Concurrent removal of intravitreal lens fragments after phacoemulsification with pars plana vitrectomy prevents development of retinal detachment.

AIM: To evaluate the outcomes of "concurrent vitrectomy" to retrieve dislocated lens fragment during phacoemulsification. METHODS: In a retrospective, observational case series, data of patients who underwent "concurrent" pars plana vitrectomy (PPV) for dislocated lens fragments between the period 2000 and 2008 were reviewed. Data collected included patient demographics, pre-operative visual acuity, intra-operative occurrence of retinal breaks, duration of follow up, post-operative intraocular pressure, final best-corrected visual acuity (BCVA), presence of cystoid macular edema (CME) and occurrence of rhegmatogenous retinal detachment (RRD). RESULTS: A total of 58 eyes of 58 patients were included in the study. At 12mo the mean postoperative BCVA was logMAR 0.17 (20/30) with a range of logMAR 0 to 0.69 (20/20 to 20/100), with 96.6% (56/58) of patients showing post-operative improvement in visual acuity (P=0.005). None of the patients developed postoperative retinal detachment, endophthalmitis or non-resolving uveitis at 12mo. CONCLUSION: Our study results suggest concurrent PPV for retained lens fragments after cataract surgery is beneficial and may decrease the risk of glaucoma and prevent development of RRD.

Spectral domain optical coherence tomography documented rapid resolution of pseudophakic cystoid macular edema with topical difluprednate.

INTRODUCTION: Pseudophakic cystoid macular edema is a common cause of poor vision after cataract surgery, and topical corticosteroids and nonsteroidal anti-inflammatory drugs are used for its treatment. We investigated the effectiveness of difluprednate (Durezol(®), recently approved by the US Food and Drug Administration) in the treatment of cystoid macular edema, assisted with spectral domain optical coherence tomography (SD-OCT). CASE REPORT: A 63-year-old African-American woman presented 6 weeks after uneventful cataract surgery in her left eye with decreased vision and associated distortion of the central visual field. Fluorescein angiogram and SD-OCT confirmed pseudophakic cystoid macular edema. Difluprednate was topically administered twice daily and monitored with serial imaging. Resolution was noted after 1 month of topical therapy, with improvement in visual acuity and resolution of distortion. CONCLUSION: Difluprednate is an effective treatment for patients with severe pseudophakic cystoid macular edema. SD-OCT allows the physician to monitor resolution of the macular edema easily.

Prophylactic circumferential intraoperative laser retinopexy decreases the risk of retinal detachment after macular hole surgery.

PURPOSE: Pars plana vitrectomy with peeling of the internal limiting membrane is a well-established technique for the treatment of idiopathic macular holes with high success rates. Complications such as retinal tears may result from vitreous incarceration at the sclerotomy sites. Prophylactic laser retinopexy (LR) has recently been shown to decrease incidence of postvitrectomy rhegmatogenous retinal detachment but its efficacy in macular hole repair has not been established. In this study we evaluated the safety and efficacy of prophylactic LR and compared the patients to a control group that did not receive prophylactic treatment. METHODS: A retrospective, consecutive chart review was conducted comparing patients who underwent macular hole repair with LR to without LR. Patient demographics were collected and the number and time interval of retinal detachment in the 2 groups were compared. Statistical analysis was conducted between the 2 groups. RESULTS: A total of 144 eyes underwent macular hole repair during the study period. A total of 76 eyes underwent LR and 68 eyes did not undergo LR. There were no significant differences in baseline characteristics between the 2 groups. At 1 year, RD occurred in 1 eye (1.31%) in the LR group and in 8 eyes (8.82%) without LR group (p<0.01). CONCLUSIONS: Prophylactic LR decreases the incidence of postoperative retinal detachment a potentially disabling complication of macular hole repair surgery.

Evaluation of a Novel, Non Contact, Automated Focal Laser with Integrated (NAVILAS) Fluorescein Angiography for Diabetic Macular Edema.

