dry eye syndrome

What causes Dry Eye Syndrome ?

What causes Dry Eye Syndrome ?

What causes Dry Eye Syndrome ?

Dry eye syndrome can occur when basal tear production decreases, tear evaporation increases, or tear composition is imbalanced. The lipid layer overlays a mucoaqueous layer. TFOS DEWS II recommends using one of two validated questionnaires for evaluating the symptoms component of a dry eye diagnosis: the Ocular Surface Disease Index (OSDI) and the five-item Dry Eye Questionnaire (DEQ-5).

Women are more likely to develop the condition due to hormonal changes during pregnancy and after menopause. This syndrome is evidenced in up to 50 percent of the population and can occur at any age. The basis for all inflammatory, painful of feverish reactions is usually an irritation of or damage to single cells. This can be triggered by mechanical, thermal or chemical stimuli.

DRY EYE SYNDROME EXAMINATION

Medications :
Cold and Allergy antihistamines, decongestants, blood pressure, diuretics, beta-blockers, sleeping pills, anxiety medications, hormone replacement therapy,rocutane. 

Dry eye syndrome through extended computer and phone use is effecting younger adults now in addition to the typical age-related groups.

 Air conditioning, low humidity environment can exacerbate the condition, as can preservatives in some overused OTC drops, eyelid makeup or even refractive surgery. 

meibomian-glands

The blink rate can point to some tear anomalies. The oily lipid layer can be graded by interferometry, the aqueous layer by tear meniscus height and the mucin layer by the non-invasive tear break up time. Even chronic cases may require topical corticosteroids, tetracyclines, and cyclosporine A as anti-inflammatory therapy.

Keratoconjunctivitis sicca is a chronic, bilateral desiccation of the conjunctiva and cornea due to an inadequate tear film.

Air conditioning, low humidity environment can exacerbate the condition, as can preservatives in some overused OTC drops, eyelid makeup or even refractive surgery. Other options include topical steroids,punctal plugs, Suitable  artificial tears -mimicking normal mucin layer, blinking efficiency exercises.

Also, Surgery/laser  to lids or eye surfaces, wrap sunglasses and minimising exposure to heaters /airconditioning. Windy, smoky, or low humidity environments increase tear evaporation. 

Treatment can include probiotics, autologous serum eye drops, face and sun creams containing tea tree oil, eyelid hygiene for rows of tiny oil-secreting glands, and seasonal allergies treatment

Dye eye treatment

natural dry treatment

Range of natural treatments:​

Including bilberry, paprika, Chamomile.
Omega 3 supplements containing retinols can improve skin by shrinking the oil-producing glands without diminishing the oil-producing meibomian glands of the eyelids required to stop evaporation.

Warm and cold compresses and humidifiers can be considered -the tear film has  a direct influence on focusing and aberrations. 
While studies do show serial IPL can restore the MG morphology viable natural therapies  can be controversial. 

Dry eye and Blephasteam

Blephasteam is a natural therapy and can be supplemented with Blephex debridement,to increase tear breakup time.

Blephasteam melts via comfortable,effective and safe moist heat technology the commonly blocked meibomian glands which cannot be safely achieved with conventional heat packs. 

However omega 3 supplements if exceeds 1200mg/day,blinking exercises are becoming  increasingly important. Humidifiers can be very helpful as can eyelid massage but need to minimise pressure on the globe hence merit of blephasteam

blephasteam

After 10 minutes of treatment where vision is not adversly effected the blocked essential evaporation reducing lipid oils are naturally released through normal blinking.Blephasteam heats your eyelids to 40°C, which has been demonstrated to be sufficient to melt the obstructing meibum with no risk to your eyes and eyelids.
This level of temperature and moisture combined with the length of the treatment has been shown to be safe and comfortable for use.

The safety and efficacy of Blephasteam have been evaluated in many clinical studies at this temperature.

