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  • 1.
    Bäckman, Anders
    et al.
    Örebro University, School of Medical Sciences. Clinical Research Centre, Örebro University Hospital, Örebro, Sweden.
    Makdoumi, Karim
    Örebro University, School of Medical Sciences. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden; Centre for Health Care Sciences, Örebro University Hospital, Örebro, Sweden.
    Mortensen, Jes
    Department of Ophthalmology, Ryhov County Hospital, Jönköping, Sweden.
    Crafoord, Sven
    Örebro University, School of Medicine, Örebro University, Sweden. Örebro University Hospital. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    The efficiency of cross-linking methods in eradication of bacteria is influenced by the riboflavin concentration and the irradiation time of ultraviolet light2014In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 92, no 7, p. 656-661Article in journal (Refereed)
    Abstract [en]

    Purpose: To determine bacterial eradication using numerous riboflavin concentrations and different ultraviolet light A (UVA) radiant and exposure time in an experimental model.

    Methods: Dilutions of Staphylococcus epidermidis were mixed with riboflavin at varying concentrations (0.007-0.09%). Effects on bacterial growth were evaluated after 0, 3, 6, 30 and 60min of UVA exposure (irradiance 30 and 3mW/cm(2)). Standard settings of UVA were compared with high-power UVA approach. Different fluid thicknesses of the exposed dilutions were also examined to improve the model.

    Results: Bacterial eradication (%) was increased after 60 compared with 30min of UVA exposure for concentrations of 0.03-0.07% but not for 0.09% riboflavin. There was a significant difference between the efficacy between 0.03 and 0.09% and eradication dropped from 80% to 50% (p=0.01). A correlation could be calculated for the amount of riboflavin at 60min of UVA and the ability to kill bacteria (p=0.01). The antibacterial effect was more pronounced when the tested bacterial suspension thickness was reduced. High-power UVA method was less potent in microbial elimination, eradicating only 60% of bacteria after 6min versus 97-99% after 60min in the low-power setting, compared with respective controls (p=0.02).

    Conclusions: In these in vitro experiments, a longer UVA exposure time in combination with lower riboflavin levels were found to be favourable in killing bacteria as compared to the standard cross-linking settings. Further studies are needed to evaluate the clinical relevance of these findings.

  • 2.
    Hellander-Edman, Anna
    et al.
    Department of Animal Environment & Health, Swedish University of Agricultural Sciences, Skara, Sweden.
    Makdoumi, Karim
    Örebro University Hospital. Department of Ophthalmology.
    Mortensen, Jes
    Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Ekesten, Bjorn
    Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Corneal cross-linking in 9 horses with ulcerative keratitis2013In: BMC Veterinary Research, ISSN 1746-6148, E-ISSN 1746-6148, Vol. 9, p. 128-Article in journal (Refereed)
    Abstract [en]

    Background: Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers. Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients. Therefore we decided to study if CXL can be performed in sedated, standing horses with ulcerative keratitis with or without stromal melting.

    Results: Nine horses, aged 1 month to 16 years (median 5 years) were treated with a combination of CXL and medical therapy. Two horses were diagnosed with mycotic, 5 with bacterial and 2 with aseptic ulcerative keratitis. A modified Dresden-protocol for CXL could readily be performed in all 9 horses after sedation. Stromal melting, diagnosed in 4 horses, stopped within 24 h. Eight of nine eyes became fluorescein negative in 13.5 days (median time; range 4-26 days) days after CXL. One horse developed a bacterial conjunctivitis the day after CXL, which was successfully treated with topical antibiotics. One horse with fungal ulcerative keratitis and severe uveitis was enucleated 4 days after treatment due to panophthalmitis.

    Conclusions: CXL can be performed in standing, sedated horses. We did not observe any deleterious effects attributed to riboflavin or UVA irradiation per se during the follow-up, neither in horses with infectious nor aseptic ulcerative keratitis. These data support that CXL can be performed in the standing horse, but further studies are required to compare CXL to conventional medical treatment in equine keratitis and to optimize the CXL protocol in this species.

