18. MGD & Blepharitis II

Question 1

MGD has a prevalence of of ...% and is the leading cause of .... MGD is usually ... and the prevalence increases with ... (<30yo = ...%; >60yo = ...%), due to increasing ... atrophy. MGD is more prevalent in ..., and also more in ... populations than .... ... show higher rates of MGD in comparison to ....

Answer 1

MGD has a prevalence of of 36% and is the leading cause of dry eye disease. MGD is usually bilateral and the prevalence increases with age (<30yo = 33%; >60yo = 71%), due to increasing acinar cell atrophy. MGD is more prevalent in men, and also more in Asian populations than Caucasians. Post-menopausal women show higher rates of MGD in comparison to pre-menopausal women.

Question 2

What are the 5 underlying factors that contribute to posterior blepharitis?

Answer 2

• Hormonal
• Medication
• Environment
• Bacteria
• Contact lens wear

Question 3

Posterior blepharitis has various underlying factors:
* Hormonal: ... deficiency (... treatment), ...'s syndrome
* Medication: oral - ..., topical - ..., glaucoma medications e.g. topical ..., ... analogues, ... inhibitors
* Environment: ... humidity environment
* Bacteria: increased colonisation of ... & ...
* Contact lens wear: higher rates of ..., abnormal ... and ... abnormalities.

Answer 3

Posterior blepharitis has various underlying factors:
* Hormonal: androgen deficiency (prostate treatment), Sjogren's syndrome
* Medication: oral - Roaccutane, topical - epinephrine, glaucoma medications e.g. topical beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors
* Environment: low humidity environment
* Bacteria: increased colonisation of Staphylococcus epidermis & Staphylococcus aureus
* Contact lens wear: higher rates of meibomian gland dropout, abnormal meibum quality and lid margin abnormalities.

Question 4

What are the 8 symptoms of meibomian gland dysfunction?

Answer 4

• Ocular dryness
• Gritty or sandy eyes
• Burning sensation
• Watery eyes
• Red eyes
• Eyes stuck shut on waking
• Symptoms worse in dry or air-conditioned environment
• Photophobia

Question 5

Meibomian gland dysfunction is caused by bacterial overgrowth, causing ..., which further leads to ..., ... and .... Meibomian duct epithelium will undergo ..., whereas acinar cells will undergo ... causing meibomian .... Meibocytes will be replaced by .... There will also be reduced .... Another important factor is ... of meibum. Bacterial overgrowth also produce ... that act on the secretions from the meibomian glands producing ... that disrupt .... This alters the ratios of ... to .... Altered secretions have ... leading to ..., therefore there is reduced outflow.

Answer 5

Meibomian gland dysfunction is caused by bacterial overgrowth, causing hyperkeratinisation, which further leads to obstructive glands, degenerative gland dilation and atrophy. Meibomian duct epithelium will undergo hypertrophy, whereas acinar cells will undergo atrophy causing meibomian gland dropout. Meibocytes will be replaced by squamous cornified epithelium. There will also be reduced meibum outflow. Another important factor is increased viscosity of meibum. Bacterial overgrowth also produce lipases that act on the secretions from the meibomian glands producing toxic free fatty acids that disrupt gland function. This alters the ratios of free fatty acids to cholesterol esters. Altered secretions have higher melting temperatures leading to sealing of the gland orifices, therefore there is reduced outflow.

Question 6

What is seborrheic MGD, what is it usually associated with?

Answer 6

Seborrheic MGD has increased amounts of seborrheic oil with low viscosity. This is usually associated with seborrheic dermatitis.

Question 7

What is rosacea and how does it associate with MGD?

Answer 7

Rosacea is the chronic facial rash involving inflammatory and vascular changes. Rosacea primarily affects the fair skinned between 40-59 yo. 40-50% patients with MGD have rosacea.

Question 8

Signs of MGD:
* Capillary ... on lid margin
* Plugging of ... by ...
* ... along eyelid margin - bacterial enzymes react with ...
* Lid margin ...
* Increased ... of eyelid margins
* Reduced ...
* Inferior ...
* corneal ...
* ...
* ... - blocked meibomian glands causing ..., may lead to ...
* Meibum consistency from normal (...) to ... (increased viscosity), the texture of ...
* poor meibomain gland ...
* increased .../ ...

Answer 8

Signs of MGD:
* Capillary telangiectasia on lid margin
* Plugging of meibomian gland orifices by white sebaceous material
* Frothy discharge along eyelid margin - bacterial enzymes react with tear lipids
* Lid margin irregularity/ notching
* Increased thickness of eyelid margins
* Reduced tear break up time
* Inferior punctate epithelial erosions
* corneal neovascularisation
* trichiasis
* chalazion - blocked meibomian glands causing inflammation, may lead to destruction of the acini
* Meibum consistency from normal (clear olive oil) to inspessiated (increased viscosity), the texture of thick cheese
* poor meibomain gland expressibility
* increased tear osmolarity/ hyperosmolarity

Question 9

How does the Korb Meibomian Gland Evaluator assess MG function?

