低氧诱导人视网膜血管内皮细胞中乙酰肝素酶和血管内皮生长因子相关性研究

目的 观察人视网膜血管内皮细胞（HREC）低氧模型中乙酰肝素酶（Hpa）、血管内皮生长因子(VEGF)和RNA 聚合酶-Ⅱ (Pol-Ⅱ)的表达变化,探讨低氧性视网膜新生血管形成中Hpa和VEGF的相关性及可能机制。方法 使用低氧模拟剂氯化钴（CoCl2）造成HREC低氧模型,分为4组,分别为正常对照组、低氧诱导组、磷酸甘露戊糖硫酸盐（PI-88）组和空白对照组。低氧诱导组为含CoCl2 100 μmol/ml的培养液培养48 h;PI-88组为含CoCl2 100 μmol/L和Hpa竞争性抑制剂PI 88 5 μg/ml的培养液干预48 h;空白对照组为等量PBS干预HREC 48 h。免疫荧光染色法观察正常对照组和低氧诱导组HREC中Hpa、VEGF以及Pol Ⅱ的表达。蛋白质免疫印迹（Western blot）检测各组间Hpa和VEGF蛋白表达变化。 结果免疫荧光染色结果显示,低氧诱导组HREC细胞质内Hpa荧光和VEGF荧光均较正常对照组增强;PI-88组细胞质内VEGF荧光较低氧诱导组减弱。低氧诱导组细胞核内Hpa较正常对照组明显增强,且分布与Pol-Ⅱ相吻合。Western blot检测结果显示,与正常对照组比较,低氧诱导组Hpa蛋白和VEGF蛋白表达均明显升高,差异有统计学意义（Hpa：F=-4.005,P＜0.05;VEGF：F=-4.063,P＜0.05）;PI-88组VEGF蛋白表达较低氧诱导组VEGF蛋白表达降低,差异有统计学意义（F=5.963,P＜0.05）。结论 低氧诱导的HREC中,Hpa的表达增高,导致VEGF的增加,促进了视网膜新生血管形成。     

Comparative toxicity of 4 commonly used intravitreal corticosteroids on rat retina

Objective: To investigate the effects of 4 commonly used steroids (dexamethasone, triamcinolone, betamethasone, and methylprednisolone) on 50 retinas of 25 adult pigmented rats.Study Design: Experimental animal study.Participants: Twenty-five pigmented Long-Evans male rats.Methods: Each steroid drug with 2 different doses (0.025 mL and 0.050 mL) was injected into the vitreous of each eye of 5 rats. The low drug dose was injected into the right eye and the high dose was injected into the left eye. Ten eyes of 5 randomly selected rats were used as a control group and intravitreal saline was injected into these eyes. Oxidative damage and intrinsic antioxidative capacity were determined by measuring retinal malondialdehyde (MDA) and glutathione (GSH) levels, respectively.Results: No statistically meaningful difference was observed in retinal GSH and MDA measurements in the lowand high-dose triamcinolone (1 and 2 mg), low-dose betamethasone (0.075 mg), and low-dose dexamethasone (0.1 mg) groups, compared with the control group. Both doses of methylprednisolone (1.6 mg and 3.2 mg), high-dose betamethasone (0.15 mg), and high-dose dexamethasone (0.2 mg) markedly altered retinal GSH and MDA levels. Conclusions: The results of our study show that the toxicity of triamcinolone is not evident even in high doses. It may be used safely. We also suggest that intravitreal use of low doses of betamethasone and dexamethasone is safer than higher doses of these drugs and both doses of methylprednisolone.     

Nerve fibre layer thinning in patients with preclinical retinopathy

Objective: To compare retinal nerve fibre layer thickness (RNFLT) obtained by optical coherence tomography (OCT) between patients with preclinical diabetic retinopathy (DR) and healthy subjects.Study Design: Cross-sectional study.Participants: Ninety-nine type I or II diabetic patients with no visible funduscopic retinal alteration and 77 healthy subjects were included in this study.Methods: All participants were evaluated for peripapillary RNFLT by Stratus OCT. In diabetic patients, levels of blood sugar and glycosylated hemoglobin were examined.Results: The mean RNFLT in diabetic patients and healthy subjects was significantly different (104.2 [SD 10.4] and 108.6 [SD 9.2] mm, respectively; p = 0.004). Compared with the healthy group, the RNFLT in the diabetic group was also significantly less in the superior quadrant and at the 5,11, and 12 o'clock sectors (p = 0.04, 0.002, and 0.001, respectively). The average RNFLT in diabetic patients with preclinical DR showed a low correlation with fasting blood sugar level (p = 0.03).Conclusions: The mean and superior quadrant peripapillary RNFLT was slightly less in diabetic patients without abnormal vascular manifestations than in healthy subjects. Furthermore, lower RNFLT values in patients with pre- clinical DR appears to be weakly associated with high levels of fasting blood sugar.     

