Related Experiment Video
Updated: Jun 9, 2026
05:46
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Bleb morphology characteristics and effect on positional intraocular pressure variation.
Jennifer S Weizer1, Anju Goyal, Patricia Ple-Plakon
1Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA. jweizer@umich.edu
Summary
Glaucoma filtration surgery leads to lower intraocular pressure (IOP) and reduced positional IOP changes compared to medical treatment. Key bleb features like height and microcysts correlate with better IOP stability.
Area of Science:
- Ophthalmology
- Glaucoma Surgery
- Ocular Fluid Dynamics
Background:
- Filtration surgery is a common treatment for glaucoma.
- Understanding bleb morphology's impact on intraocular pressure (IOP) stability is crucial.
Purpose of the Study:
- To investigate the relationship between bleb morphology and positional IOP change (supine vs. sitting).
- To compare positional IOP changes between eyes treated with filtration surgery and those treated medically.
Main Methods:
- Observational case series grading bleb height, extent, vascularity, microcysts, and "ring of steel."
- Positional IOP change analyzed using paired t test and regression analysis.
Main Results:
- Decreased bleb height, absence of microcysts, and increased vascularity were linked to larger positional IOP changes.
- Medically treated eyes showed significantly larger positional IOP changes than surgically treated eyes (6.1 vs. 4.6 mm Hg).
Conclusions:
- Successful filtration surgery reduces both IOP and positional IOP fluctuations.
- Bleb characteristics such as higher elevation, presence of microcysts, and less vascularity are associated with improved IOP stability.
Related Concept Videos
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:27Open Angle Glaucoma: Treatment
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:22Microbiome of the Eye
The human eye has a specialized microbiota that reflects its unique anatomical and immunological environment. This low-biomass microbial community predominantly colonizes the conjunctiva and eyelid margins, playing a vital role in ocular surface homeostasis and defense. Despite its proximity to the richly colonized facial skin, the ocular surface maintains a distinct microbial profile due to continuous mechanical and biochemical defense mechanisms.The conjunctival surface hosts fewer microbial...