Retinal vascular occlusion after vitrectomy with retrobulbar anesthesia-observational case series and survey of literature

Background: Severe postoperative loss of vision has been occasionally reported as a rare complication of retrobulbar anesthesia, and several possible causes have been proposed in the literature. In this work, our own and other investigators' experiences with these complications are surveyed with a view to identifying its pathophysiology. Patients: This observational case series refers to six patients who presented during a 3-month period with occlusion of either the central artery itself (n = 3) or a branch thereof (n = 3) 2-14days after uneventful vitreoretinal surgery following retrobulbar anesthesia with a commercial preparation of mepivacaine (1% Scandicain®, Astra Chemicals, Sweden) containing methyl- and propyl parahydroxybenzoate as preservatives. Results: Three of the patients carried risk factors, which were medically controlled. In three individuals, vasoocclusion was observed after a second vitreoretinal intervention, which was performed 3-12months after uneventful primary surgery. Good visual recovery was observed in only one instance. Conclusions: In patients who were anesthetized with preservative-free mepivacaine, no vasoocclusion occurred. In individuals who were anesthetized with mepivacaine containing the preservatives methyl- and propyl parahydroxybenzoate, a tenfold increase in the incidence of eyes requiring re-operation was documented, with a 2- to 14-day lapse in the onset of vasoocclusion. These findings reveal a possible implication of preservatives contained in the local anesthetic solution for the vasoocclusive events. Due to this potential hazard, the use of preservative-free preparations of local anesthesia in ocular surgery is emphasized in order to prevent this sight-threatening complicatio

Sustained Disease Control in DME Patients upon Treatment Cessation with Brolucizumab.

Background: Treatment cessation due to a dry retina has not been systematically addressed in diabetic macular edema (DME). In three out of four patients receiving 6 mg of brolucizumab in the KITE study, treatment was terminated after the study ended. Methods: The KITE study was a double-masked, multicenter, active-controlled, randomized trial (NCT03481660) in DME patients. Per protocol, patients received five loading injections of Brolucizumab at 6-week intervals, with the option to adjust to 8 weeks in case of disease activity or to extend in the second year to a maximum of 16 weeks in the absence of retinal fluid. Results: After two years, one patient required eight weekly injections, while three patients reached a maximal treatment interval of 16 weeks. The severity of diabetic retinopathy improved in all patients with no dye leakage according to fluorescein angiography (FA) and no retinal fluid according to OCT in three patients. Treatment was paused in these three patients for >36 months, while the fourth patient required continuous treatment at 5-week intervals after switching to other licensed anti-VEGF agents. Conclusions: The adoption of treatment according to individual needs, including considering treatment cessation, may contribute to improved treatment adherence in many patients and be more frequently possible than expected

The antibody response in experimental ocular toxoplasmosis

BACKGROUND: The dynamics of the humoral immune response in ocular toxoplasmosis (OT) are poorly understood. We therefore investigated this process in a rabbit model of the disease. MATERIALS AND METHODS: Of 24 infection-naïve adult rabbits, 12 were left untreated and 12 were systematically infected with 5,000 tachyzoites of the non-cyst-forming BK strain of Toxoplasma gondii. Three months later, all rabbits were inoculated transvitreally with 5,000 tachyzoites of Toxoplasma gondii. Paired samples of aqueous humor and serum were analyzed temporally for their total and specific IgG contents. RESULTS: In infection-naïve rabbits with primary OT, specific IgG reached detectable levels in the inoculated eyes between 5 and 15 days after inoculation. In infection-immunized rabbits with secondary OT, a significant increase in specific IgG was regularly detected after 5 days. The antibody ratio C was diagnostic (>/=3) from day 15 onward in primary OT and from day 21 onward in secondary OT. In the uninfected partner eyes, the antibody ratio C was found sporadically diagnostic from day 15 onward in primary OT, but at no time in secondary OT. Specific IgG persisted both locally and in the serum until the end of the monitoring period (100 days). CONCLUSION: Our findings relating to the rabbit model of OT reveal three features of clinical relevance: a diagnostic window precedes the establishment of a humoral immune response; specific antibodies persist long after the cessation of disease activity; and in primary OT, the antibody ratio C may also increase in the uninfected partner eye

