CATARACT SURGERIES BY PHACO-SANDWICH TECHNIQUE THROUGH SCLEROCORNEAL TUNNEL, A COHORT STUDY IN OMAN

J Ayub Med Coll Abbottabad; 18(4)
CATARACT SURGERIES BY PHACO-SANDWICH TECHNIQUE THROUGH
SCLEROCORNEAL TUNNEL, A COHORT STUDY IN OMAN
Mohammad Naqaish Sadiq, Anant Pai*, Padma Mohan.J.Kurup **
Consultant Ophthalmologist and Head of Department of Ophthalmology, Rustaq General Hospital Sultanate of Oman, * Specialist in
Ophthalmology, Sohar Hospital, Sultanate of Oman, ** Epidemiologist, Rustaq General Hospital Sultanate of Oman.
Background: To evaluate the changes in Preoperative and Postoperative keratometry results and
rapid visual rehabilitation in Cataract surgery by our phaco-sandwich technique through the self
sealing sclero-corneal tunnel incision without phacoemulsification. Methods: 96 eyes of 88
patients with age-related cataracts underwent small incision suture less cataract surgery without
phacoemulsification. All eyes were operated by the phaco-sandwich technique through
sclerocorneal tunnel with 6 mm frown-shaped external scleral incision. 6 mm single piece PMMA
lens was implanted in the capsular bag. Patients were evaluated at 1week, 4 weeks and 12 weeks
post-operatively. Results: Ninety six eyes of eighty eight patients were our cohort. During the first
post-operative week 8 eyes (8.3%) had uncorrected visual acuity (UCVA) of 6/6. By the end of 12
post-operative weeks, 33 eyes(34.5%) had UCVA of 6/6. 64 (66.7%), 72(75%) and 80(83.3%)
eyes had best correctable visual acuity (BCVA) of 6/6 after 4 weeks, 8 weeks and 12 weeks
respectively. 64 (66.7%) eyes after 4 weeks, 72 (75%) after 8 weeks and 80 (83%) after 12 weeks
had best correctable visual acuity (BCVA) of 6/6. Conclusion: Suture less, small-incision cataract
surgery is an economical, safe and effective method of managing cataract cases. This technique
also ensures satisfactory and rapid rehabilitation for patients. This procedure can be effectively
applied to clear the backlog of cataract-related blindness in places wherein the resources for phaco
facilities are not available.
Keywords : Small incision cataract surgery, Phacoemulsification, Phacosandwich
INTRODUCTION
Only the patients who had age-related cataracts were
included in this study. Patients with glaucoma,
Now-a -days, the trend in cataract surgery is to
patients with previous ocular surgery in the operative
achieve cataract extraction and intraocular lens (IOL)
eye (e.g. filtering surgery) and rigid non-dilatable
implantation through the smallest possible incision.
pupils were excluded. Preoperative assessment
This concept of reduction in incision size has played
included a complete, biomicroscopic examination of
a big role in bringing about faster stability of wound
anterior and posterior segments, evaluation of cornea,
healing and post-operative astigmatism which has
grading of the nucleus and cataract, applanation
helped in early rehabilitation of cataract patients post-
tonometry, keratometry, and biometry and IOL
operatively. Presently, there are different techniques
power calculation.
for achieving this small incision cataract surgery; and
they will continue to evolve in future. The popular
Surgical Technique: Pupillary dilatation was
phacoemulsification is one among them. But it
achieved with 2 instillations each of 1% Tropicamide
requires costly instrumentation which also needs
and 10% Phenylephrine eye drops into the
continuous maintenance. To overcome the limitations
conjunctival cul-de-sac. All patients were operated
of this instrument dependent phaco techniques,
under per bulbar local anaesthesia (3 ml of 2%
instrument independent (i.e. non-phaco) techniques
Lignocaine + 3 ml of 0.5% Bupivacaine along with
are becoming popular and are being accepted by the
15 Units/ml of Hyaluronidase enzyme). No digital
cataract surgeons the world over. Though the non-
massage or Honnan’s balloon were used in order to
instrumental phaco techniques involve incisions
avoid hypotony of the eye ball, after injecting the
larger than the phaco incisions, the incisions
anesthetic agent into the orbit. The surgeries were
employed in these techniques are secure and optimal
performed by the first 2 authors.
to allow the implantation of rigid IOL but without
The conjunctiva and Tenon's capsule were
inducing much astigmatic effect.
dissected from the limbus from 10 O’clock to 2
We present our technique and results
O’clock. The conjunctiva was dissected upto 4 mm
following non-phaco small incision cataract surgery
behind the limbus. Minimum wet field cautery was
in a cohort of 88 patients.
applied to cauterize the bleeding vessels.
MATERIALS AND METHODS
Scleral tunnel and side port incision: A 6.0 mm
pre-set steel marker was placed 1.5 mm behind the
96 eyes of 88 patients were included in this study. All
limbus superiorly to mark the site and shape of the
patients signed the informed consent before surgery.
frown shaped incision (Fig.No.1). Partial thickness