  • 3.
    Makdoumi, Karim
    Örebro University, School of Health and Medical Sciences.
    Ultraviolet light A (UVA) photoactivation of riboflavin as a potential therapy for infectious keratitis2011Doctoral thesis, comprehensive summary (Other academic)
    List of papers
    1. Infectious keratitis treated with corneal crosslinking
    Open this publication in new window or tab >>Infectious keratitis treated with corneal crosslinking
    2010 (English)In: Cornea, ISSN 0277-3740, E-ISSN 1536-4798, Vol. 29, no 12, p. 1353-1358Article in journal (Refereed) Published
    Abstract [en]

    Purpose: To describe 7 eyes with severe infectious keratitis treated using collagen crosslinking (CXL) with riboflavin. Materials and Methods: Seven eyes of 6 patients with severe infectious keratitis were treated with corneal crosslinking. Three patients were contact lens users. Symptom duration before CXL ranged between 0 and 7 days. Corneal melting was present in all cases. Photodocumentation of the keratitis was carried out and repeated at follow-up. All but 1 patient received topical antibiotic treatment in addition to the CXL treatment. CXL was conducted according to the standardized protocol for keratoconus. Results: In all but 1 eye, patients experienced improvement in symptoms within 24 hours. Two patients reported no symptoms whatsoever at this time. Corneal melting was arrested and complete epithelialization was achieved in all cases. In the 2 eyes with hypopyon, this regressed completely within 2 days after the CXL. Follow-up ranged between 1 and 6 months. Discussion: Our experience based on the above and other cases suggest that CXL could be an effective tool in battling difficult cases of infectious keratitis. This treatment could present many advantages but will need further investigation.

    Keywords
    CXL, crosslinking, riboflavin, keratitis, UV-A, ultraviolet A, corneal melting
    National Category
    Surgery
    Research subject
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-20751 (URN)10.1097/ICO.0b013e3181d2de91 (DOI)000284580000003 ()
    Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2017-12-08Bibliographically approved
    2. Evaluation of antibacterial efficacy of photo-activated riboflavin using ultraviolet light (UVA)
    Open this publication in new window or tab >>Evaluation of antibacterial efficacy of photo-activated riboflavin using ultraviolet light (UVA)
    2010 (English)In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 248, no 2, p. 207-212Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: To evaluate the antibacterial efficacy of photo-activated riboflavin using Ultraviolet A (UVA) on three bacterial strains commonly detected in keratitis. METHODS: Three bacterial strains (Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa) were cultured on blood/hematin-agar plates and dispersed in PBS. Dispersion was done of 10 microl of bacterial stock-solutions in 90 microl of RPMI, where different riboflavin molarities had been added, to achieve a bacterial concentration of 1-4 x 10 (4)/ml. Riboflavin end molarities before illumination were 0, 100, 200, 300 and 400 microM. Each solution had a negative control. The solutions were illuminated with UVA (365 nm) for 30 minutes (5.4 J/cm(2)) and then continued for a total time of 60 minutes (10.8 J/cm(2)). A count of CFU was conducted after incubation and results compared. RESULTS: In all tested strains, a slight decrease of bacteria was seen when exposed to UV for 30 minutes. A doubling of the UV dose showed a marked decrease of bacterial count in all bacteria tested. The combination of UV and riboflavin showed a more extensive reduction of CFU, confirming an interaction effect between UV and riboflavin. CONCLUSION: Riboflavin photo-activation using UVA (365 nm) can achieve an extensive eradication of bacteria, and the combination is more potent in reducing bacterial number than UV alone.

    National Category
    Medical and Health Sciences
    Research subject
    Medicine
    Identifiers
    urn:nbn:se:oru:diva-12083 (URN)10.1007/s00417-009-1231-2 (DOI)000273313100008 ()19921518 (PubMedID)
    Available from: 2010-10-05 Created: 2010-10-05 Last updated: 2018-02-27Bibliographically approved
    3. Response to: Bactericidal effect of photo-activated riboflavin using UVA
    Open this publication in new window or tab >>Response to: Bactericidal effect of photo-activated riboflavin using UVA
    2010 (English)In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 248, no 5, p. 757-758Article in journal (Refereed) Published
    National Category
    Surgery
    Research subject
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-20755 (URN)10.1007/s00417-009-1286-0 (DOI)000276071100021 ()
    Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2017-12-08Bibliographically approved
    4. UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study
    Open this publication in new window or tab >>UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study
    Show others...
    2012 (English)In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 250, no 1, p. 95-102Article in journal (Refereed) Published
    Abstract [en]

    Background: The aim of this work as to investigate the photochemical interaction used in corneal crosslinking (CXL) as the primary therapy for bacterial keratitis.