Effects of daunorubicin, mitomycinC, azathioprine and cyclosporinA on human retinal pigmented epithelial, corneal endothelial and conjunctival cell lines

Background: We wished to investigate the toxicity of four immunosuppressant and antimetabolic drugs, which are known to influence postoperative wound healing, on three different human ocular cell lines. Methods: Acute toxicity to cyclosporinA, azathioprine, mitomicynC and daunorubicin was assessed in Chang cells by monitoring their uptake of propidium iodide during a 3-h period. Chronic toxicity was assessed by monitoring the proliferation and viability of subconfluent cultures of Chang cells, human corneal endothelial cells (HCECs) and retinal pigmented epithelial (RPE) cells after continuous exposure to the drugs for 7 days. Results: Acute toxicity testing revealed no obvious effects. However, the chronic toxicity tests disclosed a narrow concentration range over which cell proliferation decreased dramatically but calcein metabolism was sustained. Although the three lines reacted similarly to each agent, HCECs were the most vulnerable to daunorubicin and mitomycin. At a daunorubicin concentration of 0.05μg/ml, a 75% decrease in calcein metabolism (P<0.001) and a ≥95% cell loss (P<0.001) were observed. At a mitomycin concentration of 0.01μg/ml, cell density decreased by 61% (P<0.001) without a change in calcein metabolism, but at 0.1μg/ml, the latter parameter decreased to 12% (P=0.00014). At this concentration the proliferation of Chang and RPE cells decreased by more than 50%, whilst calcein metabolism was largely sustained. Cyclosporin inhibited cell proliferation moderately at lower concentrations (<5μg/ml; P=0.05) and substantially at higher ones, with a corresponding decline in calcein metabolism. Azathioprine induced a profound decrease in both parameters at concentrations above 5μg/ml. Conclusion: Daunorubicin, cyclosporin and azathioprine could be used to inhibit excessive intraocular scarring after glaucoma and vitreoretinal surgery without overly reducing cell viability. The attributes of immunosuppressants lie in their combined antiproliferative and immunomodulatory effect

Atypical Vogt-Koyanagi-Harada disease or new uveomeningitic syndrome?

Purpose: To report on a patient affected by bilateral intermediate uveitis (IU) as the initial sign of an uveomeningitic syndrome. Methods: Thorough history, physical examination and ancillary laboratory and radiological testing were performed in this observational case study. Results: A 23-year-old Caucasian man developed bilateral IU, primarily diagnosed as "idiopathic” since a detailed etiologic work-up was not indicative of underlying disease. Seven months later, he presented with poliosis and vitiligo. Lumbar puncture revealed cerebrospinal fluid pleocytosis. Optical coherence tomography showed bilateral subclinical macular edema (ME). The visual acuity was still 20/20 in both eyes. Clinical, laboratory and radiological results did not fit into any known syndrome. Conclusions: According to all the tests performed, the disease in our patient is a uveomeningitic disease with IU and ME which could be interpreted as an atypical form of Vogt-Koyanagi-Harada disease or a new uveomeningitic syndrome because there is no evidence for any other known diseas