Specific heat is defined by the amount of heat needed to raise the temperature of 1 gram of a substance 1 degree Celsius (°C). Water has a high specific heat capacity.It takes higher energy to increase the temperature.Because of the moist heat transfer within the blephasteam to the eyelids a lower temperature than otherwise be needed to melt the obstructed meibimian oil can be applied. This difference is achieved by the latent heat condensing as water from vapour releasing heat energy.    
Blephasteam is applied before Meibomain Gland Expression as it provides optimal conditions (such as consistent temperature and duration of heat) to prepare the glands and oils for unblocking. 

Meibomian Gland Dysfunction MGD

The Tear Film and Ocular Surface Society [TFOS] ​ DEWS II (International Dry Eye Workshop ) referenced more than 1,000 publications for an evidence based review of eye therapies. ​

meibomian gland dsyfunction

The ocular surface disease index  OSDI   confirms the possibility of DED requiring diagnostic tests of  non-invasive tear break-up time, osmolarity and ocular surface staining to determine if cause predominantly evaporative or aqueous deficiency.
In this eye disease, reduced tear secretion leads to inflammation and eye nerve damage which can be assessed. 
We can avoid  people making  the mistake of self diagnosing eg  eye drops for their allergens, or swollen eyes with cucumber slices or tea bags or use the wrong eye ointments based on their on waking symptoms. Warm compresses often preceded by cold can reduce inflammation and help lipid flow.

Meibomian Gland grade

Grade
Effect
Atrophied or blocked
1
Congealed or semi-solid discharge
2
Coloured liquid discharge
3
Clear liquid oil discharge

The correct frequency of blinking milks your meibomian gland oils which are very temperature sensitive.
Reduced frequency of blinking which can happen easily deteriorates the tear film leading in severe cases to such conditions as keratoconjunctivitis sicca.

To avoid optical aberrations a quality tear film is paramount as light can scatter from the highly powered corneal suface. In computer vision syndrome the blink rate is reduced rather than complete and frequent blinks. 

Tears are complex being  hundreds of different protein, fatty oil, water, mucus types
In the first 6 postnatal months, the lipid layer of the tear film is much thicker than in adults. The NIBUT in newborns is prolonged compared with adult values. This thick lipid layer in infants provides the stability that may help prevent the thin aqueous layer from evaporating.
Pain in this condition is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity.
Also advancing age and conditions such as Rosacea, Blepharitis, Sjögren’s syndrome, Lupus, Scleroderma,  Rheumatoid Arthritis, Diabetes, Thyroid disorders, Parkinsons Disease and Vitamin A deficiency, Eyelid health eg  bacterial films, oil gland congestion   ​​

Eyelid warming is important as it is used to melt the solid or blocked lipids into a more viscous oil again. This allows the natural oils in your tear film to flow freely again and to form the oily layer of the tears which reduces evaporation.In case of Meibomian Gland Dysfunction, the oily secretions become more solid, ultimately blocking the glands. This can lead to atrophy of the glands and produce the symptoms of this eye syndrome. Warm compresses require continued reheating which is unnecessary with Blephasteam.

Optimel Leptospermum spp. honey products used twice daily over two months can improve MGD and evaporative dry eye . Improvement in staining was significantly greater with the drops while the gel was significantly more effective at improving meibum quality and gland expressibility

Blepharitis causes

Meibomian gland dysfunction
Certain medications such as antihistamines and HRT
Allergies (contact lens solution, makeup, certain eye drops or ointments)
Acne rosacea
Seborrheic dermatitis (dandruff of the scalp and eyebrows)
Changes in oestrogen levels eg menopause,pregnancy.
Bacterial infection
Lashmites
Acne rosacea

Common signs and symptoms include: 

Redness of the eyes and/or eyelids

Watery sticky eyes
Flaking or crusting of skin on the eyelids on waking
Crusting at the eyelid margins (base of the eyelashes), generally worse on waking
Gritty sensation of the eye or foreign-body sensation
Eyelash loss
Foreign body sensation
Excessive or frothy tears
Sensitivity to light
Excessive blinking

 

BLEPHEX debridement (removal) of biofilm and debris from the eyelids can effectively offer relief while removing excessive oils and debris that may cause symptoms. Demodex parasite mites (that live on humans) are referred to as eyelash mites. If mite populations increase can cause itching or inflammation
Tea Tree Oil is the most effective treatment for blepharitis caused by demodex. Blephadex offers a combination of cleanser with Tea Tree & Coconut Oil.

