2.Effect of laser in situ keratomileusis on accommodation.
Lei, LIU ; Jing, YUAN ; Jing, LI ; Xinyu, LI ; Yulong, WANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2008;28(5):596-8
The accommodative function before and after laser in situ keratomileusis (LASIK) was observed, and the effect of LASIk on accommodation was investigated. In a prospective clinical trial, 48 myopic patients (96 eyes) subject to bilateral LASIK in Refractive Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (China) from March 2006 to June 2006 were selected and studied. Refractions, accommodative range, amplitude of accommodative response and high frequency component (HFC) of accommodative microfluctuations were measured with NEDIK-730A before and one week and 30 days after operation. Dominant and non-dominant eyes were determined by hole-in-card method. It was found that all of the operative eyes showed an uncorrected visual acuity of 0.8 or better one week postoperatively, and 1.0 or better 30 days postoperatively. Compared with those preoperatively, accommodative range and HFC had no significant difference at first week and 30th day after operation in both dominant eyes and non-dominant eyes (P>0.05), but there was a significant difference in the amplitude of accommodative response/accommodative stimulus ratio (A/S) after operation (P<0.01), and no significant difference was found in accommodation between one week and 30 days postoperation. No ocular dominance's change was noted. There was no significant difference in accommodative function between dominant eyes and non-dominant eyes. It was suggested that LASIK produced no significant effect on accommodation.
Accommodation, Ocular/*physiology
;
Keratomileusis, Laser In Situ/*adverse effects
;
Myopia/*physiopathology
;
Myopia/*surgery
;
Postoperative Period
;
Prospective Studies
;
Young Adult
3.Intervention of laser periphery iridectomy to posterior iris bowing in high myopic eyes.
Hong-tao WANG ; Ning-li WANG ; Shu-ning LI
Chinese Medical Journal 2012;125(24):4466-4469
BACKGROUNDFor some high myopic patients with posterior iris bowing, laser periphery iridectomy should be performed pre-operation to prevent pupil block glaucoma if these patients would have phakic intraocular lens implantation to correct high myopia. So we had the opportunity to analysis the influence of laser iridectomy on posterior iris bowing.
METHODSEighteen high myopic patients with posterior iris bowing (11 males and 7 females) were involved in the study in Beijing Tongren Eye Center from March 2008 to July 2008. Phakic intraocular lens were implanted to correct their ametropia. The mean age was (32 ± 6) years (range, 25 - 40 years). The center anterior chamber depth, the pupil diameter, the posterior iris bowing depth and the anterior chamber angle were measured with anterior segment coherence tomography (AS-OCT) under the normal condition, myosis condition induced by 2% pilocarpine, laser periphery iridectomy after myosis, and 2% pilocarpine eluting condition respectively.
RESULTSThere was no significant difference of center anterior chamber depth under the four conditions (P = 0.512). The pupil constricted after pilocarpine (P = 0.001). After laser iridectomy performed and pilocarpine eluted, posterior iris bowing depth reduced more than that in normal condition (P = 0.003). The anterior chamber angle reduced significantly after laser periphery iridectomy and pilocarpine eluted (P = 0.012).
CONCLUSIONLaser periphery iridectomy can reduce the posterior iris bowing, which might be due to the change in aqueous circulate pathway.
Adult ; Female ; Humans ; Iridectomy ; methods ; Iris Diseases ; surgery ; Male ; Myopia ; surgery
4.Changes of angle Kappa and corneal morphology changes in myopic patients after Sub
Yi DING ; Zhipei ZHANG ; Xiaoshan MIN ; Xiaobo XIA ; Shengfa HU
Journal of Central South University(Medical Sciences) 2021;46(2):162-168
OBJECTIVES:
To investigate angle Kappa and diopter distribution in myopic patients and the changes of angle Kappa and corneal morphology after Sub-Bowman-Keratomileusis (SBK), and to analyze the effects of the surgery on corneal morphologic changes and the patients' near fixation characteristics.
