Phaco chop and drill‐and‐crack equally effective for phacoemulsification of hard cataracts: Study
According to a recent research, it has been observed that the phaco chop and drill‐and‐crack techniques are equally effective for disassembly of hard NO4 and NO5 cataracts, as published in the Journal of Acta Ophthalmologica .
The complete disassembly of nuclear is the most challenging step in hard cataract surgery through microincision. Phaco chop is a bimanual phacoemulsification technique to remove cataracts. Studies have shown that compared with four-quadrant 'divide and conquer', the phaco chop technique uses less phaco time and energy, significantly reducing endothelial cell damage. Other advantages of phaco chop include reduction of zonular and capsular stress because forces are directed toward an opposing instrument and the phaco tip is kept in a central 'safe zone' in the middle of the pupil. This technique has also been successfully adapted to the canine phacoemulsification procedure.
However, the the drill-and-crack technique, which combines phaco chop and the prechopper, makes a deep hole (drill) in the central nucleus with the phaco tip and divides the nucleus (crack) with the prechopper inside the hole.
Hence, Hazem Abdelmotaal and colleagues from the Department of Ophthalmology, Faculty of medicine, Assiut University, Assiut, Egypt decided to quantify the intraoperative parameters and postoperative outcomes after using the phaco chop technique in one eye and drill‐and‐crack technique in the other eye in patients with bilateral dense brunescent cataract.
The authors used the Lens Opacities Classification System III grading system to select 132 eyes of 66 patients with bilateral nuclear opalescence (NO) grade NO4 or grade NO5. One eye in each patient with bilateral dense brunescent cataract was subjected to phacoemulsification using the phaco chop technique, while the other eye was subjected to phacoemulsification with the drill‐and‐crack technique for nucleus disassembly. The intraoperative parameters were quantified. Surgical outcome was assessed preoperatively and 1 day, 4 weeks and 12 weeks postoperatively, and the outcomes of the two techniques were compared.
The following results were obtained-
a. There was no significant difference between the techniques in operative parameters [cumulative dissipated energy (p = 0.74), surgical time (p = 0.68) or surgical difficulty during nucleus disassembly (p = 0.80)].
b. There was no significant difference in the postoperative change in central corneal thickness between the techniques at day 1, 4 weeks and 12 weeks or in corneal endothelial cell density loss at 4 and 12 weeks (p > 0.05).
c. There was no significant difference between the techniques in the mean corrected distance visual acuity (logarithm of the minimum angle resolution) at 4 weeks postoperatively (p = 0.25).
Therefore, the authors concluded that "the phaco chop and drill‐and‐crack techniques are equally effective for disassembly of hard NO4 and NO5 cataracts."