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@#AIM: To study the postoperative optical zone decentration and visual quality by taking visual axis corneal reflect point(VACRP)and corneal vertex(CV)as the ablation center, exploring the femtosecond laser small incision lenticule extraction(SMILE).<p>METHODS: Prospective randomized controlled trial. Totally 70 myopic patients(140 eyes)who underwent SMILE surgery in our hospital from May to June 2020 were randomly divided into two groups, 68 eyes of 34 cases took the VACRP as the ablation center(VACRP group), and 72 eyes of 36 cases took the CV as the ablation center(CV group). The visual acuity, refractive diopter, offset from corneal ablation center, and high-order corneal aberrations were observed before and 3mo after surgery. <p>RESULTS: Three months after operation, there was no difference in uncorrected visual acuity, best corrected visual acuity and refractive diopter between the two groups(<i>P</i>>0.05). The ablation center deviation in CV group(0.20±0.13mm)was less than that in VACRP group(0.27±0.14mm, <i>P</i><0.01). The total corneal high-order aberration(totHOA), spherical aberration(totZ40), vertical coma(totZ3-1)and horizontal coma(totZ31)in CV group were lower than VACRP group(<i>P</i><0.05). Three months after operation, the totHOA, total high-order aberration change(ΔtotHOA), totZ40, totZ3-1 in VACRP group were correlated with ablation center deviation(<i>r</i>=0.470, 0.486, 0.254, -0.366, <i>P</i><0.001, =0.001, 0.037, 0.002), totZ31 in CV group was correlated with the ablation center deviation(<i>r</i>=-0.352, <i>P</i>=0.002).<p>CONCLUSION: SMILE surgery can obtain satisfactory uncorrected visual acuity and the same level of refractive diopter with the VACRP and the CV as the ablation center, but taking the CV as the ablation center can reduce the postoperative decentration and high-order corneal aberrations and obtain better visual quality.
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@#AIM: To evaluate the centration of the SBL-3 multifocal intraocular lens, the size of the distant and near power zone in the pupil area and the area of the visual axis using Itrace visual function analyzer. <p>METHODS: Retrospective case study. From January 2018 to January 2019, 51 eyes of 36 patients underwent phacoemulsification cataract combined with regional refraction multifocal intraocular lens implantation at Beijing Aier-Intech Eye Hospital were enrolled. The centration, visual axis, angle α, angle Kappa and the orientation of the intraocular lens measured by Itrace were used to calculate the position of the visual axis in the intraocular lens and the changes in the proportions of the distant and near power zones in the pupil area. <p>RESULTS: The centration(R)of intraocular lens is 0.217±0.09mm. The distribution of the visual axis in the intraocular lens is 0.217±0.09mm. The visual axis is evenly distributed in the distant and near power zones. There was no statistical significance between the two groups with postoperative visual acuity ≥0.8 and <0.8(<i>P</i>>0.05). The size of the angle Kappa is 0.187±0.079mm. The displacement of angle Kappa on the y-axis is 0.10±0.06mm. There was no statistical significance between the changes in the pupil size of distant and near power zones in the pupil area caused by the deviation of the pupil and the postoperative visual acuity ≥0.8 and <0.8(<i>P</i>>0.05). <p>CONCLUSION: The intraocular lens centration and axial data measured by the Itrace visual function analyzer can be used to estimate the area where the visual axis is located and the size of the distant and near power zones in the pupil area, thereby assisting in evaluating the postoperative visual quality of the regional refraction multifocal intraocular lens implanted after cataract surgery.
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PURPOSE: To analyze the positional relationships of various centers in patients undergoing femtosecond laser-assisted cataract surgery (FLACS). METHODS: The locations of the pupil center (PC), limbal center (LC) and lens center were analyzed in each patient using optical coherence tomography during FLACS in 35 eyes of 35 patients. Using the preoperative corneal aberrometry device, angle kappa and the location of the visual axis (VA) were calculated. After acquiring the relative horizontal and vertical coordinates of each center, the distance and location among each center were compared. The relative location and distance of each center were statistically evaluated. RESULTS: The distance from the PC to the lens center was 0.147 ± 0.103 mm, that from the LC to the lens center was 0.205 ± 0.104 mm, and that from the VA to the lens center was 0.296 ± 0.198 mm. The distance from the PC to the VA was 0.283 ± 0.161 mm, that from the LC to the VA was 0.362 ± 0.153 mm, and that from the lens center to the VA was 0.296 ± 0.198 mm. Among the various centers, the PC was the closest to the lens center, whereas the LC and VA were the farthest. Based on the location of the lens center, the PC, LC, and VA exhibited differences in the X and Y coordinate positions (vertical p = 0.004, horizontal p < 0.001). Among them, the LC was significantly inferior and temporal compared to the PC (vertical p = 0.026, horizontal p = 0.023). Based on the location of the VA, the respective locations of the PC, LC and lens center in two dimensions did not significantly differ (vertical p = 0.310, horizontal p = 0.926). CONCLUSIONS: This study demonstrated the positional and locational relationships between the centers regarding FLACS. The locations of the PC, LC, and VA were different from the lens center with the PC being the closest. Surgeons should be aware of these positional relationships, especially in FLACS.
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Humans , Aberrometry , Cataract , Pupil , Surgeons , Tomography, Optical CoherenceABSTRACT
Purpose: To study the long-term safety profile and visual outcomes of primary intraocular lens (IOL) implantation in infants <6 months of age. Methods: This was a retrospective observational study conducted at a tertiary eye care center in South India. Infants under 6 months meeting the selection criteria who underwent cataract surgery (lens aspiration, primary posterior capsulorhexis, and anterior vitrectomy) with primary IOL implantation between January 2008 and December 2011 and minimum 3-year follow-up were included. Patient demographics, serial refractions, visual acuity, complications, and associated amblyopia/strabismus were reviewed. Visual acuity, myopic shift, and complications were the outcome measures. Results: Sixty-nine eyes of 38 infants (31 bilateral; mean age: 4.6 months) were reviewed. Mean follow-up was 51 months (range: 36�). Median logMAR best-corrected visual acuity at the final visit was 0.74 (interquartile range [IQR]: 0.50�98) in eyes with bilateral cataracts and 0.87 (IQR: 0.60�14) in eyes with unilateral cataracts with an average myopic shift of 6.7 diopters over 4.2 years. Most common postoperative complication was visual axis opacification (VAO) (13 eyes, 18%), necessitating membranectomy followed by pigmentary IOL deposits (11 eyes, 15%), and IOL decentration and glaucoma in four eyes each (5.6%). Mixed linear effect model found no significant association of age, gender, laterality, and postoperative complications with final visual acuity (P ? 0.05). Eyes with unilateral cataracts had a greater myopic shift than bilateral cases (P = 0.03). Conclusion: Primary IOL implantation in infants <6 months is reasonably safe in appropriately selected infants. VAO was the most common postoperative complication, and a large myopic shift was observed.
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AIM:To investigate the effect of different cutting centers on the visual acuity, refractive diopter and visual quality of patients undergoing laser assisted in situ keratomileusis (LASIK).METHODS: A total of 80 patients (160 eyes) with myopia treated by elective LASIK were divided into two groups.Thirty-six cases (72 eyes) with visual axis corneal reflection point (VACRP) as the cutting center were included into the VACRP group while 44 cases (88 eyes) with pupil center (PC) as the cutting center were included into the PC group.The uncorrected visual acuity (UCVA), the best corrected visual acuity (BCVA), refractive diopter, corneal aberration [total corneal and anterior corneal surface higher-order aberrations (HOA), spherical aberration (Z40), vertical coma (Z3-1), horizontal coma (totZ31) and offset of cutting centers were determined before surgery and 1mo after surgery.RESULTS: There was no difference in the probability of UCVA ≥ 0.1, BCVA and refractive diopter between the two groups at 1mo after surgery (P>0.05).The astigmatism and cutting center deviation of VACRP group were lower than those of PC group (P<0.05).The totHOA, totZ40, totZ3-1, totZ31, froHOA, froZ3-1、froZ31 and froZ40 were lower in VACRP group than PC group at 1mo after surgery (P<0.05).CONCLUSION: The UCVA of patients treated with both cutting centers for LASIK is good but VACRP has more advantages in reducing the offset of cutting center and improving postoperative visual quality.