Prevalence and determinants of retinopathy in a cohort of Lebanese type II diabetic patients

Objective: Our aim was to determine the prevalence and the risk factors for diabetic retinopathy (DR) in a cohort of type II diabetic patients in LebanonDesign: Prospective observational cohort study.Participants: Five hundred consecutive patients with type II diabetes mellitus followed at the American University of Beirut Medical Center diabetes clinic were enrolled in the study.Methods: All patients 18 years or older with diabetes mellitus who did not have gestational diabetes and who were able to complete the laboratory data and the retinal examination were invited to participate in the study; they were followed up for a period of 3 years.Results: DR was present in 175 patients (35%), 130 (26%), and 45 (9%) having nonproliferative and proliferative DR, respectively. Clinically significant macular edema was present in 42 patients (8%). Microvascular and macrovascular diabetic complications, duration of disease, glycemic control, presence of hypertension (p < 0.003), systolic blood pressure (p = 0.04), and insulin use (p < 0.001) were individually significantly associated with a higher prevalence of DR on bivariate analysis. However, on multivariate regression analysis, only glycosylated hemoglobin >7% (odds ratio [OR] 2.81, 95% CI 1.06-7.43, p = 0.038), duration of diabetes (per 10 years, OR 9.0, 95% CI 4.0-20.0, p < 0.001), macroalbuminuria (OR 2.6, 95% CI 1.14-5.96 p = 0.023), and systolic blood pressure (per 10 mm Hg, OR 1.27, 95% CI 1.0-1.56, p = 0.037) were independent risk factors for DR.Conclusions: The elevated prevalence of DR in type II diabetic patients with high risk profiles calls for early medical intervention and education about DR and its identified controllable risk factors.     

Effects of alpha-lipoic acid on retinal ganglion cells,retinal thicknesses,and VEGF production in an experimental model of diabetes

Purpose

The purpose of the present study was to investigate the effect of alpha-lipoic acid (ALA) on the thicknesses of various retinal layers and on the numbers of retinal ganglion cells and vascular endothelial growth factor levels in experimental diabetic mouse retinas.

Methods

Twenty-one male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). One week after the induction of diabetes, the mice were divided randomly into three groups: control group (non-diabetic mice treated with alpha-lipoic acid, n = 7), diabetic group (diabetic mice without treatment, n = 7), and alpha-lipoic acid treatment group (diabetic mice with alpha-lipoic acid treatment, n = 7). At the end of the 8th week, the thicknesses of the inner nuclear layer (INL), outer nuclear layer (ONL), and full-length retina were measured; also retinal ganglion cells and VEGF expressions were counted on the histological sections of the mouse retinas and compared with each other.

Results

The thicknesses of the full-length retina, ONL, and INL were significantly reduced in the diabetic group compared to the control and ALA treatment groups (p = 0.001), whereas the thicknesses of these layers did not show a significant difference between ALA treatment and control groups. The number of ganglion cells in the diabetic group was significantly lower than those in the control and ALA treatment groups (p = 0.001). The VEGF expression was significantly higher in the diabetic group and mostly observed in the ganglion cell and inner nuclear layers compared to the control and ALA treatment groups (p = 0.001). Therefore, the number of ganglion cells and VEGF levels did not show significant differences between the ALA treatment and control groups (p = 0.7).

Conclusions

Our results show that alpha-lipoic acid treatment may have an impact on reducing VEGF levels, protecting ganglion cells, and preserving the thicknesses of the inner and outer layers in diabetic mouse retinas.

