Corneacare Logo
  • CorneaCare Logo
  • Shop
    • Shop All
    • Eyelid Hygiene
    • Eye Vitamins
    • Eye Drops
    • Eyecare Bundles
  • Education
    • Dry Eye Disease
      • Dry Eye 101
      • Causes & Diagnosis
      • Lifestyle
      • Treatment
      • Why It Matters
    • Eye Health & Wellness
    • Eye Glossary
    • Take the Quiz
  • Community
  • App
  • Take the Quiz
  • Contact us
  • Login
  • My Account
Login
Cart Icon 0
Take the Quiz
  • Shop
  • Education
  • Our App
  • Take the Quiz
  • Shop
  • Education
  • Our App
  • Take the Quiz

A-Z Glossary

Table of Contents

Bowman’s Layer

Vasudha Rao
Written byVasudha Rao
Vasudha Rao
Vasudha Rao4th Year Optometry Student, UC BerkeleyBerkeley, CA

Bio

Vasudha Rao is a fourth-year optometry student at the UC Berkeley School of Optometry with aspirations of specializing in ocular disease or community care. She is currently on clinical rotations. She enjoyed serving veterans at the Miami Veterans Affairs Hospital and learning from renowned clinicians at the Bascom Palmer Eye Institute as a part of her clinical training. Vasudha is passionate about helping underserved communities receive optometric care, and actively volunteers to provide vision screenings to those in need. In her spare time she enjoys partaking in a game of Scrabble, enhancing her cooking skills, and sharing her clinical cases on her Instagram page @visions.of.vasudha.

  • Last updated November 3, 2022

What is Bowman’s Layer?

Bowman’s layer is the second layer of the cornea, which is the clear outer covering of the eye. Bowman’s membrane is also known as Bowman’s membrane. Bowman’s membrane is between the corneal epithelium and the corneal stroma. Bowman’s membrane of the eye is made up of a network of collagen fibers. The collagen fibers are important to maintain the structure of the cornea. Bowman’s membrane does not regenerate if it is damaged from eye disease or eye surgery. 

Key Takeaways

  • Bowman’s membrane is the second layer of the cornea, located between the outermost epithelium and the middle stroma. 
  • Bowman’s layer is composed of a dense network of collagen fibers that reinforce the structure of the cornea. 
  • Eye conditions such as pterygium, recurrent corneal erosion, band keratopathy, or photorefractive keratectomy (PRK) surgery can damage Bowman’s layer. 
You brush your teeth,
moisturize your skin,
what about your eyes?
Take the quiz
Eyecare Quiz on Cellphone

Understanding Bowman’s Layer

The cornea is the clear dome-shaped tissue that covers the front of the eye. The cornea is an important tissue to maintain the clarity of vision: it is transparent to allow light through, and it bends light rays so the eye can focus clearly. The human cornea has six layers:

  • Epithelium: the outermost layer, regenerates quickly after surface damage
  • Bowman’s Membrane: a collagen sheet that provides structural support, but cannot regenerate
  • Stroma: regular collagen that makes up 90% of the cornea
  • Descemet’s layer: elastic, trauma resistant, regenerates after injury
  • Endothelium: has metabolic pumps that prevent corneal swelling, but cannot regenerate

Bowman’s membrane is a densely woven sheet made of collagen fibers. It is acellular, meaning it does not have any cells and it only has collagen fibrils. It is approximately 10 microns thick, which is about the thickness of a strand of spider web silk. Type 1 collagen is in Bowman’s layer, which is also the type of collagen found in skin, tendons, teeth, and bones. The role of Bowman’s layer is not entirely known, but it is thought to serve as structural support and as a protective barrier to the inner corneal layers. 

Development of Bowman’s Membrane

Bowman’s membrane is produced due to  interactions between the corneal epithelial cells and keratocytes. Keratocytes produce collagen, a protein that provides structural support and stretchiness to many of the bodily tissues. Bowman’s membrane develops between weeks 13 and 19 of gestation. Bowman’s layer thins with age in the normal cornea, losing approximately 30% of its thickness by 80 years of age. 

The Function of Bowman’s Membrane

The role of the Bowman’s membrane remains unclear. However, recent research has postulated that the Bowman’s layer acts as a protective barrier to prevent bacterial invasion. It also is a barrier against the penetration of ocular drugs, so it reduces drug side effects and absorption.  It may also provide structural support to the cornea and maintain the corneal shape. 

