Management of post cataract surgery

Astigmatism

H.R.Ziai MD

Since phaco became routine procedure, Ast. is not an important problem, however, it needs to disccused about.

Sources of post op. Astimatism

• Pre-existing Astimatism

• Incision induced Astimatism

• Suture induced Astimatism

• Wound burn

Incision induced Astimatism

Any incision, relaxates meridian which is vertical to the incision

Suture induced Ast.

Any tight suture,

steepens it’s own

meridian

• Any loose suture (wound

gap) flattens it’s own

meridian

• Any none radial suture,

induces irregular Ast.

(None predictable)

• Vertical mismatch, induces predictable astigmatism:

- Deep corneal to superficial scleral bite, flattens corneal curvature

- Superficial corneal to deep scleral bite, steepens corneal curvature

Wound burn:

It induces irregular wound

& irregular Ast. , that

often can not be

compensated.

How to manage it?

Management:

• Preoperative

• Interaoperative

• Post operative

Preoperative:

• PHACO, Except for

difficult or impossible

cases.

Interaoperative:

• Incision (main incision &

relaxing incision)

• Suture

• Avoiding wound burn

Main incisionBoth phaco & ECCE• More posterior incision Ast.• Smaller incision Ast.• Three-plane incision Ast.

Site of incision:• Temporal approach incision,

induces less Ast. , because it’s farthest from the visual axis.

• Although small incision of phaco, induces minimal cylinder, it is better to make incision on the steep meridian.

• Relaxing incision (Astigmatic Keratotomy, AK)

• If, pre-existing cylinder is more than 1.75D, relaxing incision on steep meridian is necessary for Ast. correction.

• Relaxing incision, also

can be made on limbus,

which is more effective

( LRI ).

• Suturing:

- Horizontal

- Vertical

- Rotational

Misalignment, induces Ast. , and so, have to be avoided.

Post operative:

• Selective suture removed• Glasses• Relaxing incision (AK)• Laser (PRK, LASIK)

Glasses:

• ECCE: 1m after suture removed

• Phaco: 2w after surgery

AK & Laser

• For ECCE >6m

• For phaco >6w