Postoperative Refractive Error Research Articles

Web-based Telemonitoring of Visual Function and Self-reported Postoperative Outcomes in Cataract Care: an International Multicenter RCT.

Comparing web-based, self-administered follow-up after cataract surgery to conventional face-to-face follow-up. Eye clinics in the Netherlands, Austria and Germany. Randomized controlled trial with an embedded method comparison study [ClinicalTrials.gov: NCT04809402]. Routine cataract patients were randomized into two groups: the 'telemonitoring' group undertook web-based vision self-assessments and questionnaires from home, while the 'usual care' group received conventional care. All participants had a 4-6 week post-surgery clinic visit for safety and validation purposes. Outcomes included: the web-test's accuracy for assessing postoperative visual acuity (VA) and refractive error; adverse event rates; and patient reported outcome measurements (PROMs). 94 participants (188 eyes) were enrolled. Web-based uncorrected distance VA testing demonstrated a negligible mean difference (-0.03±0.14 logMAR) when compared to conventional ETDRS chart testing, with 95% limits-of-agreement ranging from -0.30 to 0.24 logMAR. The web-based refraction assessment overestimated the postoperative refractive error (mean difference 0.15±0.67 diopters), resulting in a poorer corrected distance VA compared to subjective refraction (mean 0.1 vs. -0.1 logMAR). Rates of adverse events and unscheduled consultations were minimal across both groups. Preoperative and postoperative PROMs questionnaires had a 100% response rate. Visual functioning (Catquest-9SF and NEI-VFQ-25) improved after surgery (mean improvement -0.80 and 16.70 respectively) and did not significantly differ between the two groups. The cataract patients in this study effectively provided postoperative outcome data via a web-interface. Both conventional and web-based follow-ups yielded similar PROMs and adverse event rates. Future developments should reduce the variability in the web-based VA test and yield representative refraction outcomes.

Comparison of Safety and Efficacy of Four-Point Scleral Intraocular Lens Fixation and the Yamane Technique.

The purpose of our study was to compare the safety and efficacy of two scleral fixation intraocular lens (IOL) methods of four-point scleral fixation (Akreos AO60) and the Yamane technique (AcrySof MA60AC). This prospective, randomized study was conducted at the Military Institute of Medicine-National Research Institute in Warsaw between 2021 and 2023. We compared both groups for cause of aphakia, ocular history, refractive status, and complication. Our study included 50 eyes from 47 patients. Four-point fixation was performed in 25 eyes (group1), and the Yamane technique was used in 25 eyes (group2). Surgical time was 24.1min ± 8.9 in group1 and 25.1min ± 9.9 in group2 (p > 0.05). The postoperative BCVA (best-corrected visual acuity) for group1 and group2 at 1year's observation was 0.10 ± 0.15 and 0.09 ± 0.17 logMAR, respectively (p > 0.05). Postoperative total refractive error (RE) was - 0.06 ± 0.71 diopters (D) for four-point scleral fixation and 0.83 ± 0.70D for Yamane technique (p < 0.05). Endothelial cell density (ECD) loss was 0.9% in group1 and 3.5% in group2 (p > 0.05). Bleeding into the anterior chamber and vitreous body was more frequent in the group of patients operated on with the use of the Yamane technique (10 cases, 20%, p = 0.01). IOL displacement was found in one case (2%) in group2. Both analyzed techniques are well tolerated and ensure good refractive results (extremely predictable in four-point scleral fixation) and have a similar safety profile. Four-point scleral fixation of IOL would appear to be safe, effective and beneficial for young, active patients, especially after trauma or recurrent subluxation. ClinicalTrials.gov identifier NCT06389643.

Accuracy of the Majority Voting Method with Multiple IOL Power Formulae.