     

Adenoma of the retinal pigment epithelium: a report of 3 cases

Objective: To report the clinical manifestations and pathologic features of adenoma of the retinal pigment epithelium (RPE).Design: Retrospective study.Participants: Three patients with an initial clinical diagnosis of choroidal melanoma.Methods: Routine eye examinations, including visual acuity, intraocular pressure, slit-lamp examination, and ophthalmoscopy, were performed. Auxiliary examinations included fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), B-scan ultrasonography, colour Doppler imaging (CDI), and MRI. Endoresection of the tumours was performed, and the specimens underwent pathological examination.Results: The tumours were of yellow-pink or brown colour and all located in the right eye. On FFA and ICGA, the tumours demonstrated hypofluorescence in the early phase and hyperfluorescence with prominent leakage in the late phase. CDI showed arterial blood signals in the tumour, and MRI showed hyperintensity in the T1-weighted image and hypointensity in the T2-weighted image. On pathological examination all the tumours were positive with periodic acid-Schiff, S-100, neurone-specific enolase, synaptophysin, epithelial membrane antigen, and vimentin staining but negative with melanoma-specific antigen HMB45, and cytokeratin. After 3 years of follow-up, there was no tumour recurrence and the retinas remained attached.Conclusions: RPE-derived adenoma is difficult to diagnose clinically. In most cases, pathological confirmation is needed. Local resection is a favorable alternative treatment for some patients.     

Inverse horse-shoe technique for the phacoemulsification of posterior polar cataract

Objective: To study a new technique of controlled hydrodelineation followed by viscodelineation and viscodissection during phacoemulsification in eyes with posterior polar cataracts and to report its effectiveness in preserving the posterior capsule.Design: Prospective interventional study.Participants: Twenty-eight eyes of 22 patients with posterior polar cataracts.Methods: All patients underwent phacoemulsification under topical anaesthesia with controlled hydrodelineation, viscodelineation, and viscodissection with minimal stress on the posterior capsule. Hydrodissection was not done. The preoperative complications and visual outcome were recorded.Results: The mean follow-up time was 8 months (range 2-24 months). Posterior capsule rupture occurred only in 2 eyes (7.1%); neither of the 2 had any vitreous prolapse, so anteriorvitrectomy was not required. Mean visual acuity improved significantly after surgery (p = 0.0001, paired t test). The causes of the low postoperative visual acuity were amblyopia in 3 eyes (10.7%) and age-related macular degeneration in 1 (3.6%).Conclusions: This inverse horse-shoe technique of controlled viscodelineation and viscodissection markedly reduced the risk of posterior capsule rupture. Moreover, if it occurred, the anterior vitreous face remained intact, so the IOL could be implanted in the sulcus without resorting to anterior vitrectomy.     

EphrinB2 and EphB4 expression in pterygia: new insights and preliminary results

Objective: Pterygium is a growth of fibrovascular tissue onto the cornea, in which the mechanisms of cell proliferation and vascularization are unknown. The ephrin-Eph system, especially ephrinB2 and its receptor EphB4, has been shown to play an important role in tumor angiogenesis. EphrinB2 and EphB4 have also been reportedly involved in the pathogenesis of ocular angiogenesis. This study was designed to investigate the expression of ephrinB2 and its receptor EphB4 in pterygia.Design: Experimental study of the expression of ephrinB2 and its receptor EphB4 in pterygia.Participants: Twenty-three primary pterygia, 5 recurrent pterygia, and 11 normal conjunctiva were studied.Methods: Immunohistochemistry studies were used to assess ephrinB2 and EphB4 protein expression levels and the tissue distribution in the samples.Results: EphrinB2 and EphB4 staining was present at a dense level in the total epithelium of the head portions of both primary and recurrent pterygial specimens, although just in the basal and parabasal layer of the epithelium of most of the normal conjunctivae.Conclusions: EphrinB2 and EphB4 appear to be overexpressed in pterygium, and they may play important roles in its development.     

