Vol.13
No. 1, October 2003
DRY
EYE CONDITION IN PATIENTS ON CHRONIC ANTIGLAUCOMA TREATMENT
Dr.
Shikha Tyagi, Dr. R.S. Gill
INTRODUCTION
Glaucomas
are a group of potentially blinding ocular conditions.
They are characterized by changes in one or more of the
following; intraocular pressure, optic nerve head and visual
fields.
The
maintstay of treatment at least in the initial stages is in
the form of antiglaucoma drugs which can be classified as
follows:-
- Cholingergics
- Adrengerics
b
adrenergic blockers are most frequently used class of drugs
for management of glaucoma. Timolol is the prototype of
this class and is a non-selective ß1 and ß2 adrenergic
antagonist. Topical medications in glaucoma are
prescribed for long periods of time and lead to a number of
changes on ocular surface.
AIM
OF STUDY
To
study dry eye condition in patients on chronic antiglaucoma
treatment.
MATERIAL
& METHODS
The
study was conducted on 256 patients of primary open angle
glaucoma at Rajindra Hospital, Patiala.
Period
of study was 6 months.
Effect
of Timolol Maleate (0.5%) on ocular surface were noted in the
form of Schirmer test and tear film break up time (BUT).
OBSERVATIONS
|
Total
number of patients :
|
|
256
|
|
Sex
distribution
:
|
Males
:
|
150
|
|
:
|
Females
:
|
106
|
|
Mean
Age
:
|
|
56.1
years
|
|
Range
of Age
:
|
|
40-68
years
|
|
Time
Period
|
Sch.
( 5-10 mm)
|
Sch.
(<5mm)
|
TF
BUT (<10sec.)
|
|
Start
of treatment
|
0
|
0
|
0
|
|
2
months
|
56.25%
(144)
|
22.2%
(57)
|
9.6%
(24)
|
|
4
months
|
11.91%
(30)
|
95.3%
(199)
|
63.25%
(118)
|
|
6
months
|
1.56%
(4)
|
98.43%
(252)
|
88.1%
(232)
|
DISCUSSION
Remarkable
developments have been made in the antiglaucoma drugs in the
last few years. Development of newer b
blockers, a
adrenergic stimulators, carbonic anhydrase inhibitors and
prostaglandin analogs have made control of damage due to
glaucoma easy but have introduced a number of adverse effects.
Adverse
effects of long term use of timolol are burning sensation,
conjunctival hyperemia, conjunctival anaesthesia, epithelial
erosions, contact lens intolerance, decreased corneal
epithelial wound healing, punctate keratopathy, dry eye etc.
Timolol
causes dry eye by
-
by
decreasing lacrimal gland secretions autonomically
and anaesthetic effect on cornea thus decreasing reflex
tear secretion by lacrimal gland.
-
Benzalkonium
chloride ( 0.01 / 100ml.) which is used as a preservative
gets inserted into lipid monolayer and disrupts it by its
detergent action.
Dry
eye leads to symptoms of foreign body sensation, burning,
irritation, stringy mucus discharge and transient blurring of
vision.
Ohtsuki
et al (2001) demonstrated that ocular surface in glaucomatous
patients treated with topical b
blockers show dry eye like changes in terms of significant
decrease in radius of tear meniscus curvature, BUT and
Schirmer test.
Arici
et al (2000) concluded that it is possible that conjunctival
surface and tear film functions change after long term
anti-glaucoma medication.
Haruta
et al (1999) found every epithelial desquamation and
detachment in rabbit eyes. There was a delay in corneal
epithelial wound healing after long term use.
Yalvac
et al (1995) studied Schirmer test, tear film break time,
conjunctival impression cytology and goblet cell density and
concluded that topical antiglaucoma drugs damage the ocular
surface after long term use.
CONCLUSION
Almost
all patients develop dry eye on long term use of topical
antiglaucoma drugs and thus tear supplements should be given
along with.
Department
of Ophthalmology,
Government Medical College and Rajindra Hospital, Patiala.