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J Ayub Med Coll Abbottabad; 18(4)
Figure-2
Figure-1
Figure-3
Figure-4

incisions- one at 7 O’clock and one at 12 o’clock
(1/3rd) scleral incision was made with Baevers’ blade
were given in cases of small CCC and hard cataracts.
on the already marked line. Scleral tunnel was
Hydro dissection and nucleus dislocation: Hydro
created by 2.25mm crescent blade. The tip of the
dissection was performed through the 9.30 O’ clock
blade is tilted anteriorly to follow the curve of the
side port entry and through the tunnel at 3, 6, 9, and
limbus and dome of the cornea. While taking care to
12O'clock position. No hydro delineation was done.
maintain the uniform thic kness of dissection, the
Final hydro dissection at 9 and 12 O'clock was more
tunnel was extended upto 1.5 mm of the clear cornea
forceful until a part of nucleus prolapsed or tilted
concentric to the limbus and extending 1mm on
anteriorly into the anterior chamber. Later, with the
either sides of the external incision. The anterior
help of healon cannula nucleus was rotated either
chamber was entered with 3.2 mm keratome; the
clockwise or counterclockwise, while healon was
internal wound was enlarged to 8 mm to 9 mm with
being injected into the capsular bag and into the
only forward moment of a 5.2-mm keratome. This
anterior chamber, simultaneously and with the lens
architecture of a funnel shaped sclero-corneal tunnel
dialer, the nucleus was completely brought into the
(i.e. wider inside but narrow outside) results in a very
anterior chamber. (Fig No. 2). Anterior chamber was
strong self-sealing wound at the same time
kept full of viscoelastic during all this procedure.
facilitating the delivery of the nucleus. At this stage.
After prolapsing the nucleus in to anterior
Side port entry was made with Beaver’s blade 1mm
chamber, viscoelastic was injected above and below
in size at 9 - 9.30 o’ clock position...
the nucleus. The upper layer shields the endothelium

