What is a bleb?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 27, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

A bleb is a small, fluid-filled bubble or sac that forms on the surface of tissue, most commonly found on the eyes, and is deliberately created during glaucoma surgery to allow excess fluid to drain from the eye, reducing intraocular pressure. In the context of ophthalmology, blebs are a crucial aspect of glaucoma management, as they play a key role in regulating intraocular pressure 1. The formation of a bleb is a intended outcome of trabeculectomy, a surgical procedure used to treat glaucoma, and its success is closely monitored post-operatively to ensure proper drainage and to prevent complications such as bleb failure 1.

Key Characteristics of Blebs

  • They are small, fluid-filled sacs that form on the surface of the eye
  • They are deliberately created during glaucoma surgery to facilitate excess fluid drainage
  • Their success is crucial for maintaining reduced intraocular pressure in glaucoma patients
  • Post-operative care includes monitoring for signs of bleb failure, such as increased inflammation or Tenon’s cyst formation 1

Clinical Significance

Blebs can be associated with various complications, including bleb leak, early bleb failure, and the formation of Tenon’s cyst (encapsulated bleb) 1. Management of these complications may involve additional treatments such as injection of antifibrotic agents, bleb massage, or surgical intervention 1. The ophthalmologist's role in perioperative care, including preoperative evaluation, postoperative follow-up, and management of complications, is critical for the success of the surgery and the patient's quality of life 1.

Treatment and Management

Treatment of bleb-related complications depends on the nature and severity of the issue, ranging from conservative management with topical medications to more invasive procedures like bleb needling or revision surgery 1. The decision to intervene is guided by the clinical presentation and the potential impact on the patient's vision and quality of life. The primary goal is to maintain a functioning bleb that effectively regulates intraocular pressure, thereby preventing glaucoma progression and preserving vision.

From the Research

Definition of Bleb

  • A bleb is a small, circumscribed collection of fluid in the skin, typically up to 1 cm in size 2.
  • It can be subcorneal, intra-epidermal, junctional, or subepidermal, and may be filled with fluid or pus 2, 3.

Types of Blebs

  • In the context of glaucoma-filtering surgery, a bleb refers to a blister-like formation on the conjunctiva, which can be microcystic, avascular, or vascular 4.
  • In cell biology, a bleb is a protrusion of the cell membrane caused by actomyosin contractions, resulting in a transient detachment of the cell membrane from the actin cortex 5.

Clinical Significance

  • Blebs can be a sign of various diseases, such as pemphigus, bullous pemphigoid, or epidermolysis bullosa 2, 3.
  • In the context of glaucoma-filtering surgery, blebs can become infected, leading to blebitis, which can be caused by various microorganisms 4.
  • Hemorrhagic bullae, a type of bleb, can be a sign of a life-threatening condition, such as necrotizing fasciitis 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Bullae and blisters--differential diagnosis].

MMW Fortschritte der Medizin, 2007

Research

Blistering disorders: diagnosis and treatment.

Dermatologic therapy, 2003

Research

A short history of blebbing.

Journal of microscopy, 2008

Research

Hemorrhagic bullae are not only skin deep.

The American journal of emergency medicine, 2008

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.