    Methods: A prospective non-randomized study was conducted including 16 patients with a clinical diagnosis of bacterial keratitis. No patient had any prior antibiotic treatment for the current infection. Photography and microbial culturing of the infected cornea were performed. Riboflavin was topically administered for 20 min and ultraviolet light (UVA) exposure settings for treatment of keratoconus were used. After the procedure, clinical examinations were done at least once daily until signs of improvement had been established. The frequency of examinations was thereafter reduced. Antibiotic therapy was initiated if infectious progression was suspected. The trial was registered at ISCRTN.org (no: 21432643).

    Results: All eyes responded to the photochemical treatment with improvement in symptoms and signs of reduced inflammation. Epithelial healing was achieved in all cases. Antibiotic administration was necessary in two cases. One patient required a human amniotic membrane transplant.

    Conclusions: This trial illustrates that photosensitization of riboflavin using UVA at 365 nm has the potential to induce healing in patients with microbial keratitis. The results from the treatment of these 16 patients with corneal ulcers indicate that UVA-riboflavin photochemical therapy merits a controlled study in order to assess its efficacy and safety compared to antibiotics.

    Place, publisher, year, edition, pages
    New York, USA: Springer, 2012
    Keywords
    UV, UVA, ultraviolet, riboflavin, CXL, keratitis, pilot study
    National Category
    Surgery Medical and Health Sciences
    Research subject
    Surgery; Medicine
    Identifiers
    urn:nbn:se:oru:diva-20752 (URN)10.1007/s00417-011-1754-1 (DOI)000299371000012 ()21874347 (PubMedID)2-s2.0-84857359468 (Scopus ID)
    Note

    Funding Agencies:

    Örebro University Hospital (Sweden) OLL-57221

    Futurum, the Academy of Health Care, Jonkoping (Sweden)

    Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2018-05-08Bibliographically approved
    5. Comparison of UV-A and UV-A/Riboflavin induced growth inhibition of Acanthamoeba Castellanii
    Open this publication in new window or tab >>Comparison of UV-A and UV-A/Riboflavin induced growth inhibition of Acanthamoeba Castellanii
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Surgery
    Research subject
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-20748 (URN)
    Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2017-10-17Bibliographically approved
  • 4.
    Makdoumi, Karim
    et al.
    Örebro University, School of Medical Sciences. Department of Ophthalmology , Örebro University Hospital, Örebro, Sweden.
    Bäckman, Anders
    Örebro University, School of Medical Sciences. Clinical Research Centre, Örebro University Hospital, Örebro, Sweden.
    Photodynamic UVA-riboflavin bacterial elimination in antibiotic-resistant bacteria2016In: Clinical and Experimental Ophthalmology, ISSN 1442-6404, E-ISSN 1442-9071, Vol. 44, no 7, p. 582-586Article in journal (Refereed)
    Abstract [en]

    Background: To evaluate the bactericidal effect of clinical ultraviolet A (UVA) settings used in photoactivated chromophore for infectious keratitis (PACK)-collagen cross-linking (CXL) in antibiotic-resistant and non-resistant bacterial strains.

    Methods: Well-characterized bacterial strains from clinical isolates, without and with antibiotic resistance, were studied in a pairwise comparison. The evaluated pathogens were Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis. Bacteria were dispersed in PBS and diluted to a concentration of approximately 4x10(5)/ml. Riboflavin was added to a concentration of 0.01%. By spreading the solution on a microscope slide, a fluid film layer, with a thickness of around 400mm, was formed and UVA exposure followed. Eight separate exposures were made for each strain (n=8). The degree of elimination in resistant and non-resistant pathogens was compared.

    Results: The bactericidal efficacy of exposure differed between the tested microorganisms, and the mean elimination ranged between 60 and 92%, being most extensive in both of the evaluated Pseudomonas strains and least in the E. faecalis strains. Similar reductions were seen in antibiotic-resistant and non-resistant strains, with the exception of S. aureus, in which the resistant strain metchicillin-resistant Staphylococcus aureus (MRSA) was eradicated in a greater extent than the non-resistant strain (P=0.030).

    Conclusion: UVA-riboflavin settings used in PACK-CXL are effective in reducing both antibiotic-resistant and non-resistant bacteria. Antibiotic resistance does not appear to be protective against the photooxidative exposure.