Bowman’s Membrane Pathologies

The Bowman’s membrane can become damaged by the following eye conditions:

  • Pterygium (Surfer’s Eye)
    This condition involves the formation of a wing-shaped, elevated area due to growth of the conjunctiva, the white part of the eye. It is caused by excessive sunlight exposure. A pterygium disrupts Bowman’s layer once it starts to grow onto the cornea..    
  • Recurrent corneal erosion
    This condition involves recurrent sloughing off of the epithelium overlying Bowman’s membrane. It is usually due to injury of the eye, which prevents epithelium from properly attaching to the underlying Bowman’s membrane. 
  • Photorefractive Keratectomy (PRK)
    This refractive surgery, an alternative to LASIK refractive surgery, removes Bowman’s membrane. Bowman’s membrane is permanently destroyed in PRK using a laser. This is done to reshape the cornea and correct for refractive errors like farsightedness, nearsightedness, and astigmatism. 
  • Band keratopathy
    In this condition, there are excess levels of calcium, and a thick white band of calcium grows across the eye. The calcium is deposited in Bowman’s membrane. 
  • Reis Buckler Dystrophy
    This rare hereditary corneal dystrophy involves disintegration of Bowman’s layer, corneal haziness, and reduced vision.

Examining Bowman’s Layer

Most corneal diseases can be detected by an eye exam where the eye doctor will check for abnormalities in the cornea and its layers, including Bowman’s membrane. An eye doctor will use a specialized instrument called a slit lamp biomicroscope, which allows for a magnified view of the cornea and its tissues. 

Because Bowman’s layer is so thin, it may be difficult to visualize even using a slit lamp microscope. A scan of the eye may be taken to examine the cornea’s microscopic structure. This scan is called an anterior segment optical coherence tomography (OCT). The OCT allows a clinician to determine what exact layer of the cornea is being affected by an ocular condition. Using the OCT device, an eye doctor can definitively determine if the eye condition is in the Bowman’s membrane or another layer.

Bibliography

  1.  “Bowman’s Membrane.” American Academy of Ophthalmology, 29 Oct. 2020, www.aao.org/eye-health/anatomy/bowman-s-membrane Accessed 1 Aug. 2022.
  2. Wilson, Steven E. “Bowman’s Layer in the Cornea– Structure and Function and Regeneration.” Experimental Eye Research, vol. 195, June 2020, p. 108033, 10.1016/j.exer.2020.108033.
  3. Wilson, Steven E., and Jong-Wook Hong. “Bowman’s Layer Structure and Function: Critical or Dispensable to Corneal Function? A Hypothesis.” Cornea, vol. 19, no. 4, 1 July 2000, pp. 417–420, journals.lww.com/corneajrnl/Fulltext/2000/07000/Bowman_s_Layer_Structure_and_Function__Critical_or.1.aspx. Accessed 1 Aug. 2022.

 

Related Terms

Loading...

YAG Capsulotomy

is a laser surgical procedure that may be performed months or years after cataract surgery

Scotopic Vision

refers to your eyes’ ability to see in low light levels

Normal Eye Pressure

is measured by the fluid pressure within the eye

Esotropia

is an eye misalignment where one eye is turned inward. The turn may be constant or intermittent

Aberrations

are flaws or imperfections in the way that an optical system constructs images

Retinal Pigment Epithelium

is a fundamental component of the retina that plays an important role in vision

Related Articles

Loading...
  • Eye Health & Wellness

Eye Bag Surgery Gone Wrong

7 min read

Understand the complications of eye bag surgery gone wrong and how it can damage the function and health of your eyes.
Heather Cottrell

Heather Cottrell

  • Eye Health & Wellness

Sharp Stabbing Pain in Eye that Comes and Goes

7 min read

Find out what’s causing that sharp stabbing pain in your eye that comes and goes. And when to see a doctor!
Heather Cottrell

Heather Cottrell

  • Eye Health & Wellness

A Black Spot in Vision of One Eye

7 min read

A black spot in the vision of one eye is probably a harmless floater, but there can be a more serious cause requiring treatment.
Heather Cottrell

Heather Cottrell

Logo_Corneacare_White

    • Shop
    • Wholesale
    • Education
    • Community
    • App
    • Eye Glossary
    Menu
    • Shop
    • Wholesale
    • Education
    • Community
    • App
    • Eye Glossary
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    • Education
    • Shop
    • Wholesale
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    • Education
    • Shop
    • Wholesale
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    • Education
    • Shop
    • Wholesale
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    • Education
    • Shop
    • Wholesale
    • Contact
    • Terms of service
    • Privacy policy
    • Shipping & Returns
    Instagram Facebook_Pink Youtube Twitter Tiktok
    Copyright – © 2023 CorneaCare, Inc. ⚡️ All rights reserved
    *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease

    Wholesale inquiry

    Please fill out the form below, and we will be in touch shortly.

    20% OFF personalized, convenient and effective eyecare
    20% OFF personalized eyecare
    Take the quiz
    Take the quiz