Level of Vascular Endothelial Growth Factor in the Vitreous Fluid of Proliferative Diabetic Retinopathy Patients and Prognosis after Vitrectomy.

PURPOSE: The aim of this study was to evaluate the relationship between the intravitreal vascular endothelial growth factor (VEGF) level and prognosis of proliferative diabetic retinopathy (PDR). METHODS: The study involved 136 eyes of 114 PDR patients who underwent an initial vitrectomy between 2006 and 2008. Intravitreal VEGF levels were determined using Bio-Plex® (Bio-Rad), with levels of 5,000 pg/mL or more classified as high-VEGF (45 eyes) and levels lower than 5,000 pg/mL as low-VEGF (91 eyes). Diabetic control, PDR severity, and frequency of postoperative complications were compared between the groups. RESULTS: There was no significant difference in preoperative status between the groups. In the low-VEGF group, a reoperation was required due to postoperative complications in 2 eyes (2.2%); 1 with vitreous hemorrhage (VH) and 1 with retinal detachment (RD). In contrast, a reoperation was required in 8 eyes (17.8%) in the high-VEGF group; 3 with VH, 2 with RD, and 3 with neovascular glaucoma. The difference between the groups was significant. There was a statistically lower postoperative corrected visual acuity logMAR (6 months after surgery) in the high-VEGF than in the low-VEGF group (p = 0.02, unpaired t test). CONCLUSION: Current findings indicate that careful observation is needed in patients with elevated VEGF levels.

Effects of intravitreal injection of bevacizumab on inflammatory cytokines in the vitreous with proliferative diabetic retinopathy.

BACKGROUND: To investigate the effects of preoperative intravitreal injection of bevacizumab (IVB) on the levels of 27 inflammatory cytokines, including interleukins (ILs) and vascular endothelial growth factor. METHODS: From among 200 patients who had proliferative diabetic retinopathy and underwent vitrectomy in our department from September 2009 to October 2010, 8 study subjects met the enrollment criteria in which both eyes at nearly equivalent stages underwent vitrectomy. The first vitrectomy for each patient was performed without IVB (control group), whereas the second vitrectomy on the contralateral eye was performed with IVB treatment (1.25 mg/0.05 mL) 3 days before surgery (IVB group). Undiluted vitreous fluid was collected at the start of each vitrectomy. A multiplex assay was used to simultaneously determine the levels of 27 inflammatory cytokines and growth factors. RESULTS: Mean vascular endothelial growth factor levels were significantly lower in the IVB group (519.69 pg/mL) than in the control group (11,807.44 pg/mL) (P = 0.012, Wilcoxon signed rank test). Moreover, the mean levels (IVB/control, pg/mL) of IL-1RA (38.50/62.31, P = 0.036), IL-5 (27.75/34.00, P = 0.018), IL-10 (433.63/1,995.94, P = 0.012), IL-12 (246.69/1,033.69, P = 0.012), IL-13 (707.50/1,450.38, P = 0.012), and interferon γ (71.13/84.69, P = 0.036) were significantly lower in the IVB group. No other significant differences were observed in the levels of the other 20 cytokines and growth factors between the 2 groups. CONCLUSION: Preoperative IVB reduced not only the intravitreal vascular endothelial growth factor level but also the intravitreal levels of other inflammatory cytokines, including IL-1RA, IL-5, IL-10, IL-12, IL-13, and interferon γ. These results indicate the interaction of some cytokines in the vitreous fluid of proliferative diabetic retinopathy patients and suggest the possibility that preoperative IVB may not only reduce vascular proliferation by its direct antivascular endothelial growth factor effect but also modulate the inflammatory response through putative cytokine networks. None of the other cytokines examined were elevated after IVB.

Effect of nilvadipine on central visual field in retinitis pigmentosa: a 30-month clinical trial.