Transconjunctival suturing of the scleral flap for overfiltration with hypotony maculopathy after trabeculectomy

Objective: To assess the efficacy of transconjunctival suturing of the scleral flap in improving hypotony maculopathy resulting from overfiltration after trabeculectomy.Design: Retrospective review.Participants: 35 eyes of 33 patients.Methods: Patients underwent transconjunctival scleral flap suturing for hypotony maculopathy following trabeculectomy using mitomycin C. The scleral flap was sutured through the conjunctiva as an outpatient clinic procedure using a spatulated needle with a 10-0 nylon suture.Results: The average age of the patients was 67.5 (SD 4.80, range 39-83) years, and 52% patients were male. The average duration of hypotony prior to transconjunctival suturing of the flap was 108.0 (SD 68.3) days. The median intraocular pressure (IOP) before suturing was 3 mm Hg, and the median IOP 6 months after the procedure was 9 mm Hg (p < 0.0001). The median best-corrected visual acuity (BCVA) before transconjunctival suturing of the scleral flap was 20/100, and the median BCVA 6 months after the procedure was 20/30 (p < 0.0001). Compared with visual acuity before suturing the average gain in BCVA was 4.9 (SD 0.8) lines.Conclusions: Transconjunctival suturing of the trabeculectomy scleral flap is an effective treatment to raise IOP and improve visual loss from hypotony maculopathy after trabeculectomy with overfiltering blebs.     

Diphenhydramine as a topical ocular anesthetic

Objective: To determine whether 5% diphenhydramine solution has an anesthetic effect when administered topically to rabbit corneas.Design: Experimental study.Participants: Twenty white New Zealand rabbits.Methods: Twenty rabbits at the University of Arkansas for Medical Sciences received 1 drop of 5% diphenhydramine solution in the left eye and 1 drop of balanced salt solution in the right eye. Corneal sensation was then measured with a Cochet-Bonnet esthesiometer at 30-, 60-, and 90-minute intervals. Rabbits were observed for conjunctival reaction. Follow-up fluorescein and Rose Bengal slit-lamp examinations were then performed to assess toxicity.Results: Diphenhydramine solution at a 5% concentration demonstrated a significant anesthetic effect 30, 60, and 90 minutes after instillation (p < 0.0001, p = 0.0001, p = 0.0164, respectively). Mild conjunctival injection occurred in all diphenhydramine-treated eyes. No toxic effects on the corneal epithelium were observed.Conclusions: When applied topically to rabbit corneas, 5% diphenhydramine solution has a significant anesthetizing effect compared with salt solution (control eyes). Topical diphenhydramine may be a safe alternative in patients requiring topical anesthesia who have multiple allergies to topical anesthetics. Additional studies are needed to determine a dose-response curve and to further evaluate corneal toxicity prior to use in humans.     

Combined horizontal rectus muscle minimally invasive strabismus surgery for exotropia

Objective: To evaluate combined horizontal rectus muscle minimally invasive strabismus surgery (MISS) for exotropia.Design: Case series.Participants: Fifty-two consecutive exotropic patients operated on by 1 surgeon with MISS combined unilateral lateral rectus muscle recession and medial rectus muscle plication.Methods: Alignment, binocular single vision, conjunctival injection and swelling, and complications during the first 6 postoperative months were recorded prospectively. Conjunctival swelling and injection on the first postoperative day were scored retrospectively and compared with historic controls operated on with combined recession-plication or recession-resection using a limbal approach.Results: Conjunctival swelling and injection were mainly mild on the first postoperative day and less pronounced than after surgery with a limbal approach (comparison of swelling and injection for MISS vs limbal opening recession-plication p < 0.001 and for MISS vs limbal opening recession-resection p < 0.001). A conversion to a limbal approach was necessary in 3/104 (3%, 95% CI 1%-7%) of all muscles. No scleral perforation or other serious complication was observed, and no patient needed a repeat operation within 6 months (0/49, 0%, 95% CI 0%-6%).Conclusions: This study demonstrates that small-incision, minimal dissection combined recession-plication surgery induces less conjunctival swelling and injection compared with the usual limbal approach.     

Assessment of perceived difficulties by residents in performing routine steps in phacoemulsification surgery and in managing complications

