target refraction
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2021 ◽  
Vol 18 (3) ◽  
pp. 415-421
Author(s):  
A. A. Kasyanov

In a number of complex refractive cases, the achievement of an accurate refractive result cannot be guaranteed. Simultaneous implantation of a toric or multifocal IOL for the correction of complex ametropias may be accompanied by a significant deviation from the target refraction. The tactics of two-stage implantation with the usage of an additional Sulcoflex IOL for the final correction of astigmatism and possible residual spherical ametropia allows achieving emmetropia. In our study, this method was used in 15 patients with difficult refractive cases. Toric, multifocal, and multifocal toric Sulcoflex IOL were used. Implantation of all Sulcoflex modifications was performed through a 2.4 mm temporal incision using wound assisted technology. In cases of high degree hypermetropia, preventive iridectomy was performed using a 23G vitrectome. The target refraction was achieved in the entire observation group. In the postoperative period, no significant level of ophthalmic hypertension was registered. No cases of introlens opacification, iridocyclitis, or rotational instability were registered either.The method of two-stage IOL implantation allows achieving the target refraction in difficult refractive situations with almost guaranteed accuracy. The calculation method provides good predictability of the refractive result. This technology significantly expands the indications for intraocular correction using toric and multifocal IOL, as well as the limits of correction of high degree astigmatism. Our Sulcoflex IOL implantation experience has shown their high efficiency and safety.


2021 ◽  
Vol 62 (9) ◽  
pp. 1172-1180
Author(s):  
Sun Young Lee ◽  
Yang Kyung Cho

Purpose: To compare the stability of intraocular lens (IOL) insertion methods of sutured haptics in the bag with scleral fixation to those of in the bag insertion and scleral sulcus fixation. Methods: In group of only phacodonesis, two IOL insertion methods, in the bag insertion and sutured haptics in the bag with scleral fixation were compared. In group of phacodonesis with less than 90° zonulysis, two IOL insertion methods, sutured haptics in the bag with scleral fixation and scleral sulcus fixation were compared. Postoperative 2 months and 12 months refraction were compared with target refraction and the refractive change between postoperative 2 and 12 months were compared in each group. The change of anterior chamber depth (ACD) at postoperative 2 and 12 months were compared with preoperative ACD, and the change of ACD between postoperative 2 and 12 months were compared in each group. Results: In group of only phacodonesis, the typical in the bag insertion group showed significant ACD change between postoperative 2 and 12 months (p = 0.010), but the group of sutured haptics in the bag with scleral fixation didn’t show the significant ACD change (p = 0.515). In group of phacodonesis with less than 90° zonulysis, the sulcus scleral fixation method showed significant ACD change and significant refractive change (p = 0.015, p = 0.004), but the group of sutured haptics in the bag with scleral fixation method didn’t show the significant ACD nor refractive change (p = 0.713, p = 0.106) between postoperative 2 and 12 months. Conclusions: In eyes with zonular instability, sutured haptics in the bag with scleral fixation method can promote the postoperative stability of IOL.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Da Young Shin ◽  
Ho Sik Hwang ◽  
Hyun Seung Kim ◽  
Man Soo Kim ◽  
Eun Chul Kim

Abstract Background The aim of this study is to analyze and compare the clinical results of toric intraocular lens (IOL) and monofocal IOL implantation when the target refraction value is -3 diopter (D) in cataract patients with corneal astigmatism > 1.5 diopters (D). Methods We performed a retrospective chart review for patients with corneal astigmatism > 1.5D who underwent cataract surgery and their target refraction is -3D. 100 eyes (100 patients; monofocal IOL, 60; toric IOL, 40) were enrolled in the current study. Near and distant uncorrected visual acuity (UCVA), corrected VA, spherical equivalent and refractive, corneal astigmatism were evaluated before and after surgery. Results The near UCVA of the toric IOL group (0.26 ± 0.33) after cataract surgery was significantly better than that of the monofocal IOL group (0.48 ± 0.32) (p = 0.030). The distant UCVA of the toric IOL group (0.38 ± 0.14) was also significantly better than that of the monofocal IOL group (0.55 ± 0.22) (p = 0.026). Best-corrected visual acuity (p = 0.710) and mean spherical equivalent (p = 0.465) did not show significant differences between the toric IOL group and the monofocal IOL group. In the toric IOL group, postoperative refractive astigmatism was − 0.80 ± 0.46D and postoperative corneal astigmatism was − 1.50 ± 0.62D, whereas the corresponding values in the monofocal IOL group were − 1.65 ± 0.77D and − 1.45 ± 0.64D; residual refractive astigmatism was significantly lower with toric IOL implantation compared with monofocal IOL implantation (p = 0.001). There were no postoperative complications. Conclusions When myopic refraction such as -3D was determined as the target power in patients with corneal astigmatism, toric IOL implantation led to excellent improvement in both near and distant UCVA.