PURPOSE: To assess the effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). DESIGN: Prospective, randomized, nonmasked, single-center trial. METHODS: Patients with RP were randomly divided into a treated group receiving oral nilvadipine at 4 mg/day for ≥30 months and a control group receiving tocopherol nicotinate at 300 mg/day, helenien at 15 mg/day or no medication for the same periods. Progression of RP was evaluated using the 10-2 SITA Fast Program of the Humphrey Visual Field Analyzer, and regression coefficients calculated from the time courses of mean deviation (MD slope) were compared between groups. RESULTS: Nineteen patients in the treated group and 14 patients in the control group completed the follow-up for ≥30 months. The mean (±standard deviation) duration of observation was 48.8 ± 11.8 months (median 48 months, range 30-66 months) for the treated group and 49.2 ± 18.1 months (median 48 months, range 30-90 months) for the control group (p = 0.94). Mean (±standard error of the mean, SEM) regression coefficients of the averaged MD values for the initial 30 months were -0.35 ± 0.17 dB/year in the treated group and -0.75 ± 0.06 dB/year in the control group (p < 0.01). Mean (±SEM) MD slopes for total observational periods were -0.49 ± 0.17 dB/year in the treated group and -0.89 ± 0.16 dB/year in the control group (mean ± SEM, p = 0.042). CONCLUSION: Nilvadipine at 4 mg/day significantly retarded progression of central visual field defects in RP in this small patient series.

Activation of mitochondrial calpain and release of apoptosis-inducing factor from mitochondria in RCS rat retinal degeneration.

The present study was performed to investigate changes of cytosolic and mitochondrial calpain activities, and effects of intravitreously injected calpain inhibitor on photoreceptor apoptosis in Royal College of Surgeon's (RCS) rats. Time courses of activities for both cytosolic and mitochondrial calpains and amount of calpastatin in RCS rat retina were analyzed by subcellular fractionation, calpain assay and western blotting. Calpain assay was colorimetrically performed using Suc-LLVY-Glo as substrate. Effects of intravitreously injected calpain inhibitor (ALLN and PD150606) on RCS rat retinal degeneration were analyzed by TUNEL staining. Effects of mitochondrial calpain activity on activation and translocation of apoptosis-inducing factor (AIF) were analyzed by western blotting. Mitochondrial calpain started to be significantly activated at postnatal (p) 28 days in RCS rat retina, whereas cytosolic micro-calpain was activated at p 35 days, although specific activity of mitochondrial calpain was 13% compared to cytosolic micro-calpain. Intravitreously injected ALLN and PD150606 effectively inhibited photoreceptor apoptosis only when injected at p 25 days, but did not inhibit photoreceptor apoptosis when injected at p 32 days. Parts of AIF were truncated/activated by mitochondrial calpains and translocated to the nucleus. These results suggest that 1), calpain presents not only in the cytosolic fraction but also in the mitochondrial fraction in RCS rat retina; 2), mitochondrial calpain is activated earlier than cytosolic calpain during retinal degeneration in RCS rats; 3), photoreceptor apoptosis may be regulated by not only calpain systems but also other mechanisms; 4), mitochondrial calpain may activate AIF to induce apoptosis; and 5), calpain inhibitors may be partially effective to inhibit photoreceptor apoptosis in RCS rats. The present study provides new insights into the molecular basis for photoreceptor apoptosis in RCS rats and the future possibility of new pharmaceutical treatments for retinitis pigmentosa.

Inhibitory effects of trehalose on fibroblast proliferation and implications for ocular surgery.

Trehalose is a disaccharide which plays an important role in preserving cells from completely dehydrated circumstances. In this study, we investigated effects of trehalose on proliferative activity of fibroblasts and epithelial cells both in vitro and in vivo. As in vitro assessment, normal human dermal fibroblasts and normal human epidermal keratinocytes were cultured in media containing various concentrations of trehalose. Growth activities of cells were evaluated with MTT assay and diff-quick™ staining. Expressions of vimentin and α smooth muscle actin (α-SMA) changed by trehalose were semiquantitatively measured by Western blot. As an in vivo study, 5% or 10% trehalose was topically instilled onto rabbit eyes after simple conjunctival incision or trabeculectomy. Condition of the surgical wound was evaluated by morphologically and immunohistochemically using isolectin B4 and antibodies specific for vimentin and α-SMA. Intraocular pressures (IOPs) after trabeculectomy were compared between eyes treated with trehalose and 0.04% mitomycin C (MMC). Results obtained by in vitro experiments showed that growth activities of cultured fibroblasts and keratinocytes were inhibited by trehalose in a dose-dependent manner. Fibroblasts were strongly inhibited by trehalose concentrations ≧ 5% of trehalose, whereas keratinocytes were less inhibited compared to fibroblasts. Expressions of vimentin and α-SMA were reduced by trehalose. With in vivo experiments, postoperative application of trehalose resulted in less firm adhesion between conjunctiva and sclera compared to controls. Immunohistochemical studies showed reduced staining of isolectin B4, vimentin and α-SMA in conjunctival wounds treated by topical trehalose. Also, after trabeculectomy, IOP remained in a low range during instillation of topical trehalose solution. We concluded that trehalose has inhibitory effects on proliferation of fibroblasts and vascular tissues, partially due to inhibition of transformation of fibroblasts into myofibroblasts in wound tissues. The present results imply that trehalose can be a potential agent for preventing postoperative fibrous scar formation after ocular surgery such as glaucoma filtration surgery.

