To Örebro University

BACKGROUND: Chronic kidney disease (CKD) is a growing health issue that is becoming more prevalent globally, increasing financial cost on healthcare systems. The purpose of this study is to investigate the incidence of eye diseases in patients diagnosed with CKD in Sweden and to evaluate which eye diseases are most likely to develop.

METHODS: A longitudinal population-based retrospective case-control study was conducted including all individuals diagnosed with chronic kidney disease during the time period 2001-2019. A total of 19 455 cases and 38 890 controls were included. For each case, two controls were matched with the same sex, age, and county of residence.

RESULTS: CKD patients had a significantly higher risk of contracting any eye disease compared to individuals without kidney disease HR 1.73 (CI 1.67-1.79), with an elevated risk for all blocks of diagnoses except for glaucoma HR 0.95 (CI 0.85-1.06). However, this condition developed earlier in cases than in controls. Subanalyses showed an increased risk for chronic eye disease patients to develop cataract HR 1.70 (CI 1.63-1.78), other retinal disorders HR 1.86 (CI 1.72-2.02), and retinal vascular occlusions HR 2.08 (CI 1.73-2.51). In general, diagnosis of an eye disease occurred earlier in cases than controls.

CONCLUSIONS: The results from this study suggest that CKD patients have an increased risk to develop eye disease. Ocular disease seems to develop considerably earlier in CKD, even without staging the severity of the disease, with particularly high risk of developing retinal diseases and cataracts. Screening for eye disease in CKD should be considered.

PURPOSE: To evaluate progression of keratoconus in patients where CXL treatment was interrupted due to insufficient swelling of the cornea.

METHODS: A retrospective review was conducted of all patients with keratoconus diagnosis who underwent CXL at the Department of Ophthalmology, Örebro University Hospital (USÖ) during the years 2010-2017. In total 377 eyes of 280 patients were screened for inclusion. In 17 eyes (15 patients), the treatment was interrupted due to insufficient swelling of the cornea. Patient journals were reviewed and keratometry examinations were analysed for long-term progression.

RESULTS: Eleven eyes (nine patients) were included in the study. Five eyes showed no signs of progression after the interrupted CXL treatment. In one eye progression continued, however, first after a period of a number of years, indicating a delayed course of clinical progression.

CONCLUSION: This study indicates that debridement of the corneal epithelium and riboflavin administration without intense UVA radiation may slow or arrest the progression of keratoconus, likely due to photosensitisation from ambient light.

PURPOSE: Myopia is the most important risk factor for developing retinal tears and retinal detachment (RD). Due to altered lifestyle factors myopia is increasing in the world. In this study, the correlation between educational level and risk for retinal detachment were analysed.

METHODS: A case-control registry study was conducted including a total of 10 268 individuals. Data were collected from registries of the Swedish National Board of Health and Welfare as well as the Swedish Central Bureau of Statistics. Cases were defined as ICD-10 H33 (retinal detachments and breaks). For each case, a matched control was selected with the same age and sex, living in the same county at the time of diagnosis. The study population was divided into seven groups with regard to educational level and compared using conditional logistic regression.

RESULTS: In the total population, the odds ratio (OR) increased in a proportional fashion with a higher level of education. The odds ratio for the total population at the highest education level was 1.77 and increased to 2.00 when excluding individuals with diabetes. Out of the 5134 cases, 72% were men and 28% women. A statistically significant difference between sexes was only confirmed for the second highest education level.

CONCLUSION: Individuals with a longer education have a significantly higher risk for retinal complications in the form of RD and breaks. Higher education is a risk factor for retinal complications in both sexes but seemingly more strongly in men.

PURPOSE: To study the risk for eye diseases in individuals with Ulcerative Colitis (UC), and to assess whether silica dust-exposure could contribute to the development of inflammatory eye diseases.

METHODS: A case-control study was conducted using a patient register processed by the National Board of Health and Welfare (NBHW) and Statistics Sweden. Cases were diagnosed with UC between 2007 and 2016. Matching was done with two random controls having the same age, sex and county of residence, without a systemic inflammatory disease. Using a job-exposure matrix, cases and controls were assessed for work-related silica dust exposure. The risk for eye disease was estimated by Cox regression analysis with calculation of Hazard Ratio (HR).

