Ophthalmology
Seán Keenan
2022
,Pathologies of the External Eye
Styes
Hordeolum externum
- Sx: Abscess or infection in the Lash follicle; Glands
of Moll (sweat); Glands of Zeis (sebum)
- Cx: Usually Staphylococci
- Dx: Area affected should point outwards
- Mx: Warm compress for 5-10 mins
Hordeolum internum
- Sx: Abscess of Meibomian glands
- Cx: Usually Staphylococci
- Dx: Area affected should point inwards
- Mx: Treat Cc with incision + cutterage
- Cc: Chalazion / Meibomian (tarsal) cyst; ↓ vision
Blepharitis
Description
- Sx: Burning, itching red margins on eyelid; Scales on lashes
- Cx: Staphylococci; Seborrhoeic dermatitis; Rosacea
- Mx: Hygiene; Consider PO Erythromycin in children
- NB: May present with seborrheic dermatitis
Pinguecula
Description
- Sx: Degenerative vascular yellow-grey conjunctival nodules
- Cx: ↑ Hair / Skin pigment; Sun damage
- Mx: Pingueculitis – Topical steroids; Pterygium – Surgery
- Cc: Pterygium – Invades cornea (exposure to wind ↑ risk)
Entropion
Description
- Sx: Lid in-turning; Usually affects >40 YO; Irritates cornea
- Cx: Degeneration of lid fascial attachment (usually lower lid)
- Mx: Relief – Tapping or Botox; Long-term – Surgical
Ectropion
Description
- Sx: Lower lid eversion; Eye irritation; Eye watering ± Keratitis
- Cx: Old age; Facial palsy
- Mx: Surgery corrects defect + upper lid implant aids closure
Upper-Lid Malposition
Description
- Sx: Hypotropic position (Pseudoptosis); Intrinsic Levator muscle
weakness (true ptosis)
- Cx: Congenital (↓ Nerve / ↓ Muscle tone); Myogenic (MD/MG);
Mechanical (xanthelasma / oedema); CNS (CNIII Palsy/Horner’s)
- Mx: Congenital – Surgical correction
Lagophthalmos
Description
- Sx: Difficulty closing eyelid; Corneal ulcer
- Cx: Exophthalmos; Mechanical impairment of eyelid; Paralysis of
Orbicularis oculi; Leprosy
- Mx: Lubricate eyes with paraffin ointment; Eye lid stich if ulcer
,Blepharospasm
Description
Blepharospasm is involuntary contraction of orbicularis oculi. Commonly occurs in response to ocular pain and can
worsen when stressed. Repetitive blepharospasm, is a focal dystonia (see abnormal movements in neurology notes).
Can often occur with other dystonias (e.g. oro-mandibular dystonia). The condition affects females 1.8x more often
than males.
Presentation Management
- Precipitates: Often preceded by exaggerated blinking - Botox: Quarterly orbicularis oculi injections
- Relieved: May be relieved by tapping eyelid - Anticholinergics: Trihexyphenidyl
Causes - Dopamine agonists: Levodopa; Bromocriptine
- Commonest: Idiopathic
- Iatrogenic: Neuroleptic drugs
- Neuro: Parkinson’s; Progressive supranuclear palsy
- Onco: Paraneoplastic syndromes (e.g. Lung ca)
, Tears and Lacrimation
Description
Tears have an important role in refraction. Most tears are produced by the lacrimal apparatus consisting of the lacrimal
gland, lacrimal lake, lacrimal sac ad nasolacrimal duct which carries the tears into the nasal cavity. Tears are composed
of a lipid layer, aqueous layer and mucin layer. The volume of tears in the eye is usually ~6 μL with a turnover rate of
1.2 μL/min. Tears are similar in electrolyte concentration to plasma, but highly rick in IgA. Tears may also contain
lysozyme and beta-lysin which aids in antibacterial qualities. Meibomian glands, conjunctival glands, goblet cells and
lacrimal glands produce tear fluids also. Reflex secretion occurs only from the lacrimal gland and occur via PsNS
stimulus from the trigeminal nerve.
