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Blepharitis

Blepharitis is an ocular condition characterized by eyelid inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation. Anterior blepharitis involves the eyelid skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. The typical presentation of blepharitis includes eyelid edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema with itching and redness Redness Inflammation, crusts and scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions around the eyelashes, and gritty sensation. Diagnosis is clinical, with a slit-lamp examination providing details of the structural changes affecting the eye. The mainstay of treatment is eyelid hygiene using warm compresses Warm Compresses Chalazion and eyelid scrubs. In moderate-to-severe cases, topical and oral antibiotics are utilized. Topical glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids also help improve symptoms but require an ophthalmology evaluation due to potential adverse effects.

Last updated: Jun 1, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

  • Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the eyelid margin
  • Chronic recurrent irritation can lead to eyelid scarring Scarring Inflammation and affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment the surrounding structures ( cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy and conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy).

Anatomy

  • Eyelids protect the eyes from injury and light. 
  • Eyelid layers (from superficial to deep):
    • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions
    • Loose subcutaneous tissue Subcutaneous tissue Loose connective tissue lying under the dermis, which binds skin loosely to subjacent tissues. It may contain a pad of adipocytes, which vary in number according to the area of the body and vary in size according to the nutritional state. Soft Tissue Abscess
    • Orbicularis oculi Orbicularis oculi Facial Muscles: Anatomy muscle:
      • Closes the eyelids
      • Assists in tear drainage
    • Tarsal plate: 
      • Connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology that gives structural rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon to the eyelid
      • Contains the meibomian glands
      • The levator palpebrae superioris Levator palpebrae superioris Orbit and Extraocular Muscles: Anatomy muscle is inserted into the superior tarsal plate.
    • Palpebral conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy: covers the inner surface of eyelids
  • Eyelid glands:
    • Meibomian glands
      • Modified sebaceous glands with openings behind the eyelashes
      • Meibum (lipid-rich secretion Secretion Coagulation Studies): prevents evaporation of tears and evens out tear film over the surface of the eye
    • Gland of Moll
      • Modified sweat glands Sweat glands Sweat-producing structures that are embedded in the dermis. Each gland consists of a single tube, a coiled body, and a superficial duct. Soft Tissue Abscess 
      • Orifice between adjacent lashes
    • Gland of Zeis
      • Sebaceous gland Sebaceous Gland Small, sacculated organs found within the dermis. Each gland has a single duct that emerges from a cluster of oval alveoli. Each alveolus consists of a transparent basement membrane enclosing epithelial cells. The ducts from most sebaceous glands open into a hair follicle, but some open on the general surface of the skin. Sebaceous glands secrete sebum. Hordeolum (Stye) 
      • Orifice into the eyelash follicle
  • Eyelashes:
    • Protect the eyes from particles or debris, which can cause infection or injury
    • Arranged in double or triple rows at the mucocutaneous junction

Types

  • Categorized based on anatomical location but often overlap 
  • Posterior blepharitis: 
    • More common
    • Primarily caused by meibomian gland Meibomian Gland Chalazion dysfunction/blockage
    • Involves the meibomian glands, tarsal plate, and blepharo-conjunctival junction
  • Anterior blepharitis: 
    • Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation around the eyelid skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions, base of the eyelashes, and lash follicles
    • Variants:
      • Staphylococcal blepharitis: crust Crust Dried exudate of body fluids (blood, pus, or sebum) on an area of damaged skin Secondary Skin Lesions around eyelashes caused by Staphylococcus aureus Staphylococcus aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications. Brain Abscess and coagulase-negative Staphylococci Coagulase-negative staphylococci Staphylococcus
      • Seborrheic blepharitis: greasy scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions and crust Crust Dried exudate of body fluids (blood, pus, or sebum) on an area of damaged skin Secondary Skin Lesions around the base of eyelids with flaky skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions changes
Sagittal cut of the upper eye lid

Sagittal Sagittal Computed Tomography (CT) cut of the upper lid featuring its internal structures

Image by Lecturio.

Pathophysiology and Etiology

Pathophysiology

  • Posterior blepharitis:
    • Functional abnormality of the meibomian glands → altered meibum composition
    • Wax-like secretions can block gland orifices.
    • Stagnant material and altered lipid composition → promotes bacterial growth → inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation
    • Chronic inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation damages eyelid structure and further facilitates gland dysfunction.
  • Anterior blepharitis: mechanism not fully understood but pathways include
    • Direct infection from Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus colonization Colonization Bacteriology 
    • Irritation from bacterial toxins and cell-mediated inflammatory response from antigens
    • Implication of parasitic infestation (Demodex mites Mites Any arthropod of the subclass acari except the ticks. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (mite infestations). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants. Scabies): Treatment of Demodex improves refractory blepharitis but exact role is still unclear.