Compared with conventional therapy, significant improvements in meibum quality and gland expressibility, reduced lid margin Staphylococcus spp. bacterial isolates and reduced ocular surface expression of the inflammatory cytokine MMP‐9 can be achieved.

The meibomian glands – situated along the eyelids can be gently compressed to examine their discharge. Healthy meibomian glands produce a thin, oily secretion, whereas dysfunctioning glands will produce a thicker, waxy secretion, or, in worse cases, no secretion at all, due to complete blockage.

If acne rosacea is likely to be a factor in your blepharitis, an oral antibiotic called doxycycline may be prescribed for several months to improve your meibomian gland function from the inside out.
​A nutritional supplement containing omega 3 oils and micro-nutrients may also be prescribed.
Treatment can take weeks to several months. During this time you will be advised not to wear contact lenses and refrain from using eye makeup. ​

CORNEAL DYSTROPHY, Dry eye, HYLO PRODUCTS, eyelid hygiene, MANUKA HONEY, I-LID 'N'LASH.OCUSOFT, LACRITEC

dry eye supplements
Persistent epithelial defects are very slow healing of corneal wounds
Neurotrophic or recurrent keratitis or ulcers are major healing difficulties caused by loss of corneal sensitivity potentially resulting in corneal perforation.
CACICOL drops can help with corneal wound healing
 
Apart from observing with high in office magnification using an illuminated self-examination mirror such as Ichek helps in identifying the debris and crusting you may have on your eyelids and eyelashes before effectively cleaning and gently scrubbing. Hylo products are for severe or persistent cases, or post-surgery use, being preservative-free eye drops in a unique bottle. They are citrate buffered – completely phosphate-free.
They precisely deliver at least 300 sterile drops per pack through the patented COMOD multi-dose application system at 60% less cost per drop. 
ocusoft

OCuSOFT  Lid Scrub  Original is recommended for routine daily eyelid hygiene, while OCuSOFT Lid Scrub PLUS is an extra-strength, “leave-on” ( can be used twice a day for several hours and rinsed off) formula recommended for moderate to severe conditions.

To use pre Moistened fresh Pad fold over your index finger onto closed eye and gently scrub over your eyelid using side-to-side strokes with the index finger for approximately 30 seconds.

Options for care: Regular use of OCuSOFT eyelid cleansers to gently remove oil and debris from your eyelids will help control these symptoms. To reduce ocular surface inflammation, anti-inflammatory therapies such as oral doxycycline may be prescribed. Many people routinely use often expired Visine or “clear eyes ” that constrict the eye’s superficial blood vessels. Your eyes can develop a tolerance to the whitening effect of these drops, and even greater redness (called rebound hyperemia) can indeed occur.

How to use I-Lid’N Lash and I-Lid’N Lash Plus
1. Apply a moist, warm compress to eyelid to loosen encrusted debris and secretions    Gently rub eyelid and eyelash roots with the pre-moistened pad in a circular motion
2. Do not rinse. Any remaining product will continue to disinfect and hydrate the skin.  Repeat as needed for the second eye using a clean wipe

manuka honey lids

Leptospermum sp honey (Manuka) can aid in this condition and meibomian gland dysfunction, Blepharitis Sore, irritated eyes, and eyelids. The only adverse effects noted with the use of Optimel Manuka+ Eye Drops in the eye are stinging and redness.

While the conventional treatment of eye hygiene and lubricants also significantly improved symptoms, the long utilised honey products improved the condition more and had an antibacterial effect, lowering Staphylococcus epidermis counts.

There is significant but transient sting on the installation of drops during the day or gel before bed though good eyelid hygiene, clean eyes and eyelid margins is good initial therapy the honey products can supplement as can  Hycor 1% ointment to the eyelid rim.

DRYEYE FORTE is manufactured in Australia and audited for compliance by the Therapeutic Goods Administration (TGA). If you are already eating a healthy diet and still experiencing dry eye symptoms, then that may suggest your diet is not be providing enough of the nutrients that are recommended to help relieve dry eye symptoms.