Trypan blue dye was used under air in cases
while the lower layer pushes the iris and posterior
of mature cataract
and Central
curvilinear
capsule posteriorly. A specially designed microvectis
capsulorrhexis (CCC) was performed with 25 G
4mm wide and 8mm long with corrugations on its
needle under sodium hyaluronate through side port
upper curved surface was introduced under the
entry. CCC with a minimum size of 6-7mm was
nucleus with one hand; and simultaneously
achieved nearly in all patients. Two relaxing
Sinskey's hook was introduced with the other hand on
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J Ayub Med Coll Abbottabad; 18(4)
to the front surface of the nucleus but away from the
of these 3 eyes had PC tear or vitreous loss. Two eyes
endothelium. Thus the nucleus was sandwiched
had localized Descemets’ detachment superiorly
between these two instruments. While keeping this
which were managed by injecting an adequate sized
sandwich away from the corneal endothelium under
air bubble in the anterior chamber at the end of the
cover of viscoelastic and well engaged between two
procedure. These 2 cases had corneal edema in the
instruments, it was easily delivered out of eye
involved area post operatively and it resolved over
through the tunnel by this bimanual phacosandwich
the next 4 weeks.
technique (Fig-3). The AC was kept deep throughout
Post-operatively, 5 eyes had transient
the procedure to protect the endothelium and the
moderate intra-ocular pressure rise on first post
posterior capsule. Most of the cortex was expressed
operative day that was attributed to retained
out through viscoexpression by injecting viscoelastic
viscoelastic material. These were successfully
while pressing the inferior lip of the tunnel. The
managed medically. 5 eyes (in addition to the two
residual cortex was aspirated by Simcoe cannula to
cases noted above which had Descemet’s
achieve a complete cortical clean-up. The viscoelastic
detachment) had localized corneal edema superiorly
was again injected into AC and the capsular bag; and
post-operatively in the area of sclero-corneal tunnel
a rigid all PMMA IOL of 6mm optic diameter and of
incision which cleared by the next postoperative visit
appropriate power was implanted and positioned into
at one week. In none of our cases we encountered
the bag (Fig-4).
posterior dislocation of nucleus/cortical matter
The tunnel wound is checked for any leak,
intraoperatively; or wound leakage, iris prolapse or
and hydration of the side port was performed at the
flat anterior chamber postoperatively.
end of the procedure. The conjunctival ends on either
At the first post-operative week, 8 eyes
end were approximated with cautery. . All patients
(8.3%) of the eyes had uncorrected visual acuity
received 2 mg of Dexamethasone and 20 mg of
(UCVA) of 6/6. By the end of 12 post-operative
Gentamycin, subconjunctivally. The eye was patched
weeks, 33 eyes (34.5%) had UCVA of 6/6 (Table no.
by eye pads and an eye shield.
1a). This indicates a statistically significant increase
All patients were examined at 1st post-operative day,
in the proportion of eyes with UCVA of 6/6 by 12
1 week, 4 weeks, and 12 weeks after surgery. All
weeks. 64 eyes (66.7%), 72 eyes (75%) and 80 eyes
patients received topical 0.1% Dexamethasone and
(83.3%) had best corrected visual acuity (BCVA) of
0.3% Ofoxacin, postoperatively for four weeks.
6/6 at, 8 and 12 weeks respectively. The reasons for
Follow-up examinations included a complete
not achieving BCVA of 6/6 in 16 of the cases have
biomicroscopic examination, naked eye visual acuity,
been shown in pie chart (Fig. 5). 11 eyes had
best correctable visual acuity and keratometry. The
trachomatous corneal opacities, 2 eyes had diabetic
data collected by these tests were entered in excel
maculopathies, 1 eye had cystoid macular edema and
spreadsheets and analyzed using statistical package
2 eyes had age related macular degeneration.
SPSS. Statistical analysis for the data of these
The mean preoperative astigmatism of 96
patients was done at 1 week, 4 weeks and 12 weeks
patients was 0.18 (SD=1.45). As shown in table no.2,
visits.
the post-operative astigmatism at 1, 4 and 12 week
was 0.38(SD=1.5), 0.26 (SD=1.4) and 0.22 (SD=1.3)
RESULTS
respectively. It was found that there was no
Of the 88 patients, 46 were females and 42 were
statistically significant difference between
males. 6 patients had undergone surgery on both
preoperative and postoperative astigmatism at 1 week
sides. Their age ranged from 49 yrs to 73 yrs (mean
(t=0.9 p=0.3), at 4 week (t=1.3 p=0.1) and at 12 week
age 57 yrs). All had their preoperative best corrected
(t=0.9 p0.35).
visual acuity less than 6/60.
Table 1: Results of Postoperative Visual acuity
Average surgical time was 25 minutes. All
testing
surgeries were uneventful intra-operatively except
(Preoperatively all had a best corrected VA of < 6/60)
that in two eyes the posterior capsule (PC) rent with
Table 1. A Uncorrected Visual Acuity of 6/6 (Total
vitreous loss was encountered while performing
Number N = 96)
cortical clean up at 12 o’clock position. This was
Post Operative
Number of eyes
managed by adequate automated vitrectomy. The
%
duration
with VA of 6/6
IOL implantation was done into the sulcus in these
At 1 week
8
8.3
cases . 3 eyes had smaller size CCCs (one had 5 mm
CCC and in the remaining two eyes CCC achieved
At 4 weeks
12
12.5
was 4.5 mm) which had to be enlarged by giving 2
relaxing incisions – one at 7 o` clock and the other at
At 12 weeks
33
34.37
12 o ‘clock position by the cystitome needle. None
Chi. Sq value=25.02, d.f=2, p=<0.001

