Toric IOL Versus Adjustable Incision for Treatment of Mild to Moderate

Astigmatism in Phacoemulsification

Dr. Khaled Ezzat Kotb AliMD.PhD.FRCS

Egypt Air HospitalCairo – Egypt

The author does not have any financial interest with any of these products

Purpose:

To compare the efficacy of implantation of toric IOL(AcrySof Toric lens T3,T4,T5) with adjustable incision in treatment of mild to moderate astigmatism in phacoemulsification, in subjects with mild to moderate astigmatism in a 12 months study.

AcrySof Toric is a single piece

acrylic lens with modified "L"

shaped haptics, posterior

toricity and marks indicating

the toric axis Its total length

is 13.0 mm and the optic

diameter is 6.0 mm.

Three models uesd:

SN60T3, SN60T4 and SN60T5 in

a spheric dioptric range from

6.0 to 30.0. The cylindrical

correcting power in the lens

plane is

1.50 D for the T3 model.

2.25 D for the T4 model.

3.00 D for the T5, model

to these parameters we used T3 model for astigmatisms 0.75

to 1.25 D T4 model for astigmatisms 1.5

to 2.0 D .T5 in astigmatisms greater than

2.25 D.

Methods:Study population: 114 eyes of 71 patients with cataract and

preoperative mild to moderate astigmatism (-0.75 D to -3.0 D)

were classified into two groups:

)1 (group A, toric IOL were implanted after phacoemulsification

(57 eyes)

)2 (group B, adjustable incision were done (57 eyes)

intraoperative with implantation of one piece acrylic IOL of

the same type.

Both groups matched for preoperative astigmatism, visual

acuity (uncorrected, UCVA; best spectacle-corrected,

BSCVA), and keratometry (K) values (flat, steep, average) .

Main outcome included: postoperative astigmatism, visual

acuity, refractive errors, K values.

Patient selection:1-patients with cataracts

2-pre existing mild to moderate (-0.75 D to -3.0 D) Considering the prevalence of astigmatism in the general population, approximately 35% of the patients undergoing cataract.

3-corneal regular astigmatism Surgical Technique for group A1. Toric online IOL calculator .

2. Upper temporal clear cornea wonud 2 mm.

3. perfect capsulorhexis .

4. Divide and conger (my preferred technique for phaco)

5. correct lens implantation within the capsular bag.

6. My usual post operative cylinder is 0.5.

Axis Markingmarking the eye before surgery and

during surgery. The marking of the eye should be extremely careful; the reference marks are placed in the limbus in two points 180° apart (3 and 9 o'clock meridians) and should be performed before entering the operation theater on a sitting patient to prevent cyclo torsion of the eyeball. The slit lamp is set to project a fine horizontal light beam across the undilated pupil in order to ensure a perfect location of the marks in the 0° - 180° meridian.

The purpose of the marks of the axis is to

identify the steepest meridian of the

cornea where the marks of the IOL

toric axis should be aligned.

Lens Orientation

After implanting the lens within the capsular bag, the lens is rotated clockwise until reaching 30° from the desired location. The viscoelastic is removed taking care that the lens is not further rotated and the aligning of the lens is carefully completed by clockwise rotation. Over rotation should be avoided; if over rotation occurs the lens should be completely rotated clockwise until reaching the final position. Meticulous orientation of the IOL is essential for an optimal visual outcome and as much time as needed should be taken to perform it correctly.

Surgical Technique for group B.

- Adjustable clear corneal wound in steep axis

2.8 mm for cylinder from 0.75 to 1.25 D

- Limbal relaxing incision ( LRI):

For cylinder from 1.25 to 3.00 I used the NAPA NOMOGRAM for with the rule astigmatism

( steep Axis 45 to 135 degree)

Paired Incision in Degree of ArcPreoperative

cylinder

20 to 30

years old

313

31 to 40

years

old

41 to 50

years

old

51to 60 years

old

61to 70 years

old

0.754035353030

1.004540403535

1.255550454035

1.506055504540

1.756560555045

2.007065605550

2.257570656055

2.508075706560

2.758580757065

3.00 9090858070

Results:

There were more improvements as regard preoperative astigmatic error ,UCVA, in patient with moderate astigmatism (-1.50 D up to -3.0 D) in group A with toric IOL, than in the group B with adjustable incision, and more improvement as regard preoperative astigmatic error, UCVA, in mild astigmatism (-0.75 D up to -1.25 D) in group B with adjustable incision than in group A with toric IOL.

Group A with tonic IOL Group B with Adjustable

insicion

Preoperative

astigmatism Posoperative astigmatism

6monthes

Posoperatie astigmatism 12

monthes

0.75 to 1.250.75No differance

1.5 to 2.250.25No differance

2.5 to 3.0 1.25No differance

Preoperatie

astigmatism Posoperative astigmatism

6monthes

Posoperative astigmatism 12

monthes 0.75 to 1.250.5No differance

1.5 to 2.250.75 No differance

2.5 to 3.0 Less 0.25 No differance

Conclusion:

Toric IOL is a good option for treatment of moderate preoperative astigmatism (1.25 to 3.00 ) than adjustable incision

but in mild astigmatism (-0.75 D up to -1.5 D) adjustable incision is more effective.

Thank you