Etiology

  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions diseases
    • Seborrheic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)
      • Usually causes anterior blepharitis
      • Honey-colored crusts along the rims of eyelids around the eyelashes
    • Rosacea Rosacea Rosacea is a chronic inflammatory disease of the skin that is associated with capillary hyperreactivity. This condition is predominantly seen in middle-aged women, and is more common in fair-skinned patients. Rosacea 
      • Usually causes posterior blepharitis
      • Inflammatory disorder resulting in flushing and facial redness Redness Inflammation
    • Atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)
      • Characterized by scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions along the lash line, edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, and hyperemia 
    • Psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis
      • Manifests with swollen eyelids and crusting of the eyelashes
      • Associated with well-defined plaques with scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions in elbows and knees
  • Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
    • Bacterial infection
    • Viral infection
      • Molluscum contagiosum Molluscum contagiosum Molluscum contagiosum is a viral infection limited to the epidermis and is common in children below 5 years of age. Lesions appear as grouped, flesh-colored, dome-shaped papules with central umbilication. Molluscum Contagiosum
      • Varicella zoster dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)
      •   Herpes simplex Herpes Simplex A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. Congenital TORCH Infections dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema)
    • Parasitic infestation
      • Demodex folliculorum Demodex Folliculorum Infectious Folliculitis (in eyelid follicles): causes anterior blepharitis 
      • Demodex brevis (in meibomian glands): causes posterior blepharitis
      • Not all with infestation develop blepharitis
  • Others
    • Irritants and allergens
      • Swollen, itchy erythematous eyelids
      • Improves with removal of offending agent
    • Medications: retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies
      • Causes posterior blepharitis
      • Improves with discontinuation of medication

Clinical Presentation

Symptoms

  • Typically bilateral
  • Chronic, episodic red, swollen, itchy eyelids
  • Gritty or burning sensation
  • Watery eyes
  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions crusting and scaling on the eyelid margin and eyelashes
  • Matting of eyelashes in the morning
  • Transient blurred vision Vision Ophthalmic Exam
  • Vesicles Vesicles Female Genitourinary Examination and ulcerations found in herpes or varicella infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease

Signs

  • Slit-lamp examination of posterior blepharitis:
  • Slit-lamp examination of anterior blepharitis:
    • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion and edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema of eyelid margin
    • Telangiectasias Telangiectasias Ataxia-telangiectasia on outer eyelid
    • Collarette: ring-like crust Crust Dried exudate of body fluids (blood, pus, or sebum) on an area of damaged skin Secondary Skin Lesions around eyelashes ( Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus)
    • Sleeve: cylindrical dandruff Dandruff Excessive shedding of dry scaly material from the scalp in humans. Seborrheic Dermatitis (Demodex infestation)
    • Greasy flakes (seborrheic type)
    • Madarosis: loss of lashes
    • Poliosis: whitening of lashes
    • Trichiasis: misdirection of lashes
    • Entropion Entropion The turning inward (inversion) of the edge of the eyelid, with the tarsal cartilage turned inward toward the eyeball. Sjögren’s Syndrome: inward turning of eyelid
    • Ectropion Ectropion The turning outward (eversion) of the edge of the eyelid, resulting in the exposure of the palpebral conjunctiva. Sjögren’s Syndrome: outward turning of eyelid
  • Other findings:
    • Conjunctival injection
    • Tear film stability: tear break-up time < 10 seconds considered abnormal
    • Cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy:

Diagnosis and Management

Diagnosis

  • Clinical, based on the signs and symptoms
  • In refractory cases: microscopic examination of the eyelashes to check for Demodex mites Mites Any arthropod of the subclass acari except the ticks. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (mite infestations). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants. Scabies helps if with typical presentation (sleeves on eyelashes)