  • 5.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences.
    Bäckman, Anders
    Örebro University, School of Medical Sciences.
    Crafoord, Sven
    Örebro University, School of Medical Sciences.
    Response to: Bactericidal effect of photo-activated riboflavin using UVA2010In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 248, no 5, p. 757-758Article in journal (Refereed)
  • 6.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences.
    Bäckman, Anders
    Mortensen, Jes
    Crafoord, Sven
    Evaluation of antibacterial efficacy of photo-activated riboflavin using ultraviolet light (UVA)2010In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 248, no 2, p. 207-212Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: To evaluate the antibacterial efficacy of photo-activated riboflavin using Ultraviolet A (UVA) on three bacterial strains commonly detected in keratitis. METHODS: Three bacterial strains (Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa) were cultured on blood/hematin-agar plates and dispersed in PBS. Dispersion was done of 10 microl of bacterial stock-solutions in 90 microl of RPMI, where different riboflavin molarities had been added, to achieve a bacterial concentration of 1-4 x 10 (4)/ml. Riboflavin end molarities before illumination were 0, 100, 200, 300 and 400 microM. Each solution had a negative control. The solutions were illuminated with UVA (365 nm) for 30 minutes (5.4 J/cm(2)) and then continued for a total time of 60 minutes (10.8 J/cm(2)). A count of CFU was conducted after incubation and results compared. RESULTS: In all tested strains, a slight decrease of bacteria was seen when exposed to UV for 30 minutes. A doubling of the UV dose showed a marked decrease of bacterial count in all bacteria tested. The combination of UV and riboflavin showed a more extensive reduction of CFU, confirming an interaction effect between UV and riboflavin. CONCLUSION: Riboflavin photo-activation using UVA (365 nm) can achieve an extensive eradication of bacteria, and the combination is more potent in reducing bacterial number than UV alone.

  • 7.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Ophthalmology, Örebro University Hospital, Region Örebro County, Örebro, Sweden.
    Bäckman, Anders
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Clinical Research Centre, Örebro University Hospital, Region Örebro County, Örebro, Sweden.
    Mortensen, Jes
    Dept. Ophthalmology, Örebro University Hospital, Region Örebro County, Örebro, Sweden.
    Magnuson, Anders
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Clinical Epidemiology and Biostatistic Unit, Örebro University Hospital, Örebro, Sweden.
    Crafoord, Sven
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital, Region Örebro County, Örebro, Sweden.
    Comparison of UVA- and UVA/riboflavin-induced growth inhibition of Acanthamoeba Castellanii2013In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 251, no 2, p. 509-514Article in journal (Refereed)
    Abstract [en]

    Purpose To investigate whether ultraviolet light (UVA) at 365 nm can inhibit/eliminate Acanthamoeba growth and if riboflavin would potentiate such an association.

    Method: Acanthamoeba castellanii in a fluid medium with a concentration of approximately 1.7 x 10(4) protozoa/ml were prepared with (0.01 %) and without riboflavin. Exposure of UVA (dose 5.475 J/cm(2)) took place twice, with each illumination period followed by culturing of 10 mu l in peptone yeast-extract glucose (PYG) medium for 7 days. Every suspension prepared had a non-exposed control solution. Determination of Acanthamoeba was conducted daily, by count in Burker chamber days 4 through 7 after exposure. Statistical analysis was done by repeated-measurement ANOVA and post-hoc analysis for unpaired samples.

    Results: The exposure of ultraviolet light resulted in an inhibited growth of Acanthamoeba compared to the non-exposed solutions, with a statistically significant reduction over time (p = 0.0003). The addition of riboflavin did not amplify the effect, and there were no tendencies for an interaction effect between UVA and riboflavin. The antiprotozoal effect of the UVA wavelength, utilized in CXL, is solely mediated by ultraviolet light, and riboflavin does not seem to amplify the antimicrobial efficacy.

  • 8.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences.
    Bäckman, Anders
    Mortensen, Jes
    Magnuson, Anders
    Crafoord, Sven
    Comparison of UV-A and UV-A/Riboflavin induced growth inhibition of Acanthamoeba CastellaniiManuscript (preprint) (Other academic)
  • 9.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Crafoord, Sven
    Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Vasoproliferative retinal tumours in a Swedish population2011In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 89, no 1, p. 91-94Article in journal (Refereed)
    Abstract [en]

    Purpose: To describe the clinical appearance and the visual outcome of a cohort of patients with vasoproliferative retinal tumours (VPRTs) that were diagnosed and treated between 2002 and 2007 at the University Hospital of Orebro.