PURPOSE: To evaluate the procedural experience and complications of a novel integrated laser delivery system (NAVILAS(®); OD-OS Teltow, Germany) that combines automated laser delivery with color fundus photography, fluorescein angiography (FA), fundus autofluorescence (FAF) and infrared imaging with a frequency doubled YAG laser. MATERIALS AND METHODS: This prospective study evaluated surgical experience with the NAVILAS automated photocoagulation system for the treatment of patients with diabetic macular edema (DME). Subjective assessment of the accuracy of laser spot placement and postoperative complications were documented. RESULTS: Twelve patients (7 males, 5 females) were enrolled in this pilot study. Five patients were phakic and 7 were pseudophakic. Image overlays and the tracking system allowed accurate delivery of laser spots of varying size, duration and power. None of the patients reported any pain and tolerated the procedure well. No complications were reported in the study. CONCLUSION: In this pilot study, the NAVILAS system allowed accurate laser spot placement with no complications in patients with DME. However a larger sample with longer follow up is required to determine the safety of this procedure.

Hypoxia initiates sirtuin1-mediated vascular endothelial growth factor activation in choroidal endothelial cells through hypoxia inducible factor-2α.

PURPOSE: Hypoxia is a critical pathological factor in a variety of retinal diseases, including age-related macular degeneration. It upregulates angiogenic growth factors and promotes neovascularization. Hypoxia changes the cellular redox state and activates class III histone deacetylase sirtuin1 (SIRT1). Activated SIRT1 signals hypoxia inducible factor (HIF)-2α, which transactivates vascular endothelial growth factor (VEGF) and erythropoietin. In this study, we investigated the role of hypoxia induced SIRT1 in choroidal neovascularization in relation to age-related macular degeneration. METHODS: Choroidal endothelial cells (RF/6A) were maintained in a semiconfluent state and hypoxia was induced by exposing the cells to cobalt chloride for 24 h. Induction of hypoxia was confirmed by flow cytometric analysis and the levels of SIRT1 were noted in a hypoxic condition as well in the cells after blocking SIRT1 activity using sirtinol. The role of SIRT1 in the activation of HIF-2α and nuclear factor-κB (RelA/p65) during hypoxia in the presence or absence of SIRT1 was assessed using immunoblot analysis. VEGF levels were quantified using enzyme-linked immunosorbent assay. RESULTS: Hypoxic induction was confirmed using flow cytometric analysis, which showed cell cycle arrest starting at a 200 µM concentration of cobalt chloride. Hypoxic treatment (200 µM concentration of cobalt chloride) increased SIRT1 levels to 7.8%, which reduced to control level after its activity was inhibited (p<0.05). Activated SIRT1 mediates HIF-2α and nuclear factor-κB (RelA/p65) expression to 4.5 fold and fivefold, respectively, compared to control, and the levels were suppressed following sirtinol treatment (4.1% and 39.3% respectively; p=0.01). Hypoxic treatment increased VEGF levels by 94.9±19.6 pg/ml compared to control levels (25.58±3.58 pg/ml). These levels decreased to 10.29±0.2 pg/ml after blocking SIRT1 activity using sirtinol, compared to control (p<0.01). CONCLUSIONS: Our study results demonstrate that hypoxia mimetic cobalt chloride induces SIRT1 and augments HIF-2α, which activates and releases VEGF.

Syphilitic chorioretinitis mimicking an anterior chiasmal syndrome.

PURPOSE: To report a case of syphilitic chorioretinitis mimicking an anterior chiasmal syndrome. METHODS: Observational case report. RESULTS: A 74-year-old man with a remote history of syphilitic chorioretinitis was noted to have an apparent junctional scotoma on a screening Humphrey visual field. Subsequent magnetic resonance imaging of the brain was normal, and the patient was referred for neuro-ophthalmologic evaluation. The fundus examination and a fluorescein angiogram demonstrated that the pattern of chorioretinal scarring corresponded to the visual field defects in both eyes. CONCLUSION: Syphilis, the great masquerader, may cause retinal disease that mimics a neurologic visual field defect.