[A case of hypertrophic pachymeningitis impeding differential diagnosis of mycosis of orbital apex syndrome].

PURPOSE: Mycosis of the orbital apex is often fatal. We report case of orbital apex syndrome, which appeared to have been caused by hypertrophic pachymeningitis with positive systemic mycosis antigens treated with systemic corticosteroid combined with antimicrobiotic therapy. CASE: A 57-year-old woman presented with disturbed ocular motility and visual disturbance of her left eye. She had rheumatoid arthritis. Magnetic resonance imaging(MRI) showed an abnormal blush in the left orbital apex and meningeal thickening in the cranial base, leading to the diagnosis of hypertrophic pachymeningitis. She also had candidemia. Systemic corticosteroids combined with antimicrobiotic therapy resulted in improved clinical ocular manifestations. She died 13 months later due to interstitial pneumonia. CONCLUSION: The diagnosis of this case was difficult because of the candidemia. But the effective steroid response indicates that the probable cause was hypertrophic pachymeningitis due to RA. To avoid complications, hypertrophic pachymeningitis associated with fungemia should be treated with corticosteroids combined with antimicrobiotic therapy.

N-Methyl-N-Nitrosourea-Induced Photoreceptor Degeneration Is Inhibited by Nicotinamide via the Blockade of Upstream Events before the Phosphorylation of Signalling Proteins.

N-methyl-N-nitrosourea (MNU), a known carcinogen, is generally used in animal models to chemically induce photoreceptor degeneration. It has been reported that nicotinamide (NAM) exerts a protective effect on MNU-induced photoreceptor degeneration. We investigated the molecular mechanisms on MNU-induced photoreceptor degeneration. Intraperitoneal MNU injection (75 mg/kg) in rats induced selective photoreceptor degeneration in 7 days. NAM administration completely inhibited photoreceptor degeneration. Photoreceptor layer abnormality was observed within 6 hours after MNU injection, whereas it was restored in the NAM-treated retina, as detected by optical coherence tomography. One day following MNU administration, phosphorylation of the cell death-associated signalling proteins c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) increased, while the apoptosis-related proteins, full-length poly(ADP-ribose) polymerase (PARP) and apoptosis-inducing factor (AIF), were depleted. These changes were not observed in the NAM-treated retinas. Cell survival signalling, such as extracellular signal-regulated kinase (ERK), Akt, and cAMP response element binding protein (CREB) phosphorylation, increased in the MNU- but not in the NAM-treated rat retinas. Increased phosphorylated ERK (p-ERK) levels were observed within 6 hours after MNU administration, suggestive of cell survival signalling activation. This did not occur in NAM-treated retinas. These results indicate that NAM regulates upstream cellular events prior to the activation of cell death-related signalling events, such as JNK and p38 phosphorylation.

Indocyanine green as useful guide for retinal vein cannulation and injection of tissue plasminogen activator in rabbits.

