Ординатура / Офтальмология / Английские материалы / Manual of Practical Cataract Surgery_Sundararajan_2009

Capsulorhexis in Detail

Capsulorhexis is one of the methods by which the anterior capsulotomy is done to deliver the Lens, wash the cortex, and finally introduce the IOL inside the bag.

This ensures a clear cut margin-border of the anterior capsulotomy which appears cosmetically good.

Also, during the procedure of aspiration of cortex, the risk of aspiration of tags of anterior capsule without our knowledge is averted.

This type of risk is very common during the can opener method of anterior capsulotomy.

Here during the aspiration of cortex, the tags of anterior capsule creates a tear extending radially to the posterior capsule which is thinner by five times than the anterior capsule.

This creates in disturbance to anterior vitreus face. This, in turn, results in vitreous disturbance along with excentric position of the pupil. This produces an inability to place the IOL in position inside the capsular bag.

Types of Capsulotomy

1.Anterior Capsulotomy.

2.Posterior Capsulotomy.

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POSTERIOR CAPSULOTOMY

This is done in the centre or axial portion of posterior capsule. The usual size of posterior capsulotomy is 4mm. This is carefully done under the microscope with the magnification to create a punched out hole which is smaller than the size of the Optic of IOL. So that it does not disturb the anterior vitreous face.

ANTERIOR CAPSULOTOMY

This is the primary procedure to create a circular rent at the centre in the axial portion with a clear-cut border to deliver the nucleus comfortably, aspirate the cortex without any complication and to introduce the IOL inside the capsular bag.

The usual diameter of the anterior capsulotomy is 5-6 mm.

USES OF CAPSULOTOMY

In anterior capsulotomy

The tags produced as a result of irregular can-opener method or any other methods is carefully prevented as this method of anterior capsulorhexis -produces a clear-cut border (like a punched out border) and that the chances of creating a tag is not possible.

This produces an acceptably (though not cosmetically) good, regular and clear-cut and circular margin in the axial portion of the globe.

In posterior capsulorhexis

The chances of formation and creation of posterior capsular opacity (as a result of failed attempt in the formation of new

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lens fibers) in young patients is carefully prevented, provided an associated anterior vitrectomy is also done.

Procedures

Capsulorhexis consists of an initial puncture of anterior capsule at the center, in the axial portion, to create a free fold of the capsule followed by a circular tear of the same flap either by utratas forceps or by any other forceps of surgeons choice, and by pulling the freely hanging flap to create a circular rent or by carefull pushing of the same flap from the attached portion of the whole capsule near the junction between the attached portion of the lens capsule and the origin of the free flap, to deliver the nucleus out and to introduce the PC IOL.

Here the pushing of the free flap from the junction is done circularly with an axis at the center.

For initial puncture, any sharp needle is enough. Once this is done, the tension in the capsule is released, which creates a gap.

Fig. 4.1

This gap creates a useful free flap with a scope to create a linear circular tear with an axis at the center of the anterior capsule starting from the lower arm.

This is achieved when the initial puncture is a slanting C, in which the lower arm is directed to create an anticlockwise circular tear either by a pull of the free flap or a push of the same from the original anterior capsule.

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If the initial puncture is a reverse slanting C, the lower arm of C is directed to create a clockwise movement of the free flap (by a forceps or a bent needle ) with an axis at the center.

The purpose is to make a circular rent with a diameter of 5 mm, upto 6mm. The lower half of free arm of C should be directed in such a way to create a circular tear or rent.

The size of the rhexis can also be 4mm in diameter. This is usefull in the posterior capsule which is thinner by 5 times than that of anterior capsule. This is useful to introduce the optic portion of the IOL behind the posterior capsule when the haptic portion is left inside. The capsular bag and vice-versa, to avoid the subsequent development of posterior capsular proliferation of new lens fibers leaving an opacity (posterior capsular opacity) especially in children and young people.

Just try to raise the flap, fold it, and from the base of the flap one can, with the tip of a cystitome, push the free flap circularly with the axis at the center or pull the flap circularly with the tip of the needle. Usually most of the surgeons use a 90 degree bent needle to push or pull. But when using a 90 degree bent needle, it usually punctures the free flap and jeopardizes the further procedures, creating tension to the surgeon during surgery.

The surgeons can do this rhexis by pulling the free anterior capsular flap. In a circular fashion to create a circular clear-cut rent with the tip of a cystitome just below the junction.

The symbol C, is to direct the line of tear in the free flap of anterior capsule to go circularly in an anti clockwise pattern on the right side. Otherwise our attempt to create a circular tear gets spoiled. Figures 4.2 and 4.3.

Push the flap as indicated above at the junction of free and attached portion of anterior capsule with the tip of the needle

Figs 4.2A to H

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Gently pull the free flap as indicated with the tip of needle

Figs 4.3A to H

REVERSE C

The anterior capsulotomy can also be made using a reverse C in which the lower arm of the reverse C is directed upto create a free flap. Here the free flap can be directed to tear as circular rent in a clockwise pattern with an axis at the center. Figure 4.4 and 4.5.

REPEAT CAPSULORHEXIS

In case the rhexis is not successful, small, irregular and not satisfactory, a repeat capsulorhexis can be done around the

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Anterior capsulorhexis — Starting from left side — Clockwise movement (roation of flap) — Reverse — C method magnified

Push the free flap at the junction with the tip of the needle at the periphery

Figs 4.4A to H

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Anterior Capsulorhexis — Starting from left side — Clockwise roation of flap) — Reverse ‘C’ = ‘C’ method magnified

Gently Pull the free flap all around with the tip of the needle at the periphery

Figs 4.5A to H

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failed 5 mm rhexis making it into a 6–7 mm rhexis. For this the lower arm of regular C or reverse C or U-shaped incision can be done around the failed one. This is useful in anterior capsulotomy only as the size is bigger.

In Regular type

The lower arm of C or U-shaped flap can be raised with the help of a cystitome outside the failed flap at 9 O’clock position the flap can be raised and pushed at an anticlockwise pattern circularly to create a clear cut border.

Or the lower arm of C or U-shaped nick can be made outside the failed one at 3 O’clock position, raise the flap with the cystitome and pull or push as per the necessity, to create a circular rent or capsulotomy. Figures 4.6 and 4.7.

METHOD- 2

Some surgeons prefer to peal the border circularly outside the original capsulotomy to make it into a 6-7mm capsulotomy with a clear - cut border. The beginner can learn and practice this on a red tomato.

METHOD-3

To admit the IOL inside the capsular bag, in case the diameter of capsule-rhexis is small, one can make 2 radial cuts from the clear-cut border of the rhexis - one at 10 O’clock position, another at 2 O’clock position. Instead, the surgeon can do this at 5 O’clock and 8 O’clock position of the border.

PURPOSE OF MAKING IT BIGGER

The purpose of making the rhexis bigger is to admit the IOL easily inside. The capsular bag and to deliver the nucleus easily from inside the capsular bag.

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Anterior Capsulorhexis from right side anticlockwise rotation of flap – Magnified

For small irregular

Make a small side incision raise the flap → pull the free flap all around from the existing

Figs 4.6A to I

PURPOSE OF CAPSULORHEXIS

In case of can - opener method, the inner border of the rhexis is irregular with the tags projecting. The tags, during the aspiration of cortex, by a cannula mounted on a syringe