2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Gianluca Besozzi ◽  
Chiara Posarelli ◽  
Maria Carmela Costa ◽  
Alessio Montericcio ◽  
Giuseppe Nitti ◽  
...  

Purpose. To assess the visual and refractive outcome of immediate intraoperative vitrectomy and intrascleral intraocular lens implantation using a “standardized” sutureless Yamane technique during cataract luxation in the vitreous chamber as a complication of phacoemulsification. Design. A prospective, interventional, consecutive case series. Materials and Methods. Twelve patients underwent vitrectomy and intrascleral intraocular lens fixation using a standardized Yamane technique as the primary procedure during complicated phacoemulsification. Patients were evaluated preoperatively and 6 months postoperatively for best-corrected distance visual acuity, correspondence to the preoperative refractive target in the spherical equivalent, endothelial cell count, and complications. Results. Mean preoperative best-corrected visual acuity was 1.16 ± 0.3 logarithm of the minimum angle of resolution (logMAR), the endothelial cell count was 1910.5 ± 297.64, and target refraction at baseline was −0.197 ± 0.087. Postoperatively, best-corrected visual acuity was significantly improved; the mean value was 0.05 logMAR ± 0.06. Mean baseline target refraction in the spherical equivalent was −0.20 ± −0.09 (range: −0.08 to −0.37), and mean final refraction was −0.44 ± −0.14 (range: −0.25 to −0.75) with no significant difference p = 0.87 . No complication was registered intra- and postoperatively. Conclusion. Standardization of the Yamane technique seemed a valuable option for patients who had complicated phacoemulsification to achieve a predictable refractive outcome. Synopsis. The predictable refractive outcome could be achieved with the immediate standardized Yamane technique in patients with intraoperative cataract luxation in the vitreous chamber during phacoemulsification.


2020 ◽  
Vol 17 (4) ◽  
pp. 739-745
Author(s):  
E. I. Belikova ◽  
T. V. Perova

The combination of such refractive errors as high and medium astigmatism with anisometropia and presbyopia considerably reduces patients’ standard of living, first of all because methods of the correction stated are very limited. Spectacle correction is, as a rule, extremely uncomfortable or impossible in case of an anisometropia of more than 2.0 dioptres and a high degree of astigmatism; opportunities of contact lenses correction are limited in case of an astigmatism of more than 2.5 dioptres. Therefore these patients are often deprived of adequate visual rehabilitation and prefer not to use means of optical vision correction at all which considerably lowers their quality of life and can be the reason of asthenopia, violation of binocular vision and decrease in fusional reserves. This problem is aggravated with the development of a presbyopia when patients get older. The first manifestations of it reveal themselves in such patients earlier than in emmetrops, their age-mates. Excimer laser technology development has made it possible to help a large number of patients with the most severe refractive disorders, but these techniques still have significant limitations in patients with presbyopia, especially in case of a patient’s strong need for keen eyesight at a close distance. In addition, these patients require a particularly careful examination and preliminary modeling of target refraction at the planning stage of a surgical intervention, for which we use soft contact lenses in our practice. Target refraction modeling with spectacle lenses does not always allow to adequately predict the patient satisfaction with the results of correction. We consider the method of target refraction modeling using soft contact lenses to be the most accurate for this objective; it is widely used in our clinic. This technique is especially effective in patients with presbyopia, who are planning excimer laser correction of the most common types of refractive errors. The article presents a clinical case of binocular excimer laser correction of a high and medium degree compound myopic astigmatism in a patient with anisometropia and presbyopia, which was performed in two stages using LASIK (Custom Q) technology after the preliminary target refraction modeling with the use of soft contact lenses.