METHODS:
The clinical data of 134 myopic patients (268 eyes) undergoing SBK from August 2015 to August 2016 were retrospectively analyzed. Angle Kappa, corneal curvature in the central corneal region of 3 mm, and post-corneal Diff value were measured by Orbscan IIz Corneal Topography System before operation, 1 month and 6 months after operation. According to the values of angle Kappa before SBK, the patients were divided into 2 groups: the large K group (angle Kappa≥5°, 71 eyes) and the small K group (angle Kappa<5°, 197 eyes). Correlation analysis of the factors influencing angle Kappa at 6 months after operation was performed.
RESULTS:
In the large K group, angle Kappa was (5.67±0.65)°, spherical equivalent was (-4.84±2.32) D, and angle Kappa was decreased after operation (both
CONCLUSIONS
The angle Kappa is decreased in low-moderate myopia patients with large angle Kappa, while is increased in high myopia patients with small angle Kappa after SBK. Myopia patients after SBK will look for the new balance of the binocular accommodation and vergence function for improving the comfort in the near-work situations.
Cornea/surgery*
;
Humans
;
Keratomileusis, Laser In Situ
;
Myopia/surgery*
;
Refraction, Ocular
;
Retrospective Studies
5.The Efficacy of Multi-Zone Cross-Cylinder Method for Astigmatism Correction.
Seong Joo SHIN ; Hae Young LEE
Korean Journal of Ophthalmology 2004;18(1):29-34
The purpose of this study is to assess the efficacy of the multi-zone cross-cylinder method as compared with the single method for astigmatism correction using LASIK. This prospective study enrolled 40 patients (52 eyes) who underwent the cross-cylinder method using LASIK, and 52 patients (60 eyes) who underwent the single method using LASIK: all patients were given a diagnosis of complex myopic astigmatism from the department of ophthalmology of this hospital between January 2002 and July 2003. Preoperatively, the mean spherical equivalent refraction was .3.85 +/- 1.13 D in the cross-cylinder group and .4.05 +/-1.20 D in the single method group (p = 0.23). The mean cylinder was .2.05 +/-1.58 D in the cross-cylinder group and .1.95 +/-1.12 D in the single method group (p = 0.31). 6 months after treatment the results were a mean spherical equivalent refraction of .0.26 +/-0.30 D in the crosscylinder group and -0.34 +/-0.35 D in the single method group (p = 0.13). The mean cylinder was .0.38 +/-0.29 D in the cross-cylinder group and .0.45 +/-0.30 D in the single method group (p = 0.096). There were no statistically significant differences between the two groups. The mean BCVA was not different from mean preoperative BCVA in both groups (i.e., 0.98 +/-0.10, 0.96 +/-0.25, p = 0.86). Postoperatively, patient complications that included night halo, glare and corneal haze were not noted in either group. In conclusion, the results of cross-cylinder method are no different from the single method for the correction of a complex astigmatism. In the future, studies will have to be conducted to assess the efficacy of the cross-cylinder method in consideration of those factors that can affect the postoperative outcome.
Adult
;
Astigmatism/*surgery
;
Corneal Stroma/surgery
;
Humans
;
Keratomileusis, Laser In Situ/*methods
;
Myopia/*surgery
;
Postoperative Complications
;
Prospective Studies
6.A Case of Surgical Repair in Strabismus Fixus with Ptosis.
Korean Journal of Ophthalmology 2004;18(2):180-184
Strabismus fixus is very rare and the convergent form is rarely accompanied by blepharoptosis. We successfully treated one patient with high myopia whose convergent strabismus fixus, accompanied by blepharoptosis, became severe after cataract surgery. We report the case with a discussion of its pathology. We performed levator advancement operation, bilateral lateral rectus 11 mm resection, and bilateral medial rectus 8 mm recession. The suture was removed after maintaining temporary traction suture for 6 days. Blepharoptosis was completely corrected by postoperative 2 months. Esodeviation was 15PD, which was not increased compared with immediately after surgery. Satisfactory cosmetic outcome was obtained.