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Background: Posterior capsule opacification (PCO) is the commonest complication of extracapsular catraract surgery in pediatric patients with an incidence as high as 95%. But there is inadequate evidence on appropriate intervention to prevent PCO. Aim: To compare the efficacy of plasma knife assisted posterior capsulotomy versus manual primary posterior capsulorhexis in Pediatric Cataract surgery. Materials and methods: The current study was a randomized open labeled controlled study, conducted in the department of ophthalmology, All India Institute of Medical Sciences, New Delhi between July 2015 to June 2016. The study population included 32 children in each of < 2 years age, suffering from bilateral cataract and each eye was randomized to different intervention groups consisting of manual posterior capsulorhexis or and posterior capsulotomy using plasma knife. Anterior vitrectomy was performed in all the eyes. Visual acuity, axial length, Intra ocular pressure, and refraction etc. were measured using appropriate methods. The retro-illuminated clinical photograph was taken using NEW CARL ZEISS f340 CANON camera and was analyzed by EPCO software. Prakash S, Giridhar, Harshila Jain. Efficacy of plasma knife assisted posterior capsulotomy versus manual primary posterior capsulorhexis in preventing visual axis opacification in pediatric cataract surgery: A randomized controlled trial. IAIM, 2017; 4(9): 171-177. Page 172 Results: There was no statistically significant difference in any of the ocular parameters at baseline and at 6 months following surgery. The log MAR visual acuity was significantly higher in intervention 1 (0.465±0.143) as compare to intervention 2 (0.397 ± 0.108) at 1 year, which was statistically significant (P value 0.036). There were no statistically significant differences in the proportion of Visual Axis Opacification (VAO) between the intervention groups. Conclusion: Visual axis opacification after pediatric cataract surgery remains comparable in both techniques at one year (plasma knife assisted posterior capsulotomy and manual capsulorhexis). Hence it can be concluded that plasma knife assisted posterior capsulotomy does not have any added advantage over manual posterior capsulorhexis in preventing visual axis opacification.
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Purpose: To study the outcome of in-the-bag implanted square-edge polymethyl methacrylate (PMMA) intraocular lenses (IOL) with and without primary posterior capsulotomy in pediatric traumatic cataract. Materials and Methods: The study was undertaken in a tertiary care center. Thirty eyes of 30 children ranging in age from 4 to 16 years with traumatic cataract which underwent cataract extraction with capsular bag implantation of IOL were prospectively evaluated. Group A included 15 eyes of 15 children where primary posterior capsulotomy (PPC) and anterior vitrectomy with capsular bag implantation of square-edge PMMA IOL (Aurolab SQ3602, Madurai, Tamil Nadu, India) was performed. Group B comprised 15 eyes of 15 children in which the posterior capsule was left intact. Postoperative visual acuity, visual axis opacification (VAO) and possible complications were analyzed. Results: Best corrected visual acuity (BCVA) of 20/40 or better was achieved in 12 of 15 eyes in both groups. Amblyopia was the cause of no improvement in visual acuity in the remaining eyes. Visual axis opacification was significantly high in Group B as compared to Group A (P=0.001). Postoperative fibrinous uveitis occurred in most of the eyes in both groups. Pupillary capture was observed in one eye in each group. Conclusion: Primary posterior capsulotomy and anterior vitrectomy with capsular bag implantation of square-edge PMMA significantly helps to maintain a clear visual axis in children with traumatic cataract.