    Methods: Nine patients with diagnosed VPRTs were included in a retrospective study. The mean age at the time of diagnosis was 50.2 years (range 7-74 years). Follow-up time ranged between 14 and 83 months (mean 42.6). Nine out of ten eyes received cryotherapy; six eyes were also treated with photocoagulation. One patient was treated with intravitreal injections of ranibizumab (Lucentis((R))) and another was referred for brachytherapy. Because of persisting macular oedema, one eye was treated with intravitreal injection of triamcinolon.

    Results: Of the treated eyes, one had anterior uveitis, six had macular oedema at baseline and four had an exudative retinal detachment at the time of diagnosis. Seven eyes underwent vitrectomy because of epiretinal membranes. Visual acuity at diagnosis was 0.21 (mean) (range 0.02-0.6) and at latest check-up 0.30 (mean) (range light perception (LP)-1.0), with improvement in six eyes and deterioration in two. Two out of four patients with retinal detachment were successfully treated surgically.

    Conclusion: VPRTs are benign intraretinal changes. Several complications are associated with this condition. All patients in this study had symptom-giving tumours and six patients (six eyes) already had profound macular oedema at presentation. In these cases, when complications have already developed, the final visual prognosis is poor, thereby making it important to detect these tumours early. The patient who received anti-vascular endothelial growth factor (VEGF; Lucentis) therapy showed a slow improvement and distinct regression in exudations during the follow-up time. However, no increase in visual acuity was seen. At latest examination a peripheral exudative retinal detachment was still observed. Whether anti-VEGF treatment is effective, as either an alternative or complementary therapy, must be established in the future.

  • 10.
    Makdoumi, Karim
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Goodrich, Ray
    Terumo BCT Inc., Lakewood CO, USA.
    Bäckman, Anders
    Örebro University, School of Medical Sciences. Örebro University Hospital. , Örebro University Hospital, Örebro, Sweden.
    Photochemical eradication of methicillin-resistant Staphylococcus aureus by blue light activation of riboflavin2017In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 95, no 5, p. 498-502Article in journal (Refereed)
    Abstract [en]

    Purpose: To compare elimination of methicillin-resistant Staphylococcus aureus (MRSA) by exposure of blue light alone and with riboflavin.

    Methods: A reference strain of MRSA was cultured and diluted in PBS with and without riboflavin (0.01%). Fifteen microlitre was added on a microscope slide, creating a fluid layer with a thickness of around 400 microns. Both of the bacterial suspensions were exposed to blue light, and the effect between exposure with and without riboflavin was compared. Evaluation involved two different wavelengths (412 and 450 nm) of blue light with a lower (5.4 J/cm(2) ) and higher dose (approximately 28.5 J/cm(2) ). The effect of 412 nm light was also evaluated for a thicker fluid layer (1.17 mm). After exposure, colony-forming units (CFUs) were determined for each solution. All measurements were repeated eight times.

    Results: The reductions in bacteria were similar for both wavelengths. With riboflavin, a statistically significant elimination was observed for both 412 and 450 nm (p < 0.001). At both dosages, the mean reduction was more pronounced with the presence of riboflavin than without it. Using the higher dose, CFU reduction was 99% and 98%, respectively, for 412 and 450 nm light. The bactericidal efficacy was high also in the deeper fluid layer (93%, higher dose).

    Conclusion: Riboflavin enhanced the antibacterial effect on the exposed MRSA strain of blue light for both 412 and 450 nm blue light. This indicates that blue light could be considered for possible implementation in deep corneal infections.

  • 11.
    Makdoumi, Karim
    et al.
    Örebro University, School of Medical Sciences. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Hedin, Marie
    Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Bäckman, Anders
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Clinical Research Laboratory.
    Different photodynamic effects of blue light with and without riboflavin on methicillin-resistant Staphylococcus aureus (MRSA) and human keratinocytes in vitro2019In: Lasers in Medical Science, ISSN 0268-8921, E-ISSN 1435-604X, Vol. 34, no 9, p. 1799-1805Article in journal (Refereed)
    Abstract [en]

    Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of infections in humans. Photodynamic therapy using blue light (450 nm) could possibly be used to reduce MRSA on different human tissue surfaces without killing the human cells. It could be less harmful than 300–400 nm light or common disinfectants. We applied blue light ± riboflavin (RF) to MRSA and keratinocytes, in an in vitro liquid layer model, and compared the effect to elimination using common disinfection fluids. MRSA dilutions (8 × 105/mL) in wells were exposed to blue light (450 nm) ± RF at four separate doses (15, 30, 56, and 84 J/cm2). Treated samples were cultivated on blood agar plates and the colony forming units (CFU) determined. Adherent human cells were cultivated (1 × 104/mL) and treated in the same way. The cell activity was then measured by Cell Titer Blue assay after 24- and 48-h growth. The tested disinfectants were chlorhexidine and hydrogen peroxide. Blue light alone (84 J/cm2) eliminated 70% of MRSA. This dose and riboflavin eradicated 99–100% of MRSA. Keratinocytes were not affected by blue light alone at any dose. A dose of 30 J/cm2 in riboflavin solution inactivated keratinocytes completely. Disinfectants inactivated all cells. Blue light alone at 450 nm can eliminate MRSA without inactivation of human keratinocytes. Hence, a high dose of blue light could perhaps be used to treat bacterial infections without loss of human skin cells. Photodynamic therapy using riboflavin and blue light should be explored further as it may perhaps be possible to exploit in treatment of skin diseases associated with keratinocyte hyperproliferation.

  • 12.
    Makdoumi, Karim
    et al.
    Örebro University, School of Health and Medical Sciences.
    Mortensen, Jes
    Crafoord, Sven
    Infectious keratitis treated with corneal crosslinking2010In: Cornea, ISSN 0277-3740, E-ISSN 1536-4798, Vol. 29, no 12, p. 1353-1358Article in journal (Refereed)
    Abstract [en]

    Purpose: To describe 7 eyes with severe infectious keratitis treated using collagen crosslinking (CXL) with riboflavin. Materials and Methods: Seven eyes of 6 patients with severe infectious keratitis were treated with corneal crosslinking. Three patients were contact lens users. Symptom duration before CXL ranged between 0 and 7 days. Corneal melting was present in all cases. Photodocumentation of the keratitis was carried out and repeated at follow-up. All but 1 patient received topical antibiotic treatment in addition to the CXL treatment. CXL was conducted according to the standardized protocol for keratoconus. Results: In all but 1 eye, patients experienced improvement in symptoms within 24 hours. Two patients reported no symptoms whatsoever at this time. Corneal melting was arrested and complete epithelialization was achieved in all cases. In the 2 eyes with hypopyon, this regressed completely within 2 days after the CXL. Follow-up ranged between 1 and 6 months. Discussion: Our experience based on the above and other cases suggest that CXL could be an effective tool in battling difficult cases of infectious keratitis. This treatment could present many advantages but will need further investigation.

  • 13.
    Makdoumi, Karim
    et al.
    Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Mortensen, Jes
    Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden; Department of Ophthalmology, Ryhov County Hospital, Jönköping, Sweden.
    Sorkhabi, Omid
    Department of Ophthalmology, Ryhov County Hospital, Jönköping, Sweden.
    Malmvall, Bo-Eric
    Department of Infectious Medicine, Futurum, the Academy of Health, Ryhov County Hospital, Jönköping, Sweden; Department of Infectious Medicine, Institution of Clinical and Experimental Medicine, University of Linköping, Linköping, Sweden.
    Crafoord, Sven
    Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study2012In: Graefe's Archives for Clinical and Experimental Ophthalmology, ISSN 0721-832X, E-ISSN 1435-702X, Vol. 250, no 1, p. 95-102Article in journal (Refereed)
    Abstract [en]

    Background: The aim of this work as to investigate the photochemical interaction used in corneal crosslinking (CXL) as the primary therapy for bacterial keratitis.

    Methods: A prospective non-randomized study was conducted including 16 patients with a clinical diagnosis of bacterial keratitis. No patient had any prior antibiotic treatment for the current infection. Photography and microbial culturing of the infected cornea were performed. Riboflavin was topically administered for 20 min and ultraviolet light (UVA) exposure settings for treatment of keratoconus were used. After the procedure, clinical examinations were done at least once daily until signs of improvement had been established. The frequency of examinations was thereafter reduced. Antibiotic therapy was initiated if infectious progression was suspected. The trial was registered at ISCRTN.org (no: 21432643).

    Results: All eyes responded to the photochemical treatment with improvement in symptoms and signs of reduced inflammation. Epithelial healing was achieved in all cases. Antibiotic administration was necessary in two cases. One patient required a human amniotic membrane transplant.

