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Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye
Published on: June 20, 2015
A study of aqueous humor dynamics in keratoconus
W T Goodman1, W D Mathers, P M Munden
1School of Medicine, University of Iowa, Iowa City, USA.
Experimental Eye Research
|January 1, 1996
Summary
Patients with keratoconus have lower intraocular pressure (IOP) due to increased aqueous humor outflow facility. This study found significantly lower IOP in keratoconus patients compared to controls, with no difference in aqueous production.
Area of Science:
- Ophthalmology
- Ocular Physiology
Background:
- Clinical observations indicate lower intraocular pressure (IOP) in keratoconus patients compared to healthy individuals.
- The underlying mechanisms for this IOP difference are not fully understood.
Purpose of the Study:
- To investigate if differences in aqueous humor dynamics, specifically production and outflow facility, explain the lower IOP in keratoconus.
- To compare aqueous humor dynamics between keratoconus patients and age-matched normal controls.
Main Methods:
- Aqueous humor dynamics were assessed using fluorophotometry in one eye of seven keratoconus patients and ten age-matched controls.
- Intraocular pressure was measured using applanation tonometry.
- Corneal stromal thickness was considered to correct for potential IOP measurement errors.
Main Results:
- Keratoconus patients exhibited significantly lower mean IOP (11.3 mmHg) than normal controls (16.6 mmHg).
- No significant difference was found in mean aqueous humor flow rates between the groups.
- Mean apparent outflow facility was significantly higher in keratoconus patients (0.21) compared to controls (0.14).
Conclusions:
- Lower intraocular pressure in keratoconus patients is associated with increased aqueous humor outflow facility.
- Aqueous humor production does not appear to be a factor in the reduced IOP observed in keratoconus.
- These findings contribute to understanding the pathophysiology of keratoconus and its effect on ocular hemodynamics.
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