This study aimed to evaluate the efficacy of a majority decision algorithm that integrates intraoperative aberrometry (IA) and two intraocular lens (IOL) frequency formulas. The primary objective was to compare the accuracy of three formulas (IA; Sanders, Retzlaff, and Kraff/Theoretical (SRK/T); and Barrett Universal II (BUII)), in achieving emmetropia in eyes implanted with TFNT lenses (Alcon). A total of 145 eyes of 145 patients were included in the evaluation. Preoperative data were obtained from IOLMaster 700, while intraoperative data were collected from ORA SYSTEMTM. Visual acuity ≥0.8 at the 3-month post-surgery mark was confirmed. We assessed refractive prediction error (RPE), which is the difference between predicted refraction (PR) and postoperative subjective refraction. This evaluation aimed to identify the optimal IOL power with the implemented algorithm. Among the 145 eyes evaluated, 55.9%, 78.7%, and 97.2% achieved postoperative subjective refraction within ±0.13 Diopters (D), ±0.25 D, and ±0.50 D, respectively. The percentages of eyes within ±0.25 D of PR varied by formula type, with values of 57%, 57%, and 54% for IA, BUII, and SRK/T, respectively. For eyes with short to medium axial length (AL<26.00 mm), the percentages within ±0.25 D of RPE were 52%, 58%, and 58% for IA, SRK/T, and BUII, respectively. In contrast, for eyes with long axial length (≥26.00 mm) the percentages were 68%, 52%, and 45% for IA, BUII, and SRK/T, respectively. The proposed majority decision algorithm incorporating IA and two IOL frequency formulas was effective in reducing postoperative refractive error. IA was particularly beneficial for eyes with long axial length. These findings suggest the algorithm has potential to optimize IOL power selection to improve quality of life of patients and clinical practice outcomes.

Visual Outcomes According to Age After Bilateral Implantation of Trifocal Intraocular Lenses.

To investigate the effect of age on visual outcomes after the bilateral implantation of trifocal intraocular lenses (IOLs). A total of 290 patients (580 eyes) who underwent bilateral implantation of a trifocal IOL were enrolled in this retrospective case-control study. Patients were divided into five age groups: 45 to 49, 50 to 54, 55 to 59, 60 to 64, and 65 years and older. Postoperative monocular uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively), uncorrected near visual acuity (UNVA), binocular distance-corrected defocus curve, spectacle dependence for near and distance vision, and patient satisfaction scores were compared among the five groups. The 45 to 49 years group had significantly better mean UDVA (0.02 ± 0.05 logMAR) and UNVA (0.02 ± 0.04 logMAR) than the 65 years and older group (0.06 ± 0.09 and 0.09 ± 0.09 logMAR; P = .029 and P < .001; respectively). However, no significant differences were observed in the mean CDVA among the groups. Binocular visual performance of the 45 to 49 years group was better than that of the 65 years and older age group at defocuses of +1.00, +0.50, -1.00, and -3.00 D. No significant differences were observed in spectacle dependence for near and distance vision or in patient satisfaction scores among the five groups. Bilateral implantation of trifocal IOLs can provide excellent near and distance vision in both young and older patients. However, UDVA and UNVA revealed considerably worse results in the older group, although no significant difference was observed in CDVA and postoperative refractive errors by age. [J Refract Surg. 2024;40(4):e270-e277.].

Effect of vault on predicting postoperative refractive error for posterior chamber phakic intraocular lens based on a machine learning model

Purpose: To investigate how vault and other biometric variations affect postoperative refractive error of implantable collamer lenses (ICLs) by integrating artificial intelligence and modified vergence formula. Setting: Eye and ENT Hospital of Fudan University, Shanghai, China. Design: Artificial intelligence and big data-based prediction model. Methods: 2845 eyes that underwent uneventful spherical ICL or toric ICL implantation and with manifest refraction results 1 month postoperatively were included. 1 eye of each patient was randomly included. Random forest was used to calculate the postoperative sphere, cylinder, and spherical equivalent by inputting variable ocular parameters. The influence of predicted vault and modified Holladay formula on predicting postoperative refractive error was analyzed. Subgroup analysis of ideal vault (0.25 to 0.75 mm) and extreme vault (&lt;0.25 mm or &gt;0.75 mm) was performed. Results: In the test set of both ICLs, all the random forest-based models significantly improved the accuracy of predicting postoperative sphere compared with the Online Calculation &amp; Ordering System calculator (P &lt; .001). For ideal vault, the combination of modified Holladay formula in spherical ICL exhibited highest accuracy (R = 0.606). For extreme vault, the combination of predicted vault in spherical ICL enhanced R values (R = 0.864). The combination of predicted vault and modified Holladay formula was most optimal for toric ICL in all ranges of vault (ideal vault: R = 0.516, extreme vault: R = 0.334). Conclusions: The random forest-based calculator, considering vault and variable ocular parameters, illustrated superiority over the existing calculator on the study datasets. Choosing an appropriate lens size to control the vault within the ideal range was helpful to avoid refractive surprises.