    Conclusions: This trial illustrates that photosensitization of riboflavin using UVA at 365 nm has the potential to induce healing in patients with microbial keratitis. The results from the treatment of these 16 patients with corneal ulcers indicate that UVA-riboflavin photochemical therapy merits a controlled study in order to assess its efficacy and safety compared to antibiotics.

  • 14.
    Makdoumi, Karim
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden.
    Nilsson, Torbjörn K.
    Department of Medical Biosciences/Clinical Chemistry, Umeå University, Umeå, Sweden; Faculty of Medicine and Health Department of Biomedicine, Örebro University, Örebro, Sweden.
    Crafoord, Sven
    Örebro University, School of Medical Sciences. Department of Ophthalmology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Levels of beta-trace protein in optic disc pit with macular detachment2017In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 95, no 8, p. 815-819Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: To report beta-trace protein (βTP) levels in the subretinal fluid (SRF) of four patients with a macular detachment associated with optic disc pit (ODP).

    METHODS: Four patients with a serous retinal detachment involving the macula was operated by pars plana vitrectomy (PPV) with C2 F6 gas tamponade and peeling of internal limiting membrane (ILM). Patients with a follow-up period exceeding one year postoperatively were included in the study. The SRF was drained using a fine cannula without laser photocoagulation, and the samples were analysed using particle-enhancing nephelometry. The levels of βTP were compared to 20 routine cerebrospinal fluid (CSF) samples.

    RESULTS: In four of the five samples from SRF had relatively low βTP levels, with a mean concentration of 6.6 mg/l (range 2.0 to 23.1 mg/l) compared to 16.0 mg/l (range 6.3-26.8 mg/l) in CSF. The only SRF sample within the range corresponding to normal CSF was the first sample from patient 4, and the analysis of the renewed aspirate during the second operation was 2.8 mg/l. Postoperatively, the regression of SRF was slow, but regression of SRF in the foveal region took place in all cases; however, visual acuity (VA) was improved in only half of the patients.

    CONCLUSION: The results from the analysed SRF regarding βTP concentration in these patients indicate that the SRF in ODP is not identical to CSF, as the concentrations of βTP differ.

  • 15.
    Mäkeläinen, Suvi
    et al.
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Gòdia, Marta
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Hellsand, Minas
    Department of Neuroscience, Uppsala University, Uppsala, Sweden.
    Viluma, Agnese
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Hahn, Daniela
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Makdoumi, Karim
    Örebro University, School of Medical Sciences. Department of Ophthalmology.
    Zeiss, Caroline J.
    Yale University School of Medicine, New Haven, Connecticut, United States of America.
    Mellersh, Cathryn
    Yale University School of Medicine, New Haven, Connecticut, United States of America.
    Ricketts, Sally L.
    Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom.
    Narfström, Kristina
    Section for Comparative Ophthalmology, College of Veterinary Medicine, University of Missouri-Columbia, Missouri, United States of America.
    Hallböök, Finn
    Department of Neuroscience, Uppsala University, Uppsala, Sweden.
    Ekesten, Björn
    Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Andersson, Göran
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Bergström, Tomas F
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    An ABCA4 loss-of-function mutation causes a canine form of Stargardt disease2019In: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 15, no 3, article id e1007873Article in journal (Refereed)
    Abstract [en]

    Autosomal recessive retinal degenerative diseases cause visual impairment and blindness in both humans and dogs. Currently, no standard treatment is available, but pioneering gene therapy-based canine models have been instrumental for clinical trials in humans. To study a novel form of retinal degeneration in Labrador retriever dogs with clinical signs indicating cone and rod degeneration, we used whole-genome sequencing of an affected sib-pair and their unaffected parents. A frameshift insertion in the ATP binding cassette subfamily A member 4 (ABCA4) gene (c.4176insC), leading to a premature stop codon in exon 28 (p.F1393Lfs*1395), was identified. In contrast to unaffected dogs, no full-length ABCA4 protein was detected in the retina of an affected dog. The ABCA4 gene encodes a membrane transporter protein localized in the outer segments of rod and cone photoreceptors. In humans, the ABCA4 gene is associated with Stargardt disease (STGD), an autosomal recessive retinal degeneration leading to central visual impairment. A hallmark of STGD is the accumulation of lipofuscin deposits in the retinal pigment epithelium (RPE). The discovery of a canine homozygous ABCA4 loss-of-function mutation may advance the development of dog as a large animal model for human STGD.

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