How manual cataract surgery rivals phaco for dry eye changes

Manual small incision cataract surgery (MSICS) does not make patients’ eyes any drier than phacoemulsification, a researcher said.

In two groups, one treated with MSICS and one with phacoemulsification, dry eye symptoms increased then declined to baseline in tandem after three months.

“The present study has shown that MSICS is as effective as phacoemulsification with no difference between both techniques as regarding effect on tear film stability and tear secretion,” wrote Mohamed Yasser Sayed Saif, assistant professor of ophthalmology, Beni-Suef University, Beni Suef, Egypt, and colleagues.

They published the finding in the International Journal of Ophthalmology and Eye Sciences.

Cataract accounts for much of the blindness in the developing world. 

Phacoemulsification has become the standard of care in the developed world, but the density of cataract in many countries, along with the expensive equipment, makes it less feasible in the developing world, Dr. Saif and colleagues wrote.

Pioneering surgeons in India and Nepal have found ways to reduce the incision size and eliminate the need for sutures in manual cataract surgery, they noted. This approach mitigated the drawbacks of conventional extracapsular procedures: the need to remove sutures after three months and postoperative astigmatism, they wrote.

After the rapid development of alternative approaches, the first trials comparing MSICS with phacoemulsification began to show visual and vision-related quality of life outcomes nearly as good as those achieved with phacoemulsification, the researchers reported.

Comparing the procedures

Few studies have compared the effects of the two procedures on tear film stability and tear film secretion. Of those  that have, they mostly focused on such subgroups as people with diabetes or preoperative dry eye.

Dr. Saif and his colleagues set out to compare the way the two procedures affected these outcomes.

They recruited 40 patients with a cataract and randomly assigned them to either phacoemulsification or MSICS. They excluded patients with diabetes, rheumatoid arthritis, and Sjögren’s syndrome.

In the phacoemulsification group, the mean age was 55.8 (± 15.8) years compared to 60.65 (± 9.2) years in the MSICS group. The phacoemulsification group was 90% female versus 45% in the MSICS group. The difference in age was not statistically significant, but the difference in gender was (P < 0.05).

Dry eye symptoms were characterized by burning, stinging, redness, sensation of a foreign body, photophobia, and blurred vision. They were graded as follows:

• 0: no dry eye symptoms.

• 0.5: trace or seldom of dry eye symptoms.

• 1: sometimes or mild dry eye symptoms.

• 2: frequent or moderate dry eye symptoms.

At baseline, none of the patients had a grade of 1 or 2. After one week, 80% of those in the phacoemulsification group and 90% of those in the MSICS group had a grade of 1 or 2. The difference compared to baseline within each group was significant, but the difference between groups was not.

After three months, 20% of those in the phacoemulsification group and 10% of those in the MSICS group had a grade of 1 or 2. The differences were not significantly different compared to baseline or between groups.

Looking at individual symptoms, the researchers found no significant differences between the two groups except for the presence of secretions three months after operation, which was significantly higher for the phacoemulsification group. 

More conclusions

The researchers found no statistically significant difference between the groups in tear film breakup time either at baseline or any point of follow-up. In both groups, this measurement decreased a week after surgery, then increased after four weeks, nearly reaching baseline at three months.

The researchers also found no statistically significant difference between the groups in corneal fluorescein staining grade at any time point. One week after surgery, 55% of the phacoemulsification eyes and 45% of the MSICS eyes were stained grade 2, and after three months, the eyes had returned to baseline.

The groups also did not differ in Schirmer test. Both showed a decrease a week after surgery, and returned to baseline at three months.

The finding that dry eye symptoms increase for a week after surgery parallels previous research. Some of these studies found that the signs and symptoms persisted longer than three months after surgery, however.

The researchers acknowledged limitations to their study. One is that the same surgeon carried out both procedures, and it is possible the surgeon was more skilled at one than the other.

In addition, the sample size might not have been sufficient to detect small differences in outcomes between the two procedures. Finally, a longer term study might yield more definitive results.

Still, they concluded that the study showed MSICS does not affect tear film stability or tear secretion differently than phacoemulsification does.

“Because MSICS is significantly faster, less expensive, and less technology dependent than phacoemulsification, it may be a more appropriate technique in eyes with mature cataract in the developing world,” they concluded.