Asma Shams, et al
complete blindness. Glaucoma is diagnosed on the
basis of intra ocular pressure, visual field testing and
optic nerve appearance on ophthalmoscopy. In
glaucoma, retinal ganglions cells axons are lost
causing thinning or atrophy of retinal nerve fiber layer
in superior and inferior arcuate bundles with exposed
smaller retinal vessels. Primary Open Angle Glaucoma
(POAG) accounts for about 50% of glaucoma
blindness6. The first line of treatment for glaucoma is
medical therapy in the form of eye drops7. Several anti
glaucoma medications are effective in lowering the
IOP and thus preventing the optic nerve damage.
Failure of medical treatment leads to interventional
laser trabeculoplasty or trabeculectomy8.
patients. Ophthalmic examination included, record of
visual acuity, slit lamp examination of the anterior
segment, Fundus examination with slit lamp using +90
D lens to assess neuroretinal rim, CD ratio, vascular
status and macula. Visual field status was analyzed
using Humphrey perimeter.
The procedure was explained to all the patients
with its benefits and complications. Informed written
consent was taken. IOP was measured before the
procedure. The patients were seated comfortably.
Topical Proparacaine 0.5% eye drops were instilled in
the eye to be treated. Ritch trabeculoplasty lens was
filled with hydroxy propyl methyl cellulose and
applied. Alcon Ophthalmus 532 Eyelite frequency
doubled Nd-yag laser Photocoagulator was used. The
aiming beam was focused at the junction of pigmented
and non pigmented trabeculum. The ideal reaction was
transient blanching or the appearance of a minute gas
bubble at the point of impact. Forty to sixty burns were
applied at regularly spaced interval. Single drop of
topical diclofenac sodium 0.1% was instilled into the
eye after procedure. IOP was checked 3 hours after the
procedure. All patients were prescribed diclofenac
sodium 0.1% eye drops 4 times a day for 5 days to
control inflammatory response.
Over the years, ophthalmologists are trying to
achieve an ideal treatment for glaucoma and the role of
microwave pulse diode laser trabeculoplasty (MDLT)
and Argon laser trabeculoplasty (ALT) in management
of POAG. It is a procedure in which tiny holes are
created in trabecular meshwork with the help of laser
thereby which improves the facility of out flow. Both
argon and microwave pulse diode lasers have been
used for this purpose. It is reported that ALT success
rate is 90%9. A study regarding MDLT has shown
success rate to be 75%10.
Purpose of our study was to compare the efficacy
of ALT and MDLT in a tertiary care hospital of
Pakistan.
All patients were followed up regularly at 1 week,
4 weeks and 6 months after the procedure. At each
visit, IOP was measured, gonioscopy was done and
fundus examination was performed with slit lamp
using 90 D lens. The final outcome was monitored at 6
months. The treatment was labeled successful if IOP
was < 21 mm Hg at 6th month. Cases failed to reduce
to that level were labeled failed and were treated with
either additional laser application sessions or anti-
glaucoma drugs.
MATERIAL AND METHODS
The study was conducted at Shaheed Mohtarma
Benazir Bhutto Medical College Lyari and Sindh
Government Lyari General Hospital, Karachi for
duration of six months from October, 2017 to March,
2018. The study was approved from institutional
review committee. One hundred and sixty patients
were selected from glaucoma clinic. Patients
diagnosed with POAG, both gender and age > 40 years
and < 70 years were included. Patients with Intraocular
pressure of more than 40 mm Hg, previous glaucoma
surgery or laser treatment and narrow angle on
gonioscopy were excluded from the study. Patients
were divided into two groups. Group A was treated
with microwave pulse diode laser while Group B was
treated with Argon laser. The data regarding reduction
in IOP < 21 mm Hg and efficacy were entered in
already designed Proforma. All patients were
evaluated by taking thorough history and examination.
General physical examination was carried out in all
RESULTS
Male to female ratio was 2:1. Mean age of the patients
was 55.69 years (range 41 – 69 years). Table 1 shows
the distribution of patients by gender and age group in
each intervention group. According to sample size, 80
eyes of 73 patients were examined and treated in the
Group A with Microwave pulse diode laser (810).
There were 57 (71.3%) males and 23 (28.8%) females
in this group. The mean age of the patients in this
group was 55.8 years (Range 42 – 69). The mean pre-
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Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 211-215