Tomography-Based Customized IOL Calculation Model

This study aimed to compare ocular wavefront aberrations for pupil diameters of 4 mm and 6 mm, and contrast sensitivity, in eyes with AcrySof IQ and AcrySof Natural intraocular lenses (IOLs). Sixty eyes of 60 patients were enrolled in this prospective randomized study. After phacoemulsification the eyes received either AcrySof IQ SN60WF or AcrySof Natural SN60AT IOLs. One month after surgery, all patients underwent complete ophthalmological examination including corneal topography, wavefront analysis for pupil diameters of 4 mm and 6 mm, and contrast sensitivity measurements with the CSV 1000E instrument under photopic and mesopic conditions with and without glare. There was no statistically significant difference between groups in age, sex or other preoperative ocular characteristics (p > 0.05). Patients with AcrySof IQ IOLs had higher contrast sensitivity at 6 c.p.d. under photopic conditions, at 6 c.p.d. and 18 c.p.d. under mesopic conditions, and at 6 c.p.d., 12 c.p.d. and 18 c.p.d. under mesopic conditions with glare (p < 0.05). Corneal spherical aberration was 0.273 ± 0.074 μm in the AcrySof Natural group and 0.294 ± 0.086 μm in the AcrySof IQ group (p = 0489). Ocular spherical aberration was 0.362 ± 0.141 μm and 0.069 ± 0.043 μm (p < 0.001) for 6-mm diameter pupils and 0.143 ± 0.091 μm and 0.017 ± 0.016 μm (p < 0.001) for 4-mm diameter pupils, with AcrySof Natural and AcrySof IQ IOLs, respectively. There were no significant differences in other higher-order aberrations between the groups (p > 0.05). Aspherical AcrySof IQ IOLs significantly reduced spherical aberration for pupil diameters of both 4 mm and 6 mm and also improved contrast sensitivity more than spherical AcrySof Natural IOLs, especially in mesopic conditions.

Anterior segment optical coherence tomography in black‐on‐clear polypseudophakia

Customized aspheric intraocular lenses calculated with real ray tracing

To compare experimental optical performance in eyes implanted with spherical and aspheric intraocular lenses (IOLs). Corneal, total, and internal aberrations were measured in 19 eyes implanted with spherical (n=9) and aspheric (n=10) IOLs. Corneal aberrations were estimated by virtual ray tracing on corneal elevation maps, and total aberrations were measured using a second-generation laser ray tracing system. Corneal and total wave aberrations were fit to a Zernike polynomial expansion. Internal aberrations were measured by subtracting corneal from total wave aberrations. Optical performance was evaluated in terms of root-mean-square (RMS) wavefront error and Strehl ratio (estimated from the modulation transfer function). Depth-of-field was obtained from through-focus Strehl estimates from each individual eye. Corneal aberrations increased after IOL implantation, particularly astigmatism and trefoil terms. Third and higher order RMS (and the corresponding Strehl ratio) were significantly better in eyes with aspheric IOLs than with spherical IOLs; however, this tendency was reversed when astigmatism was included. Spherical aberration was not significantly different in eyes with aspheric IOLs, whereas it was significantly positive in eyes with spherical IOLs. Third order aberrations were not significantly different across groups. Depth-of-field was significantly larger in eyes with spherical IOLs. Spherical IOLs showed better absolute optical quality in the presence of negative defocus >1.00 D. Our study shows a good degree of compensation of the corneal spherical aberration in eyes implanted with aspheric IOLs, as opposed to eyes implanted with spherical IOLs. Other sources of optical degradation, both with aspheric and spherical IOLs, are non-symmetric preoperative corneal aberrations, incision-induced aberrations, and third order internal aberrations. Although best corrected optical quality is significantly better with aspheric IOLs, tolerance to defocus tended to be lower.

Swept-source anterior segment optical coherence tomography in late-onset capsular block syndrome: High-resolution imaging and morphometric modifications after posterior capsulotomy