RESULTS: A total of 58 989 individuals were included, comprising 19 663 cases and 39 326 controls. The sex distribution was similar. Overall, individuals with UC had an increased risk for eye disease, specified in ICD 10 chapter VII (H00-H59) with HR 1.25 (CI 1.20-1.32). The highest HR on block-level for cases was 1.52 (CI 1.36-1.70), (H15-H22), which includes episcleritis, keratitis and anterior uveitis. The risk for ocular disease was higher in silica dust-exposed than non-exposed with a HR of 1.44 (CI 1.16-1.78) and 1.25 (CI 1.19-1.31), respectively. Among cases, the risk for iridocyclitis (H20) was further elevated by silica dust exposure, with HR of 3.84 (CI 1.64-8.97) in exposed compared to 1.94 (1.57-2.41) in non-exposed.

CONCLUSION: UC is associated with an increased risk for eye diseases, including inflammatory conditions. Our findings highlight that silica dust-exposure may be of importance in the pathogenesis of uveitis.

OBJECTIVE: To investigate the increased risk for carpal tunnel syndrome (CTS) in men and women with hand-arm vibration (HAV) exposure.

DESIGN: Case-control study of CTS where 4396 cases was obtained from National Outpatient Register between 2005 through 2016. Cases were matched to controls and exposure was estimated using a job exposure matrix.

RESULTS: Exposure to HAV increased the risk of CTS with an OR of 1.61 (95% CI 1.46-1.77). The risk was highest in men <30 years of age and among women <30 years no increased risk was observed. The risk increased with a mean year exposure above 2.5 m/s2 to OR 1.84 (95% CI 1.38-2.46).

CONCLUSIONS: HAV exposure increase the risk of CTS in both genders, with highest risk increase in younger men. This emphasize identification of HAV exposure in patients with CTS.

Vibration white finger (VWF) is a complication from exposure to hand-arm vibrations. Poor knowledge of the pathophysiology of VWF means that making an accurate prognosis is difficult. Thus, a better understanding of VWF's pathophysiology is of importance.The purpose of this study was to investigate whether there were arterial abnormalities in the hands in patients with VWF and a positive Allen's test, using ultrasound and MRA imaging.This was a case series where arterial abnormalities in the hands were investigated in ten participants with VWF and using prolonged Allen's test (> 5 s). The participants had an average vibration exposure of 22 years and underwent Doppler ultrasound and Magnetic Resonance Angiography (MRA) to check for arterial abnormalities.The participants had VWF classified as 1-3 on the Stockholm workshop scale. Ultrasound and MRA identified vascular abnormalities in all participants, the predominant finding was missing or incomplete superficial arch. Also, stenosis was identified in four participants.This study reveals a high proportion of arterial stenosis and abnormalities in patients with VWF and a prolonged Allen's test.

PURPOSE: To describe the long-term results of surgical repair of patients with optic disc pit maculopathy (ODP-M).

METHODS: Prospective, consecutive, noncomparative follow-up study including 12 patients with ODP-M treated by pars plana vitrectomy (PPV), peeling of internal limiting membrane followed by gas tamponade. Subretinal fluid (SRF) was drained in 11 eyes through a retinotomy without laser photocoagulation. Preoperatively, macular detachment with retinoschisis was seen in 9 out of 12 eyes with three eyes having only subretinal fluid in the macular area. The median age at surgery was 20 years (range 9-60 years).

RESULTS: Follow-up time from initial surgery was 63 months (median). Eight eyes were anatomically reattached after one operation without remaining SRF in the macula. Two patients required a reoperation due to leakage from the retinotomy and another two underwent a second PPV procedure due to late recurrences. Successful healing was at follow-up control observed in 11 of 12 eyes. There was no statistically significant difference in visual acuity between patients before and after surgery (p = 0.24). Central visual field defects with depressed mean deviation were detected in all treated eyes.

CONCLUSION: In this long-term study of ODP-M final outcome regarding healing was relatively efficacious, however, a relatively large proportion had complications associated to retinotomies. We conclude that drainage of SRF should likely be avoided since it appears to contribute little to the resorption rate of SRF and seems to linked to unnecessary risks.

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.

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.