Objective: To analyze the perceived difficulties of residents in performing the routine steps of phacoemulsification surgery and in managing complications.Design: Cross-sectional questionnaire-based study.Participants: Thirty-six residents performing phacoemulsification during their learning curve.Methods: On an 8-point Likert scale, residents noted comfort levels with various steps of cataract surgery and with managing complications.Results: The respondents were grouped into Group 1 (second-year residents, n = 19) and Group 2 (third-year residents, n = 17). Residents in Group 2 had greater surgical experience than residents in Group 1 (p = 0.001). The most difficult step in cases of phacoemulsification for Group 1 was loading a foldable intraocular lens (IOL) (mean score 6.05, SD 1.57), and for Group 2 it was nuclear emulsification (mean score 3.59, SD 1.42). Both second- and third-year residents found capsular bag dialysis the most difficult complication (mean scores 6.0 [SD 1.9] and 5.75 [SD 2.14], respectively). The second-year residents had significantly more difficulty with errant capsulorrhexis, anterior chamber IOL placement, and repeated iris prolapse as compared with third-year residents. Group 2 residents reported that mature, senile cataracts were the most difficult cases for them to manage (mean score 6.23, SD 1.56).Conclusions: This study identifies perceived difficulties that residents experience in routine cases of cataract surgery, highlighting specific areas in which they may benefit from additional training and practice.     

The relationship between scotoma displacement and preferred retinal loci in low-vision patients with age-related macular degeneration

Objective: Adaptive strategies in low-vision patients with age-related macular degeneration use preferred retinal loci (PRLs) for the purpose of achieving better visual function. In the process of redirecting the eye toward the PRL, central scotomata are displaced eccentrically. The consequential effect of the first on the second may offer an indirect method for PRL identification. The purpose of this study was to clarify the relationship between scotoma displacement and PRL location.Design: Prospective, nonrandomized, observational case series.Participants: Forty-one adults with a confirmed diagnosis of age-related macular degeneration.Methods: Scotoma characteristics were obtained with automated perimetry. PRL topography was obtained with the Nidek MP-1 instrument. Outcome measures selected for this study were scotoma displacement and PRL eccentricities estimates.Results: We tested 16 males and 25 females aged 70-98 years (mean 82.5 [SD 6.71] years) with best-corrected visual acuity of 0.81 (SD 0.24) logMar units (20/128). PRL location logically matched scotoma displacement in 30 study subjects (73.17%, p < 0.00432). In this subgroup (n = 30), PRL eccentricity (5.55 [SD 3.35]°) was almost identical to scotoma displacement eccentricity (5.22 [SD l.98]°) (p < 0.65).Conclusions: Scotoma displacement recorded with macular perimetry methods offers reasonable indirect estimates of PRL location.     

Visual acuity after intravitreal triamcinolone for diabetic macular edema refractory to laser treatment: A meta-analysis

Objective: To quantify the effect on visual acuity of intravitreal triamcinolone for the treatment of laser-refractory diabetic macular edema (DME).Study Design: Meta-analysis of eligible studies identified by searching MEDLINE, EMBASE, the Cochrane Library, and Google.Participants: 7 randomized controlled trials and 3 cohort studies.Methods: A search of the literature between 1950 and September 2008 identified 540 articles. Studies that evaluated the efficacy of triamcinolone for the treatment of DME refractory to laser photocoagulation, reported visual acuity data, and compared the intervention with an appropriate control group were included. Exclusion criteria were studies of non-DME, triamcinolone used as an adjunct to another treatment, and triamcinolone delivery other than intravitreally.Results: Using a random-effects model, there was a statistically significant summary mean difference in visual acuity of −0.3 13 logarithm of the minimum angle of resolution (logMAR) units (95% CI −0.55 1, −0.074) after 1 month of follow-up. This difference declined to −0.125 logMAR units (95% CI −0.181, −0.070) by 3 months and to −0.043 logMAR units (95% CI −0.090, 0.003) by 6 months. No evidence of publication bias was present. There was a high level of heterogeneity in this group of studies (meta-analysis of 1-month follow-up data: Q-statistic = 21.987, p < 0.001), attributable primarily to study design.Conclusions: These meta-analyses demonstrate that intravitreal triamcinolone results in a temporary improvement of visual acuity in patients with laser-refractory DME, with a peak benefit of approximately 3 lines of visual acuity 1 month postinjection.     