A review: role of ultraviolet radiation in age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in the western world. The retina is highly susceptible to photochemical damage from continuous exposure of light and oxygen. The cornea and the lens block a major portion of the ultraviolet (UV) radiation from reaching the retina (<295 nm). The relationship between UV light exposure and AMD is unclear, although short wavelength radiation and the blue light induce significant oxidative stress to the retinal pigment epithelium. Epidemiologic evidence indicates a trend toward association between severity of light exposure and AMD. In this review, we discuss type 1 and type 2 photochemical damage that occurs in response to UV exposure. We examine the impact of different doses of exposure to UV radiation and the subsequent production of oxidative stress in AMD. Local and systemic protective mechanisms of the retina including antioxidant enzymes and macular pigments are reviewed. This article provides a review of possible cellular and molecular effects of UV radiation exposure in AMD and potential therapies that may prevent blindness resulting from this disease.

Tumor necrosis factor-alpha (TNF-α) levels in aqueous humor of primary open angle glaucoma.

PURPOSE: Tumor necrosis factor alpha (TNF-α), a macrophage/monocyte derived pluripotent cytokine is associated with tissue ischemia, neuronal damage and remodeling. The physiological level of TNF-α in aqueous humor of normal and glaucomatous eyes is unknown. In this study, we evaluated the TNF-α levels in aqueous in patients with primary open angle glaucoma (POAG) and compared them to controls. METHODS: 50-100 µL of undiluted aqueous humor samples were obtained from eyes of 32 POAG patients who underwent cataract extraction, trabeculectomy or aqueous shunt implantation. Controls were obtained from 32 normal subjects who underwent routine cataract surgery. TNF-α levels were quantified using singleplex bead immunoassay analysis. RESULTS: The average TNF-α level in POAG samples was 2.72 ± 1.5 pg/mL (mean ± SD). The average TNF-α level in normal samples was 1.59 ± 0.46 pg/mL (mean ± SD). Significant increase of TNF-α levels in POAG samples was noted in comparison to normal samples (P < 0.001). CONCLUSION: TNF-α levels are elevated in aqueous in patients with POAG compared to normal subjects based on highly sensitive Luminex(®) bead immunoassay and may be a reliable biomarker in the progression of glaucoma.

Cortical visual impairment: etiology, associated findings, and prognosis in a tertiary care setting.

PURPOSE: To evaluate the etiology, prognosis, and associated neurological and ophthalmologic findings of children with cortical visual impairment (CVI) at a tertiary care referral facility. METHODS: Records from patients visiting the Vanderbilt University Pediatric Ophthalmology Center during 2002 to 2005 were reviewed, and 98 patients were identified with an International Classification of Disease (9th ed.) coding of CVI (377.75). The charts were reviewed to assess presenting symptoms. The clinic and imaging notes were correlated with visual function (graded on a scale of I to VI). RESULTS: The most common etiologies were perinatal hypoxia (35%), prematurity (29%), hydrocephalus (19%), structural central nervous system abnormalities (11%), and seizures (10%). Many children (69%) had multiple etiologies. Associated ophthalmic abnormalities included esotropia (19%), exotropia (40%), nystagmus (21%), and optic atrophy (42%). Significant refractive error (> +3.00 D or < -2.00 D) was common (20%). Associated neurological findings included seizures (60%), cerebral palsy (37%), periventricular leukomalacia (12%), hemiparesis (21%), and hearing loss (11%). Fifty-three percent of children initially diagnosed with CVI were followed for a period of 0.5 to 10 years. Forty percent of the patients showed no improvement in visual function; 34% had minimal improvement, and 17% had mild improvement. Only 6% of the patients had significant improvement in visual function. Eight patients had fixing and following or better acuity at last follow-up. CONCLUSIONS: The major risk factors for CVI are perinatal hypoxia, premature birth, and hydrocephalus. Most patients have associated serious neurological and ophthalmologic abnormalities. While many patients have some recovery in vision acuity, most never see well. Patients with the most improvement in visual function were those having better initial acuity.