New Lens Fragmentation Pattern For Femtosecond Laser-Assisted Cataract Surgery

Lens fragmentation during femto-laser assisted cataract surgery (FLACS) may be performed using different patterns, among which “chop-like” or “matrix” are the most common. Chop-like fragmentation usually requires more manipulations and more ultrasound for nucleus removal, while matrix pattern may cause excessive gas bubbles formation due to more laser energy. Combined “matrix-chop” pattern created with respect to different hardness of lens material within the nucleus may be useful for optimal balance of laser and ultrasound power. The aim of this study was to evaluate the feasibility of novel combined matrix-chop “DiamondCut” lens fragmentation pattern (LFP) for cataracts of various density.

Department of Eye Diseases of Samara State Medical University (Samara, Russian Federation), Department of Cataract and Refractive microsurgery of Samara Regional T.I. Eroshevsky Ophthalmic Hospital (Samara, Russian Federation). 

DiamondCut LFP is double-line “chop” cross with central “matrix” softening. Rectangular shape of lens fragments is intended to facilitate further manipulations within the lens capsule by prevention of wedge-counteraction effect of triangular nucleus pieces in conventional chop.142 eyes of 142 patients were divided into 4 groups depending on LOCS III cataract density (CD): CD1 - 20 eyes, CD2 - 72 eyes, CD3 - 34 eyes, CD4 - 16 eyes and were operated by 6 different surgeons using conventional FLACS technique except new “DiamondCut” LFP for laser step. Mean maximum vacuum (MMV) required for lens fragments fixation, mean phaco power (MPP), mean phaco time (MPT), effective phaco time (EPT) and overall impression of surgeons were evaluated.

Postoperative clinical appearance and visual outcomes of all the patients were essentially normal for contemporary FLACS. MMV was 238±81 mmHg in group CD1, in group CD2 – 249±82 mmHg, in group CD3 – 238±78 mmHg , CD4 group – 358±16 mmHg. MPP in CD1 group was 16,8±2,44%, in CD2 – 18,2±6,55%, in CD3 – 19,44±2,71%, in CD4 – 31,27±1,24%. MPT was 20:38±0:29 in CD1, 21:02±0:12 in CD2, 21:38±0:12 in CD3 and 29:51±0:08 in CD4. Mean EPT was 03:57± 00:25sec in CD1 group, 04:48± 00:37 sec in CD2, 05:15± 01:08 sec in CD3, 09:12± 00:43 sec in CD4. There were no capsular bag ruptures in any of 142 cases. All surgeons noted simplified FLACS procedure with unusually easy lens fragmentation, smooth and fast surgery with DiamondCut LPF.

New combined lens fragmentation pattern “DiamondCut” requires mild ultrasound and vacuum with no excessive laser cuts for any cataract density and may simplify FLACS. Further comparative studies of different laser lens fragmentation patterns are required.