Quantitative in vivo assessment of intraocular lens calcification: correlation between OCT opacity and straylight measurement.

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

We report the use of anterior segment optical coherence tomography (AS-OCT) as a valuable tool for capsular block syndrome diagnosis and follow-up. The purposes of this study are to report a case of late-onset capsular block syndrome or lacteocrumenasia and to describe differential diagnosis with other more common phacoemulsification complications such as intraocular lens (IOL) or posterior capsule opacification. We report the case of a 56-year-old man with a clinical history of cataract surgery in his left eye. Five years after cataract surgery, he complained of blurred vision and was referred for IOL removal to our hospital. After careful slit-lamp examination, we found that the lens was clear, and opacity belonged to the accumulation of a whitish material in the capsular bag behind the lens. AS-OCT gave the definite diagnosis of capsular block syndrome. Intraocular lens removal had been wrongly indicated, and we treated our patient by YAG laser posterior capsulotomy. AS-OCT confirmed the absence of a further accumulated material, so no other interventions were needed. After treatment, best-corrected visual acuity improved from 0.48 to 0.1 logMAR. Capsular block syndrome is a rare late-onset complication of cataract surgery causing a deep visual acuity decay. A precise slit-lamp examination and AS-OCT, together, avoid misdiagnosis and unnecessary surgical treatment, which may be needed in case of IOL opacity or fibrotic-like lacteocrumenasia. AS-OCT also helps in determining the treatment outcome. Immediate best-corrected visual acuity improvement is reached after a successful intervention.

Differentiating between various intraocular lens (IOL) changes can be a challenge. In particular, certain IOL models carry the risk of late postoperative calcification. A major cause of IOL exchange surgery could be avoided if appropriate modifications were made during the IOL manufacturing process. The use of a hydrophilic acrylate carries the risk of IOL calcification, especially when a secondary procedure, such as a pars plana vitrectomy or other procedures using gas or air, is performed. In secondary IOL calcification, there is a wide range of opacification patterns, which are usually located in the centre on the anterior surface of the IOL or sometimes elsewhere. Often, granular deposits accumulate just below or on the surface of the IOL, leading to significant deterioration in visual quality and eventually requiring IOL exchange surgery. Therefore, in the case of eyes requiring secondary surgical intraocular intervention in the future, the use of hydrophilic IOLs should be critically evaluated. With regard to hydrophobic IOL materials, there are clear differences in the susceptibility to the formation of glistenings. Over time, there has been a significant decrease in glistening formation over the past 30years due to optimisation of the material. With hydrophobic IOLs, special care should also be taken to avoid mechanical damage. In general, the only treatment option for functionally-impairing IOL opacification is surgical lens exchange, which carries potential risks of complications. In cases with a low degree of functional impairment, and especially in eyes with additional ocular diseases, it may be difficult to weigh the risk of additional surgery against the potential benefit. In some cases, it may be more appropriate not to perform an IOL exchange despite the IOL opacification. Recent visualisation methods that allow high-resolution analysis of the opacities in vivo and in vitro may be used in the future to estimate the functional effects of various IOL material changes on the optical quality.

Opacification of intraocular lenses (IOLs) due to the formation of calcium phosphate occurs because of their contact with the aqueous humor (AH), which is supersaturated with respect to calcium phosphate. Calcification of IOLs was simulated in vitro using a batch reactor in which the IOLs were exposed to solutions simulating AH. Based on the precise and reproducible measurement of the rates of formation of mineral deposits on the IOLs, it is possible to develop reliable screening tests of different types of IOL materials. Depending on their material composition, IOLs are expected to present different active sites for the growth of deposits. Measurements of the kinetics of formation of hydroxyapatite (Ca5(PO4)3OH; HAP) were used to compare the relative tendency of IOL towards calcification. The trend the IOLs tested showed towards calcification was found to correlate with contact angle values. In the case of hydrophobic IOLs, the surface charge calculated from the corresponding zeta potential measurements was low in comparison with the respective high (absolute) values of the mineralizing hydrophilic IOLs, suggesting strong correlation between surface charge and tendency to calcify. The in vitro results align with the in vivo tests, suggesting that in vivo tests can be safely substituted or at least significantly reduced by the in vitro model.Graphical

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

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.