DEMODEX treatment routine needs to be convenient enough to be continued for life to avoid relapses as blepharitis is often a chronic condition.

OCUSOFT allows  you to employ your own daily regime  by cleansing your eyelids and eyelashes by

  • Ocusoft lid scrub swabstix
  • OCuSOFT Oust Demodex Cleanser Extra Strength Foam
  • Blephex debridement can be used for more severe cases or by lid spud as dry eye can be worse in the morning as the lids have been closed at night and often toxic meibum is along the lid margins which needs to be flushed away and tear equilibrium restored.  To use the pre-lathered Ocusoft foam formula, make sure your hands are clean pump the Lid Scrub foam onto a clean, lint-free washcloth or fingertip.
 

LACRITEC is a formulation that works from the inside out to provide continuous dry eye relief.
•Lacritec delivers a proprietary blend of omega fatty acids sourced from Flax Seed, Fish Oil, and Borage Oil.
•Australian developed, patented formulation works to support a healthy tear film thereby increasing Tear Film Breakup Time, and reduce inflammation in tear glands.
•Much more powerful than flaxseed oil or fish oil alone, also provides the unique omega fatty acid, GLA, from Borage Oil that cannot be easily obtained from diet alone.

I-LID ’N LASH
The convenient, one-step lid and lash cleanser to disinfect and hydrate
Formulated with sodium hyaluronate, I-LID ‘N LASH cleans and removes ocular debris while hydrating sensitive skin.
Daily use helps to maintain lid and lash health for patients with dry eyes, sensitive skin or Meibomian Gland Dysfunction.

I-LID ’N LASH PRO
This is a stronger hydrating cleansing gel with 20% Tea Tree Oil, an essential oil derived mainly from Melaleuca alternifolia, to disinfect lids and lashes requiring advanced cleansing. 

DRYeye Forte features GLA from plant-based Borage Oil, as well as high quality, mercury-tested fish oil. When fish omegas EPA and DHA team up with GLA, inflammation is reduced in a complementary fashion.

DRYeye Forte is a blend of concentrated omega-3 EPA & DHA from Fish Oil, omega-6 GLA from Borage Oil, Vitamin D3 and antioxidants thatincreases tear production and quality which can reduce inflammation.

Ingredients include mercury tested, sustainably sourced omega-3 fish oil,providing high strength EPA & DHA. Some essential fatty acids are not easily obtained from a typical diet, such as gamma-Linolenic acid GLA from Borage Oil

Combined with other important nutrients such as anti-inflammatory Vitamin D and the rich antioxidants of mixed tocopherols, DRYeye Forte’s patented formula helps fight inflammation and support the three layers of the tear film.

Results are typically experienced within 6 to 8 weeks. The dosage may vary according to your weight and the severity of your dry eye symptoms. As symptoms recede, dosage may then be reduced to a maintenance level.

DRYeye Forte is a patented oral formulation in a soft gel capsule that works from the inside out to target the root causes of dry eye.

DRYeye Forte may be combined with artificial tears, drop or sprays. Because it is an oral formulation that targets dry eye syndrome from within, it works by a complementary mode of action to these topical products.
It is possible for certain individuals to be intolerant of individual ingredients. High doses of Omega-3, Omega-6, and Vitamin E may increase the risk of bleeding if you are taking blood-thinning medications.

It is generally recommended that you take your DRYeye Forte capsules with or after food, in the morning.

Eyelid hygiene is one of the mainstays in the management of Blepharitis, Meibomian Gland Dysfunction, Demodex infestation, and other lid margin related diseases. Removing oil and debris from the eyelids can reduce inflammation. Demodex inflammation response is seen in facial and ocular rosacea also.

 Demodex is the most common organism found in the human body especially in hair follicles and sebaceous glands and is seen at the base of eyelash specifically with at least 10x magnification.
Symptoms of Demodex infestation include ocular discomfort, itchiness, burning, foreign body sensation, blurry vision, and dryness.

