Ask the Expert (1) .. Chirasri Jayaweera Bandara on Cataracts

ASK THE EXPERT.........(1)

A New Series on our Blog. I shall request colleagues to enlighten us on topics of great interest to us as we are all well into the stage where these topics have become more relevant to us. 

The first is on cataracts and cataract surgery by our Batch expert Chirasri Jayaweera Bandara,  retired Consultant Eye Surgeon who very kindly responded to my request.

CATARACT  SURGERY - Dr Chirasri Jayaweera Bandara

TYPES OF CATARACTS: 

1.Senile       2.Congenital

3.Traumatic                     4.Metabolic            5.Druginduced

a.Contusion                     a.Diabetes                   a. Corticosteroids

b.Penetrating injury         b. Galactosemia                  oral & topical

c.Radiation         c.Hypocalcaemia      b.Phenothiazines

d.Electrical injuries

e.Chemical injuries         d. Wilson’s disease       c. Miotics

                                       e. Myotonic Dystrophy  d. Amiadarone

                                                                             e. Statins

                                                                             f. Tamoxifen                                

 VARIETIES OF CATARACTS     

1. Cortical -  Lens opacities in the periphery

2. Nuclear -  Lens opacities in the nucleus

3. Posterior Sub Capsular (PSC) Lens Opacity – Starts as a small lens opacity at the back of the lens right in the path of light

·      Early decrease in vision is noted by patients in the 2^nd and 3^rd  varieties of 

      cataracts mentioned above.

·      This is felt mostly when exposed to the sun as pupils get constricted and block the light through the periphery of the lens. Wearing dark glasses will help initially at this stage.

·      Treatment for cataracts is only surgery when vision is compromised.

·      Surgery is done when patients find it difficult to carry out their daily routine satisfactorily.

SURGERY

Historically done under general anaesthesia or retrobulbar Lignocaine injection. 

At present, it is usually with topical anaesthesia ( Lignocaine ) and occasionally with subtenon Lignocaine injection.

 

IN THE PAST

IntraCapsular Cataract Extraction (ICCE)

The whole cataract was extracted after pupillary dilatation and after making the incision at the superior half of the limbus. (corneoscleral junction).

This was done with the Erysophake or Intracapsular forceps or the Cryoprobe. 

Next,  ExtraCapsular Cataract Extraction (ECCE)

After pupillary dilatation, an incision is made at the superior half of the limbus, then a Capsulotomy is done where the anterior capsule is cut in a circular manner with a bent tip of a 26 G needle. The circular piece of the anterior capsule was removed, leaving an annular anterior capsule and the whole of the posterior capsule intact. 

Once the cataract is removed the vision will only be 1/60   (i.e. only one meter

distance will be visible).

In the past after cataract extraction patients were given very thick glasses.

+10  to +12 Diopter power glasses (“ bothal adi “ glasses ) as IOLs were not available. 

 INTRA  OCULAR  LENSES  (IOL)            

Biometry is done prior to the surgery to calculate the IOL power to suit the patient's eye measurements.

PMMA  PolyMethylMethAcrylate  IOL is inserted through the large limbal incision after extracapsular cataract extraction. Because of the relative rigidity of these lenses, a large incision was required.

CURRENTLY

PHACOEMULSIFICATION  CATARACT  SURGERY 

Preoperatively,

·       Best corrected vision is noted.

·       Cataract assessment is done at the slit lamp.

·       The eyelids for blepharitis, clarity of the cornea, type of cataract and the viability of the capsular bag and the zonules which hold it in place are examined.

·         Intra Ocular Pressure ( IOP) is checked.

·        Pupils are dilated and the retina is checked to assess visual prognosis.

·       Fasting blood sugar, ECG along with a general systemic examination is done.

·       Antiplatelets and anticoagulants are omitted with cardiology guidance, but this is not compulsory as the incision could be made at a bloodless area through the cornea.

·       IOL  power is calculated with biometry.

·       The pupil is dilated fully.                                                           

Intraoperatively,

·       Topical Anaesthesia Lignocaine is instilled along with dilute betadine solution prior to commencing the surgery.

·       Sterile drape applied.

·       Speculum placed to keep the lids opened and eyelashes out of the field of surgery.  

·       Done under an operating microscope with the patient lying supine.

·       Surgeon sits at the head end of the operating table or on the (temporal) side of the head.

·       Incision 2.2 mm made with a Keratome at the limbus. (main port)

·       Combined solution with anaesthetic and dilating agent is introduced into the anterior chamber.

·       Methylene blue is injected into the anterior chamber to stain the anterior capsule of the      cataract.

·       26 G Needle tip is bent in preparation of capsulotomy.

·       Methylene blue (injected earlier) is washed off with balanced salt solution (BSS) .

·       Viscoelastic material is introduced into the anterior chamber to maintain intraocular space for the next steps of the surgery.

·       Capsulotomy is done in a circular curvilinear manner central to the dilated pupil with the bent tip of a 26 G  needle or with a Capsulorrhexis forceps.

·       Circular piece of the anterior capsule is removed.

·       Hydrodissection is done by injecting Balanced Salt Solution (BSS) under the remaining capsule to separate the nucleus from the capsule.

·       Two side ports 1.1 mm are made opposite to each other, generally around 90 degrees from the main port (according to the surgeon’s preference).

·       The Phacoprobe is introduced through the main port into the anterior chamber.

 

                     PHOTO 1  PHACOPROBE

Note at the bottom (diagram)                         The Ultrasound power line is attached to the centre of the probe, the irrigation and aspiration lines alongside. Also note above (diagram)        The irrigation port near the tip and  aspiration port at the tip.

