What I Have Learned In The Past 30 Years Performing Over 25,000 Cataract Procedures

I have been very fortunate to practice in the era of posterior chamber IOLs and phacoemulsification.  These two advances in the 1980s gave cataract surgeons such as myself the ability to more predictably and safely correct vision.  Starting in the mid 90s, incision sizes became smaller and foldable IOLs that could take advantage of these smaller incisions became commonplace.  Astigmatism control after cataract surgery also became more predictable with the smaller incisions allowing better "fine tuning" of the final refractive outcome.  This astigmatism control was necessary when further astigmatism modulating procedures such as limbal relaxing incisions (LRIs) or toric IOLs were added to our armentarium.  

The other huge evolution in cataract surgery was in the refinement of the phacoemulsification technology.  Torsional phaco  (Ozil tm) allowed more efficient nuclear breakup with less energy transmitted to the cornea and subsequently, quieter better seeing eyes when compared to our original longitudinal phaco technology.  More advanced IOL calculating formulas such as the Holliday 2 formulas combined with more accurate means to measure the axial length of the eye with laser interferometry have also contributed to more predictable refractive outcomes.

The challenges I face today are different from those faced ten or twenty years ago.  Intraoperative complications such as dropped crystalline lenses, broken capsules and vitreous loss are rare in my hands; however, refractive surprises where the patient ends up a diopter +/- from the target refraction occurs in about 3-5 % of pts.  This occurs because the pts eye does not "fit" the preop formula calculations or because the IOL moves in the capsular bag when the bag fibroses.  In fact, a "refractive surprise" is the most common reason a patient will sue their cataract surgeon.  Patients expectations today are often unrealistic and sometimes ridiculous.  Our informed consent for cataract surgery has a bolded, underlined separate paragraph to try to drive this point home to patients in addition to discussing this at the time of their preoperative evaluation.  Just like a LASIK patient may need an enhancement "tweak," the cataract patient may similiarly need spectacle or laser vision correction tweaking.  

Not surprising, the more the patient pays for extra services such as astigmatism correction, or presbyopia correction, the greater the expectation.  One of my biggest concerns with Femto-assisted cataract surgery is that these refractive "misses" will still occur at the same rate (lots of data to support this) and these patients will be very unhappy after paying a hefty premium, yet will need another excimer laser to tweak their refractive outcome.  I have spoken to several of my colleagues  around the country using the femto who have experienced anger and disappointment from their patients with these refractive surprises DESPITE being informed about this possibility preop.   

 In my experienced  hands, the femto laser will not provide a safer or more predictable outcome.  I would be happy to challenge anyone to a head to head study comparing our results  against theirs with or without femto technology.   Our ability to safely remove the cataract is not the issue.  Our presbyopic IOL technology  in 2014 has a long way to go in delivering high quality vision in different lighting conditions at all focal points.  That is where the r&d needs to occur. 

I am not anti-femto and in fact think it will be essential in the future when more sophisticated IOL technology will require the capability of this laser.  Similiarly, when the laser can more safely break up the entire nucleus and require no phaco energy,  then there will be an advantage to this technology.   I am sorry to get sidetracked on this femto rant, however, I find it very frustrating that many ODs and MDs are not looking at this from the perspective of what is best for patient outcome.   I am very happy to look any patient in the eye and tell them that in my hands they will be wasting their $$ to use this technology at this time.   Unfortunately, 99% of patients do not know the critical question to ask their surgeon which is ..."in your hands will excimer- assisted cataract surgery confer a safer and better result?"

I want to thank all of you for supporting us at Capital Eye Consultants and I look forward to the my next 25,000 cataract procedures providing your patients the very best outcomes possible.  