Long-Term Outcomes of Keratoprosthesis With Biological Haptic: A Review of 25 Years of Single-Center Surgeries.

To study the outcome of eyes that underwent surgery for keratoprosthesis with a biological haptic, osteo-odonto-keratoprosthesis (OOKP) or tibia keratoprosthesis, by a single surgeon over a time span of more than 25 years. One hundred thirty eyes that had received a keratoprosthesis with a biological haptic between 1994 and 2022 by a single surgeon were included in this retrospective analysis. Main outcome parameters were postoperative best corrected visual acuity, postoperative refractive error, postoperative complications, anatomical and functional survival of the prosthesis as well as comparison of subgroups of the 2 different types (OOKP n = 78; tibia keratoprosthesis n = 52) of keratoprostheses, and subgroup analysis of different indications for surgery. Patients were examined every 6 months. The longest follow-up was 25.8 years. Reasons for implantation were graft-vs-host disease (6.9%), vascularized corneas and dry eye (22.9%), physical or chemical burns (29.8%), Stevens-Johnson syndrome (9.9%), and ocular cicatricial pemphigoid (30.5%). The functional success rate with postoperative visual acuity of better than 0.7 log MAR was achieved by 56.9%. The OOKP subgroup showed a better mean visual outcome. 14 keratoprostheses (10.7%) had to be explanted over the whole time span. In the time leading to explantation, refraction showed a statistically significant myopic shift when compared with the non-explanted prosthesis. Anatomical survival rates were better for the OOKP in the first 12 years after implantation. The study shows that keratoprosthesis with a biological haptic has favorable long-term outcomes. The retention rate stayed very high with excellent functional outcomes.

A COMPARATIVE STUDY OF OPTICAL BIOMETRY AND IMMERSION A-SCAN ULTRASOUND IN PATIENTS UNDERGOING PHACOEMULSIFICATION WITH FOLDABLE INTRAOCULAR LENS IMPLANTATION SURGERY

Objective: The objective of this study was to compare optical biometry with immersion A-scan ultrasound biometry in terms of axial length (AL) and post-operative refractive error by assessing 1-month post-operative refraction in patients undergoing phacoemulsification with foldable intraocular lens (IOL) implantation surgery. Methods: The study was carried out in the Ophthalmology Department of Bharati Vidyapeeth (Demeed to be University) Medical College and Hospital Sangli, from November 2019 to April 2021. A total of 60 eyes of 60 patients were included in the study. All patients underwent both techniques of biometry, namely, optical and immersion A-scan biometry. Mean AL was calculated and compared between the two methods. Then patients were divided into two groups: Group A and Group B; randomization was done on the basis of odd and even numbers. All patients underwent phacoemulsification with foldable IOL implantation surgery and followed up on 1 week and then on 1 month. All patients were operated by single surgeon and a single technique was used. Actual post-operative refractive error, that is, mean of spherical equivalent was compared between two groups on 1-month follow-up. Results: At 1-month follow-up, actual post-operative refractive error was obtained after calculating spherical equivalent for all the patients and we found that, the mean of actual post-operative refractive error for Group A was higher (−0.371±0.24 D) compared to Group B (−0.264±0.16 D) and the comparison was statistically significant (p=0.049). Conclusion: Optical biometry is slightly more accurate than ultrasound biometry, in terms of accuracy and reproducibility of the IOL power calculation, but ultrasound biometry is adequate in case optical biometry is unavailable.

Research progress on prediction of postoperative intraocular lens position.

With the progress in refractive cataract surgery, more intraocular lens (IOL) power formulas have been introduced with the aim of reducing the postoperative refractive error. The postoperative IOL position is critical to IOL power calculations. Therefore, the improvements in postoperative IOL position prediction will enable better selection of IOL power and postoperative refraction. In the past, the postoperative IOL position was mainly predicted by preoperative anterior segment parameters such as preoperative axial length (AL), anterior chamber depth (ACD), and corneal curvature. In recent years, some novel methods including the intraoperative ACD, crystalline lens geometry, and artificial intelligence (AI) of prediction of postoperative IOL position have been reported. This article attempts to give a review about the research progress on prediction of the postoperative IOL position.

