The Correlation between POST-LASIK and Dry Eye Syndrome
Ibrahim Achmad030.09.117
FACULTY MEDICINE OF TRISAKTI UNIVERSITY2012
BACKGROUND
Nowadays eye surgeries are
very often
LASIK(Laser-Assisted In situ
Keratomileusis)
The most commonly
Young people
fully active who want to improve their
quality of Life
Not to depend on glasses or contact
lenses
side effects /adverse effects
DRY EYE SYNDROME
ANATOMY OF CORNEA
FUNCTION OF CORNEA
a protective membrane
refraction media
sensory media for the eye
Produce component of tear film via Goblet cell
Etc.
LASIK
Definition:LASIK is a refractive surgery procedure that involves the use of a microkeratome
How it works?
LASIKchanges the curvature of the central part of
the cornea
correct the refractive errors
mild to high myopiahyperopia
astigmatism
LASIK(2)
Procedure
AnesthesiaOpen the external of cornea
Re-Shaped internal cornea(correct the refraction)
LASIK(3)
Procedure(2)
1 2
3 4
Make a cornea flap with a blade
The Laser correct the refraction error
DRY EYE SYNDROME
DefinitionDry eye syndromes or Keratoconjunctivitis Sicca is a multifactorial disease of the ocular surface caused by an inadequate quantity or quality of the tears
Disturbances
Multifactorial
Dry eye syndrome
DRY EYE SYNDROME(2)
Produce water/aqueous layer
ProduceOil/Lipid layer
Produce(Goblet cell)
Mucin layer/Mucus
DRY EYE SYNDROME(3)
Classification
Primary Lacrimal Gland Deficiencies
Secondary Lacrimal Gland Deficiencies
Conditions associated with obstruction of lacrimal gland ducts
conditions affecting sensory innervations
age related dry eye
conditions with lacrimal gland infiltration, e.g.
sarcoidosis ,lymphoma, acquired
immunodeficiency syndrome (AIDS), or graft
versus host disease
trachoma, cicatrical pemphigoid, erythema
multiform, and chemical and thermal burns
herpes simplex keratitis, herpes zoster ophthalmicus, penetrating keratoplasty, PRK, LASIK, diabetes
mellitus, and topical anesthetic abuse, as well as secretomotor innervation, e.g. damage to the VII
cranial nerve and certain systemic medications
CORRELATIONThe Mechanism for the Dry Eye Syndrome
Post LASIK Theory 4, 5, 6, 7, 8, 9, 10, 11
Other
Anatomy Trauma
Changes in corneal curvature
Decrease limbal Goblet cells
Abnormalities in the distribution of tears
Stromal Nerve Fibers Decreases With 90%
Dry Eye Syndrome
The Neurogenic Theory
The inflammatory theory
Sensory-Stimulated Reflex Cornea Decreased
Decrease tear
production
Decrease Blink Rate
Production of pro-inflammatory cytokines
Induced neurotrophic epitheliopathy
The Risk Factors
CORRELATION(2)
Dry Eye Syndrome
The Neurogenic Theory
Sensory-Stimulated Reflex Cornea Decreased
Decrease tear production
Decrease Blink Rate
Neurogenic Theory
Sub basal nerve bundles and superficial stromal nerve
bundles in the flap interface are cut by the microkeratome
*only nerves entering the flap through the hinge region being spared
Rapid and forceful blinking can increase the thickness of the lipid layer. A low blink rate can thin the lipid layer.4, 5, 9, 10
Stimulation of the lacrimal gland and secretion :the cornea → trigeminal nerve → brainstem → facial nerve → lacrimal gland reflex arc
CORRELATION(3)
Stromal Nerve Fibers Decreases With 90%
Dry Eye Syndrome
The inflammatory theory
Production of pro-inflammatory cytokines
Induced neurotrophic epitheliopathy
Inflammatory Theory
It is described a neurotrophic epitheliopathy, it was established that post LASIK the number of stromal nerve fibers decreases with 90%. 11
CORRELATION(4)
Other
Anatomy Trauma
Changes in corneal curvature
Decrease limbal Goblet cells
Abnormalities in the distribution of
tears
Dry Eye Syndrome
Others
CORRELATION(5)
Risk Factors
Hinge (smaller width, superior position – sectioning of the nerve fibers from the nasal and temporal sub epithelial plexus)
Flap (a large diameter, thicker, done mechanically or with the femtosecond laser )
Larger ablation ( for the patients with higher diopters)
Surgical risk factors Other risk factors
Preoperative and postoperative corneal sensation at the nasal flap hinge, at the central cornea and within the temporal flap edge was measured before and after LASIK for a 3-week period using the Cochet-Bonnet esthesiometer.
Corneal sensation initially decreased in all three positions of the flap measured after LASIK and the greatest decrease was in the central cornea. 5
CORRELATION(6)
Risk Factors
Surgical risk factors Other risk factors
1. Female sex2. Smoking3. Moderate or large refractive errors/ the size of the ablation4. Low corneal sensibility5. Diseases of the ocular6. Environmental factors(air conditioning, pollution, wind)7. The use of computers(long periods of watching the
computer)
the greater the myopic correction, the greater the dry eye symptoms evaluated 28 eyes of 18 patients (range1.50–11.25 D) who underwent LASIK
GQ Guilherme, Camacho W ,Behrens A. Postrefractive surgery dry eye.
Current Opinion in Ophthalmology 2008; 19: 335–41
INCIDENTJapan (Hickichi)
13,517, including all age groups, reported dry eye symptoms among 28.7% of respondents.
*women reported severe symptoms more often than men
2,127-person sample 17% suffered from dry eye symptoms
Canadians (Caffery)(The report included 60% women and 24% contact lens wearers)
at a ratio of 46:1. Half (50.1%) of the contact lens wearing group reported dry eye symptoms
INCIDENT(2)
reported that the incidence of chronic dry eye after LASIK in Asian eyes was 28 percentAsian(Julie and colleagues)
Asia has the highest incident of all three.
Julie MA, Lee ML, Suzanne G, Maclennan B (2005): Dry eye after LASIK Comparison of outcomes for Asian and Caucasian eyes. Clin Exp Optom; 88:2: 89-96.
Indonesia ?
REGENERATION
*patients who seek refractive surgery are often contact lens intolerant and may have preclinical dry eye before surgery
3 months after LASIK
5 months after LASIK
12 months after LASIK
2 years after LASIK
Regeneration of anterior stromal, subbasal, and epithelial nerve fibers
Deep stromal nerves may show abnormal morphology even 5 months after the procedure
Corneal sensitivity seems to be at its lowest 12 weeks after LASIK, and by 12 months sensitivity has recovered to normal levels
Corneal sensitivity was close to normal values by 2 years post LASIK
AW Micheal. Current Understanding of the Pathophysiology of Dry Eye Disease. Eyewitness Second Quarter. 2002
ST Ilpo.2008. Corneal Nerves In: Refractive Surgery and Dry Eye. thesis, department of ophthalmology university of helsinki
CONCLUTION
There is a correlation between Post-LASIK between dry eye syndrome. Many theories about the correlation. The mechanism for the dry eye syndrome post LASIK can be explained by neurogenic theory is theory of decreasing Sensory-Stimulated Reflex Cornea, Inflammatory theory, and others is about anatomy and trauma because of the LASIK. and from several sources is associated with risk factors such as during surgery and factors of the patients themselves such as a woman, smoking, and others.
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