The effect of oral acetazolamide on weight gain in children

Objective: Oral acetazolamide is a potent medical treatment for pediatric glaucoma, but ophthalmologists may have concerns that it retards weight gain in children and may choose surgical management instead.Design: Retrospective chart review.Participants: Twenty-two well children with glaucoma taking acetazolamide orally for ≥ 3 months.Methods: Abnormal weight gain was determined using downward crossing of 2 percentile lines on growth charts and change in z score for weight using a hierarchical linear model.Results: One patient with Sturge-Weber syndrome and growth failure was excluded when growth hormone deficiency was diagnosed. Two patients crossed 2 lines downward; both showed metabolic acidosis. The trend for the 2 reversed after medication was discontinued. The other 20 tracked steadily on growth curves. Eleven patients (11/22, 50%) showed a decline in z score for weight over the follow-up period, and the remainder showed an increase, for an overall estimate of slope in this sample of 0.01, which was not significant (p = 0.8).Conclusions: Oral acetazolamide may cause poor weight gain in a small subset of children on treatment. Metabolic acidosis may be a mediating factor for growth failure. Our data suggest that acetazolamide does not cause significant weight changes in cases of pediatric glaucoma. Growth parameters should be followed. Growth hormone deficiency should be considered in Sturge-Weber syndrome. Prospective study is needed.     

Combination therapy in exudative age-related macular degeneration: visual outcomes following combined treatment with photodynamic therapy and intravitreal bevacizumab

Objective: To measure visual outcomes following combined treatment with photodynamic therapy (PDT) and intra-vitreal bevacizumab for exudative age-related macular degeneration (AMD).Design: Single-centre, retrospective cohort analysis.Participants: One hundred and seventy-four eyes in 174 patients, representing a consecutive series of all patients with at least 6 months’ follow-up after combined treatment with PDT and bevacizumab for exudative AMD.Methods: Each patient was treated with PDT, followed by intravitreal injection of bevacizumab approximately 30 minutes later. The patients were then followed at 8-12-week intervals. The primary outcome of the study was the mean change in visual acuity (VA) from baseline.Results: One hundred seventy-four eyes in 174 patients completed at least 6 months’ follow-up, with a mean duration of 10 months. The mean number of treatments was 3.0 for bevacizumab and 1.4 for PDT. After stabilization, the mean treatment-free interval was 193 days, and 52% of the patients did not require postinduction retreatment. Mean VA improved from baseline at 2,4, and 6 months of follow-up (p < 0.05). In the subgroup analysis, treatment-naïve patients had more favorable visual outcomes (p < 0.05).Conclusions: The combination of PDT and intravitreal bevacizumab is an effective therapy for preserving VA in patients with exudative AMD.     

The prevalence of diabetic retinopathy as identified by teleophthalmology in rural Alberta

Objective: The purpose of this study was to assess the prevalence of diabetic retinopathy (DR) as identified by teleophthalmology in a sample population of people with diabetes living in rural Alberta and to identify the risks and benefits of a teleophthalmology program for these patients.Design: Retrospective consecutive case series.Participants: Three hundred ninety-four diabetic patients (788 eyes).Methods: Medical histories were obtained, following which patients underwent visual acuity and intraocular pressure measurements and stereoscopic, 7-field, digital retinal photography. Images were graded by ophthalmologists in Edmonton, Alta., according to a modified Early Treatment Diabetic Retinopathy Study scoring template. Diagnosis, treatment, and follow-up recommendations were communicated to local health care providers and data were collected for review.Results: Three hundred ninety-four patients (788 eyes) were assessed via 593 teleophthalmology visits over the 3-year period. DR was identified in 27.2% of patients (2.3% with proliferative DR and 24.9% with nonproliferative DR). A variety of other diagnoses, independent of DR, were also made. Recommendations for follow-up teleophthalmology and in-person referral were completed in 76.8% and 87.3% of patients, respectively, although many were completed later than was recommended. Teleophthalmology saved approximately 450 round trips from Edson to the nearest urban centre (Edmonton) over the 2-year period, equating to approximately 1900 hours and 180 000 km of driving.Conclusions: Teleophthalmology can effectively identify DR while reducing travel time and distance for patients with diabetes living in a rural community. However, many patients did not follow up or attend referral appointments in a timely fashion, underscoring the need for ongoing quality assessment.     

Contribution of Nitric Oxide-Producing Cells in Normal and Diabetic Rat Retina

Purpose

To examine the immunohistochemical localization of l-arginine and l-citrulline and determine where and how nitric oxide (NO) is produced in the normal and streptozotocin (STZ)-induced diabetic rat retinas.

