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

How to Prevent Complications in Manual Phaco? 19

Fig. 1.34

Now engage the under surface of the nucleus near the equator and rotate in an anti, clockwise manner, till the entire nucleus comes into anterior chamber.

Figs 1.35A to C

No, inject viscomet both above in anterior chamber and below the nucleus.

20 Manual of Practical Cataract Surgery

Fig. 1.36

During the entire procedure, inject viscomet, sufficiently to keep anterior chamber well formed.

During the first clockwise rotation procedure, if the nucleus does not appear into anterior chamber easily, or if you see that the nucleus recoils back into its original position, it signifies that there is an

1.Adhesion or

2.Small pupil (undilated).

3.Small rhexis.

Adhesions

Fig. 1.37

In case, you are not able to locate the cause of recoil, i.e., the site of adhesion, it is better to avoid unnecessary venture, do the well practiced procedure, planned ECCE and nucleus delivery by squeezing the equator of the nucleus out.

–If insufficiently dilated pupil = there is posterior synechia.

–If you notice a dimple at the centre of iris, there is adhesion at the mid position of iris.

–If recoils or a pull is noticed at the pheriphery, then there is adhesion at the periphery.

–If you are able to locate the posterior synechia release with iris repositor.

–Otherwise, you are likely to rupture the posterior capsule and allow the nucleus to sink.

How to Prevent Complications in Manual Phaco? 21

Caution

It is always better not to allow the nucleus to sink into vitreous.

SMALL RHEXIS

This may also be due to small rhexis. The diameter of normal rhexis is 5 mm. If you make a slightly wider rhexis, (about 6 mm) the nucleus rotation and nuclear delivery also is easy, (The reason behind is already mentioned)

Once small rhexis is already done, the relaxing incision of anterior lens capsule will be helpful.

Make an incision at ALC at 5 and 8 O'clock position or at 12 O'clock position alone.

Figs 1.38A and B

ALC - Anterior lens capsule.

SMALL PUPIL (UNDIALATED)

In Px syndrome or iris adhesions due to uveitis, pupil may not dilate.

Under such conditions, try to release the synaechia, by sweeping with iris repositor all around through the pupil. Or do a key hole iridectomy (i.e., make a P.I, at 12 O'clock posistion. Then by introducing one edge of scissors though the P.I upto pupil and cut it.

22 Manual of Practical Cataract Surgery

Fig. 1.39

Now dial up the nucleus into anterior chamber after making the nucleus to enter into anterior chamber fully, it is your duty now to deliver the nucleus out.

NUCLEUS DELIVERY

Inject plenty of viscomet under the nucleus and above the nucleus. Now by introducing the viscomet needle upto 6 O'clock position, inject viscomet, more and allow the nucleus to be drifted out automatically by slightly depressing the posterior lip of sclera.

Figs 1.40A and B

If the corneo, scleral incision is slightly bigger the nucleus automatically finds its way out by the viscomet pressure.

If the C.S incision appears small inject some viscomet then extend the inner incision on either side slightly and

24 Manual of Practical Cataract Surgery

And sandwiching the nucleus on either side. Now, gradually drag the nucleus out, so that it does not touch the endothelium at any point in a curved fashion, gradually pulling out and up towards the surgeon.

Fig. 1.43

If the C.S tunnel is slightly bigger try injecting viscomet at 6 O'clock postion of anterior chamber, allow the entire nucleus to be drifted out automatically, depressing the posterior lip of tunnel with the same viscomet cannula.

During the delivery of nucleus, it is likely, without the surgeons knowledge, that the surgeon may introduce vectis under the iris through the pupillary border at 6 O'clock position and pull the iris also out, along with the nucleus - i.e., either partial or total iridodialysis.

So to avoid, carefully see that the vectis is passed under the nucleus through the transparent semi-cataractous nucleus. This is visible in microscope.

Or even at 12 O'clock position by creating a partial dialysis at 12 O'clock position.

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The Method

After the hydrodissection, and once the nucleus is rotated and brought out into anterior chamber. Fill the anterior chamber with viscomet (Viscoelastic fluid ) both above and below the nucleus. The posterior capsule is situated under the iris diaphragm.

Fig. 1.47

Now, introduce the irrigating vectis through the limbal opening, without the flow of fluid, under the nucleus into the anterior chamber, so that the concave surface of the vectis engages the under surface of nucleus upto the equatorial position.

Fig. 1.48

Now, open the valve in the BSF dripset, so that the BSF flows well into the anterior chamber. The fluid pressure pushes the nucleus out and simultaneously drag the nucleus out.

1.Fluid pressure pushes nucleus out.

2.Hook the nucleus out.

3.Depress the posterior scleral lip so that nucleus comes out easily.