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J Ayub Med Coll Abbottabad; 18(4)
Table 1. B Best Corrected Visual Acuity of 6/6
phacoemulsification with many additional advantages
(n = 96)
viz. a universal applicability to all grades of cataract,
Post Operative
Number of eyes
economical and relatively safer and easier learning
%
duration
with VA of 6/6
curve. Many different techniques exist for the nuclear
management for the non-phaco small incision
At 1 week
64
66.7
technique. The most popular among them are:
At 4 weeks
72
75
Michael Blumenthal’s anterior chamber maintainer
(ACM) technique, Luther Fry’s phacosandwich
At 12 weeks
80
83.3
technique3, Peter Kansas’ phacofracture technique,
Chi. Sq value=7.1, d.f=2, p=0.03
manual multiphacofragmentation and irrigating vectis
Table 2: Preoperative & Post operative Astigmatism
technique4-5.
(1, 4 and 12 weeks)
In this series, we adopted the phaco-

sandwich technique. We chose this technique because
No. of
Mean± S.D
this technique ensures the safe nuclear delivery with
Eyes
minimal iatrogenic insult to the corneal endothelium.
Preoperative
96
0.18 ± 1.45
The anterior instrument (i.e. the Sinsky hook/lens
Postoperative at week 1
96
0.38 ± 1.5
dialer) will help in protecting the endothelium and
Postoperative at week 4
96
0.26 ± 1.4
the specially designed corrugated microvectis will
Postoperative at week 12
96
0.22 ± 1.3
ensure the controlled delivery of the nucleus through

the tunnel. The enlarged internal tunnel allows the
nucleus to rest in it and to come out in toto without
damaging endothelium. We chose the frown shaped
Trachomatous Corneal
13%
Opacity
external incision since it is associated with minimum
6%
Diabetic Maculopathy
surgically induced astigmatism (SIA).6 We have also
seen in this series that there was no any significant
13%
Cystoid Macular
change in astigmatism following the surgery. The
Oedema
statistical analysis showed no significant difference
68%
Age related Macular
between preoperative and postoperative astigmatism
Degeneration
at 1 week (t=0.9, p=0.3), at 4 weeks (t=1.3, p=0.1)

Fig- 5: Causes for final BCVA <6/6
and at 12 weeks (t=0.9, p=0.35)
In this technique it is the stability of
DISCUSSION
surgeon’s two hands which accounts for the safe
removal of the nucleus without insulting endothelium
Senile age-related cataract causes about 50% of
and posterior capsule. Neither there is any chance of
world blindness1. The techniques of cataract surgery
nucleus drop. In cases of very large and hard cataract
have changed enormously in last few years and will
we recommend that tunnel may be enlarged up to
undoubtedly continue to evolve at an ever increasing
7mm but one suture should be placed to neutralize
pace. Nowadays, technologies with the use of small
surgically induced astigmatism5.