Management

  • Eyelid hygiene
    • Mainstay treatment for blepharitis
    • Warm compresses Warm Compresses Chalazion (10 minutes, 4 times/day) to soften crusts/ scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions and warm the secretions
    • Lid massage to express secretions
    • Lid wash to clear away debris
    • Artificial tears to relieve dryness
  • Eliminate triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) or offending agent
  • Demodex-associated disease
    • Tea tree oil eyelid and shampoo scrubs: shown to be effective 
    • Oral ivermectin Ivermectin A mixture of mostly avermectin h2b1a (rn 71827-03-7) with some avermectin h2b1b (rn 70209-81-3), which are macrolides from streptomyces avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other chloride channels. It is a broad spectrum antiparasitic that is active against microfilariae of onchocerca volvulus but not the adult form. Anthelmintic Drugs
  • Topical antibiotics 
    • If initial symptomatic measures fail
    • Eradicates bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology in the lashes and conjunctivae
    • Options: bacitracin, erythromycin Erythromycin A bacteriostatic antibiotic macrolide produced by streptomyces erythreus. Erythromycin a is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50s ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins. Macrolides and Ketolides, azithromycin Azithromycin A semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis. Macrolides and Ketolides
  • Oral antibiotics
    • For chronic-moderate to severe blepharitis
    • For blepharitis not responding to topical medications
    • Options: doxycycline, minocycline Minocycline A tetracycline analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant staphylococcus infections. Tetracyclines, zithromax
  • Topical glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids
    • Only prescribed after evaluation from an ophthalmologist
    • Can increase intraocular pressure Intraocular Pressure The pressure of the fluids in the eye. Ophthalmic Exam so follow-up is required for reevaluation
  • Topical cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants
    • For blepharitis resistant to standard therapies

Differential Diagnosis

  • Conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy, the outer lining of the eye. Etiology can be infectious Infectious Febrile Infant or non-infectious. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with redness Redness Inflammation and discharge on one or both eyes Both Eyes Refractive Errors. Bacterial conjunctivitis Bacterial Conjunctivitis Conjunctivitis often has purulent discharge Purulent Discharge Dacryocystitis whereas viral causes have watery discharge.
  • Dacryocystitis Dacryocystitis Dacryocystitis is inflammation of the lacrimal sac due to nasolacrimal duct obstruction and the subsequent stasis of tears. The condition can have an acute or chronic onset. Acute dacryocystitis presents within hours or days with redness, swelling, tenderness, and excessive tearing. Dacryocystitis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the nasolacrimal sac commonly caused by duct obstruction. The condition presents as redness Redness Inflammation and swelling Swelling Inflammation in the area of the tear duct. Tear stasis facilitates bacterial overgrowth Bacterial overgrowth Lactose Intolerance and infection occurs, manifesting as mucopurulent discharge. For management, warm compresses Warm Compresses Chalazion are applied and antibiotics are given if indicated. For persistent obstruction, nasolacrimal duct Nasolacrimal Duct Nasolacrimal duct. Dacryocystitis intubation Intubation Peritonsillar Abscess and other surgical interventions are treatment options.
  • Hordeolum Hordeolum A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye) ( stye Stye A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye)): an abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease affecting the eyelash follicle or eyelid gland. The condition usually presents as a locally painful, erythematous, swollen eyelid margin. Most lesions resolve spontaneously, but gentle warm compresses Warm Compresses Chalazion facilitate drainage. If the abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease does not resolve, incision and drainage Incision And Drainage Chalazion by an ophthalmologist are performed.
  • Chalazion Chalazion A chalazion is one of the most common inflammatory lesions of the eyelid. It is caused by obstruction of the Meibomian or Zeis glands, leading to granulomatous inflammation and resulting in a firm, rubbery, slow-growing nodule that is typically non-tender. Chalazion: a firm, nontender mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast at the eyelid resulting from obstruction of the Zeis or meibomian glands. The condition is usually managed conservatively with warm compresses Warm Compresses Chalazion. Persistence of the lesion requires incision and curettage Curettage A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. Benign Bone Tumors or glucocorticoid injection by an ophthalmologist.

References

  1. Denniston, A., Murray, P. (2014) Oxford Handbook of Ophthalmology, Third edition.Oxford University Press.
  2. Eberhardt, M., Rammohan, G. (2020). Blepharitis. https://www.ncbi.nlm.nih.gov/books/NBK459305/
  3. Lowery, R., Law, S., Dahl, A.(2019). Adult Blepharitis. Retrieved September 23, 2020, from https://emedicine.medscape.com/article/1211763-overview
  4. Putnam,C. (2016) Diagnosis and management of blepharitis. Clin Optom (Auckl), 8: 71–78. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095371/
  5. Schtein, R.,Jacobs, D., Givens, J. (2020). Blepharitis. UpToDate. Retrieved September 23, 2020, from https://www.uptodate.com/contents/blepharitis?search=blepharitis&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1

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