Intraocular Pressure and Hemodialysis Midwestern Brazil
Condition: Renal Insufficiency, Chronic; Glaucoma
MeSH terms: Glaucoma; Renal Insufficiency; Renal Insufficiency, Chronic
Study type: Interventional

Summary: 
      Objective: To evaluate the variation in intraocular pressure in patients with chronic kidney
      disease, according to the time interval between hemodialysis sessions and to the influence of
      weight and blood pressure on intraocular pressure.

      Methods: This was a cross-sectional study in which 78 eyes of 39 patients on hemodialysis, at
      the Santa Casa de Misericordia de Goiânia hospital, were analyzed in June 2014. Patients were
      divided into groups according to the days on which they underwent hemodialysis. The mean,
      standard deviation, and median of the intraocular pressure, blood pressure, and weight were
      calculated. P-values <0.05 were considered statistically significant.
    

Detailed description: 
      This cross-sectional observational study followed the guidelines of the Declaration of
      Helsinki, and all patients signed an informed consent form approved by the Ethics and
      Research Committee of the Pontifical Catholic University of Goiás (Pontifícia Universidade
      Católica de Goiás - PUC-GO). The inclusion criteria were chronic renal patients, who were
      older than 18 years of age, were part of the hemodialysis program of the Santa Casa de
      Misericordia de Goiânia (SCMG) hospital, signed the informed consent form and were able to
      undergo a physical examination. Exclusion criteria were patients on hemodialysis who were not
      chronic renal patients; patients who refused to participate in the study or could not undergo
      a physical examination; patients who did not undergo hemodialysis in the week of the study;
      prior ophthalmic eye disease or surgery; and patients allergic to anesthetic drops or dyes.

      Patients were divided into groups according to the days on which they underwent hemodialysis.
      A total of 39 patients who were on hemodialysis at SCMG for six days in the month of June
      2014 were analyzed. The patient's eye fundus was evaluated through direct ophthalmoscopy with
      a PanOptic device (Welch Allyn). Intraocular pressure was measured with a Kowa HA-2 Perkins
      applanation tonometer. The tonometry included three measurements in the central region of the
      cornea before and after hemodialysis. In all patients, the measurements were performed three
      times on the days when hemodialysis sessions were performed, with 24 hours between each
      session, and the means of the measurements were obtained. All parameters were measured under
      prior corneal anesthesia with 0.1% proparacaine and 0.25% fluorescein eye drops.

      The variables studied were age, gender, base etiology for CKD, and variations in body weight
      and IOP before and after hemodialysis. Mean blood pressure (MBP), systolic blood pressure
      (SBP), diastolic blood pressure (DBP), and ocular perfusion pressure (OPP) were obtained
      before and after hemodialysis. The following mathematical models were used: MBP = (DBP) + 1/3
      (SBP) - (DBP) and OPP = 2/3 (MBP-IOP), as described in the literature (18-20). The data were
      collected using a form devised for the study from the medical records of the chronic renal
      patients undergoing hemodialysis at SCMG and registered in the system.

      The data were tabulated in a Microsoft© Excel 2007 spreadsheet and analyzed using the
      Statistical Package for the Social Sciences, version 20 (SPSS, Chicago, IL). The mean,
      standard deviation, median IOP measurements, blood pressure, and weight were obtained. Data
      normality was assessed by the Kolmogorov-Smirnov test. The significance of differences
      between measurements obtained before and after hemodialysis was assessed by the Wilcoxon
      test. The relationship between IOP and weight was assessed by Pearson's or Spearman's
      correlation. P-values <0.05 were considered significant.
    

Intervention name(s): Kowa HA-2 Perkins applanation tonometer.
Intervention type(s): Other
Intervention description(s): Patients were divided into groups according to the days on which they underwent hemodialysis. Intraocular pressure was measured with a Kowa HA-2 Perkins applanation tonometer. The tonometry included three measurements in the central region of the cornea before and after hemodialysis. In all patients, the measurements were performed three times on the days when hemodialysis sessions were performed, with 24 hours between each session, and the means of the measurements were obtained. All parameters were measured under prior corneal anesthesia with 0.1% proparacaine and 0.25% fluorescein eye drops.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Glaucoma; Renal Insufficiency, Chronic; Low Tension Glaucoma; Ocular Hypertension