Central retinal vein occlusion (CRVO) is caused by a fibrin clot in central retinal vein and is one of the intractable diseases that deteriorate visual acuities. Tissue plasminogen activator (TPA) is a thrombolytic agent that has a high affinity for fibrin and that activates plasminogen into plasmin. Injection of TPA into the retinal vein was helpful to treat CRVO. But TPA injection into retinal vein was difficult for clinical use, because TPA solution was transparent and confirmation of its injection was not easy. Indocyanine green (ICG) has been used as an angiographic agent and a tissue-marking agent in ocular surgeries. We studied the effectiveness and safety of ICG assisted injection of TPA into the retinal vein in rabbits. The major retinal vein was punctured using a micropipette fabricated from a glass tube, then TPA/ICG was injected. Total of 12 eyes and 5 eyes were enucleated 7 days and 1 month after injection of TPA/ICG for histological observations including immunostaining of glial fibrillary acidic protein (GFAP) and TUNEL staining, respectively. GFAP is expressed in Müller cells under pathologic conditions and indicates retinal damages. TUNEL indicates apoptosis of sensory retina cells. Retinal vein cannulation was easily performed, as retinal vein became green following injection of TPA/ICG. Histologically, no retinal damages, due to the TPA/ICG solution, were observed. GFAP and TUNEL staining were negative. TPA/ICG causes no disturbance in retinal circulation when performed correctly. Because of its safety, ICG is a useful agent as a guide for retinal vein injection of TPA.

Macular edema associated with intraocular ointment after cataract surgery.

PURPOSE: To report a case with macular edema associated with uveitis, a decreased corneal endothelial cell density, and vitreous opacity caused by migrated intraocular antibiotic ointment after uneventful cataract surgery. OBSERVATIONS: A 63-year-old man underwent uneventful sutureless superior clear corneal phacoemulsification and implantation of an intraocular lens in his right eye. Eleven months later, he complained of blurred vision when he gazed downward. Three months later, uveitis, vitreous opacity, and retinal hemorrhage were noted. Optical coherence tomography and fluorescein angiography demonstrated macular edema in the right eye. A slit-lamp examination revealed many tiny oily deposits on the iris surface. One month later, a globular oily droplet was detected at the 12 o'clock position of the iridocorneal angle. Because the corneal endothelial cell density appeared to be progressively decreased, the oily droplet was removed, and the anterior chamber was irrigated with a balanced salt solution using an irrigation-aspiration cannula. After surgery, the macular edema, vitreous opacity, and retinal hemorrhage disappeared. CONCLUSIONS AND IMPORTANCE: In this case, ofloxacin ointment had presumably migrated into the anterior chamber through a corneal incision after cataract surgery. The fact that the droplet of ointment was able to be detected more than one year after the cataract surgery suggests that dispersed tiny droplets can slowly coalesce into a globular droplet and wander between the anterior and posterior chambers, thereby causing uveitis, corneal endothelial cell damage, and macular edema. The removal of the intraocular ointment resolved these complications. This is the second report of intraocular ointment causing macular edema.

Prolonged rhodopsin phosphorylation in light-induced retinal degeneration in rat models.

PURPOSE: The effects of various light-induced stresses on the retina were examined in the retinal degenerative rat model. METHODS: Retinal morphology and electroretinograms (ERGs) were analyzed after application of light-induced stress of several intensities (650, 1300, 2500, or 5000 lux). For evaluation of rhodopsin (Rho) function, the kinetics of Rho regeneration and dephosphorylation were studied by spectrophotometric analysis and immunofluorescence labeling with antibodies specifically directed toward the phosphorylated residues (334)Ser and (338)Ser in the C terminus of Rho. Retinal cGMP concentration was determined by ELISA. Expression levels of neurotrophic factors (FGF2, brain-derived neurotrophic factor [BDNF], platelet-derived growth factor [PDGF], and ciliary neurotrophic factor [CNTF]) were evaluated quantitatively by RT-PCR. RESULTS: Light intensity-dependent deterioration of ERG responses and thinning of the retinal outer nuclear layer were observed in wild-type and Royal College of Surgeons (RCS) rat retinas. Under dark adaptation after light-induced stress, the kinetics of Rho regeneration were not different between wild-type and RCS rat retinas. Rho dephosphorylation at (334)Ser and (338)Ser was extremely delayed in RCS rat retinas compared with wild-type without light-induced stress, but Rho dephosphorylation at those sites became slower in both RCS and wild-type rat retinas. In terms of expression of neurotrophic factors, almost no significant changes were observed between the animals after light-induced stress. CONCLUSIONS: The present study indicates that light-induced stress causes intensity-dependent deterioration in retinal function and morphology in wild-type and RCS rat retinas. Disruption of the phototransduction cascade resulting from slower kinetics of Rho dephosphorylation appears to be involved in retinal degeneration.

