AlM: To investigate the effect of endocapsular phacoemulsification cataract extraction and intraocular lens (lOL) implantation with a 1. 8mm or 3. 0mm clear corneal incision on total root mean square ( RMS ) value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film.
METHODS:ln a prospective study, 156 age- related patients ( 196 eyes ) were randomly distributed into two groups. 1. 8mm-group comprised 94 eyes that had a silicone lOL inserted through a 1. 8mm sutureless clear corneal incision, while, 3. 0mm- group comprised 102 eyes through a 3. 0mm clear corneal incision. Postoperatively, the changes in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film at 1wk, 1 and 3mo were determined respectively.
RESULTS:ln both groups, postoperatively at 1wk,there were statistically significant differences ( P<0. 05 ) in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film, while, there were statistically minimal differences ( P< 0. 05 ) between 1. 8mm-group and 3. 0mm-group at 1mo, but were not statistically significantly different ( P > 0. 05 ) between two groups at 3mo postoperative.
CONCLUSlON:This study confirms that incision size has strong impact on the corneal higher-order aberrations, especially, 3. 0mm incision caused significant differences in the total RMS value of cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film compared with 1. 8mm micro-incision, therefore, micro-incision is very beneficial for clinical use in phacoemulsification.

BACKGROUNDSpinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined. This double-blind, randomized, dose-response study determined the ED50 (50% effective dose) and ED95 (95% effective dose) of spinal hyperbaric ropivacaine for cesarean section anesthesia.

METHODSSixty parturients undergoing elective cesarean section delivery with use of combined spinal-epidural anesthesia were enrolled in this study. An epidural catheter was placed at the L1 approximately L2 vertebral interspace, then lumbar puncture was performed at the L3 approximately L4 vertebral interspace, and parturients were randomized to receive spinal hyperbaric ropivacaine in doses of 10.5 mg, 12 mg, 13.5 mg, or 15 mg in equal volumes of 3 ml. Sensory levels (pinprick) were assessed every 2.5 min until a T7 level was achieved and motor changes were assessed by modified Bromage Score. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and no intraoperative epidural supplement was required. ED50 and ED95 were determined with use of a logistic regression model.

RESULTSED50 (95% confidence interval) of spinal hyperbaric ropivacaine was determined to be 10.37 (5.23 approximately 11.59) mg and ED95 (95% confidence interval) to be 15.39 (13.81approximately 23.59) mg. The maximum sensory block levels and the duration of motor block and the rate of hypotension, but not onset of anesthesia, were significantly related to the ropivacaine dose.

CONCLUSIONThe ED50 and ED95 of spinal hyperbaric ropivacaine for cesarean delivery under the conditions of this study were 10.37 mg and 15.39 mg, respectively. Ropivacaine is suitable for spinal anesthesia in cesarean delivery.

Adult ; Amides ; pharmacology ; Anesthesia, Obstetrical ; Anesthesia, Spinal ; Anesthetics, Local ; pharmacology ; Cesarean Section ; Dose-Response Relationship, Drug ; Double-Blind Method ; Female ; Humans ; Logistic Models ; Pregnancy