Dry Eye

Question 1

Dry Eye definition

Answer 1

Multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles.

Question 2

Tear film instability

Answer 2

Excessive depletion of aqueous component of tears, mainly due to evaporation.

Question 3

Result of tear film instability

Answer 3

Tears can become concentrated and lose their function. Ocular surface is left unprotected and is exposed to harsh environment.

Question 4

Osmolarity in tears

Answer 4

Measure of solute content in the tear film. NaCl makes up the majority of solutes in the tear layer.
Hyperosmolar tears are salty/conc. tears.

Question 5

Hyperosmolar tears

Answer 5

Create a toxic environment around the epithelial cells of ocular surface, causing dehydration, shrinkage and eventually, their death.

Question 6

Normal health tears components- long list

Answer 6

Electrolytes: Na, K, Cl, Ca,
Proteins: Lysosyme, Lactoferris, lipcalin, EGF,
Cytokines: IL-1, TNA- alpha, IL- IRA, TGF, Mucin 1, Mucn4, Mucin SAC
IGA, IGG, IGM, polar phospholipids.

Question 7

Hyperosmolarity- Core mech of DED

Answer 7

Tear hyperosmolarity can damanage the epithelial cells directly or can initiate inflammatory events that result in damage to epithelial cells, surface microvilli, barrier function, the glycocalyx, and goblet cells.

Question 8

Ocular surface inflammation is initiated by

Answer 8

Increase tear osmolarity, expressed through elevated pro inflammatory markers. MMP 9, IL 1Ra, IL8, etc…

Question 9

Neurosensory abnormalities

Answer 9

Free corneal nerve endings between the superficial epithelial cells of the ocular surface - makes the vulnerable to rpt damage from environmental exposure (Inc tear evap, hyperomolarity, and inc pro inflammatory markers).

Question 10

Corneal nerve damage ___ to longstanding DED is a recognized phenomenon.

Answer 10

Secondary

Question 11

Neurosensory element is thought to be involved with cases where ocular pain symptoms ______ outweigh the clinic signs.

Answer 11

Disproportionally

Question 12

Dry Eye Vicious Cycle broad

Answer 12

Tear film instability -> Tear cell hyperosmolarity - > Apoptosis of conjunctiva and cornea -> Inflammation (Neurogenic, lacrimal gland) -> Tear film insta.

Question 13

Dry eye Cycle MGD

Answer 13

Tear film instability -> Flora changes -> Esterase/lipase release toxins -> Eyelid inflammation -> Lipid changes -> Tear film instability

Question 14

Dry Eye Vicious cycle detailed

Answer 14

Tear film instability -> Tear cell hyperosmolarity - > Cell damage -> Apoptosis of conjunctiva and cornea -> Nerve stimulation -> Inflammation (Neurogenic, lacrimal gland) -> Cytokine release MMP activation - > Goblet cells loss -> Tear film insta.

Question 15

Aqueous Deficient Dry Eye

Answer 15

DE from autoimmune, disorders of lacrimal functional unit, etc…

Question 16

Evaporative Dry Eye

Answer 16

MGD, deformitties of the lacrimal unit, etc..

Question 17

Mixed Dry Eye

Answer 17

Aqueous and Evaporative causes mixed.

Question 18

Differential Diagnoses of DE

Answer 18

Conjunctivitis (allergic, viral, or bacterial), GPC, Anterior Bleph, Demodex, Keratitis, Atopic keratoconjunctivitis, conjunctivochalsis, epithelial basement membrane dystrophy.

Question 19

DE left untreated can lead to

Answer 19

Chronic eye inflammation, abrasion of cornea, corneal ulcer and scarring, permanent vision problems.

Question 20

Tear conservation Therapeutic options DE

Answer 20

Punctual occlusion, moisture chamber goggles

Question 21

Tear stimulation therapeutic options DE

Answer 21

topical and oral secretagogues: topical/systemic meds that stim aqueous, mucin, and lipid secretions.
Nasal neurostimulation.

Question 22

Anti inflammatory therapy DE

Answer 22

Short term topical steroids, cyclosporine/restatsis, topical or systemic antibiotics, Lifitegrast opththalmic solution (Xiddra, shire).

Question 23

Surgical treatment DE

Answer 23

Lid corrections, amniotic membrane grafts