Comparison of intraocular lens tilt after capsular sutured scleral fixation with capsular segments versus uneventful cataract surgery.

To evaluate and compare intraocular lens (IOL) tilt between uneventful phacoemulsification with in-the-bag IOL implantation and sutured scleral fixation (SSF) of the lens bag with a capsular tension segment (type 6 D / Morcher) using a Sheimpflug camera. Clinical Practice, Hospital. Barcelona and A Coruña, Spain. Retrospective, comparative multicenter study. IOL tilt was compared between patients who underwent sutured scleral fixation with a capsular tension segment in a single eye (SSF group, n = 15) with patients who underwent uneventful IOL implantation (control group, n = 12) that were matched by biometric measurements. Post-operative refractive accuracy of biometric formulas by means of mean absolute error (MAE) was also reported. All patients underwent a general ophthalmic evaluation, anterior segment photography, and postoperative optical biometry (Zeiss IOLMaster® 500). In addition, IOL tilt was measured with a Scheimpflug camera (Pentacam R, Oculus Optikgerate Gmbh). Mean vertical tilt was similar in both groups (2.20+/-2.47° SSF vs 1.97 +/- 1.79° control; p = 0.836) but mean horizontal tilt tended to higher values in the SSF series (2.09 +/- 2.74° vs 0.94 +/- 1.17°; p = 0.139). Considering post-operative refractive error in diopters by MAE calculations, there was an underestimation of IOL power in the SSF group which was only statistically significant for Barrett Universal II (1.07 vs 0.32; p = 0.028) and Hill-RBF (0.95 vs 0.26; p = 0.024) formulas, but not for SRK/T (0.99 vs 0.42; p = 0.285) and Kane (0.96 vs 0.33; p = 0.083). Sutured scleral fixation of capsular tension segments in the presence of zonular instability does not seem to induce clinically significant IOL tilt compared to uneventful cataract extraction cases.

Astygmatyzm w kontekście operacji usunięcia zaćmy z wykorzystaniem torycznych soczewek wewnątrzgałkowych – aktualny przegląd piśmiennictwa

Assessment and management of astigmatism is often difficult, and one of the specific situations in which this problem must be faced is when a patient with astigmatism is qualified for cataract surgery. A relatively predictable method of astigmatism correction during a single procedure and also the method of choice in the treatment of cataracts accompanied by corneal astigmatism is cataract phacoemulsification with implantation of toric intraocular lenses. The aim of the study is to review the current literature on this topic. The prevalence of corneal astigmatism ≥1.0 D in patients with cataract varies in various studies from 34.8 to 66.9%, which illustrates the scale of demand for this procedure. The paper discusses the key aspects of pre-operative assessment of astigmatism, including the changes that occur with the aging process. The importance of measuring the posterior corneal astigmatism and the consequences of its neglect in the form of deviations in the assessment of total corneal astigmatism and postoperative residual refractive errors were emphasized. Attention was paid to available updates of toric calculators and innovations in cases of irregular astigmatism.