Acute posterior multifocal placoid pigment epitheliopathy and granulomatous uveitis following influenza vaccination.

PURPOSE: To report a case of acute placoid multifocal posterior pigment epitheliopathy (APMPPE) following influenza vaccination. The patient exhibited granulomatous uveitis during the recovery phase. OBSERVATIONS: A woman in her thirties developed flu-like symptoms seven days after receiving an influenza vaccination. Approximately 2 weeks later, the patient reported with conjunctival injection, blurred vision, and pain in her left eye. She was examined in our clinic, and the best-corrected visual acuity was 20/15 OD and 20/20 OS. Multiple whitish spots were observed bilaterally in the deep retinal layer along with edema of the left optic disc. Both indocyanine green and fluorescein angiographic findings suggested a diagnosis of APMPPE. Although APMPPE lesions were gradually resolved after one month, keratic precipitates, anterior chamber and vitreous cellular infiltration, iris and angle nodules, and macular edema were observed and were treated with topical steroid eye drops. No systemic disorders including sarcoidosis, tuberculosis, and Wegener's granulomatosis were present. CONCLUSION AND IMPORTANCE: As influenza vaccinations are administered worldwide, ophthalmologists should be aware of the ocular side effects following vaccination. Although rare, the possibility of APMPPE occurrence following influenza vaccination should be considered; additionally, the recovery phase of APMPPE may be associated with granulomatous uveitis that requires steroid therapy.

Study of effects of antiglaucoma eye drops on N-methyl-D-aspartate-induced retinal damage.

PURPOSE: To study the effects of antiglaucoma eye drops on N-methyl-D-aspartate (NMDA)-induced retinal damage. METHODS: Several antiglaucoma eye drops, beta-blockers, alpha/beta-blockers, an alpha1-blocker, an alpha2-agonist, and a prostaglandin derivative, were topically administrated to NMDA-treated rat eyes daily for 2 weeks, and the retinal thickness, the number of retrograde-labeled retinal ganglion cells (RGCs), and the results of a cDNA microarray analysis were studied. RESULTS: Intravitreal administration of NMDA caused a significant decrease in the thickness of the retinal layers and induced upregulation of glial fibrillary acidic protein (GFAP). Topical administration of beta-blockers (timolol, betaxolol, and carteolol) and a prostaglandin derivative (latanoprost) showed almost no significant effects on retinal thickness, the number of RGCs, or expression of GFAP. In contrast, the alpha/beta-blockers (nipradilol and levobunolol), the alpha1-blocker (bunazosin HCl), and the alpha2-agonist (brimonidine) showed preservation effects on retinal thickness and the number of RGCs, and marked suppression of NMDA-induced upregulation of GFAP. Among 1101 genes related to cellular regulatory mechanisms, the expression of two genes, both for insulin-like growth factors, (IGF-1) and ErbB3, was altered upon administration of the alpha/beta-blockers, the alpha1-blocker, and the alpha2-agonist. CONCLUSION: Our present study suggests that modulations of the alpha-adrenergic receptor, alpha1-blocking and alpha2-stimulation, by antiglaucoma eye drops may cause beneficial effects on NMDA-induced retinal damage in the rat.

A case of childhood vitrectomy performed for dense vitreous hemorrhage secondary to leukemia therapy and tumor lysis syndrome.

PURPOSE: To report a case of vitrectomy performed in a child with dense massive vitreous hemorrhage due to secondary acute myelogenous leukemia (AML) and tumor lysis syndrome. CASE: A 4-year-old boy with clear-cell renal cell carcinoma was successfully treated with chemotherapy in 2011. However, in May 2012, he developed secondary AML. Although he was treated with combined chemotherapy and radiation, tumor lysis syndrome occurred with renal and heart failure complications. After an ultrasound examination by pediatricians found bilateral subretinal protrusions, he was referred to our clinic. Fundus examinations confirmed that the protrusions were bilateral subretinal or choroidal hemorrhages. A few weeks later, dense vitreous hemorrhages occurred bilaterally, and he completely lost vision in both eyes. Electroretinograms were extinguished in both eyes. After improvement of his general condition, we performed a 25-gauge vitrectomy combined with lens extraction in his left eye in December 2012. After removal of the vitreous hemorrhage, we found the subretinal hemorrhage had already been absorbed, leaving a mottled fundus color. However, the optic disc was not pale. Nine months after the surgery, his best-corrected visual acuity finally improved to 0.1. CONCLUSION: We successfully treated a case of severe vitreous hemorrhage secondary to leukemia therapy and tumor lysis syndrome using 25-gauge vitrectomy. This procedure may be safe and effective to perform, even in children with complications.