Methods

NO is produced when l-arginine is changed to l-citrulline by NO synthase (NOS). In normal and STZ-induced diabetic rats, using an immunohistochemical method, we examined the retinal distribution of l-arginine and l-citrulline after intracardiac perfusion. We studied the distribution of NOS after immersed fixation and analyzed the number of neuronal NOS (nNOS)-positive neurons.

Results

We observed l-arginine localization in the internal limiting membrane (ILM), the ganglion cell layer (GCL), and the inner nuclear layer (INL). l-Arginine immunoreactivity in the diabetic rat retinas was found in the inner plexiform layer (IPL), as well as in the normal retina. l-Citrulline immunoreactivity in the normal and diabetic retinas was observed in the ILM, the GCL, the IPL, and the INL. nNOS staining in the normal and diabetic rat retinas was observed in the GCL, the IPL and the INL. The number of nNOS-positive amacrine cells was less in the diabetic rat retinas.

Conclusion

NO might be produced in the GCL and amacrine cells, which show immunoreactivity to l-arginine, l-citrulline, and nNOS. In the early stage of diabetic retinopathy in STZ rat retinas, diabetes disturbed the function of the nNOS-positive amacrine cells and reduced NO production via nNOS. Jpn J Ophthalmol 2005;49:363–370 © Japanese Ophthalmological Society 2005     

Outcome of intravitreal bevacizumab for idiopathic choroidal neovascularization in a Chinese population

Objective: To assess the long-term visual and anatomical outcomes and safety of intravitreal injection of bevacizumab for idiopathic choroidal neovascularization (ICNV) in Chinese patients.Design: Retrospective interventional case series.Participants: Seventy-seven eyes of 77 patients with ICNV.Methods: Patients were given intravitreal injection of bevacizumab (1.25 mg/0.05 mL) for ICNV between March 2006 and May 2008. Main outcome measures were changes in best-corrected visual acuity (BCVA), central foveal thickness, which was measured by optical coherence tomography, and fluorescein angiography findings.Results: Mean follow-up was 14.3 (SD 2.4, range 10∼20) months. Mean BCVA improved from 0.66 (SD 0.36) logMAR at baseline to 0.25 (SD 0.28) logMAR at final follow-up (p < 0.001). Sixty-one patients (79%) gained BCVA of ≥2 Snellen lines, and 1 eye (1%) lost BCVA of ≥2 Snellen lines. Mean central foveal thickness decreased from 365 (SD 124) μm at baseline to 211 (SD 94) μm at final visit (p < 0.001). Sixty-two eyes (81%) needed reinjection. Both BCVA improvement and the change in central foveal thickness between the 1 — time injection group and the multi-injections group were not statistically significant (p = 0.45 and p = 0.19, respectively). No significant ocular or systemic adverse effects were observed.Conclusions: The long-term results suggest an encouraging efficacy and safety of intravitreal bevacizumab for ICNV in Chinese patients.     

Intraocular pressure adjusted for central corneal thickness as a screening tool for open-angle glaucoma in an at-risk population

Objective: Evaluation of intraocular pressure (IOP) adjusted for central corneal thickness (CCT) screening for open-angle glaucoma (OAG) in an at-risk population.Study Design: Community-based screening clinic.Participants: Three hundred and forty-nine persons of black race, or >50 years of age, or with a positive family history of glaucoma.Methods: Ophthalmological examination including Goldmann applanation tonometry, ultrasonographic corneal pa-chymetry, and visual field testing. Glaucomatous optic nerve damage with visual field loss was the gold standard. IOP was adjusted for CCT based on 3 nomograms. Results were compared with screening using unadjusted IOP. Outcome measures included sensitivity, specificity, areas under the receiver operating characteristic (ROC) curves, positive and negative predictive values (PPVs and NPVs), as well as positive and negative likelihood ratios.Results: No significant difference in CCT was found between those with glaucoma (560 [SD 37] µm, n = 31) and those without (557 [SD 35] um, n = 233). Screening adjusted IOPs for glaucoma with an IOP > 21 mm Hg resulted in PPVs of 23.8% to 25% and NPVs of 89.3% to 89.6%, similar to preadjustment values. Areas under the ROC curves varied from 0.544 to 0.571 post adjustment from the initial value of 0.574.Conclusions: IOP adjusted for CCT is unlikely to improve tonometry as a screening tool for OAG in an at-risk population.