Answer 9

Assess 15 glands across the lower lid by apply pressure simulating deliberate blink on the meibomian gland. Slit lamp is used to evaluate the secretions.

Question 10

What are the 4 main aims of MGD treatment?

Answer 10

• Reduce or eliminate inflammation
• Restore active gland secretion
• Remove of the blockage of MG orifices
• Manage dry eye related conditions

Question 11

Warm compresses is one of the treatments for .... It aims to .... Meibum melts normally at ...ºC whereas in MGD >...ºC is needed to liquefy the ... with a minimum of ... minutes to reach eyelid temperature. Minimum temperature required for effective heat treatment is ...ºC and is recommended to apply for ... minutes. There is an in-office treatment called ..., which delivers moist warm air chambers to ... and maintain .... Lid massages are also useful in expressing the .... ... and ... are useful in maintaining eyelid hygiene.

Answer 11

Warm compresses is one of the treatments for MGD. It aims to melt the viscous meibum that blocks the meibomian glands. Meibum melts normally at 32ºC whereas in MGD >38ºC is needed to liquefy the meibum's oil with a minimum of 4 minutes to reach eyelid temperature. Minimum temperature required for effective heat treatment is 41.5ºC and is recommended to apply for 8-10 minutes. There is an in-office treatment called Blephasteam, which delivers moist warm air chambers to heat the eyelids and maintain stable temperature. Lid massages are also useful in expressing the oils. Lid wipes and foams are useful in maintaining eyelid hygiene.

Question 12

What is mechanical debridgement of lid margins?

Answer 12

Removal of keratinised tissue that can block the flow of meibum form the meibomian glands. Golf spud is use and lissamine green is used to stain the keratinised tissue on the exposure surface on the lid margin

Question 13

Intense Pulsed Light (IPL) delivers pulses of .... This is initially used for the treatment of .... IPL is ..., where it targets the lower layers of skin without .... Light energy is absorbed by ... and ... in skin and can induce ... of .... This helps reduce ..., therefore reduce ... and ... of .... IPL is only used to treat the ... to prevent potential hard to ocular structures.

Answer 13

Intense Pulsed Light (IPL) delivers pulses of high intensity non-coherent light. This is initially used for the treatment of rosacea. IPL is non-ablative, where it targets the lower layers of skin without affecting the top layers. Light energy is absorbed by melanin and haemoglobin in skin and can induce thrombosis of blood vessels. This helps reduce telangiectasia, therefore reduce redness and source of inflammatory mediators. IPL is only used to treat the lower eyelids to prevent potential hard to ocular structures.

Question 14

LipiFlow is a ... combining eyelid ... and .... The lid warmer applies ...ºC directly to ... surfaces of .... The system applies ... motions to evacuate the liquified meibum. There is significant improvement in ... scores, ... scores and ... yielding liquid secretions.

Answer 14

LipiFlow is a thermal pulsation system combining eyelid warming and massage. The lid warmer applies 42.5ºC directly to palpebral surfaces of upper and lower eyelids. The system applies peristaltic motions to evacuate the liquified meibum. There is significant improvement in OSDI scores, meibomain gland secretion scores and number of meibomian glands yielding liquid secretions.

Question 15

Oral antibiotics are used for patients who are ... to ... treatments.
... is a tetracycline with broad-spectrum ... activity. It also has ... effect at concentrations below that is used to treat infection. It decreases ... production and is also a potent ... , which is a key component of the inflammatory cycle in dry eye disease. This start with a dose of ...mg ... for 1 month, then ...mg ... for 2-3 months, then either discontinue or c.... Studies have shown reduction..., ... stability/, reduction ..., improvement ... and reduction ....Side effects include ... disturbances, and increase ` … sensitivity. These should be avoided in …, … and … women`.

Answer 15

Oral antibiotics are used for patients who are unresponsive to topical treatments. Doxycycline is a tetracycline with broad-spectrum bacteriostatic activity. It also has anti-inflammatory effect at concentrations below that is used to treat infection. It decreases staphylococcal lipase production and is also a potent matrix metalloproteinase inhibitor (MMP-9), which is a key component of the inflammatory cycle in dry eye disease. This start with a dose of 100mg bid for 1 month, then 50mg bid for 2-3 months, then either discontinue or continue as a maintenance dose. Studies have shown reduction in abnormal meibomian gland appearance, tear film stability, reduction in dry eye symptoms, improvement in MG secretions and reduction in conjunctival lissamine green staining. Side effects include GIT disturbances, and increased ` UV sensitivity. These should be avoided in children, pregnant and lactating women`.

Question 16

Manuka honey has ... and ... properties. It has low ..., high ... and contains ... and .... This can inhibit growth of ..., reduce ..., promote ..., and reduce levels of ... . There are ... and ... that contain manuka honey as active ingredients. These have been found to improve MG ..., MG ..., reduce ... and reduces the need for ... following treatment.

