Sir,

I read with special interest the article by Ahfat et al1 about the various aspects of phacoemulsification surgery in patients who have had pars plana vitrectomy (PPV) in the past.

It is quite a well-conducted study and I would like to extend my appreciation to all the authors. The authors have noted that postoperatively the improvement in the visual acuity was the least (57.1%) in the diabetic retinopathy group. It would be interesting to know if the improvement was compromised by the worsening of the diabetic retinopathy after the surgery, as is known to happen.2 I was involved with similar such studies where we studied the challenges of phacoemulsification in a group of patients who had retinitis pigmentosa (RP) and another group of patients who had PPV. Both groups were similar as the vitreous support was inadequate, vitreous being very fluid in RP. We applied different hydrodissection procedures during the phacoemulsification surgery. In one group we only performed hydrodelineation and the other group was subjected to standard hydrodissection. We had significantly more complications (posterior capsular rupture) in the hydrodissection group as compared to the hydrodelineation.

Hydrodelineation helps by supporting the posterior capsule during the surgery without any increase in the risk of zonular dialysis. The results were similar in both the groups, that is, RP and PPV. We think this was because the posterior capsule was unstable and support from the vitreous was insufficient in these patients, and therefore hydrodelineation was a safer technique. I quite agree with the authors about the ‘infusion deviation syndrome’, and a lower infusion bottle height keeps the anterior chamber reasonably stable and prevents surgical surprises.