The ingredients in OCuSOFT Lid Scrub Orignal are Water, PEG-80 Sorbitan Laurate, Sodium Trideceth Sulfate, PEG-150 Distearate, Disodium Lauroamphodiacetate, Cocamidopropyl Hydroxysultaine, Sodium Laureth-13 Carboxylate, Sodium Chloride, PEG-15 Cocopolyamine, and Quaternium-15.

Ocusoft Oust containing tea tree oil is also “leave on overnight ” even on face reserved for infestations from the Demodex Mite and reducing inflammation that it creates.  Once you are done cleansing that eyelid, turn the pad over and use the opposite side to repeat the procedure with your other eyelid. You can use one pad for both eyelids, followed by rinsing off.

Improves dry eye relief with continued use; maximum results typically experienced within 4-6 weeks.

  • Concentrated Omega-3 Triglycerides (fish)    332mg, 
  • Flax Seed Oil (Linseed)  334 mg  
  • Borago officinalis seed oil fixed       434 mg   

• Convenient one-step cleaning – no need to rinse the product off
• The water-based formulation will not burn or sting if it gets into the eyes
• Sodium hyaluronate hydrates the sensitive skin around the eyes
• The formulation cleanses overnight to reduce the microbiological count 
• Effective water-based cleanser
• Hydrating ingredients including hyaluronic acid
• Soothes inflamed skin around the eyes
• Removes water-based make-up
• Does not sting, burn or irritate sensitive eyes

I-LID ’N LASH PLUS
The anti-bacterial lid and lash cleanser with 5% Tea tree Oil, sodium hyaluronate and cleansing and hydrating properties. 

Each application will help to:
• Clean and disinfect, remove oil-based makeup. 
• Reduce ocular inflammation
• Enhance the effectiveness of artificial tears  Safe for contact lens wearers 

LID ’N LASH PRO helps manage symptoms associated with Meibomian gland dysfunction, Rosacea, Dry eye, Demodex, Chalazia and other lid margin diseases.

Used in conjunction with I-LID ’N LASH® PLUS, this provides a two-step process developed to address more advanced lid margin issues. Step 1 – In clinic application of I-LID ’N LASH PRO therapeutic benefits for patients with symptoms of Blepharitis, Rosacea, Demodex & MGD
1. An anesthetic drop is used in the eye before the treatment.
2. From a clean wipe or the palm of the hand, the gel is applied to the patient’s eyelids while the patient closes the eye lightly, without squinting, keeping closed for the duration of the treatment.
3 The gel is applied using a finger or a cotton swab on the lid margin, up to the brow line
4. For optimal results, the gel stays on the area around the eye and the lid margin for a period of 10 minutes while keeping
the eye shut.
5. The excess gel is wiped off from around the eye with a clean tissue and rinsed with warm water.

Step 2 – Daily follow up regimen by the patient using I-LID ’N LASH PLUS
The patient follows up with a jar of I-LID ’N LASH PLUS, applied once or twice daily for 30 days.

Prescription NameRestasisXiidra
Use per Day2 times/day, 12-hour span2 times/day, 12-hour span
Type of RxImmune-suppressive, preservative-free. 60 vials/30-day pkg or multi-dose bottlePreservative-free. 60 vials/30-day pkg
Ingredientscyclosporine ophthalmic emulsionlifitegrast ophthalmic solution
ImprovesIncrease tear production

Reduce inflammation

Reduces inflammation in dry eye disease
Improvement NoticedAfter 3 months.,

Significant after 6 months.

After 2 weeks
Side EffectsPossible slight burning effect, redness, blurry visionPossible slight burning effect, redness, blurry vision. May have unusual short-term taste changes.
For How LongContinuousContinuous
ManufacturerAllergan PLCShire PLC

ADVANCED DRY EYE DISEASE TREATMENTS AND REPORTING

Report the type of SYMPTOMS you experience and when they occur:
Such as dryness, grittiness, scratchiness,soreness,Irritation,burning ,watering or eye fatigue though objective assessment can be carried out.