self-sealing incisions have taken a major lead in
When compared to phacoemulsification, this
cataract surgery. During past few years
non-phaco small incision technique has many
phacoemulsification has largely replaced ab-externo
advantages. This can be adopted safely in hyper
extracapsular cataract extraction with posterior
mature cataracts where zonules are weak and in very
chamber intraocular lenses (ECCE+PC IOL) with
hard nuclear cataracts. Also, the chances of the most
sutures. However because of expensive machine and
dreaded complication of posterior dislocation of the
its consumable, costly maintenance and difficult
nucleus or the nuclear fragment which can be
learning curve phacoemulsification has played a very
encountered during the phacoemulsification is not
limited role in reduction of cataract blindness in low
encountered during this non-phaco technique. Since
income countries.2,3,4 Since the phaco procedure is
none of any extraneous energy (i.e. ultrasound
wholly machine dependent, an unfortunate machine
energy) is used during this procedure, one will not
failure or its malfunction in the middle of the surgery
encounter any complications related to ultrasound
can also make the operating surgeon land into
energy viz. any corneal burns or iris chaffing or any
precarious and dangerous situations.
additional damage to the adjacent normal tissues.
Phaco-instrument
independent, i.e.(non-
Endothelial cell loss is found to be equal in both
phaco or manual phaco) techniques based on the
phaco and the non-phaco small incision technique7.
concept of scleral tunnel enable the surgeon to get
We have not done the objective specular microscopy
the equally good results as by in strumental
for endothelial cell count in our patients. The other
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J Ayub Med Coll Abbottabad; 18(4)
advantage over the phaco technique is the lesser cost
3.
Fry LL. The Phaco sandwich technique. In: Rozakis
involved since this technique does not require
GW(Ed),Cataract Surgery: Alternative Small incision
techniques. Thorofare NJ Slack1990; 91-110.
expensive instrumentation.
4.
Gutierrez-Carmona FJ. Mannual multiphacofragmentation
Our technique can replace the conventional
through a 3.2 mm clear corneal incision. J Cataract Refract
ECCE method and can achieve postoperative results
Surg 2000 ; 26:1523-1528,.
similar to those of instrumental phacoemulsification.
5.
Zvia Burgansky MD, ItzhakIsakov MD, Haggay Avizmer
MD, Elisha Bartov MD. Minimal astigmatism after
The advantages of this small incision technique over
sutureless planned extracapsular cataract extraction.
the conventional ECCE are: reduced surgical time8,
J Cataract Refract Surg 2002; 28:499-503.
no wound leakage and no iris prolapse, no flat
6.
Singer JA. Frown incision for minimizing induced
anterior chamber postoperatively9, early stabilization
astigmatism after small incision cataract surgery with rigid
optic intraocular lens implantation. J Cataract Refract Surg
of postoperative refraction with faster visual
1991; 17: 677-688 .
recovery10 and a lower incidence of fibrinous iritis
7.
Hayashi K, Hayashi H, Nakao F, Hayashi F. Risk factors for
than ECCE surgery11. Most investigators have
corneal endothelial injury during phacoemulsification.
observed that it takes 1 to 4 weeks to achieve a stable
J Cataract Refract Surg 1996; 22:1079-84.
8.
Fish JR. Creation of a no-stitch cataract incision. J Cataract
postoperative refraction12, and there is minimal
Refract Surg 1991;17:713-15
surgically induced astigmatism5. All these facts have
9.
Atisub T, Thongplengsri C, Panegputhiopong P. Small
been reinforced by this study.
Incision Sutureless Cataract Surgery with and without
To conclude, this technique is an effective,
Phakoemulsification, Thai J Ophthalmol 1992; 6(1):31-39.
10. Anders N, Pham DT, Antoni HJ, Wollensk J. Postoperative
fast, and economical alternative ensuring satisfactory
astigmatism and relative strength of tunnel incision: a
astigmatism free rehabilitation for the patients13. We
prospective clinical trial. J Cataract Refractive Surg 1997; 23:
recommend that , since this technique does not
332-36.
require expensive instrumentation and visual
11. Guzek JP, Ching A. Small-incision manual extracapsular
cataract surgery in Ghana, West Africa. J cataract Refract
recovery is as rapid as that of phacoemulsification,
Surg. 2003 Jan;29(1):57-64.
one can safely and reliably employ this technique to
12. Sinskey RM, Stoppel JO. Induced astigmatism in a 6.0 mm
achieve small incision cataract surgery most of the
no-stitch frown incision. J Cataract Refract Surg 1994;
time if not 100% of the time14 while addressing the
20: 406-409
13. Sood A, Kumar S, Badhu B, Kulshreshtha V. Astigmatism
backlog of cataract related blindness. 15
and Corneal Thickness in Conventional Large Incision
Versus Manual Small Incision Cataract Surgery. Asian J
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_____________________________________________________________________________________________________________________
Address for c orrespondence: Dr. Mohammad Naqaish Sadiq, Consultant and Head, Department of
Ophthalmology, Rustaq General Hospital P.O.Box.67, PC 329 Ministry of Health, Sultanate of Oman.
E mail: naqaishsadiq@yahoo.com


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