Aged
;
Blepharoptosis/complications/*surgery
;
Female
;
Humans
;
Myopia/complications
;
Oculomotor Muscles/*surgery
;
Ophthalmologic Surgical Procedures/methods
;
Strabismus/complications/*surgery
;
Treatment Outcome
7.Static and dynamic contrast sensitivity of myopic eyes before and after laser in situ keratomileusis.
Xiao-wei LIU ; Guo-xiang PANG ; Xi-pu LIU ; Ru-xin JIANG ; Yu-mei JIN ; Yu-min SUN ; Zhong-hai WANG
Acta Academiae Medicinae Sinicae 2003;25(5):585-589
OBJECTIVETo evaluate the static and dynamic contrast sensitivity changes in myopic patients before and after laser in situ keratomileusis (LASIK).
METHODSSeventy-three eyes in 37 patients with myopia (with or without astigmatism) who received LASIK were tested for static and dynamic contrast sensitivities using the METRO VISION MON ELEC I system at 0.7, 1.4, 2.7, 5.5, 11, and 22 cpd and cps prior to LASIK, and at one-, three-, and six-month intervals after LASIK.
RESULTSAll eyes gained naked visual acuity of more than 0.5 after LASIK. The contrast sensitivity was depressed at all frequencies 1 month after LASIK, as compared to one week prior to LASIK. The depression at 2.7, 5.5, 11 (P < 0.01) and 22 cpd (P < 0.05) was statistically significant for static contrast sensitivity, and also at 5.5 (P < 0.01) and 11 cps (P < 0.05) for dynamic contrast sensitivity. Myopic eyes between 6.25 D and 14.0 D, and astigmatic eyes 2 DC and more, suffered more static and dynamic contrast sensitivity depression than the myopic eyes between 1.25 D and 6.00 D and astigmatic eyes less than 2 DC. Contrast sensitivities were improved and exceeded preoperative levels 3 months after LASIK, and improved even more 6 months after LASIK. All sequences were statistically significant for static contrast sensitivity (P < 0.01), while only 2.7, 5.5, and 11 cps were statistically significant for dynamic contrast sensitivity (P < 0.01). The astigmatic eyes 2 DC and more showed less improvement, even below the preoperative level at 1.4 cps of dynamic contrast sensitivity.
CONCLUSIONSWhile temporary depression of contrast sensitivity for myopic eyes after LASIK was seen, contrast sensitivity soon returned to exceed preoperative levels at 3 months after LASIK, while improving even more 6 months after LASIK.
Adolescent ; Adult ; Astigmatism ; surgery ; Contrast Sensitivity ; Cornea ; surgery ; Female ; Humans ; Keratomileusis, Laser In Situ ; Male ; Myopia ; physiopathology ; surgery ; Visual Acuity
8.The mechanism and application of the correction for spherical myopia using small beam excimer laser.
Yunhai ZHANG ; Jianxin SHEN ; Wenhe LIAO ; Bin SUN
Journal of Biomedical Engineering 2005;22(2):355-359
In the laser ablation refractive surgeries, the corneal ablation model and its realization by laser are difficult to design. They greatly affect the results of those surgeries. This paper firstly presents a mathematical model for corneal ablation to correct the refractive error of spherical myopia, and then gives a technique of planning laser focus positions on cornea to realize the ablation model. Based on the principle of the correction for spherical myopia using small beam laser, our excimer laser corneal surgery system has been able to perform such refractive surgery. Now the corneal surgery system has been applied to clinical practice. Thirty-nine eyes with spherical myopia underwent LASIK using this kind of system. Their refractive states have been greatly improved. Preoperatively, the mean sphere was -5.57+/-2.95 D and the mean uncorrected visual acuity 0.12+/-0.07. One day after surgery, the mean sphere was -0.03+/-0.57 D and the mean uncorrected visual acuity 0.90+/-0.29. One month after surgery, the mean sphere was -0.68+/-0.98 D, and the mean uncorrected visual acuity 1.0+/-0.26.
