Factors influencing corneal biomechanical changes after microincision cataract surgery and standard coaxial phacoemulsification.
OBJECTIVE
To determine the factors affecting corneal biomechanics using biomechanical waveform analysis after microincision cataract surgery (MICS) and standard coaxial phacoemulsification with different incision sizes.


METHODS
Vissum-Instituto Oftalmologico de Alicante, Alicante, Spain.


METHODS
This prospective nonrandomized study comprised eyes with significant cataract that had MICS (sub-1.8 mm incision) or coaxial phacoemulsification (2.75 mm incision). Corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured by biomechanical waveform analysis (Ocular Response Analyzer) preoperatively, immediately postoperatively, and at 1 month. Results were analyzed and compared between groups.


RESULTS
In the MICS group (n = 30), there was a significant increase in Goldmann-correlated intraocular pressure (IOP) and corneal-compensated IOP, although CH decreased in the immediate postoperative period (P<.05). At 1 month, all parameters in the MICS group returned to normal. The coaxial group (n = 30) had an increase in Goldmann-correlated IOP and corneal-compensated IOP, both of which were higher than normal at 1 month. Backward multiple regression analysis showed significant correlations between CH and preoperative Goldmann-correlated IOP and preoperative CRF (r(2) = 0.631, P<.05); between age, axial length (AL), and preoperative CRF (r(2) = 0.418, P<.05); and between the change in CH and AL, total incision length, and preoperative CH (r(2) = 0.429, P<.05).


CONCLUSIONS
Cataract surgery with MICS and coaxial phacoemulsification significantly altered corneal biomechanics. Corneal hysteresis was inversely correlated with Goldmann-correlated IOP; CRF was inversely correlated with age and AL. The MICS technique provided more stable corneal biomechanical properties than standard coaxial phacoemulsification 1 month postoperatively.
Alió
Jorge L
JL
Vissum Corporation-Instituto Oftalmologico de Alicante, Division of Ophthalmology, Miguel Hernández University, Departamento de Optica (Piñero), Farmacologia y Anatomia, Universidad de Alicante, Spain. jlalio@vissum.com
Agdeppa
Ma Cecilia C
MC
Rodríguez-Prats
Jose Luis
JL
Amparo
Francisco
F
Piñero
David P
DP
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D003315:Cornea / Q000502:physiology*; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D018918:Phacoemulsification / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors