PT10

Red flag symptoms of the eye?

True eye pain, loss of vision, vomiting, limbal redness only, irregular shaped pupil, photophobia, foreign body, contact lenses

What is dry eyes caused by?

Decreased tear production, increased tear evaporation

Symptoms of dry eyes?

Dryness, grittiness or soreness in both eye, vision might be affected, watering

Pathology of deficient tears dry eyes?

Lacrimal glands fail to produce enough fluid and proteins to maintain the aqueous layer of the tear film

Pathology of vapourative dry eye?

Meibomian glands fail to secrete enough oil substamce to maintain the lipid layer of the tear film

Consequence of both types of dry eyes?

Lead to hyperosmolarity of tears, induced cycle of inflammation and corneal damage

What are the 3 layers that cover the cornea?

Mucin layer, aqueous layer, lipid layer

Describe the function of the mucin layer?

Sponge like meshwork of fluid and glycoprotein produced by goblet cells, helps aqueous layer spread evenly over the eye and adhere to it

Describe the function of the aqueous layer?

Thickest layer, contains water, electrolytes, oxygen, proteins and secreted mucin, keeps eye moist maintains pH, deliver O2, antibacterial enzymes, antibodies to corneal surface, remove debris

Describe the function of the lipid layer?

Produced by meibomian glands and the Zeis glands, reduces evaporation of the aqueous layer

How would you diagnose dry eyes?

Observation, fluorescein dye test, Schirmer’s test, tear break up time

What other condition could dry eyes be or be a part of?

Conjunctivitis, Sjogren’s syndrome, filamentary keratitis, infectious diseases, corneal damage

What considerations are there for differential diagnosis?

Symptoms, vision, duration and severity, dry mouth and other mucus membranes, discharge, cause, systemic conditions, one or both eyes

What lifestyle factors need to be considered?

Eyes and eye lids, contact lenses, environmental factors

What are the characteristics of mild dry eyes?

Mild or episodic discomfort under environmental stress, no visual symptoms, variable results for all diagnostic test, no or mild staining of conjunctiva or cornea

What are the characteristics of moderate dry eyes?

Moderate episodic or chronic with or without stress, visual symptoms annoying, variable conjunctival staining, tear break up time less than 10 secs, Schirmer score less than 10mm, reduced tear meniscus

What are the characteristics of severe dry eyes?

Severe frequent symptoms without environmental stress, constantly limiting activity, marked corneal staining, filamentary keratitis, tear break up time less than 10, Schirmer score less than 5 mm

What are the characteristics of very severe dry eyes?

Constant disabling symptoms. marked conjunctival staining, filamentary keratitis, ingrown eyelashes, immediate tear break up time, Schirmer score less than 2mm

Describe the lifestyle interventions for dry eyes?

Eyelid hygiene, limiting the use of contact lenses, stopping medication that exacerbates dry eyes, using humidifier to moisten air, stopping smoking, reduce screen time

What is the first line treatment for mild to moderate dry eyes?

Hypromellose applied every 30 minutes, carbomer or polyvinyl alcohol less frequent use, ointments not used for contact lenses or preservatives

What is the second line treatment for moderate dry eyes?

Switching to preservative free product

If patient wears contacts?

Sodium chloride can be used as comfort drops to help facilitate lens removal

What is the treatment used for severe dry eyes?

Preservative free, ocular ointments at night, mucus/inflammation needs specialist intervention, punctual occlusion

What are liposomal sprays used for?

Evaporative dry eyes, restoring lipid component , closed eye application

Describe the benefits of liposomal sprays?

Specifically address disrupted lipid layer, stabilise the outer lipid layer, last for 4 hrs, can be used with contact lenses. easy to use, long expiry date

Describe the disadvantages of liposomal sprays?

Not in guidelines, expensive, not allowed on prescription