component of vessel walls. More prolonged or higher level expression of VEGF in the retina resulted in neovascularization and retinal detachment, both of which were also significantly reduced by BIVendostatin. These data suggest that endostatin may be an endogenous inhibitor of vasopermeability as well as neovascularization. In patients with diabetic retinopathy, endostatin gene transfer may provide a way to decrease the risk of three causes of visual loss: macular edema, neovascularization, and retinal detachment.

Intraocular expression of endostatin reduces VEGF-induced retinal vascular permeability, neovascularization, and retinal detachment

Endostatin, a proteolytic fragment of collagen XVIII, is an endogenous inhibitor of tumor angiogenesis that also inhibits choroidal neovascularization. In this study, we assessed the effects of increased intraocular expression of endostatin on vascular endothelial growth factor (VEGF)-induced changes in the retina. After subretinal injection of a pair of gutless adenoviral vectors (AGV) designed to provide tamoxifen-inducible expression of endostatin, diffuse endostatin immunoreactivity was induced thoroughout the retina by administration of tamoxifen. Induction of endostatin in double transgenic mice with doxycycline-induced expression of VEGF in the retina resulted in significant suppression of leakage of intravascular [3H]mannitol into the retina. The ability of endostatin to reduce VEGF-induced retinal vascular permeability was confirmed by using [3H]mannitol leakage and two other parameters, fluorescein leakage and retinal thickness, after subretinal injection of a bovine immunodeficiency lentiviral vector coding for endostatin (BIV-vectored endostatin, or BIVendostatin). Subretinal injection of BIVendostatin resulted in more discrete, less intense staining for endostatin in the retina than that seen with the inducible AGV system, which suggested lower levels and allowed visualization of sites where endostatin was concentrated. Endostatin staining outlined retinal blood vessels, which suggested endostatin binding to a component of vessel walls. More prolonged or higher level expression of VEGF in the retina resulted in neovascularization and retinal detachment, both of which were also significantly reduced by BIVendostatin. These data suggest that endostatin may be an endogenous inhibitor of vasopermeability as well as neovascularization. In patients with diabetic retinopathy, endostatin gene transfer may provide a way to decrease the risk of three causes of visual loss: macular edema, neovascularization, and retinal detachment.

Topical nepafenac inhibits ocular neovascularization

PURPOSE

Topical nepafenac readily penetrates the cornea and is metabolized to amfenac, a potent cyclooxygenase (COX)-1 and COX-2 inhibitor. In this study, we tested the effect of topical nepafenac in three murine models of ocular neovascularization (NV).

METHODS

A masked trial was performed to compare the topical effects of vehicle with one of several concentrations of nepafenac (0.01%, 0.03%, 0.1%, or 0.5%), 0.1% diclofenac, or 0.5% ketorolac tromethamine in mice with oxygen-induced ischemic retinopathy, mice with choroidal NV (CNV) due to laser-induced rupture of Bruch's membrane, or transgenic mice with increased expression of vascular endothelial growth factor (VEGF) in photoreceptors (rho/VEGF transgenic mice).

RESULTS

Mice treated with 0.1% or 0.5% nepafenac had significantly less CNV and significant less ischemia-induced retinal NV than did vehicle-treated mice. Nepafenac also blunted the increase in VEGF mRNA in the retina induced by ischemia. In rho/VEGF transgenic mice, nepafenac failed to inhibit neovascularization. In additional studies, compared with vehicle-treated mice, mice treated with 0.1% or 0.03% nepafenac had significantly less CNV, whereas eyes treated with 0.1% diclofenac showed no significant difference. Mice treated with 0.5% ketorolac tromethamine for 14 days had high mortality, but when evaluated after 7 days of treatment showed no difference from mice treated with vehicle for 7 days.

CONCLUSIONS

Topical nepafenac inhibits CNV and ischemia-induced retinal neovascularization by decreasing production of VEGF. The absence of effect in rho/VEGF transgenic mice is consistent with this mechanism. Topical nepafenac may provide an effective new treatment for ocular neovascularization. The excellent corneal penetration of nepafenac certainly plays an important role in this effect. It is possible that other antiangiogenic agents are also amenable to topical application after formulations are identified that maximize their corneal penetration. Because of the many advantages of the topical route of delivery, this is a possible topic for exploration.

Sustained transduction of ocular cells with a bovine immunodeficiency viral vector

Human immunodeficiency viral (HIV) vectors mediate long-term transduction of many types of nondividing cells in vivo. Bovine immunodeficiency virus (BIV) is a lentivirus that shares many characteristics with HIV, but does not cause human disease. In this study, we investigated the potential of BIV vectors for ocular gene therapy. An enhanced green fluorescent protein (eGFP)-encoding reporter gene was packaged in recombinant BIV vector (BIV.eGFP). Adult C57BL/6 mice were given an intravitreous (5 x 10(4) or 5 x 10(5) transducing units [TU]) or subretinal (5 x 10(5) TU) injection of BIV.eGFP and then GFP expression was assessed at several time points. In vivo examinations of mice showed that subretinal injection of BIV.eGFP resulted in strong expression of GFP from the first examination at 1 week through the final examination at 20 weeks. Only a few mice that received intravitreous injection of BIV.eGFP showed GFP expression by ocular examinations until 11-12 weeks, when most showed small areas of expression. Postmortem examinations showed prominent GFP expression in retinal pigmented epithelial (RPE) cells throughout the region of subretinal injection of vector, although occasional negatively staining RPE cells were scattered among the much more numerous, brilliantly staining cells. Ciliary epithelial cells frequently expressed GFP, as did occasional Müller cells and rarely other retinal cells. The expression was stable from the first time point (2 weeks) to the last (20 weeks). Postmortem examination of eyes given an intravitreous injection of BIV.eGFP showed transduction of cells in the corneal endothelium and a few scattered retinal cells. There was no evidence of inflammation or toxicity in any eyes. These data show that BIV vectors mediate rapid and sustained transduction of RPE cells, suggesting that they may be useful for ocular gene therapy targeting RPE cells.

Enhanced expression of adhesion molecules of the retinal vascular endothelium in spontaneous diabetic rats

Otsuka Long-Evans Tokushima Fatty (OLETF) rats are a spontaneously diabetic strain with clinical features resembling those of human noninsulin-dependent diabetes mellitus. These rats show increased leukocyte entrapment in the retina. The present study was designed to investigate the immunolocalization of intercellular adhesion molecules-1 (ICAM-1) and P-selectin in the retinas of OLETF rats. Four 72-week-old male OLETF rats and 4 age- and sex-matched Long-Evans Tokushima Otsuka (LETO) control rats were used. Western blot analysis and immunohistochemical study were performed using an anti-P-selectin monoclonal antibody (mAb) and an anti-ICAM-1 mAb. Western blot analysis showed increased expression of both ICAM-1 and P-selectin in the retinas of OLETF rats. Immunohistochemically, OLETF rats expressed greater amounts of ICAM-1 and P-selectin in the retinal vascular endothelium than did LETO rats. These findings demonstrated the upregulation of ICAM-1 and P-selectin in the retina of OLETF rats. The enhanced expression of these adhesion molecules might participate in the pathogenesis of early diabetic microangiopathy in the retina.