Dear friends, lets get back to ophthalmology! I’d like to share an interesting compilation of facts regarding selection of cataract cases for the surgeon who wants to change – over from using the ‘divide & conquer’ technique to the ‘chopping’ technique via phacoemulsification.
Using torchlight, every ophthalmologist who knows his/their basics would correlate nuclear softness or firmness to the color of the nucleus as it transitions from yellow to gold and then to brown. But at the slit – lamp it is essential to catch another detail – the size of the endonucleus! Is it small, medium, or large? For example, a medium sized nucleus would have a larger endonucleus compared to softer lenses with smaller endonuclei.
ESTIMATING THE SIZE OF THE ENDONUCLEUS
*High myopes with oil – droplet nuclear cataracts have only a tiny, central, opalescent endonucleus, with most of the lens being the epinucleus.
* In some nuclear sclerotic cataracts, a golden or brunescent fetal nucleus is visible at the slit – lamp, but the nucleus peripheral and anterior to it is pale yellow. Here, a medium sized endonucleus is surrounded by an epinucleus of similar dimensions.
* Finally there are nuclear sclerotic cataracts in which brunescence extends all the way forward to the anterior lens capsule, indicating huge endonucleus with little or no epinucleus.
IMPORTANCE OF KNOWING THE SIZE OF THE ENDONUCLEUS
* Peripheral and deeper troughs are required to crack larger/denser nuclei when using the ‘divide & conquer’ technique. In chopping, the chopper and phaco tips must penetrate deeper than usual for a larger nucleus unless you want to end up with a superficial chop, resulting in failed division.
* Soft to medium density endonucleus are preferable for those starting out with horizontal chopping technique.
WHEN TO TAKE UP BRUNESCENT CATARACTS WITH LARGE ENDONUCLEUS
Since there is little margin for error, these should not be attempted until one has mastered chopping in less difficult cases.
WHAT TRANSITIONING SURGEONS SHOULD AVOID
Unless the ‘transitioners’ happen to be surgeons with superhuman skills, its best to avoid the following conditions, which have a small chance of being predisposing factors to demolition day:
1. Uncooperative patients
2. One – eyed patients
4. Loose zonules
5. Excessively deep or shallow anterior chambers
6. Deep – set eyes
7. Small palpebral fissures
8. Small pupils
9. Intraoperative floppy iris syndrome
10. Poor corneal clarity
11. Poor red reflex.
Wow! Ophthalmology can be so attractive and boring at the same time! I don’t know about you guys, but I’m off to bed. Wishes for a happy last day of 2013!