AIM: To define the corneal hysteresis(CH), corneal resistance factor(CRF), Goldmann-correlated intraocular pressure(IOPg) and corneal compensated intraocular pressure(IOPcc) prior to and following coaxial micro-incisi...AIM: To define the corneal hysteresis(CH), corneal resistance factor(CRF), Goldmann-correlated intraocular pressure(IOPg) and corneal compensated intraocular pressure(IOPcc) prior to and following coaxial micro-incision phacoemulsification in patients with corneal astigmatism. METHODS: Of 97 patients with cataracts were enrolled in the study. Group 1 included patients with corneal astigmatism(K1-K2) values of K1-K2<+1.0 D, and group 2 with values of K1-K2 ≥+1.0 D and ≤+2.25 D. Coaxial micro-incision phacoemulsification of a corneal incision of 2.0 mm with intraocular lens(IOL) implantation was performed. CH, CRF, IOPg, IOPcc, waveform score(WS) were measured preoperatively and one week, one month postoperatively using an Ocular Response Analyzer. Axial length(AXL) was calculated by Tomey Optical Biometer OA 2000.RESULTS: Group 1 consisted of 51 patients with mean corneal astigmatism value of +0.49±0.25 D. Group 2 included 46 patients with astigmatism of +1.43±0.43 D. In group 1, CRF(t=2.68, P<0.05), CH(t=2.64, P<0.05) and WS(t=3.51, P<0.05) were significantly lower one week postoperatively, when compared to the preoperative values. CRF significantly decreased(t=3.61, P<0.05) when measured one month following the surgery. In group 2 CH(t=5.92, P<0.05), and WS(t=3.96, P<0.05) were significantly lowered one week after cataract surgery. Moreover, we observed a significant decrease in IOPg(t=2.24, P<0.05), CRF(t=5.05, P<0.05) and CH(t=2.31, P<0.05) one month after phacoemulsification. There was no statistically significant(t=-0.83, P=0.41) difference in AXL between study groups.CONCLUSION: CRF, CH and IOPg are reduced in patients with preoperative corneal astigmatism equal or higher than +1.0 D and lower than +2.25 D. Hence, bias of IOPg measurement in these patients may cause underestimation of the real IOP both before and after cataract surgery. The measurement of IOPcc allows the precise assessment of IOP pre-and postoperatively, independently on corneal astigmatism, CH and CRF values.展开更多
Purpose: To investigate the correlation of various corneal hysteresis(CH) factors in Chinese adults.Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the ...Purpose: To investigate the correlation of various corneal hysteresis(CH) factors in Chinese adults.Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure(IOPG) and CH were measured using an ocular response analyzer(ORA).Central corneal thickness was measured using the ORA's integrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values.The Pearson correlation coefficient was used to test correlations between CH and quantitative factors. The chi-square test was used to detect differences in categorical values.Results: Longer axial length(P =0.0001), lower IOPG(P =0.03), older age(P=0.003),and thinner central corneal thickness(P=0.0001) were significantly associated with lower CH.The anterior chamber depth(P=0.34), gender(P =0.23), and corneal curvature(P=0.18) had no relationship to CH.Conclusion: Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measurement of corneal biomechanical properties in Chinese adults.But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.展开更多
Background:To evaluate,using a rabbit model,the influence of the wound healing process at the flap edge on corneal biomechanics after sutured,glued,and non-augmented microkeratome flaps.Methods:Unilateral 160μm thick...Background:To evaluate,using a rabbit model,the influence of the wound healing process at the flap edge on corneal biomechanics after sutured,glued,and non-augmented microkeratome flaps.Methods:Unilateral 160μm thick laser in situ keratomileusis(LASIK)flaps using a mechanical microkeratome were performed on the corneas of the left eyes of 36 rabbits.Animals were then divided into 3 groups of 12 rabbits each:A:the flaps were glued with human fibrin tissue adhesive(Tisseel);B:the flaps were sutured;and C:the flaps were allowed to heal without the use of sutures or glue(non-augmented).The contralateral eyes served as controls.Reichert ocular response analyzer(ORA)was used to measure corneal hysteresis(CH),corneal resistance factor(CRF),Goldmann-correlated intraocular pressure(IOPg)and cornea-compensated IOP(IOPcc)at 6 weeks and 3 months postoperatively.In vivo confocal microscopy(IVCM)was also used to study the corneal wound healing process in all groups.Results:Both mean CH and mean CRF were significantly higher in sutured and glued groups compared with the non-augmented group at 6 weeks and 3 months postoperatively(P<0.0001).No statistically significant difference in corneal biomechanics was found between controls and groups A and B at any time points.Activated keratocytes were detected at the wound edge and peripheral flap interface in sutured and glued groups.Conclusion:The healing process at the wound edge is critical for optimal corneal integrity.Fibrin glue may serve as a safe and effective substitute to sutures in enhancing the corneal flap edge healing response and in increasing its mechanical strength.展开更多
