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Red eye

Subconjunctival haemorrhage – Heme under the subconjunctiva due to bleeding into the subconjunctival space usually asymptomatic risk and contributing factors may include
○ trauma
○ rubbing
○ cough or straining
○ hypertension
○ antiplatelets and anticoagulation
○ bleeding disorders -if recurrent unilateral

.The sclera can be completely covered in blood in severe cases Normal VA PERLA well demarcated bright red patch on the white of sclera No corneal involvement IOP normal No pain but may cause slight irritation. Reassurance No treatment required resolves within 2-3 weeks Lubricants can be considered in cases of mild discomfort

Conjunctivitis – Infectious or non-infectious inflammation of the bulbar and palpebreal conjunctiva Conjunctivitis can be bacterial , viral or allergic Symptoms include gritty / FB sensation
○ bacterial – often mucopurulent discharge / lashes stuck together
○ viral – watery , clear , mucous discharge suggests viral origin

This is distinction is not always reliable

Episcleritis-Benign , self limiting, inflammatory disease affecting the episclera Episclera is the loose connective tissue between the conjunctiva and sclera Idiopathic in nature Rarely associated with systemic disease Causes relatively mild occular discomfort Risk factors include
○ female sex ( 70 % )
○ age ( 5th decade )
○ systemic autoimmune conditions B/L recurrent episcleritis may suggest a systemic disease association

redness or pain in one or both eyes presentation is with dilated superficial blood vessels in a localised area of the sclera – in contrast to conjunctivitis which is more diffuse edema of episclera tenderness over area of injection VA is normal PER to light No photophobia No corneal staining. Usually self- limiting Topical lubricants Oral NSAIDs Review as appropriate

Scleritis- Inflammation of sclera 
( the white outer wall of the eye ) Severe , intense eye pain often described as deep , drilling pain like toothache – this can wake the patient up at night ( pain is worse at night ) More common in young women aged 30-50 yr Half the patient have no underlying cause but 30-40 % may have an underlying systemic autoimmune condition It can be classified as
◘ anterior – which is further classified as diffuse , nodular or nodular necrotising
◘◘ posterior – less common
. The eye is intensely red and VA- may be reduced Pupils – normal Photophobia – may be present Anterior chamber – clear Pain increases with eye movement The eye may be tender to touch. Refer urgently for same day assessment – scleritis is a severe , destructive and sight threatening condition Early identification and referral is vital as it can also lead to diagnosis of other organ-involving vasculitis Scleritis can lead to globe perforation

Anyerior uveitis / Iritis –Idiopathic inflammation of the uvea – iris , choroid and or ciliary body ( ant segment of the eye ) May be associated with 
○ conn tissue disorders as rheumatoid arthritis and SLE
○ Infections as syphilis , TB , Lyme disease , toxoplasmosis , herpes virus , CMV
○ some drugs as rifabutin , cidofovir , moxifloxacin Uveitis can be
○ anterior- most common
○ intermediate uveitis / pars planitis
○ posterior uveitis / chroiditis / chorioretinitis
○ panuveitis / diffuse uveitis Complications – glaucoma , cataract, optic n damage , retinal detachment. Circumlimbal redness watering eye pain – constant and developing over hrs ( ciliary muscle spasm ) can cause headache consensual photophobia blurred vision VA – normal or decreased Poorly reacting constricted pupil. Refer urgently Topical steroids + – cycloplegics 
( dilating pupil ) analgesia Steroid drops to be used only after an ophthalmological assessment 
( may worsen prognosis for patients with HSV keratitis )

Corneal causes –Corneal ulcer
Keratitis is corneal epithelial defect with stromal haze due to microorganisms which can be bacterial , viral or fungi
often due to contact lens use Corneal abrasion
○ corneal abrasions are defects in the epithelial surface of the cornea
usually happen due to trauma to the surface of the eye for e.g fingernail scratching
walking into a tree branch
getting grit in the eye Corneal FB
○ common
○ generally h/o trauma
○ use of tools like hammer
○ wind blowing into the eye
○ a feeling something blow into the eye

. Microbial keratitis – pain , conjunctival injection ,photophobia , blurred vision and FB sensation
discuss with the eye clinic as clinical signs do not reliably distinguish different organisms . wherever possible the nature of causative organism should be investigated by collection of samples for microscopy, culture and sensitivity
 Corneal abrasions
○ if time -resources available this can be managed in primary care ,also managed frequently in A&E
○ symptoms include immediate pain
watering , FB sensation , light sensitivity , blurred vision
○ corneal staining
○ refer if no improvement or worsening 24 hrs after initiation of treatment in primary care
 Corneal FB
○ visible corneal FB
○ red eye
○ FB sensation
○ visible with corneal staining
○ metal FB can be difficult to remove
 Corneal ulcer and contact lens related red eye
○ photophobia
○ blurred vision
○ discharge
○ pain
○ conjunctival injection
○ eye lid swelling
○ ulcer evident on staining

Acute angle closure glaucoma –Closure or narrowing of the anterior chamber angle leading to ↑↑ IOP and eventual damage to the optic nerve Risk factors include
○ ↑ ed age
○ female – long sighted
○ Asian ethnicity
○ shallow anterior chamber Usually unilateral Severe and rapidly progressive picture. Marked VA reduction Hazy cornea Fixed and mid dilated pupils which react poorly to light Diffuse redness Headache Lights seen surrounded by halos Photophobia Tender and hard eye
ciliary injection Nausea or vomiting

Other causes –Adnexal causes
○ Dry eye
○ Blepharitis
○ Ectropion
○ Entropion
○ Trichiasis Chemical burn Orbital cellulitis Pre-septal cellulitis Cluster headache Endopthalmitis is severe inflammation of the anterior and / or posterior chambers of the eye Trauma


  1. Differentiating Urgent and Emergent Causes of Acute Red Ete for the Emergency Physician Christopher J Gilani et al West J Emerg Med . 2017 Apr , 18(3) : 507-517
  2. Red eye CKS NHS
  3. Diagnosis and Management of Red Eye in Primary Care Holly Cronau MD et al Am Fam Physician . 2010 Jan 15;81 (2) : 137-144 Karla J Johns MD
  4. Managing the Red Eye -Eye Care Skills: presentations for Physicians and other Healthcare Professionals Version 3 American Academy of Ophthalmology 2009
  5. GP Handbook- Common eye condition management Moorsfield Eye Hospita NHS Foundation Trust
  6. Causes , Complications & Treatment of a Red Eye BPL Sims J.Scleritis : presentations, disease associations and management. Postgraduate Medical Journal 2012 ; 88 :713-718
  7. Lansingh VC, Eckert KA, Ramos SV, Star EML (2018) From Acute Disease to Red Flags: A Review of the Diverse Spectrum of Red Eye Encountered in the Primary Care Setting. Prim Health Care 8: 316
  8. Microbial keratitis RCO Focus An occasional update commissioned by the College Autumn 2013


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