Answer 16

Manuka honey has antimicrobial and anti-inflammatory properties. It has low pH, high osmolarity and contains hydrogen peroxide and methylglyoxal. This can inhibit growth of microorganisms, reduce oedema, promote epithelialisation, and reduce levels of MMP-9 . There are eye drops and eye gels that contain manuka honey as active ingredients. These have been found to improve MG expressibility, MG quality, reduce bacterial colony counts and reduces the need for artificial tear lubricants following treatment.

Question 17

Demodex mites are the most common ... on the human skin, they only survive ... if removed from the host. They may be considered as a ... relationship where one organism benefits, the other organism ... but is .... Demodex is usually managed by ... instead of .... Demodex infestations occurs more frequently in .... There are two types of demodex: demodex ... and demodex ....
* Demodex ... has higher prevalence. Demodex lacks an ..., therefore digested material is released into the surrounding tissue at the end of its .... Diseased caused by demodex is called ..., which can lead to symptoms typical of ..., including ocular ..., ... and .... Patients with itchy lids are ...x more likely to have demodex. There is a positive correlation between the presence of demodex and ....

Answer 17

Demodex mites are the most common ectoparasite on the human skin, they only survive a few days if removed from the host. They may be considered as a commensal relationship where one organism benefits, the other organism does not benefit but is unharmed. Demodex is usually managed by reducing numbers to restore balance instead of eradication. Demodex infestations occurs more frequently in elderies above 60yo. There are two types of demodex: demodex folliculorum and demodex brevis. Demodex folliculorum has higher prevalence. Demodex lacks an anus, therefore digested material is released into the surrounding tissue at the end of its life-cycle. Diseased caused by demodex is called demodicosis, which can lead to symptoms typical of blepharitis, including ocular discomfort, swollen eyelids and itching. Patients with itchy lids are 2.5x more likely to have demodex. There is a positive correlation between the presence of demodex and contact lens intolerance.

Question 18

Demodex mites carry ... and ... that alter eyelid ... and can trigger an ... response and a ... hypersensitivity reaction. MGD is found to be more ... in individuals with demodex mites. Patients with ... are 7x more likely to be infested with demodex.

Answer 18

Demodex mites carry streptococci and staphylococci that alter eyelid microbial flora and can trigger an inflammatory response and a delayed hypersensitivity reaction. MGD is found to be more severe in individuals with demodex mites. Patients with acne rosacea are 7x more likely to be infested with demodex.

Question 19

Demodex folliculorum inhabits the ... feeding on ... and ... cells. Demodex produces ... of ... dandruff that form around the base of the eyelash root. These are composed of accumulated ... and .... Cuffs are ... for the presence of demodex folliculorum. These cuffs also contain ... and ... that cause ... and .... Collarettes are caused by ... overgrowth and are displaced along the shaft of ... with .... Comprehensive ocular surface assessment including ... is essential to ensure accurate diagnosis.

Answer 19

Demodex folliculorum inhabits the base of the lash follicle feeding on sebum and epithelial cells. Demodex produces cuffs of cylindrical dandruff that form around the base of the eyelash root. These are composed of accumulated undigested material and keratin cells. Cuffs are pathognomonic for the presence of demodex folliculorum. These cuffs also contain demodex lipases and proteases that cause ocular surface irritation and inflammation. Collarettes are caused by staphylococcal bacterial overgrowth and are displaced along the shaft of lash with lash growth. Comprehensive ocular surface assessment including eyelash evaluation is essential to ensure accurate diagnosis.

Question 20

Demodex brevis inhabit deep in lash's ... and ... and feed on .... Following the death of the demodex brevis, there is a ... remains inside ... and ... exacerbating sebaceous gland blockage.

Answer 20

Demodex brevis inhabit deep in lash's sebaceous gland and meibomain gland and feed on sebaceous gland epithelium. Following the death of the demodex brevis, there is a build-up of decomposing mite remains inside hair follicles and sebaceous glands exacerbating sebaceous gland blockage.

Question 21

How does tea tree oil help treat demodex?

Answer 21

Tea tree oil contains terpinen-4-oil, which has antibacterial, antifungal, anti-inflammatory and acaricidal (anti-mite) effects. It attracts mite out of the lash follicle and reduce their survival time. Combination therapy with ivermectin and metronidazole may be needed in persistent cases. However, high concentrations of tea tree oil is toxic to the cornea and conjunctiva.

Question 22

What are the at home treatments of demodex?

Answer 22

• Tea tree lid wipes
•SteriLid eyelid cleanser
• Blephadex eyelid cleanser
• OCuSOFT lid scrub
• Manuka honey

Question 23

What are the in-office treatments for demodex?

Answer 23

• OCuSOFT Oust Demodex Swanston
• IPL

Question 24

What are the patient expectations that need to be set for eyelid diseases?

Answer 24

These conditions often cannot be completely cured; Condition is chronic and will return; With good compliance, a px can go for years with only few symptoms