文摘AIM: To define the corneal hysteresis(CH), corneal resistance factor(CRF), Goldmann-correlated intraocular pressure(IOPg) and corneal compensated intraocular pressure(IOPcc) prior to and following coaxial micro-incision phacoemulsification in patients with corneal astigmatism. METHODS: Of 97 patients with cataracts were enrolled in the study. Group 1 included patients with corneal astigmatism(K1-K2) values of K1-K2<+1.0 D, and group 2 with values of K1-K2 ≥+1.0 D and ≤+2.25 D. Coaxial micro-incision phacoemulsification of a corneal incision of 2.0 mm with intraocular lens(IOL) implantation was performed. CH, CRF, IOPg, IOPcc, waveform score(WS) were measured preoperatively and one week, one month postoperatively using an Ocular Response Analyzer. Axial length(AXL) was calculated by Tomey Optical Biometer OA 2000.RESULTS: Group 1 consisted of 51 patients with mean corneal astigmatism value of +0.49±0.25 D. Group 2 included 46 patients with astigmatism of +1.43±0.43 D. In group 1, CRF(t=2.68, P<0.05), CH(t=2.64, P<0.05) and WS(t=3.51, P<0.05) were significantly lower one week postoperatively, when compared to the preoperative values. CRF significantly decreased(t=3.61, P<0.05) when measured one month following the surgery. In group 2 CH(t=5.92, P<0.05), and WS(t=3.96, P<0.05) were significantly lowered one week after cataract surgery. Moreover, we observed a significant decrease in IOPg(t=2.24, P<0.05), CRF(t=5.05, P<0.05) and CH(t=2.31, P<0.05) one month after phacoemulsification. There was no statistically significant(t=-0.83, P=0.41) difference in AXL between study groups.CONCLUSION: CRF, CH and IOPg are reduced in patients with preoperative corneal astigmatism equal or higher than +1.0 D and lower than +2.25 D. Hence, bias of IOPg measurement in these patients may cause underestimation of the real IOP both before and after cataract surgery. The measurement of IOPcc allows the precise assessment of IOP pre-and postoperatively, independently on corneal astigmatism, CH and CRF values.
基金supported by grants of Far Eastern Memorial Hospital (FEMH-99-HHC-002), Taiwan, China
文摘Purpose: To investigate the correlation of various corneal hysteresis(CH) factors in Chinese adults.Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure(IOPG) and CH were measured using an ocular response analyzer(ORA).Central corneal thickness was measured using the ORA's integrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values.The Pearson correlation coefficient was used to test correlations between CH and quantitative factors. The chi-square test was used to detect differences in categorical values.Results: Longer axial length(P =0.0001), lower IOPG(P =0.03), older age(P=0.003),and thinner central corneal thickness(P=0.0001) were significantly associated with lower CH.The anterior chamber depth(P=0.34), gender(P =0.23), and corneal curvature(P=0.18) had no relationship to CH.Conclusion: Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measurement of corneal biomechanical properties in Chinese adults.But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.
文摘Background:To evaluate,using a rabbit model,the influence of the wound healing process at the flap edge on corneal biomechanics after sutured,glued,and non-augmented microkeratome flaps.Methods:Unilateral 160μm thick laser in situ keratomileusis(LASIK)flaps using a mechanical microkeratome were performed on the corneas of the left eyes of 36 rabbits.Animals were then divided into 3 groups of 12 rabbits each:A:the flaps were glued with human fibrin tissue adhesive(Tisseel);B:the flaps were sutured;and C:the flaps were allowed to heal without the use of sutures or glue(non-augmented).The contralateral eyes served as controls.Reichert ocular response analyzer(ORA)was used to measure corneal hysteresis(CH),corneal resistance factor(CRF),Goldmann-correlated intraocular pressure(IOPg)and cornea-compensated IOP(IOPcc)at 6 weeks and 3 months postoperatively.In vivo confocal microscopy(IVCM)was also used to study the corneal wound healing process in all groups.Results:Both mean CH and mean CRF were significantly higher in sutured and glued groups compared with the non-augmented group at 6 weeks and 3 months postoperatively(P<0.0001).No statistically significant difference in corneal biomechanics was found between controls and groups A and B at any time points.Activated keratocytes were detected at the wound edge and peripheral flap interface in sutured and glued groups.Conclusion:The healing process at the wound edge is critical for optimal corneal integrity.Fibrin glue may serve as a safe and effective substitute to sutures in enhancing the corneal flap edge healing response and in increasing its mechanical strength.