To measure and compare the optical quality of spherical and aspheric toric intraocular lenses (IOLs). Wavefront aberrations of AcrySof Toric and IQ Toric IOLs (Alcon Laboratories) for different powers were measured at 3- and 5-mm pupils by Nimo TR0805 instrument. The Zernike coefficients of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. The point spread functions (PSFs) of each IOL evaluated were calculated from the wavefront aberrations. The PSF images also were calculated from the IOL wavefront aberrations, adding the cornea's aberrations to simulate the optical quality after their implantation. Spherical toric IOLs showed positive and aspheric toric IOLs negative spherical aberrations. Statistically significant differences were found in spherical aberration root mean square (RMS) values between spherical and aspheric IOLs for both pupil sizes (p<0.05). Aspheric toric IOLs showed higher spherical aberration RMS values. We found differences in PSF images between both IOL designs at 5-mm pupil. The PSFs corresponding to the aspheric toric IOLs showed more spread out than the PSFs corresponding to the spherical toric IOLs. However, when corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs. At 3-mm pupil, the optical quality between the IOL designs was similar, but at 5-mm pupil the optical quality was higher for spherical IOLs than aspheric IOLs. However, when theoretical corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs, due to the compensation between aspheric toric IOL negative spherical aberration and corneal positive spherical aberration.

Background Cornea astigmatism can be effectively corrected by implanting Toric intraocular lens (IOL) during cataract surgery and therefore improve visual acuity of patients.However, the decentration and rotation position errors were inevitable sometime.What's the difference of effect of position errors on quality of image between spherical IOL and Toric IOL needs further research. Objective This study was to evaluate the optical performance and wavefront with rotation and decentration of Toric IOL. Methods Different decentration for SN60AT IOL(spherical IOL) and Toric IOL in Hwey-Lan Lion model eyes was set with the role as follows: decentration 0.25 mm to 0.75 mm in a 5°-interval from 0° to 90°.Furthermore, Toric IOL was rotated at 5° and 10°, respectively.Then the image performances of SN60AT IOL and Toric IOL at different decentration distances and rotated degrees were evaluated with modulation transfer function (MTF) and value of wavefront aberration under all conditions. Results At the centration, the MTF curves of spherical IOL and Toric IOL were similar under 3, 4 and 5 mm pupil diameter at each spatial frequency.Under the condition of 4 mm pupil diameter, when the decentration was 0.25 mm, the MTF values of SN60AT IOL at 6 c/d and 12 c/d were 0.581 087 and 0.411 960, respectively.T3 IOL were 0.454 259 and 0.382 313, T4 IOL were 0.426 020 and 0.360 490, T5 IOL were 0.425 606 and 0.359 877.When the decentration was 0.50 mm, the MTF values of SN60AT at 6 c/d and 12 c/d were 0.573 073 and 0.412 787, respectively.T3 IOL were 0.450 943 and 0.379 481, T4 IOL were 0.423 153 and 0.356 664, T5 IOL were 0.422 881 and 0.356 230.When the decentration was 0.75 mm, the MTF values of SN60AT at 6 c/d and 12 c/d were 0.560 038 and 0.413 624, respectively.T3 IOL were 0.445 597 and 0.374 322, T4 IOL were 0.418 522 and 0.350 087, T5 IOL were 0.418 468 and 0.349 976.When the IOL decentralized along 0°, 5°, 10°, 90°meridian line, the MTF values were almostly same.The root mean square (RMS) of spherical IOL and Toric IOL was increased when the IOL decentralized from 0 mm to 0.75 mm, with the most increasing level in coma aberration and slight increase in trefoil aberration.When the T4 IOL decentralized from centre to 0.75 mm, the coma increased from 0 to C(3, -1) -0.049 79 μm, C(3, 1) -0.037 59 μm and the trefoil aberration increased from 0 to C(3, 3) 0.005 72 μm, C(3, -3) 0.004 64 μm.With the increase of rotation degrees (from 5°to 10°) of Toric IOL, the MTF was worse at high spatial frequency.Toric IOL rotation caused the increase of astigmatism and residual astigmatism and spherical error, but not high order aberration. Conclusions The tolerance of Toric IOL to decentration is very close to the spherical IOL, and optical performance is only associated with the amount of decentration but not direction.The aberration caused by Toric IOL decentration is mainly coma.The rotation of Toric IOL causes astigmatism error but not high order aberrations. Key words: Lenses, intraocular; Refraction, ocular/physiology; Astigmatism/physiopathology; Lens implantation, intraocular; Decentration; Optical performance; Visual acuity/physiology; High order aberrations