2020 ◽  
Vol 13 (4) ◽  
pp. 15-20
Author(s):  
Dmitrii Fedorovich Belov ◽  
Vadim Petrovich Nikolaenko

Aim to compare intraocular lens (IOL) power calculation before and after different types glaucoma procedures. Material and methods.Into the study, 115 patients were included, divided into 3 groups: group 1 patients, in whom sinustrabeculectomy was performed (n= 86); group 2 patients with implanted Ex-PRESS shunt (n= 19), group 3 patients after Ahmed glaucoma valve implantation (n= 10). For each patient before surgery optical biometry (IOL-Master 500) was performed and IOL power calculation using Barrett Universal II Formula (target refraction emmetropia). Baseline data were compared with corresponding examinations results obtained in 6 months after glaucoma procedure, to evaluate its effect on main biometric parameters of the eye and the IOL calculation accuracy. Results.Despite significant changes of optical and anatomic indices, mean values of target refraction before and after glaucoma surgery did not differ significantly: 0.00 0.03 versus 0.03 0.52 D (p= 0.628), 0.00 0.1 versus 0.19 0.61 D (p= 0.173), 0.04 0.08 versus 0.11 0.42 D (p= 0.269) for groups, respectively. However, there was a pronounced trend to the increase of target refraction data scattering. Conclusion.Glaucoma procedures cause changes of biometrical parameters of the eye, which leads to decrease in accuracy of IOL calculation. Consequently, when choosing intraocular lens, it is recommended to use measurement results obtained after glaucoma surgery. Keywords:intraocular lens; IOL power calculation; glaucoma; sinustrabeculectomy; Ex-PRESS shunt; Ahmed glaucoma valve; biometry; phacoemulsification; axial length; anterior chamber depth; keratometry.


2020 ◽  
Author(s):  
Da young Shin ◽  
Ho Sik Hwang ◽  
Hyun Seung Kim ◽  
Man Soo Kim ◽  
Eun Chul Kim

Abstract Background: The aim of this study is to analyze and compare the clinical results of toric intraocular lens (IOL) and monofocal IOL implantation when the target refraction value is determined -3 diopter (D) in cataract patients with corneal astigmatism >1.5 diopters (D).Methods: We performed a retrospective chart review for patients with corneal astigmatism >1.5D who underwent cataract surgery and their target refraction is determined -3D. 100 eyes (100 patients; monofocal IOL, 60; toric IOL, 40) were enrolled in the current study. Near and distant uncorrected visual acuity (UCVA), corrected VA, spherical equivalent and refractive, corneal astigmatism were evaluated before and after surgery.Results: The near UCVA of the toric IOL group (0.26±0.33) after cataract surgery was significantly better than that of the monofocal IOL group (0.48±0.32) (p=0.030). The distant UCVA of the toric IOL group (0.38 ± 0.14) was also significantly better than that of the monofocal IOL group (0.55 ± 0.22) (p = 0.026). There were no significant intergroup differences in postoperative best-corrected visual acuity (p = 0.710) and mean spherical equivalent (p = 0.465). In the toric IOL group, postoperative refractive astigmatism was -0.80 ± 0.46D and postoperative corneal astigmatism was -1.50 ± 0.62D, whereas the corresponding values in the monofocal IOL group were -1.65 ± 0.77D and -1.45 ± 0.64D; residual refractive astigmatism was significantly lower with toric IOL implantation compared with monofocal IOL implantation (p = 0.001). There were no postoperative complications and no adverse events were reported.Conclusions: When myopic refraction such as -3D was determined as the target power in patients with corneal astigmatism, toric IOL implantation led to excellent improvement in both near and distant UCVA.