Preservation of retinal morphology and functions in royal college surgeons rat by nilvadipine, a Ca(2+) antagonist.

PURPOSE: The Royal College of Surgeons (RCS) rat is the most extensively studied animal model for understanding the molecular pathology in inherited retinal degeneration, such as retinitis pigmentosa (RP). The purpose of the present study was to evaluate the pharmacologic effects of several Ca(2+) antagonists on the retinal degeneration of RCS rats. METHODS: Several Ca(2+) antagonists, diltiazem, nicardipine, nilvadipine, and nifedipine, were intraperitoneally administered and retinal morphology and functions analyzed. RESULTS: Among the Ca(2+) antagonists, only intraperitoneally administered nilvadipine preserved retinal morphology and electroretinogram responses in RCS rats during the initial stage of retinal degeneration. Studies using immunohistochemistry, RT-PCR, and Western blot analysis revealed significant enhancement of rhodopsin kinase and alphaA-crystallin expression and suppression of caspase 1 and 2 expression in the retina of nilvadipine-treated rats. CONCLUSIONS: These data suggest that nilvadipine is beneficial for the preservation of photoreceptor cells in RCS rats and can be used to treat some patients with RP.

Clinical and immunologic aspects of cancer-associated retinopathy.

PURPOSE: To report clinical and immunologic aspects of cancer-associated retinopathy (CAR). DESIGN: Observational consecutive case series. METHODS: A retrospective review was made of 18 consecutive patients with cancer-associated retinopathy who had antiretinal antibody determination by Western blot testing. RESULTS: Clinically, a variety of ophthalmic observations including electroretinography impairment, retinal vessel narrowing, deterioration of visual acuity, visual field changes, and uveitis were frequently observed. As retinal autoantigens in the 18 cases, recoverin was found in all 18 cases (100%), heat shock cognate protein 70 (HSC70) was found in six cases (33%), and other proteins were found in four cases (20%). These antibodies were detected in only 60% of the patients at the initial examination, however, and then became increasingly apparent on the subsequent testing that was performed three times on serum samples obtained sequentially during the following months. CONCLUSION: For diagnosis of cancer-associated retinopathy, the presence of serum autoantibody toward recoverin is essentially required in addition to the characteristic clinical aspects noted above.

[Surgical treatment with dacryocystitis and retinal detachment in a patient with Wegener granulomatosis].

BACKGROUND: We report surgical treatment of a patient with dacryocystitis and retinal detachment (RD), which are rare ophthalmic involvements of Wegener granulomatosis (WG). CASE: The patient was a 26-year-old man with WG. He was diagnosed as having WG 4 years ago and he has been treated by maintenance doses of predonisolone and cyclophosphamide. Rheumatoid factor and serum antinuclear antibody were negative. Cytoplasmic pattern-antineutrophil cytoplasmic antibody (C-ANCA) and renal function were normal. He was found to have nasolacrimal duct obstruction and lattice degeneration bilaterally, retinal tear with RD in the left eye and tear without RD in the right eye. No sign of vasculitis was found in fluorescein angiography. Bilateral dacryocystorhinostomy was performed without any sign of postoperative necrosis of the wound. After the surgery, epiphora and eye discharge disappeared and lacrimal passage has been maintained without obstruction. The pathological findings of his nasal mucosa and lacrimal sac showed chronic inflammation and no typical changes of WG. There was no abnormal change in the conjunctiva and sclera after an uncomplicated scleral buckling surgery. CONCLUSION: We conclude that operations such as dacryocystorhinostomy and scleral buckling surgery may be performed successfully when WG is controlled within the normal limits of C-ANCA.

Long-term effects of nilvadipine against progression of the central visual field defect in retinitis pigmentosa: an extended study.