 JOHN C BALDINGER MD

   The Simplified Severity Scale For Defining      Risk of AMD Progression.(From AREDS 2)

There is a relatively simple scale for determining likelihood of progression in AMD.  This scale was derived from the Age-Related Eye Disease Study Research Group, AREDS Report No. 18.  Using their methods, you assign 1 point for large drusen and 1 point for pigmentary change for each eye.  Then add the two eyes together for a possible score of 0 to 4.  These numbers yield a 5-step scale giving the approximate 5 year risk of at least one eye developing advanced AMD.  So, if a person scores 0, they have a 0.5% chance of developing advanced AMD.  1 Factor is a 3% risk, 2 Factors is a 12% risk, 3 Factors is 25% risk, and 4 factors is a 50% risk.  For persons with no large drusen, presence of intermediate drusen in both eyes is counted as 1 risk factor.  This can be beneficial not only for your information and the patients, but can be useful for PQRS.  For Measure 14: Age Related Macular Degeneration(AMD), you have to document Macular Thickening using the terms "macular thickening, intraretinal thickening, serous detachment of the retina, or pigment epithelial detachment".  You also must grade the severity of the macular degeneration - "mild, moderate, or severe".   Although, there is no scale given for these definitions, you could certainly derive your own using the severity indicators 

JAMES W MATTERN OD

      Modern Vitrectomy Is Safe

Modern vitrectomy is as safe or safer than cataract surgery.  The chance of developing complications of retinal detachment or endophthalmitis from vitrectomy is comparable to cataract surgery.

Long gone are the days where vitrectomy is a dangerous operation.  Technology has improved the efficacy and safety of vitrectomy.  While the retinal diseases treated with vitrectomy can still significantly impact vision, complications causing loss of vision occur much less often.

Since vitrectomy was invented in the mid-1970's, the operation has become standard for removal of vitreous hemorrhage, repair of retinal detachment, removal of epiretinal membranes, repair of macular holes, etc.

Safe as Cataract Surgery

Over the last decade, 25 gauge vitrectomy has become quite popular.  The obvious advantages include thinner instruments which allow the modern vitreo-retinal surgeon the convenience of "no-stitch" vitrectomy. 

Operating time is shortened as I no longer need to start the case by cutting through conjunctiva, making stab incisions through sclera and then closing with sutures at the end.  Now, the instruments are simply introduced through both conjunctiva and sclera with a single stab incision (the instruments are simply poked directly into the eye).  These wounds are so small, they self-seal at the end of the operation.

Obviously, there is convenience for the patient, too.  Faster healing and comfort (less irritation as there are no sutures) all translate to fewer post-op visits. 

23 gauge instruments, by the way, are intermediate in thickness between the older 20 gauge instruments and the thinner 25 gauge. 

For the purposes of discussion, I'll limit myself to 25 vs. 20 gauge instruments.

The rate of endophthalmitis has always been lower with vitrectomy, 20 gauge or otherwise.

The thinner 25 gauge systems are also safer for the patient.  While the rate of endophthalmitis has always been lower than cataract surgery, the thinner systems now create fewer retinal tears.

Q.  What's unique about a drinking straw from MacDonald's?

A.  The diameter is wider than other straws allowing you to drink faster. 

Poiselle's Law states that the resistance of flow through a tube decreases with an increase in the radius.

25 gauge vitrectomy instruments cause fewer retinal tears due Poiseuille's law.  The thinner tubes simply can NOT generate enough force to engage the vitreous and tear the retina compared to the fatter/thicker 20 gauge instruments.

Simply put, the newer instruments can NOT pull on the retina and cause tears compared to 20 gauge.

(Experiment:  Try drinking with a coffee stirrer versus a conventional straw.  That's the difference between 20 gauge and 25 gauge vitrectomy instruments.  Coffee stirrer is the 25 gauge instrument and the conventional straw is 20 gauge.)

Most operating rooms now have wide-angle viewing systems (WAVs) which allow me to have a panoramic view of the fundus as I operate.  This allows me to see most of the vitreous and retina as I operate, thus allowing easier of identification of retinal pathology, such as retina tear.

Because of the wide field, the peripheral retinal can now be examined with the aid of the operating microscope offering enlarged and enhanced view of the periphery.

The WAVs offer convenience for the surgeon, but more importantly, provide a safer operating environment.

What Does this Mean?

Modern vitrectomy has become a safe operation.  Complications can occur in any surgical procedure, but now vitrectomy is as safe or safer than cataract surgery.

The advances made through thinner instrumentation have improved the safety of the operation in addition to allowing faster and more comfortable surgery.  WAVs, too, while principally designed for the surgeon, have made retinal surgery safer.

By the way...I hear 27 gauge instrumentation may be on the horizon!

RANDALL WONG MD