Keratoconjunctivitis Sicca (Dry Eyes)
Causes Investigations
- ↓ Tear production by lacrimal glands - Schirmer’s Test: Filter paper <15 mm in 15 mins
o Commonest: Old age Management
o AID: Sjögren’s syndrome; Sarcoid - Replace: Artificial tears
o Infx: Mumps
o Onco: Lymphoma; Leukaemia
o Other: Amyloidosis; Haemochromatosis
- Excessive evaporation of tears
o ↓ Blinking: Post-exposure keratitis
- Mucin deficiency in tears
o Deficiency: Avitaminosis A
o Derm: SJS; Pemphigoid; Chemical burns
Seán Keenan
2022
,Pathologies of the External Eye
Styes
Hordeolum externum
- Sx: Abscess or infection in the Lash follicle; Glands
of Moll (sweat); Glands of Zeis (sebum)
- Cx: Usually Staphylococci
- Dx: Area affected should point outwards
- Mx: Warm compress for 5-10 mins
Hordeolum internum
- Sx: Abscess of Meibomian glands
- Cx: Usually Staphylococci
- Dx: Area affected should point inwards
- Mx: Treat Cc with incision + cutterage
- Cc: Chalazion / Meibomian (tarsal) cyst; ↓ vision
Blepharitis
Description
- Sx: Burning, itching red margins on eyelid; Scales on lashes
- Cx: Staphylococci; Seborrhoeic dermatitis; Rosacea
- Mx: Hygiene; Consider PO Erythromycin in children
- NB: May present with seborrheic dermatitis
Pinguecula
Description
- Sx: Degenerative vascular yellow-grey conjunctival nodules
- Cx: ↑ Hair / Skin pigment; Sun damage
- Mx: Pingueculitis – Topical steroids; Pterygium – Surgery
- Cc: Pterygium – Invades cornea (exposure to wind ↑ risk)
Entropion
Description
- Sx: Lid in-turning; Usually affects >40 YO; Irritates cornea
- Cx: Degeneration of lid fascial attachment (usually lower lid)
- Mx: Relief – Tapping or Botox; Long-term – Surgical
Ectropion
Description
- Sx: Lower lid eversion; Eye irritation; Eye watering ± Keratitis
- Cx: Old age; Facial palsy
- Mx: Surgery corrects defect + upper lid implant aids closure
Upper-Lid Malposition
Description
- Sx: Hypotropic position (Pseudoptosis); Intrinsic Levator muscle
weakness (true ptosis)
- Cx: Congenital (↓ Nerve / ↓ Muscle tone); Myogenic (MD/MG);
Mechanical (xanthelasma / oedema); CNS (CNIII Palsy/Horner’s)
- Mx: Congenital – Surgical correction
Lagophthalmos
Description
- Sx: Difficulty closing eyelid; Corneal ulcer
- Cx: Exophthalmos; Mechanical impairment of eyelid; Paralysis of
Orbicularis oculi; Leprosy
- Mx: Lubricate eyes with paraffin ointment; Eye lid stich if ulcer
,Blepharospasm
Description
Blepharospasm is involuntary contraction of orbicularis oculi. Commonly occurs in response to ocular pain and can
worsen when stressed. Repetitive blepharospasm, is a focal dystonia (see abnormal movements in neurology notes).
Can often occur with other dystonias (e.g. oro-mandibular dystonia). The condition affects females 1.8x more often
than males.
Presentation Management
- Precipitates: Often preceded by exaggerated blinking - Botox: Quarterly orbicularis oculi injections
- Relieved: May be relieved by tapping eyelid - Anticholinergics: Trihexyphenidyl
Causes - Dopamine agonists: Levodopa; Bromocriptine
- Commonest: Idiopathic
- Iatrogenic: Neuroleptic drugs
- Neuro: Parkinson’s; Progressive supranuclear palsy
- Onco: Paraneoplastic syndromes (e.g. Lung ca)
, Tears and Lacrimation
Description
Tears have an important role in refraction. Most tears are produced by the lacrimal apparatus consisting of the lacrimal
gland, lacrimal lake, lacrimal sac ad nasolacrimal duct which carries the tears into the nasal cavity. Tears are composed
of a lipid layer, aqueous layer and mucin layer. The volume of tears in the eye is usually ~6 μL with a turnover rate of
1.2 μL/min. Tears are similar in electrolyte concentration to plasma, but highly rick in IgA. Tears may also contain
lysozyme and beta-lysin which aids in antibacterial qualities. Meibomian glands, conjunctival glands, goblet cells and
lacrimal glands produce tear fluids also. Reflex secretion occurs only from the lacrimal gland and occur via PsNS
stimulus from the trigeminal nerve.
Keratoconjunctivitis Sicca (Dry Eyes)
Causes Investigations
- ↓ Tear production by lacrimal glands - Schirmer’s Test: Filter paper <15 mm in 15 mins
o Commonest: Old age Management
o AID: Sjögren’s syndrome; Sarcoid - Replace: Artificial tears
o Infx: Mumps
o Onco: Lymphoma; Leukaemia
o Other: Amyloidosis; Haemochromatosis
- Excessive evaporation of tears
o ↓ Blinking: Post-exposure keratitis
- Mucin deficiency in tears
o Deficiency: Avitaminosis A
o Derm: SJS; Pemphigoid; Chemical burns