Report the FREQUENCY of your symptoms and SEVERITY using a rating system/diary eg

0 = No Problems
1 = Tolerable – not perfect, but not uncomfortable
2 = Uncomfortable – irritating, but does not interfere with my day
3 = Bothersome – irritating and interferes with my day
4 = Intolerable – unable to perform my daily tasks

Rosacea

Report use of eye drops for lubrication or other treatments and medications used as can have dry eye side effects. Intense pulse light (IPL) of 500nm light in a series of calibrated  pulses  stimulate the Meibomian glands in order for them to return their normal function by closing the blood vessels that secrete inflammatory mediators. The 20-25  glands in both top and bottom lids  decline with age. Over 40 we have between 10-12 on each lid. The Inferior glands tend to dysfunction first though. Minimum required is 3-4 each lid for comfortable eyes in most people.

In rosacea, abnormal blood vessels release pro inflammatory agents
Those inflammatory agents propagates to the eyelids via the orbital vasculature.
IPL targets chromophores ( chemical  responsible for its colour) and destroys abnormal blood vessels, removing a major source of the inflammation.

Lipiflow treats the symptoms of dry eye but not the root cause which in the majority of cases is MGD caused by skin and ocular inflammation. This inflammation or rosacea can be treated quite successfully with IPL therapy. Peer review and clinical studies have some variance in the preferred modality.

Whilst in blephasteam which liquefies the Meibomian glands IPL therapy adds another 4-5 mechanisms in treating DED other than just the liquefaction and then expression of the meibomian glands.

Some patients quality of lipid can be reasonable even with high MGD drop out but sometimes DED symptoms can occur even with relatively healthy Meibomian glands.

There have been no major studies comparing the clinical efficacy of these devices head-to-head. IPL and Lipiflow are for different purposes although they can be complimentary.
IPL reduces inflammation and telangiectatic vessels around the eyelid margins whereas Lipiflow unblocks meibimian glands.
The lipiscan only images the Meibomian glands whereas the Lipiview also  measures the lipid content in the tear  film and shows the quality and the frequency of the blinking pattern.

Large randomised controlled trials are difficult to set up as they are so expensive to run – independent granting agencies don’t tend to fund dry eye research as they devote their attention to more sight or life-threatening disease. The industry has an interest in clinical efficacy data, obviously, for shaping their future direction, and investigator-initiated trials where possible are carried out but with possible conflict and perceived bias cross comparative studies tend not to occur.

Some IPL manufacturers include
M22 (Lumenis)
E-Eye (E-Swin)
Quadra4 (Dermamed)
Diamond Q4 (Dermamed)

IPL can restore some function and reverse anatomical changes in rosacea and the abnormal blood vessels which release pro-inflammatory agents.
Those inflammatory agents propagate to the eyelids via the orbital vasculature. IPL targets chromophores and destroys abnormal blood vessels, removing a major source of the inflammation. By contrast, Lipiflow(vectored thermal pulsation (VTPTM) technology) heats and massages for a continuous 12min but serial Blephasteams every week for 4-5 weeks could achieve a similar outcome.

Other mechanisms in play for IPL :
. Temporary increase of temperature at the eyelids and liquefaction of the meibum
. Reduction of rosacea and turnover of dead skin cells, therefore decreasing the risk of clogging the glands
. Eradication of Demodex mites (which carry B. Oleronius bacteria), therefore reduces bacterial load
. IPL increases the expression of anti-inflammatory agents. Rejuvenation of the Meibomian glands by photo modulation

By analyzing cytokine levels in tears as an inflammatory marker pre/post-IPL clinical efficacy can be gleaned.
• All MGD/IPL studies to date use gel.
• Coupling gel aids with the transmission of energy into the skin.
• The first law of photobiology (the Grotthus-Draper law) states that light must be absorbed to produce a chemical or physical change, which results in a biological response.
No gel would result in a lower biological response due to reflection and reflections have increased the potential for surface skin burns.

Some patient’s quality of life can continue even with high MGD drop out but not generally.
Many studies show a reduction in symptoms and an improvement in meibum quality and gland function for patients suffering from dry eye disease caused by meibomian gland dysfunction treated with intense pulsed light therapy. However sufficient control populations for comparison are not commonplace as are evidence-based guidelines.