PURPOSE: To assess the long-term effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). METHODS: Patients with RP were randomly divided into a treated group receiving oral nilvadipine and a control group. Progression of RP was evaluated with MD slope and the average sensitivity of the central 2° (ΔCENT4). RESULTS: The mean MD slopes were -0.55/-0.39 (right/left eyes, n = 19) dB/year in the treated group and -1.37/-1.15 (right/left eyes, n = 22) dB/year in the control group (P = 0.016/0.050, resp.). In both eyes, however, no statistical difference was observed between the two groups for the ΔCENT4 values. CONCLUSION: Although we confirmed that nilvadipine significantly retarded the progression of the average of MD value defects in the central 10°, it was not specific for the central 2° of the visual field in RP.

Effects of solid hyaluronic acid film on postoperative fibrous scar formation after strabismus surgery in animals.

PURPOSE: The purpose of this study was to investigate the inhibitory effect of solid hyaluronic acid-carboxymethylcellulose film on the formation of wound adhesion after strabismus surgery on rabbit eyes. METHODS: The authors performed strabismus surgery on rabbit eyes with hyaluronic acid film applied under and above the muscles. Histological examination was performed 90 days postoperatively using Masson trichrome staining. The length of adhesion tissues in the operated area was quantitatively compared between film-treated and control eyes. RESULTS: Hyaluronic acid film significantly prevented the formation of adhesions between muscle, conjunctiva, and sclera after strabismus surgery (t test, P < .05). CONCLUSION: The current results indicate that hyaluronic acid film can inhibit the formation of postoperative adhesion around conjunctiva, muscle, and sclera to some extent. The authors conclude that this substance offers potential benefits for ophthalmic surgery, not only with strabismus surgery but also procedures such as scleral buckle.

Solid hyaluronic acid film and the prevention of postoperative fibrous scar formation in experimental animal eyes.

OBJECTIVE: To investigate the inhibitory effect of solid hyaluronic acid-carboxymethyl cellulose film (hyaluronic acid film) on the formation of postoperative wound adhesion on rabbit eyes. METHODS: We first created a conjunctival flap under which hyaluronic acid film was inserted. Then, we performed trabeculectomy on other rabbit eyes with hyaluronic acid film applied under and above the scleral flaps. Expression of proliferative cell nuclear antigen and alpha-smooth muscle actin (alpha-SMA) were histologically and immunohistochemically examined. RESULTS: Hyaluronic acid film significantly prevented adhesions after both kinds of surgery. Particularly, subconjunctival scar formation was significantly inhibited when the film was simply inserted under the wound. Furthermore, the adhesion around the scleral flap of trabeculectomy was less formed in eyes treated with hyaluronic acid film than in control eyes. Immunoreactivity to proliferative cell nuclear antigen almost disappeared after 28 days postoperatively in both treated and control groups. The alpha-SMA-positive cells appeared much less around the film-treated wound than the control eye. CONCLUSION: The present results indicate that hyaluronic acid film can inhibit the formation of postoperative adhesion around the conjunctiva and sclera. CLINICAL RELEVANCE: The results of this study indicate that this substance has potential benefits for improving ophthalmic surgery, such as filtering surgery for glaucoma.

Misregulation of rhodopsin phosphorylation and dephosphorylation found in P23H rat retinal degeneration.

To examine rhodopsin (Rho) functions in P23H rat, kinetics of Rho regeneration and dephosphorylation were investigated by spectrophotometric analysis and immunofluorescence labeling method using specific antibodies toward phosphorylated 334Ser or 338Ser site. Rho dephosphorylation at both sites was extremely delayed in P23H retina as compared to normal ones. Kinetics of Rho regeneration was not altered between normal and P23H rats under dark adaptation. Next, to study the effects of several Ca(2+)channel blockers on this model, retinal function and morphology were evaluated. Among them, nilvadipine showed a significant protective effect against P23H retinal degeneration. Neurotrophic factor, fibroblast growth factor-2 and Arc, known to suppress the apoptosis in the central nervous system, were significantly upregulated upon administration of nilvadipine. The present study indicates that misregulation of Rho phosphorylation may be involved as an important step in retinal degeneration of P23H and administration of nilvadipine may be a potential therapeutic agent for the retinal degenerations.