                                           

·        A groove is made in the cataract with the Phacoprobe as shown below.

                             

PHOTO 2  GROOVING

·       The nucleus is rotated and another grove is made at right angled to the former.

·       The nucleus is first cracked into 2 as shown below.

PHOTO 3  NUCLEUS OF THE CATARACT CRACKED INTO 2    

·       The halves are then cracked further resulting in 4 quadrants.

·        Finally it is emulsified and aspirated.

·       Then the remaining cortical lens matter is aspirated and a clean capsular bag with an annular peripheral ring of the anterior capsule and the whole intact posterior capsule is left for IOL insertion.

·       Foldable Acrylic IOL is introduced through the main port. The IOL

      unfolds itself into the capsular bag.

·       Premium IOLs – Multifocal/astigmatic IOL s are also available on request.

·       The incisions are sealed by hydrating with BSS which will cause a small localized opacity lasting only a few minutes

PHOTO  4   FOLDABLE  ACRYLIC  I.O.L.

POST  OP 

·       Antibiotics, Steroids and Non Steroidal Anti Inflammatory Drugs (NSAID)

      eye drops are prescribed, with a tailing off dose spanning a month or so

(if uncomplicated)

·       Surgery could be done as a day surgery (in the Private sector in Sri Lanka)

·       In the Government Hospitals in Sri Lanka, the patients are routinely admitted the previous day and they may be discharged the next day.

·       Glasses are prescribed for near work (presbyopic glasses).

·       Patients who get Multifocal IOL inserted at the time of surgery, could do near work without the need for presbyopic glasses. 

Surgery was done by my daughter Anjali Jayaweera Bandara Senior Registrar, Eye Hospital Colombo.

I am thankful to Anjali for recording her surgery and producing the video with captions.

Note from Speedy...

What follows is a video of a cataract surgery performed by Chira's daughter Anjali Jayaweera Bandara Senior Registrar, Eye Hospital Colombo.

Please read the steps of the surgery given above before watching the video of cataract surgery. 

Please click on the image to commence the video.

To see the video in FULL SCREEN, when the video starts, please click the icon at the bottom right (as in any YouTube Video). The icon will appear ONLY when you start the video.

 ASK THE EXPERT.........Questions on  Cataract Surgery (sent by Mahendra )

 

1.  Q.  Will all who develop cataracts need an operation if they live long enough?

    A. Not if the vision is good and you are managing your daily routine satisfactorily. 

2.  Q.  How important is the timing of when to remove?

A.  When you cannot manage your daily routine and feel you need better vision. 

3.  Q.  Will a delay in an operation lead to a poorer outcome?

     A.   When the cataract becomes hypermature, the proteins leak out through the   

    capsule, causing a reaction in the anterior chamber, increasing the intraocular pressure which results in a painful red eye. This is called Phacolytic Glaucoma.

    Then the patient is initially treated to reduce the eye pressure and inflammation preoperatively. In some cases, vision may not be very good.    

4.  Q.    Is it common for senile macular degeneration to coexist with cataracts?

     A.  No, it generally has a different pathology and is not as common as senile cataracts 

5.  Q.  What are the indications for operation?

     A.  Poor vision, when the patient cannot manage the daily routine.

          When glaucoma is secondary to cataract

          A breach in the lens capsule (in case of traumatic cataracts)      

6. Q.  Can both eyes be done at the same time?

     A.  Not routinely, because of the rare complication of infection. 

7.  Q.  If not how far apart should they be if both need doing?

      A.  Generally, after 3 months but it could be done before if indicated. 

8. Q.  How safe is it?

     A. Safe in good hands. 

9. Q.  Are there recognised complications?

     A.   Posterior capsular rupture (PCR) during surgery.

            Rare complication of lens drop into the vitreous after PCR.

            All these could be managed successfully.

           Rare complication of infection.   

10. Q.  How long does a cataract extraction take to perform from the time of entry to the theatre to leaving?

       A.    Between 20 to 25 minutes. ( the surgery itself 15 to 20 minutes.) 

11.  Q.  Is it always a day operation?

        A.  It is day surgery in the private sector in Sri Lanka but in the Government

sector patients are admitted the previous day and maybe discharged the following day. 

12.   Q.  Am I conscious during the operation?

         A. Yes, surgery is done under topical anaesthesia or occasionally local nerve blocks.

          Not done under GA unless exceptional cases or opted for. 

13.   Q. How do I keep my eye still during the operation?

         A. The patient is simply asked to look straight and it is aided by instruments by the surgeon. 

14.    Q.  How much aftercare is required after the operation?

          A. Not much but to instil antibiotic and steroid eye drops and to wear an eye shield for physical protection. 

15.    Q. How soon can I drive a car again?

         A.  In a couple of days depending on the vision in the other eye. 

16.     Q. What types of lenses are used to replace the affected lens?

         A. Foldable Intraocular lenses made of Acrylic material are inserted during Phaco surgery.

PMMA (PolyMethylMethaAcrylate) material IOLs are inserted in Extra Capsular Cataract Extraction. PMMA IOLs are rigid could be inserted after phaco surgery too after enlarging the incision. (If foldable IOLs are not available.)

     Multifocal IOL are also inserted on request by the patient, where spectacles are not required for close work. 

17.   Q. What can a person expect as an outcome and when will the benefits be seen?

            A. Excellent outcome and benefits will be seen immediately intraoperatively provided the rest of the eye is normal. 

18.    Q.  Can any Ophthalmologist do it or are there those who have specialised?

          A.  Any Consultant Ophthalmologist, Senior Registrar and trained Registrar

           can do the surgery.     

If readers have suggestions for the next Ask the Expert, please email me.

Speedy