LipiScan can image both eyes in about a minute whereas the more thorough LipiView  II  utilizes Dynamic Meibomian Imaging™  (DMI)  to distinctively image meibomian gland structure. The interferometer features patented technology analyzing over one billion data points to isolate the lipid layer of the tear film, measuring the thickness to sub-micron levels to evaluate the dynamic response of the lipids to blinking.

IPL is a completely different mechanism and has additional benefits beyond just heating the Meibum. Photothermolysis of the abnormal vasculature and stimulation of mitochondria put this device as superior arguably.           

Establishing the cause is fundamental. Even a stomach infection can be connected. eg  Helicobacter pylori (Hp) infection associated with dry eyes, glaucoma and other eye diseases has been  reported.

Global testing

  1. Non-invasive tear film stability assessment (using reflected mires)
  2. Osmolarity testing
  3. Fluorescein and lissamine green staining of cornea, conjunctiva and lid margin

Testing for aqueous deficiency
Tear meniscus height (slit lamp estimate)
Phenol red thread (moderately invasive)
Schirmer test (useful when applied without anesthetic only for confirming severe aqueous deficiency, as a highly invasive test)
Tear meniscus height quantified digitally from infrared imaging (IR minimises the risk of reflex tearing)

Testing for evaporative dry eye

  1. Lid margin assessment thickening, rounding, notching, telangiectasia, capped orifices
  2. Lash assessment for madarosis, poliosis, misdirection, crusting, and cylindrical collarettes
  3. Diagnostic gland expression performed digitally to evaluate meibum expressibility and quality
  1. Lid margin assessment (as for basic testing, plus infrared meibography)
  2. Lash assessment ( epilation for Demodex evaluation under 100x light microscopy)
  3. Diagnostic gland expression for meibum expressibility 
  4. Lipid layer interferometry  
Dry  eye diagnosis is based  on traditional and emerging technologies such as
  • Questionnaires,
  • Functional Visual Acuity tests ( quantifies vision quality between blinks as worse in dry eye conditions).
  • Tear volume Schirmer test (  application of a filter paper test strip in the inferior temporal conjunctival sac of both eyes- length of the tear wetting is measured in millimeters
  • Phenol red thread test( The alkaline pH of the tears causes the dye to turn from yellow to red and then the length of the tear wetting is measured in millimeters)
  • Tear meniscus height measurement by anterior OCT. 
  • Fluorophotometry ( records the fluorescein concentration of different parts of the eye including the cornea and vitreous.)
  • Tear film stability Invasive Tear Break up time ( The time (in seconds) between a blink and the appearance of a dark spot in the fluorescein is the TBUT) . The Non-invasive tear break up time uses rings captured as they are reflected off the precorneal tear film. The time between the blink and the first sign of ring distortion is the NI-TBUT
  • Tear turnover rate/tear clearance Fluorescein clearance, TFI, fluorophotometry (Tear Function Index (TFI) and fluorescein clearance test (FCT) measure tear clearance and are performed by instilling fluorescein and a testing strip in the lower cul-de-sac. Serial measurements are taken and the amount of residual dye present on a strip is compared with a standard colour scale)
  • Tear film composition Osmolarity Biomarkers: MMP-9, lysozyme (Specific biomarkers for dry eye may be present in the tear film to aid in diagnosis) 
  • Corneal evaluation Fluorescein staining Epithelial thickness, confocal microscopy, thermography (infrared measure of the temperature of the cornea normally higher in dry eyes.
  • Conjunctival evaluation Lissamine green, rose bengal Biopsy, impression cytology, confocal microscopy ( Confocal microscopy examines the  in the epithelial and stromal layers, as well as the corneal nerves in dry eyes)
  • Lid evaluation Slit lamp evaluation of lid morphology, expression of meibomian glands,meibomoscopy, blink rate, Meibography,
  • Lid wiper epitheliopathy ( alteration of the epithelium of that portion of the marginal conjunctiva that wipes the ocular surface, diagnosed by staining with fluorescein and rose bengal, is a frequent finding with wearers of soft contact lenses.
  • Sjögren’s syndrome testing by serological tests, and a combination of signs and symptoms, biopsies
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