Trainee surgeons hold didactic wisdom

By Cheryl Guttman

ORLANDO, FL - Lessons learned by ophthalmic surgeons in training also have something to teach those already in practice, according to Kerry D. Solomon MD who spoke at a cataract surgery session of the annual meeting of the American Academy of Ophthalmology.

He presented the findings from a review of 1,325 cases of phacoemulsification performed over a four-year period by 20 residents at South Carolina's Ralph H. Johnson Veterans' Administration Medical Centre (VAMC), Charleston and the hospital of the Medical University of South Carolina.

The study showed capsular tears occurred in 6% of eyes and were most common during phacoemulsification procedures. The risk of capsular tear was not associated with surgical experience but the rate was higher for procedures performed at the Veterans' hospital compared to the university.

Some 80% of cases complicated by capsular tears achieved visual acuity of 20/40 or better. The majority of cases with poor vision outcome occurred in the setting of cystoid macular oedema (CMO) development or in diabetic patients.

Increased surgical time appeared to be associated with the development of CMO and endophthalmitis. The study revealed the trainee surgeons needed to perform approximately 50 cases before they were able to consistently complete operations over an acceptable time.
"Hopefully this research provides a few pearls to all practitioners about ways to minimise problems during cataract surgery and improve outcomes," Dr Solomon remarked.

The review included all eyes undergoing phacoemulsification where a resident was the primary surgeon and the surgical logs were available. The study excluded cases of combined surgery and eyes with a traumatic cataract or pre-existing zonular dehiscence.

Almost half (49%) of the capsular tears occurred during phacoemulsification. Irrigation and aspiration was the second most common situation during the procedure for the rupture to occur (26% of cases) followed by IOL insertion (11%).
"It was somewhat surprising to find so many cases occurring during IOL insertion but I would suspect those tears might have developed earlier and not identified until the implant was being placed," Dr Solomon said.

As expected, nuclear sclerotic cataracts were the most common cataract type associated with tears. However, 41% of patients with capsular bag tears had significant posterior sub-capsular cataracts.

That latter finding is noteworthy because posterior sub-capsular cataract was associated with a need for pars plana vitrectomy (PPV) as well as a poor visual outcome, Dr Solomon observed.

"I think it is significant to point out that all six cases requiring PPV to retrieve dropped lens material were in eyes with a significant posterior sub-capsular cataract. Available follow-up for five of those eyes showed two had a final visual acuity worse than 20/40.

"My feeling is that when working with those softer lenses, there is a tendency to perform deeper phacoemulsification, leading to earlier capsular rupture with dislocation of lens material posteriorly," Dr Solomon said.

The most common complication after posterior capsular tear was CMO which occurred in 10% of eyes followed by secondary PPV (7.7%). In addition, retinal detachment occurred in four eyes. There were two cases each with inflammation greater than one and endophthalmitis, as well as one case of choroidal haemorrhage.

A review of the charts for eyes that developed CMO showed that the average operative time for their surgeries was 96 minutes - approximately twice as long as that of the group overall.

In three of seven eyes with available follow-up, CMO persisted despite immediate initiation of topical NSAID treatment and subsequent addition of sub-Tenon's steroid injections.

Final visual acuity for those eyes was worse than 20/40. Those eyes accounted for 29% of all posterior capsular tear cases with a poor visual outcome.
"These findings tell us that CMO needs to be addressed aggressively and avoided if possible by minimising the operative time," Dr Solomon stressed.

Of the four eyes that developed a retinal detachment, one was a high myope, two underwent PPV for dropped lens material and the fourth patient was a diabetic. All had IOL implantation in the sulcus.

Both eyes that developed endophthalmitis had sutured, clear cornea incisions. Their operative times, 221 and 205 minutes, respectively, were the longest in the entire series. Both eyes had a final visual acuity of 20/40 or better.
Of the 1,325 cases reviewed, 1,076 (81%) were performed by residents at the VA medical centre and 249 (19%) at the university hospital.

Of the 78 capsular bag tears in the series, 71 occurred at the VAMC and seven at the university hospital. That accounts for 6.5% of surgeries performed at the VAMC and 2.8% of eyes operated on at the university hospital.

"At the university, residents operate under absolute supervision but that is not the case at the VA hospital. The findings of this study would support the value of close supervision for surgeons in training," Dr Solomon explained.

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