title: Retinal Changes in Uncomplicated and Severe Plasmodium knowlesi Malaria.
abstract: BACKGROUND
  Plasmodium knowlesi causes severe malaria, but its pathogenesis is poorly understood. Retinal changes provide insights into falciparum malaria pathogenesis but have not been studied in knowlesi malaria.
  
  
  METHODS
  An observational study was conducted in Malaysian adults hospitalized with severe (n = 20) and nonsevere (n = 24) knowlesi malaria using indirect ophthalmoscopy (n = 44) and fundus photography (n = 29).
  
  
  RESULTS
  The patients' median age was 44 years (range, 18-74 years). No coma or deaths occurred. Photography detected retinal changes in 11 of 12 patients (92%) with severe and 14 of 17 (82%) with nonsevere knowlesi malaria. Nonspecific retinal whitening occurred in 3 (35%) and 5 (29%) patients with severe and nonsevere disease, respectively; hemorrhages in 2 (17%) and 3 (18%); loss of retinal pigment epithelium in 1 (8%) and 4 (24%); and drusen in 9 (71%) and 12 (75%). All changes were mild, with no significant differences between severe and nonsevere disease. Patients with retinal hemorrhages had lower platelet counts than those without (median, 22 vs 43 × 10(9)/L; P= .04).
  
  
  CONCLUSIONS
  The paucity of specific retinal findings associated with disease severity in knowlesi malaria contrasts with the retinopathy of severe adult falciparum malaria with and without coma, suggesting that falciparum-like microvascular sequestration in the brain is not a major component in severe knowlesi malaria pathogenesis.
authors.affiliation: Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia.
authors.forename: Gayathri
authors.initials: G
authors.lastname: Govindasamy
authors.affiliation: Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit.
authors.forename: Bridget E
authors.initials: BE
authors.lastname: Barber
authors.affiliation: Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia.
authors.forename: Shuaibah A
authors.initials: SA
authors.lastname: Ghani
authors.affiliation: Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Infectious Diseases Unit, Clinical Research Centre, Queen Elizabeth Hospital Jesselton Medical Centre, Kota Kinabalu, Sabah, Malaysia.
authors.forename: Timothy
authors.initials: T
authors.lastname: William
authors.affiliation: Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Grigg
authors.affiliation: College of Medicine and Veterinary Medicine, University of Edinburgh, United Kingdom.
authors.forename: Shyamanga
authors.initials: S
authors.lastname: Borooah
authors.affiliation: College of Medicine and Veterinary Medicine, University of Edinburgh, United Kingdom.
authors.forename: Bal
authors.initials: B
authors.lastname: Dhillon
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.
authors.forename: Arjen M
authors.initials: AM
authors.lastname: Dondorp
authors.affiliation: Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
authors.forename: Tsin W
authors.initials: TW
authors.lastname: Yeo
authors.affiliation: Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Royal Darwin Hospital, Darwin, Northern Territory, Australia.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Anstey
authors.affiliation: College of Medicine and Veterinary Medicine, University of Edinburgh, United Kingdom Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Maude
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008288:Malaria / Q000150:complications* / Q000453:epidemiology; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016790:Plasmodium knowlesi; D012160:Retina / Q000473:pathology*; D012164:Retinal Diseases / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D012171:Retinal Vessels / Q000473:pathology*; D055815:Young Adult
keywords: malaria; plasmodium knowlesi; retinopathy