To assess visual acuity outcomes in pseudophakic eyes with a multifocal (MF)-IOL (intraocular lens) and endothelial failure receiving Descemet membrane endothelial keratoplasty (DMEK). This is a retrospective case-series analyzing patients from the prospective Cologne DMEK database where visual acuity outcome in 14 eyes of 9 patients requiring DMEK after MF-IOL implantation was compared with 14 eyes of 14 age-matched controls for DMEK after monofocal IOL implantation. All patients suffered from Fuchs endothelial corneal dystrophy. The average age at presentation was 69 ± 8.9 and 68 ± 7.6 years for cases and control group, respectively. Average pretransplant best-corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution was 0.45 ± 0.32 and 0.39 ± 0.19 among cases and control groups, respectively. After exclusion of 4 eyes with other visual acuity limitations and their age-matched control eyes, final average BCVA at follow-up among cases was 0.1 ± 0.07 at 3 months and 0.15 ± 0.10 at 6 months, whereas it was 0.14 ± 0.10 at 3 months ( P = 0.435) and 0.05 ± 0.05 at 6 months ( P = 0.054) of follow-up among the control group. When including eyes with IOL calcification, BCVA at 1 and 2 years in cases was significantly worse compared with controls. IOL calcification was more common in eyes with preexisting MF-IOL (3/14). Good visual outcomes can be achieved in eyes where DMEK is done after MF-IOL implantation. Visual acuity recovery may be slower and slightly lesser compared with eyes with preexisting monofocal IOL in situ. The risk of IOL calcification seems higher in MF-IOLs.

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.

Postoperative opacification of a hydrophilic acrylic intraocular lens (IOL) is an uncommon complication. A 57-year-old diabetic female who had undergone phacoemulsification with IOL implantation in her right eye 16 years back presented with diminution of vision in the same eye for 3 years. Significant IOL opacification was observed clinically and anterior segment optical coherence tomography clearly delineated the intraoptic deposits, sparing the haptics, and edges of the optic. IOL explant and exchange was performed leading to restoration of visual acuity to 6/9. Histochemical evaluation of the IOL confirmed that the hydrophilic acrylic IOL optic had calcium deposits.

BackgroundInvestigating the efficacy and safety of phacoemulsification with intraocular lens (IOL) implantation in corneal opacities.MethodsThis retrospective study was conducted in a tertiary medical center. Twenty-three eyes of 19 patients with cataracts and corneal opacities obscuring the pupillary center having received phacoemulsification with IOL insertion without any ancillary techniques were enrolled. The primary study outcome measures were uncorrected and best corrected visual acuity (BCVA), and complications. Backscatters of corneal scar lesions were evaluated by slit lamp-based haze grading, Scheimpflug Pentacam and anterior segment optical coherence tomography (ASOCT). Visual outcomes after cataract surgeries and improvement range were used to determine the safety and efficacy of cataract surgery for our patients.ResultsAll patients underwent uneventful capsulorhexis and phacoemulsification. The mean age was 72.22 ± 10.1 years, and the mean follow-up period was 18.57 ± 15.42 months. The mean BCVA significantly improved from 1.45 ± 0.65 preoperatively to 0.94 ± 0.55 logMAR postoperatively (p < 0.001), and the number of eyes with a BCVA of 20/100 or better increased from 4 to 14. Complications included corneal edema in two eyes and reactivation of the previous corneal pathology in five eyes. Four eyes did not achieve an improvement in visual acuity after surgery, which may have been due to co-existing ocular co-morbidities. Both Pentacam corneal densitometry and ASOCT demonstrated no significant correlations with final visual outcome. However, a statistically significant relationship between the severity of corneal opacity and improvement range in BCVA (r = − 0.782, P = 0.001) was found by our OCT grading method.ConclusionsPhacoemulsification and IOL implantation in selected cases of coexisting cataracts and corneal opacities is safe that can provide suboptimal but long-term vision when penetrating keratoplasty is not possible or at high-risk of graft failure. ASOCT is a simple tool to predict visual outcomes after cataract surgery in opacified corneas.