Humans
;
Lasers, Excimer
;
Models, Biological
;
Myopia
;
surgery
;
Photorefractive Keratectomy
;
methods
;
Treatment Outcome
;
Visual Acuity
9.Clinical evaluation of laser in situ keratomileusis operation with three different ablative patterns.
Ling-na MAO ; Wen-jun JIANG ; Ya-bo YANG
Journal of Zhejiang University. Medical sciences 2011;40(1):78-84
OBJECTIVETo evaluate the clinical outcome among three different laser in situ keratomileusis (LASIK) ablations: Q-factor customized ablation (aberration smart ablation, ASA), wave-front guided ablation (WASCA) and ablation under wave-front guiding plus iris recognition system (IR+WASCA).
METHODSThis prospective study comprised 96 eyes of 96 patients, and they were randomly divided into three groups: 30 patients in ASA group, 32 in WASCA group, and 34 in IR+WASCA group. There were no any statistical differences in spherical equivalent (SE), age, sex, pupil diameter, higher-order aberrations (HOA) among three groups preoperatively. Wave-front analysis was performed before and 1, 3 months after operation.
RESULTAll patients got an uncorrected visual acuity (UCVA) ≥ 0.8 1 and 3 months after operation. The residual SE was in ± 0.50D both at 1 and 3 months after surgery. There was no statistical difference in SE value, HOA, change of HOA, and coma aberration postoperatively among three groups. Horizontal coma (Z3¹) aberration took the majority of coma. HOA, total coma aberrations and spherical aberration increased postoperatively (P = 0.000), but without significant difference between 1 month and 3 months after surgery.
CONCLUSIONThat three customized LASIK are all effective, safe, accurate and stable; meanwhile WASCA may have better UCVA than the other two groups postoperatively.
Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ ; methods ; Myopia ; surgery ; Prospective Studies ; Treatment Outcome
10.Corneal refractive surgery and phakic intraocular lens for treatment of amblyopia caused by high myopia or anisometropia in children.
Chunyu TIAN ; Xiujun PENG ; Zhengjun FAN ; Zhengqin YIN
Chinese Medical Journal 2014;127(11):2167-2172
OBJECTIVEA systematic review of literature was performed to compare various visual function parameters including the final visual acuity outcome and/or adverse events between corneal refractive surgery (CLRS) and phakic intraocular lens implantation (p-IOLi) in the treatment of refractive amblyopic children.
DATA SOURCESTwo reviewers independently searched the PubMed, EMBASE, and Controlled Trials Register databases for publications from 1991 to 2013.
STUDY SELECTIONThere were 25 articles, including 597 patients and 682 eyes, was included in CLRS group. Among them, 21 articles reported the use of CLRS in the treatment of myopic anisometropia for 318 patients (13 photorefractive keratectomy or laser epithelial keratomileusis and eight laser in situ keratomileusis). And 11 articles had the results of CLRS in treating hyperopic anisometropic amblyopia children. Eleven articles reported the effect of p-IOLi for treating high myopia or anisometropic amblyopia, including 61 patients (75 eyes). Age, pre- and postoperation best-corrected vision acuity (BCVA), and spherical equivalent (SE) were compared in CLRS and p-IOLi groups.
RESULTSThe average age of CLRS group and p-IOLi group has no statistically significant difference. The SE in CLRS group for myopic anisometropia amblyopia patients was (-10.13 ± 2.73) diopters (D) and for hyperopic anisometropia amblyopia patients was (5.58 ± 1.28) D. In p-IOLi group the SE was (-14.01 ± 1.93) D. BCVA was improved significantly in both groups, and even better in p-IOLi group. Refractive errors were corrected in both groups, but there was no clinically significant difference in final SE between each group. More than one-half of the children had improved binocular fusion and stereopsis function in both groups.
CONCLUSIONSBoth CLRS group and p-IOLi group showed their advantage in treating refractive amblyopia in children. In comparing p-IOLi with CLRS for treatment of refractive amblyopia, no statistically significant difference in final BCVA was observed.
Amblyopia ; etiology ; surgery ; therapy ; Anisometropia ; complications ; Child ; Child, Preschool ; Humans ; Myopia ; complications