To evaluate the application of anterior segment-optical coherence tomography (AS-OCT) in posterior capsule opacification (PCO) severity assessment and analyse the relationship between PCO severity and intraocular lens (IOL) characters. PCO patients were prospectively recruited. Cross-sectional images of the anterior segment at horizontal and vertical meridians were acquired with AS-OCT. The area of the IOL-PC (posterior capsular) space and PCO severity (area, thickness, and density at 3 mm and 5 mm IOL optic regions) were measured. The relationship between PCO severity and visual acuity, comparisons of PCO severity and IOL-PC space using varied IOL designs were analysed. One hundred PCO eyes were enrolled. IOL-PC space, PCO thickness and area were positively correlated with axial length. In addition, PCO area and thickness were positively correlated with visual acuity when it was ≤0.52 logMAR. The cut-off level of visual acuity should be 0.52 logMAR. With varied IOL designs, 3-piece C haptic IOL showed a smaller PCO area and thickness than the 1-piece 3 haptic IOL and 1-piece 4 haptic IOL. PCO area and thickness values for an IOL with a diameter ≤11.0 mm was greater than for an IOL with a diameter of 12.5 mm, and the differences were statistically significant. PCO area and thickness increased when IOL haptic angulation increased (from 0 to 12 degrees). In PCO eyes, cut-off level of visual acuity is 0.52 logMAR. With more severe PCO, visual acuity maybe not enough to describe the visual function impairment. PCO severity and IOL-PC space are significantly correlated with axial length and IOL design and material.

Fellow-eye comparison of 2 aspheric microincision intraocular lenses and effect of asphericity on visual performance

Having substituted the hydrophilic and hydrophobic groups alternately on the soft acrylic resin intraocular lens (IOL) surface by using an ArF excimer laser and a Xe₂ excimer lamp, we have developed the IOL that is free from fibrin. Acrylic resin or PMMA lens has been used as an intraocular lens for 50 years. However, protein and fat are stuck onto the IOL surface after a long implantation, which opacifies the surface (after-cataract). Thus, we designed the micro domain structures of hydrophilic and hydrophobic groups on the IOL surface for fibrin-free. Firstly, the IOL was irradiated with the Xe₂ excimer lamp in the presence of perfluoropolyether in order to make it hydrophobic. By this photochemical reaction, the CF3 functional groups were substituted on the IOL surface. Secondly, the ArF laser was projected on the IOL through the mask pattern in reduced size in the presence of water in order to be hydrophilic. With the photochemical reaction, the OH groups were substituted at the part exposed. The fibrin adsorption test of the modified IOL surface was carried out with FT-IR; which revealed that the fibrin-sticking rate of the treated sample has decreased by 23% compared with that of the non-treated sample. As a result, the fibrin-free IOL has been made by modifying the surface of the IOL to have the micro domain structures of the hydrophilic and hydrophobic groups that are arrayed alternately. In conclusion, the ideal intraocular lens has been demonstrated.

To present a case where following Implantable Collamer Lens (ICL) implantation the patient developed toxic anterior segment syndrome (TASS) with a subsequent pupillary block as a consequence of the occlusion of the AquaPORT (STAAR Surgical) flow hole. Case report and literature review. A V4c toric ICL (STAAR Surgical) was implanted in the left eye of a 32-year-old woman. After 1 week, the lens was 15° off axis and uneventful lens alignment correction was performed. At postoperative day 1, an intraocular pressure (IOP) of 11 mm Hg and mild corneal edema were observed. At postoperative day 7, there was an uncorrected distance visual acuity of 20/800, an IOP of 44 mm Hg, diffuse corneal edema, and fibrin strands in the anterior chamber. TASS was diagnosed and topical steroids, cycloplegia, antiglaucoma drops, and oral acetazolamide were prescribed. At postoperative day 9, dispersed endothelial pigment with a fixed mid-dilated pupil were identified. Anterior segment optical coherence tomography showed strands of fibrin blocking the central ICL hole and angle closure. Pupillary block related to the fibrin occluding the AquaPORT hole consecutive to TASS was diagnosed. The patient underwent ICL removal, but had a persistent atonic, hyporeflexive pupil as a complication. This case demonstrates that an AquaPORT hole may not be enough to prevent pupillary block in cases with postoperative intraocular inflammation, causing severe postoperative complications such as Urrets-Zavalia syndrome. Clinicians should consider this diagnosis in cases with corneal edema in the early postoperative period following AquaPORT ICL insertion. [J Refract Surg. 2020;36(12):856-859.].