2020 ◽  
Vol 17 (3) ◽  
pp. 351-360
Author(s):  
G. A. Gamidov ◽  
I. A. Mushkova ◽  
S. V. Kostenev ◽  
A. A. Gamidov

Purpose: to develop an effective and safe method of cyclotorsion compensation, to improve the clinical and functional results of the of myopic astigmatism correction with SMILE surgery.Patients and methods: Two equivalent groups of 30 people (30 eyes) were formed with cyclotorsion from ±5 degrees («Standard» and «Verion»). The correction for cyclotorsion was carried out only in the «Verion» group. Before the laser-refraction surgery, all eyes were examined using «Verion» image guided system (Alcon, USA) to determine cyclotorsion. In the «Verion» group, the obtained cyclotorsion data was used to aligement the astigmatism axis by Introducing into the «Visumax» femtolaser system. Further, the operation was carried out according to the standard protocol. At 3 months after SMILE surgery, all patients were examined by a UDVA, CDVA, objective refraction. Furthermore, efficiency and safety, as well as vector analysis of corneal astigmatism according to Alpins were calculated indices at 3 months after surgery.Results: The mean and standard deviation of cyclotorsion of the «Standard» and «Verion» groups was 6.16 ± 1.31 D and 6.30 ± 1.36 degrees, respectively (p > 0.05). The increasement of 1 or more UDVA lines was noted at 20 % and 7 %, respectively after 3 months in the «Standard» and «Verion» groups. The safety index (postoperative UDVA / preoperative UDVA) in both groups was not statistically significantly different (p > 0.05). The predictability of the spherical equivalent within ±0.5 D relative to the target refraction (emmetropia) in the «Standard» and «Verion» groups was 70 % and 100 %, respectively. The predictability of the cylindrical component of refraction within ±0.5 D relative to the target refraction (emmetropia) was 40 % and 90 % for the «Standard» and «Verion» groups, respectively (p < 0.05). Difference vector was 1.01 ± 0.59 D in the group «Standard» and 0.64 ± 0.33 D in the «Verion» group (p < 0.05). Correction index was 0.80 ± 0.43 in the «Standard» group and 0.99 ± 0.04 in the «Verion» group (p < 0.05).Conclusions: Сyclotorsion compensation using the «Verion» image guided system is a safe method. It improves the efficiency and predictability of correction myopic astigmatism in patient undergoing to SMILE surgery. This method recommended for patients with cyclotorsion from ±5 degrees and myopic astigmatism from –0.75 D. 


2020 ◽  
Author(s):  
Da young Shin ◽  
Ho Sik Hwang ◽  
Hyun Seung Kim ◽  
Man Soo Kim ◽  
Eun Chul Kim

Abstract Background: To analyze and compare the clinical results of toric intraocular lens (IOL) and monofocal IOL implantation when the target refraction value is determined -3 diopter (D) in cataract patients with corneal astigmatism >1.5 diopters (D).Methods: We performed a retrospective chart review for patients with corneal astigmatism >1.5D who underwent cataract surgery and their target refraction is determined -3D. 100 eyes (100 patients; monofocal IOL, 60; toric IOL, 40) were enrolled in the current study. Near and distant uncorrected visual acuity (UCVA), corrected VA, spherical equivalent and refractive, corneal astigmatism were evaluated before and after surgery.Results: The near UCVA of the toric IOL group (0.26±0.33) after cataract surgery was significantly better than that of the monofocal IOL group (0.48±0.32) (p=0.030). The distant UCVA of the toric IOL group (0.38 ± 0.14) was also significantly better than that of the monofocal IOL group (0.55 ± 0.22) (p = 0.026). There were no significant intergroup differences in postoperative best-corrected visual acuity (p = 0.710) and mean spherical equivalent (p = 0.465). In the toric IOL group, postoperative refractive astigmatism was -0.80 ± 0.46D and postoperative corneal astigmatism was -1.50 ± 0.62D, whereas the corresponding values in the monofocal IOL group were -1.65 ± 0.77D and -1.45 ± 0.64D; residual refractive astigmatism was significantly lower with toric IOL implantation compared with monofocal IOL implantation (p = 0.001). Conclusions: When myopic refraction such as -3D was determined as the target power in patients with corneal astigmatism, toric IOL implantation led to excellent improvement in both near and distant UCVA.


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