Surface calcification of a 3-piece silicone intraocular lens in a patient with asteroid hyalosis: A clinicopathologic case report

Purpose: To provide a mathematical calculation scheme for customized intraocular lens (IOL) design based on high resolution anterior segment optical coherence tomography (AS-OCT) of anterior eye segment and axial length data.Material and Methods: We use the corneal and anterior segment data from the high resolution AS-OCT and the axial length data from the IOLMaster to create a pseudophakic eye model. An inverse calculation algorithm for the IOL back surface optimization is introduced. We employ free form surface representation (bi-cubic spline) for the corneal and IOL surface. The merit of this strategy is demonstrated by comparing with a standard spherical model and quadratic function. Four models are calculated: (1) quadratic cornea + quadratic IOL; (2) spline cornea + quadratic IOL; (3) spline cornea + spline IOL; and (4) spherical cornea + spherical IOL. The IOL optimization process for the pseudophakic eye is performed by numerical ray-tracing method within a 6-mm zone. The spot diagram on the fovea (forward ray-tracing) and wavefront at the spectacle plane (backward ray-tracing) are compared for different models respectively.Results: The models with quadratic (1) or spline (3) surface representation showed superior image performance than the spherical model 4. The residual wavefront errors (peak to valley) of models 1, 2, and 3 are below one micron scale. Model 4 showed max wavefront error of about 15 µm peak to valley. However, the combination of quadratic best fit IOL with the free form cornea (model 2) showed one magnitude smaller wavefront error than the spherical representation of both surfaces (model 3). This results from higher order terms in cornea height profile.Conclusions: A four-surface eye model using a numerical ray-tracing method is proposed for customized IOL calculation. High resolution OCT data can be used as a sufficient base for a customized IOL characterization.

To predict multiple postoperative parameters following implantable collamer lens (ICL) surgery with generative artificial intelligence, using preoperative anterior segment optical coherence tomography (AS-OCT) images as the input. Daikanyama Eye Clinic, Tokyo, Japan; Miyata Eye Hospital, Miyazaki, Japan; Nagoya Eye Clinic, Nagoya, Japan; Yokohama Sky Eye Clinic, Kanagawa, Japan. Retrospective Study. Our research involved paired preoperative and postoperative AS-OCT images from 1010 patients (1585 eyes) who underwent horizontal ICL implantation, and 86 patients (86 eyes) who received vertical implantation from four clinical centers. A Generative Adversarial Network, ICL-GAN, was employed to predict postoperative structures based on preoperative AS-OCT slice from each eye. Postoperative parameters, including vault, AOD500, and TIA500, were measured from the predicted postoperative structures. The prediction error was evaluated using the mean absolute error (MAE) and root mean square error (RMSE). The correlation and agreement between the prediction and the achieved values were also analyzed. The vaults measured from the predictions of postoperative anatomical structure have a strong correlation with the achieved values on horizontal data (r=0.659, p<0.01 for ICL size of 12.1mm, r=0.799, p<0.01 for 12.6mm, and r=0.737, p<0.01 for 13.2mm) and when compared with the NK-formula and KS-formula achieved the minimum prediction errors (MAE are 105 μm, 114 μm, and 111 μm). ICL-GAN also performed best on the vertical implantation data. The AOD500 and TIA500 also showed good correlation and agreement with the achieved values. The generative artificial intelligence demonstrates the capability to predict multiple postoperative parameters following ICL surgery.