Anti-retinal autoantibodies in experimental ocular and systemic toxoplasmosis

Background: Patients with ocular toxoplasmosis (OT) develop autoreactivity to several retinal antigens, including retinal S-antigen. By establishing an experimental rabbit model of systemic and of primary and secondary ocular toxoplasmosis, we wished to investigate the onset and development of humoral response to retinal S-antigen. Methods: Of twelve infection-naïve rabbits, six were left untreated, and the other six were infected subcutaneously with 5,000 tachyzoites of the highly virulent, non-cyst-forming BK-strain of Toxoplasma gondii. Three months later, the left eye of each animal was infected transvitreally with 5,000 tachyzoites of the same strain. The right eye of each rabbit served as an uninfected control. Blood and aqueous humor were collected prior to infection, and up to 90days thereafter. Using the ELISA technique, all samples were analyzed in parallel for total IgG, and antibodies against toxoplasmic, bovine retinal S-antigen and peptide 35 from human S-antigen. Results: In infection-naïve rabbits Toxoplasma-specific antibodies were detected 10 to15days after systemic and ocular infection. Serum antibodies against retinal S-antigen and peptide 35 were not detected in response to systemic Toxoplasma infection. After ocular challenge, aqueous-humour levels of antibodies against retinal S-antigen and peptide 35 in the infected eye began to rise 10 to 15days later in infection-naïve, but not in infection-immunized animals. During the early post-infection period, the concentrations of anti-retinal antibodies in the infected eye correlated with the severity of inflammatory tissue destruction, but returned to baseline later even though the inflammatory response persisted. In the uninfected partner eye, concentrations of anti-retinal and toxoplasmic antibodies did not correlate with each other. Conclusion: Our data afford no evidence of similarities between toxoplasmic and retinal antigens, nor of infection-induced humoral autoimmunity. They indicate rather that retinal autoantigens are liberated in the context of inflammatory tissue destruction due to ocular toxoplasmosi

Evolution of HIV-1-related conjunctival molluscum contagiosum under HAART: report of a bilaterally manifesting case and literature review

Purpose: To present a rare case of bilateral conjunctival molluscum contagiosum (MC) in an HIV-positive individual who had unilateral lesion excision before induction of highly active antiretroviral therapy (HAART), and to discuss the pathophysiological consequences of immune restoration. Methods: Case report: A 40-year-old male Caucasian presented with atypical, bilateral lesions of the limbal conjunctiva due to MC. Before the induction of HAART, nodules in the left eye were excised whilst the single lesion in the right eye was left untouched. Results: The clinical diagnosis of conjunctival MC was confirmed histopathologically. Six months after the induction of HAART, the untouched lesion (right eye) had regressed and there was pronounced local injection of the conjunctiva. MC lesions did not recur after excision (left eye), and signs of inflammation were absent. Conclusion: Conjunctival MC is rare and associated with immune deficiency. To the best of our knowledge, the presented case is the first reported instance of bilateral, multi-lesional MC of the conjunctiva in an HIV-positive patient undergoing HAART. Attention must be paid to the possible complications associated with the restoration of immunocompetenc

Visual Outcome after Intravitreal Anti-VEGF Therapy for Macular Neovascularisation Secondary to Sorsby's Fundus Dystrophy: A Systematic Review.

The aim of this paper is to summarise our own and to review published experience regarding the long-term outcome of intravitreal treatment for macular neovascularisation (MNV) secondary to Sorsby's fundus dystrophy (SFD). A systematic literature search using the MeSH terms [Sorsby] and [anti-vascular endothelial growth factor (VEGF)] was conducted in NCBI/PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), ScienceDirect, Google Scholar and ClinicalTrials.gov to identify publications reporting anti-VEGF treatment outcomes in SFD. Treatment outcomes were extracted for this meta-analysis from 14 publications and an own patient reporting a total of 31 cases with a mean follow-up (FU) of 54 months. Both eyes were affected in ten (32.3%) instances. Heterogenous reporting limited the comparability of the outcomes. All papers in common, however, reported satisfied to excellent responses to anti-VEGF therapy if patients were diagnosed and treated immediately after onset of symptoms. Of 20 eyes, for which visual acuity was reported before and after treatment, five worsened and seven improved by more than 1 line, whereas eight eyes maintained their function by end of the follow up, and 11 eyes (55%) maintained a driving vision (Snellen VA ≥ 0.5). Of six eyes with a VA < 0.5, VA improved in one to VA ≥ 0.5, whereas of 14 eyes with an initial VA ≥ 0.5, this dropped to <0.5 despite therapy. In MNV secondary to SFD, the delay between first symptoms and access to anti-VEGF treatment determines subretinal scar formation and thereby, functional prognosis. If treated early, this is generally favourable under regular controls and a consequent anti-VEGF treatment of MNV activity