Document Detail


Aqueous humor dynamics during the day and night in juvenile and adult rabbits.
MedLine Citation:
PMID:  20107172     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: To determine the day and night differences in intraocular pressure (IOP), aqueous flow, outflow facility, uveoscleral outflow, and central corneal thickness (CCT) in juvenile and adult rabbits. METHODS: Studies were performed on twelve 3-month-old and ten 12-month-old male New Zealand White rabbits. Daytime measurements were made between 9 AM (3 hours after lights on) and 3 PM, and nighttime measurements were made between 11 PM and 5 AM. IOP was measured by pneumotonometry and aqueous flow by fluorophotometry. Outflow facility was determined by both fluorophotometry and tonography. Uveoscleral outflow was calculated by the Goldmann equation. CCT was measured by ultrasound pachymetry. Repeated-measures ANOVAs and Student's two-tailed t-tests were used for statistical comparisons. RESULTS: When nighttime versus daytime readings were compared, IOP, aqueous flow and uveoscleral outflow were higher, fluorophotometric outflow facility was lower, and CCT was thinner in both age groups. When the juvenile rabbits were compared to adult rabbits, IOP was lower, aqueous flow and uveoscleral outflow were higher, and fluorophotometric outflow facility and CCT were not different during the day or night. Tonographic outflow facility did not change in a 24-hour period in the juvenile rabbits. CONCLUSIONS: The increased IOP at night in rabbits can be explained mainly by a decrease in outflow facility. An increase in aqueous flow at night is counterbalanced by an increase in uveoscleral outflow. Although the rates of aqueous flow and uveoscleral outflow slow with maturity, their relative day/night differences remain the same.
Authors:
Min Zhao; Joseph J Hejkal; Carl B Camras; Carol B Toris
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-01-27
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  51     ISSN:  1552-5783     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-05-20     Completed Date:  2010-06-11     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3145-51     Citation Subset:  IM    
Affiliation:
Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198-5840, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Aqueous Humor / secretion*
Circadian Rhythm / physiology*
Fluorophotometry
Intraocular Pressure / physiology*
Male
Rabbits
Sclera / physiology
Tonometry, Ocular
Uvea / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Gelatinase expression in retinoblastoma: modulation of LH(BETA)T(AG) retinal tumor development by an...
Next Document:  Association of POAG risk factors and the Thr377Met MYOC mutation in an isolated Greek population.