Results of surgical treatment of children with lens subluxation

AIM: To assess the effectiveness of the surgical treatment of patients with lens subluxation, who were under 18 years old.&#x0D; MATERIAL AND METHODS: This study presented an analysis of the results of surgical treatment of eight patients with lens subluxation. The operations were performed in the Department of Ophthalmology of the State Healthcare Institution of Healthcare MCMC “Bonum,” carried out in 2020–2022. The inclusion criteria were as follows: age under 18 years, Marfan-like phenotype, stages 2–4 subluxation, absence of retinal changes and other eye pathologies, and surgical treatment performed in 2020–2022. The mean age at the detection of lens subluxation was 3.9±2.0 years, and the age during primary surgery was 5.4±1.9 years. All patients underwent phacoaspiration of the subluxated lens with anterior vitrectomy, simultaneous implantation, and sclerocorneal fixation of the intraocular lens by the same surgeon using the same equipment and consumables.&#x0D; RESULTS: The ophthalmological status was mainly assessed, and a statistical difference (p 0.05) was found between pre- and postoperative indicators. Before surgery, the maximum corrected visual acuity was 0.15±0.12 (min 0.02; max 0.5); spherical equivalent, 6.8±4.7 (min -15; max +16); total astigmatism value, 3.25±1.15 (min, 1; max, 6.5); and corneal astigmatism, 2.4±0.9 (min, 1; max, 3.9). After the surgical treatment, the maximum corrected visual acuity was 0.53±0.31 (min, 0.05; max, 0.9); spherical equivalent, −0.6±1.71 D (min −3.5; max +3); total astigmatism, -1.63±0.75 D (min, -0.25; max, −2.75); corneal astigmatism, 2.4±0.7 D (min 1; max 3.5). All operations were performed without complications. The postoperative period in patients was regarded as unreactive.&#x0D; CONCLUSION: The results show that sclerocorneal fixation allows for reliable and safe fixation of intraocular lenses without capsule support. A statistically significant increase in visual acuity was found after surgery; however, for optimal functional results in the postoperative period, refractive errors and pleoptic treatment must be controlled.

Comparison of spherical equivalent determined by Sanders-Retzlaff-Kraff-II (SRK-II) formula with target post-operative final refraction in patients undergoing cataract surgery

The most challenging subject in patient satisfaction after cataract surgery depends upon post-operative refractive outcomes. Accurately predicting post-operative refraction is necessary during the calculation of Intraocular lens (IOL) power. The Sanders-Retzlaff-Kraff (SRK) II formula is one of the few formulae being used for the calculation of IOL power. Our study is to compare the accuracy of the SRK-II formula with targeted final refraction of patients undergoing phacoemulsification. This study was performed on 102 eyes that underwent phacoemulsification. IOL power was calculated using the SRK-II formula. One and a half months after surgery, refraction was performed. Differences between actual post-operative refraction and predicted spherical equivalent was calculated and termed absolute refractive error. Paired t-test was used for comparing actual post-operative refraction and predicted spherical equivalent.The mean absolute error (MAE) of the SRK-II formula was 0.44 D (diopters) overall. The percentage of eyes within ±0.5 D of the predicted spherical equivalent was 81%. Patients having post-operative refractive error within ±1.0 D for short, average, and long axial length were 88% (P value 0.21), 92% (P value 0.0009), and 91% (P value 0.18) respectively.We found that the SRK-II formula was accurate and reliable for predicting the post-operative refractive error in eyes with normal axial lengths as the post-operative refraction is near emmetropia and is a good method for IOL power calculation with normal axial lengths.

Comparison of Biometric Formulae for Intra Ocular Lens Power Calculation

Purpose: To determine the accuracy of different biometric formulae for intraocular lens power (IOL) calculation in predicting a target postoperative refraction within ± 1.0 diopters in patients with long axial length undergoing phacoemulsification. Study Design: Cross sectional study. Place and Duration of Study: Department of Ophthalmology and visual sciences, Unit 1 Dow University of Health Sciences, Dr. Ruth KM Phau Civil Hospital Karachi from February 2019 to August 2019. Methods: The study included 45 eyes with cataract and preoperative uncorrected visual acuity ranging from 6/60-6/12, axial length of 24.5 to 27.0 mm with no other ocular problem. IOL power was calculated with SRK-T, Holladay 1 and Haigis formula installed in optical biometer AL-Scan (Nidek Co, Ltd., Gamagori, Japan) and by Barrett universal 2 formula from http://www.apacrs.org/barrett_universal2/. Patients underwent phacoemulsification by single surgeon. Follow up included refractive status using Autorefractokertometer, URK-700 (Unicos Co., Ltd., Korea) at 6th week post-operatively. Deviation of actual postoperative refraction from the predicted target preoperative refraction were calculated and values within ± 1.0 diopter were considered accurate. Data was analyzed using SPSS version 22. Results: Outcome in terms of postoperative refractive error (+1D to -1D) with respect to biometric formula showed 100% accuracy using Haigis formula, 90% accuracy using SRK-T formula, 72.72% accuracy using Barrett universal II formula and 66.67% accuracy using Holladay-1 formula. Conclusion: Haigis formula proved to be more reliable and accurate than SRK-T, Holladay 1 and Barrett universal II formulae for calculation of intraocular lens power in eyes with long axial length.