정진호 1 ⋅김미금 2,3 ⋅위원량 2,3 ⋅이진학 3,4 인천광역시 의료원 안과 1 , 서울대학교 의과대학 안과학교실 2 , 서울대학교병원 임상의학연구소 인공안구센터 3 , 분당 서울대학교병원 안과 4 목적: 구면 및 비구면 인공수정체(intraocular lens; IOL)를 삽입한 눈의 광학기능을 비교하고자 한다.대상과 방법: 69명 88안에서 구면(Sensar AR40

The authors describe the anterior segment optical coherence tomography (AS-OCT) findings of a 25-year-old patient with acute hydrops associated with keratoconus. The patient presented with decreased visual acuity, pain, and redness in the left eye. The symptoms, clinical presentation, and topographical findings of the right eye confirmed this condition to be acute corneal hydrops. The patient was closely followed up with hyper-osmotic (NaCl 5%) and nonsteroidal anti-inflammatory (ketorolac tromethamine 0.5%) topical treatment. At the initial examination and during follow-up, the evaluation of the anterior segment was performed using optical coherence tomography. Changes in the stroma and Descemet's membrane during the healing process of acute hydrops could be demonstrated by high-resolution AS-OCT.

Objective: To optimize the spherical aberrations of toric intraocular lens (IOL): to design toric IOLs with different spherical aberrations, and to study the rotation, the tolerance to decentration, and imaging rules. Methods: In this experimental study, the spherical aberrations of toric IOLs were optimized in the Hwey-Lan Liou model eye. The spherical structure, the curvature radius, and the thickness of the anterior and posterior surfaces of the toric IOLs, and the aspheric coefficients of the anterior surface of toric IOLs were optimized respectively. The targets was optimized to produce IOLs with -0.26 μm, -0.1 μm and 0 μm spherical aberrations. In the computer optical simulation system, the effect on the modulation transfer function (MTF) was evaluated when spherical and aspherical IOLs were decentrated in the horizontal direction with 0.25 mm, 0.50 mm and 0.75 mm at 3- and 5-mm pupil diameters. The effect on MTF was also evaluated when the two types of IOLs were rotated by 3°, 5° and 10° at 4-mm pupil diameter. Results: At the center, the aspherical toric IOL displayed a better image performance with the increased pupil diameter. When the decentration was 0.5 mm at 3-mm pupil diameters, the imaging quality of the -0.26 μm toric IOL decreased and was worse than that of 0 or -0.1 μm IOL. At 5-mm pupil diameter, when the decentration was 0.75 mm, the MTF of -0.26 μm toric IOL was close to that of the spherical toric IOL, while the MTF of toric IOL with 0 μm and -0.1 μm spherical aberration was slightly better than that of the spherical toric IOL. The MTF of aspherical toric IOLs was better than that of the spherical toric IOL with 3° to 5° rotation, but the curve was equal or even worse than that of the spherical toric IOL with 10° rotation in high spatial frequency. Conclusions: Toric IOLs with a spherical aberration of -0.26 μm have good imaging quality at the center but lower tolerance to decentration. The proper optimization of the spherical aberration of toric IOLs can improve the imaging quality of the model eye, while maintaining the tolerance for decentration and rotation errors. Optimized toric IOLs can attain better optical quality under comprehensive conditions. Key words: cataract; artificial lenses; astigmatism; cornea; decentration; rotation; modulation transfer function; model

To optimize the implantable collamer lens (ICL) sizing method using anterior segment optical coherence tomography (AS-OCT). Nagoya Eye Clinic, Nagoya, Japan. Interventional case series. A stepwise multiple regression analysis was performed using the optimal ICL size as a dependent variable and preoperative AS-OCT parameters as explanatory variables for 81 eyes of 41 patients, and the NK-formula version 2 (NK-formula V2) was obtained. Thereafter, 68 eyes of 42 patients were implanted with the ICLs selected as closest to the optimal ICL size calculated by the NK-formula V2. At 3 months postoperatively, the achieved vault was measured by AS-OCT to evaluate the optimization of the sizing method. The anterior chamber width (ACW) and crystalline lens rise were selected as significant parameters for the regression model (R = 0.61, P < .001), as with the previous NK-formula. Of the 68 eyes, 36 patients/62 eyes (91.2%), 5 patients/5 eyes (7.3%), and 1 patient/1 eye (1.5%) were in the moderate, high, and low vault categories, respectively. In the 68 eyes, the vault showed no correlation with the optimal ICL size (R = 0.0185, P = .269), whereas the vault showed a negative correlation with the optimal ICL size in both the 12.6 mm ICL subgroup (R = -0.409, P = .0088) and the 13.2 mm ICL subgroup (R = -0.818, P = .0013). This optimization approach showed excellent ability to select an appropriate ICL to be implanted regardless of the value of other ocular parameters and age, except ACW.