BackgroundTo compare the intraocular lens (IOL) tilt and decentration and visual outcomes of transscleral sutured IOL fixation and sutureless flanged IOL fixation. To investigate the influence of IOL tilt and decentration on internal higher-order aberrations (HOAs) in these two techniques.MethodsPatients who received transscleral sutured or sutureless flanged IOL fixation procedures were included in this prospective, non-randomized, comparative study. Corrected distance visual acuity (CDVA) was measured at baseline and at every postoperative visit for 12 months. IOL tilt and decentration were measured using a second-generation anterior segment optical coherence tomography (Casia2) and internal HOAs were measured using iTrace Visual Function Analyzer at 3 months postoperatively.ResultsThe study included 27 eyes from the transscleral sutured IOL fixation group and 26 eyes from the sutureless flanged IOL fixation group. There was no significant difference in CDVA between the two groups at all time points. The two groups did not differ in refractive difference from the predicted value, corneal endothelial cell loss, IOL tilt, IOL decentration, internal astigmatism or internal HOAs. Vertical IOL decentration significantly correlated with total internal optical aberration (r = 0.288, P = 0.036), total internal HOA (r = 0.440, P = 0.001), internal coma (r = 0.348, P = 0.001), vertical internal coma (r = 0.388, P = 0.004), average height of modulation transfer function (r = − 0.364, P = 0.007) and Strehl ratio (r = − 0.297, P = 0.031). Horizontal IOL decentration significantly correlated with horizontal internal coma (r = 0.312, P = 0.023).ConclusionsTransscleral sutured IOL fixation and sutureless flanged IOL fixation had similar IOL positions and visual outcomes. IOL decentrations correlated with internal HOAs and thus should be avoided.

Aims/Purpose: To develop a method for measuring the exact dimensions of the ciliary sulcus in order to improve the predictability of accommodative intraocular lens sizing.Methods: Patients scheduled for cataract surgery have been pre‐operatively examined with the anterior segment optical coherence tomographer (AS‐OCT) CASIA2 (Tomey, Nagoya, Japan). Optimized scan protocols were defined to improve the image quality of the ciliary structures. The horizontal scan from 0° to 180° was taken to represent the space where a sulcus‐fixated accommodative intraocular lens (IOL), whose diameter must agree with that of the ciliary sulcus, may be placed. The images were corrected for the optical distortion induced by the cornea's refraction. The sulcus‐to‐sulcus (STS) size as well as the depth of the sulcus plane (SPD) was measured using the integrated software calliper by two independent raters. Inter‐rater variability and correlation were evaluated. In addition, STS measurements were compared to other ocular diameter measures, such as angle‐to‐angle (ATA) and anterior chamber width (ACW). Data were analysed by means of correlation coefficient R2 and Bland–Altmann analysis.Results: 55 eyes of 28 patients were included in the study. The optimized scan protocols improved overall image quality and subjective visibility of ciliary anatomy compared to the default protocol. STS ranged from 10.66 mm to 12.89 mm, ACW from 10.76 mm to 12.74 mm and ATA from 10.69 to 12.46 mm. SPD ranged from 3.73 mm to 5.0 mm, while ATA depth was between 2.74 mm and 3.95 mm. Readings of both raters were highly correlated (R2 &gt; 0.98). Manual readings of STS correlated poorly with automated ACW and ATA measurements (R2 &lt; 0.66). The mean difference was 0.018 mm for STS and −0.011 mm for SPD. The levels of agreement were within [−0.109; +0.145] mm for STS and [−0.112; +0.091] mm for SPD.Conclusions: Despite the absorption of light by the iris pigment, the infrared light from the AS‐OCT is able to penetrate the posterior chamber to some degree. Therefore, the new AS‐OCT method for sulcus‐to‐sulcus and ciliary dimensions measurements seems to be feasible, reliable and is less bothersome for the patients compared to ultrasound bio‐microscopy. This approach could be useful for sulcus fixated accommodative IOLs and for sizing determination of posterior chamber phakic IOLs.