Comparison of dominant- and non-dominant-hand cateract surgery outcomes by a single surgeon

PurposeTo compare dominant and non-dominant hand phacoemulsification surgery outcomes. MethodsThis retrospective, single-center study included 300 patients who underwent phacoemulsification surgery by a single, right-handed surgeon. The patients were divided into two groups according to whether the surgeon used his dominant or non-dominant hand during surgery. Right eye operations were performed with the right hand, and left eye operations were performed with the left hand. Detailed ophthalmological examinations were performed on all patients preoperatively and postoperatively. Intraoperative phacoemulsification parameters, the presence of intraoperative and postoperative complications, postoperative refractive errors, visual acuity, and surgically induced astigmatism values were compared between the groups. ResultsThere were 171 patients in the dominant hand phacoemulsification group and 129 patients in the non-dominant hand phacoemulsification group. The distributions of age, gender, systemic diseases, and lens opacification were similar between the groups (p>0.05, for all). No statistically significant difference was observed between the two groups in terms of total operation time, phaco power, ellips fx, or ultrasonic time (p>0.05, for all). There was also no significant difference in relation to intraoperative and postoperative complication distributions, postoperative third-month refractive errors, visual acuity, or surgically induced astigmatism values (p>0.05, for all). ConclusionThis study demonstrated that cataract surgery performed by a single surgeon can be effectively and safely performed using both hands on patients in a real operating theater environment. More objective results can be obtained with surgeries performed by a larger number of experienced surgeons.

Ray-tracing-guided myopic LASIK: real-world clinical outcomes.

To assess effectiveness of individualized ray-trace based laser in situ keratomileusis (LASIK) for correction of myopia in everyday clinical practice. Single-site private practice. Retrospective nonrandomised unmasked chart review. Consecutive, myopic eyes (range ≤-8.25 diopters [D] sphere; astigmatism 0 to -4.25 D) treated with ray-trace based LASIK were included. Patients underwent wavefront, tomography, and biometry assessment using the InnovEyes Sightmap diagnostic device. The ray-trace based algorithm (InnovEyes algorithm) then generated an individualized 3D eye model and calculated a customized LASIK ablation profile. Postoperative visual acuity, refractive error and whole eye higher-order aberrations (HOAs) were evaluated over 3 months. The procedure was performed on 400 eyes (200 patients). Mean preoperative manifest refraction spherical equivalent was -3.39 ± 1.58 D (right eye -3.84 ± 1.63 D, left eye -3.98 ± 1.75 D). At month 3, uncorrected distance visual acuity (UDVA) was ≥20/20 in all eyes, ≥20/16 in 89% (right eye 90%, left eye 89%), ≥20/12 in 51% (54% right eye; 47% left eye), and 20/10 in 8% (right eye 8%; left eye 9%) of eyes respectively. UDVA was within 1 line of preoperative corrected distance visual acuity in 98% of eyes (right eye 98.5%; left eye 98%) and 39% of eyes (right eye 38%; left eye 39%) gained 1 line improvement. There was a statistically but not clinically significant increase in total HOAs (right eye 0.06 ± 0.133 μm; left eye 0.057 ± 0.125 μm; P < .001). The spherical aberration decreased (right eye -0.047 ± 0.095 μm, P < .001; left eye -0.051 ± 0.091 μm, P < .001). Ray-trace based LASIK was safe and effective for correction of myopia with and without astigmatism. Approximately, half the eyes achieved ≥20/12.5 UDVA and 8% achieved 20/10. There was no clinically significant increase in total whole eye HOAs.

Multifocal Polypseudophakia With Rayner Sulcoflex Trifocal and In-the-Bag Alcon PanOptix Diffractive Trifocal Intraocular Lenses: A Case Report

Purpose: To describe the use of a sulcus diffractive multifocal intraocular lens (IOL) used in series with an intracapsular diffractive multifocal IOL to improve uncorrected near visual acuity (UNVA). Methods: A 66-year-old pseudophakic woman with bilateral multifocal IOLs presented with symptoms of negative dysphotopsia and poor reading vision in the right eye. A diffractive multifocal sulcus IOL was inserted in the right eye. Results: After 1 month, the patient's right UNVA had improved from N10 to N6. Subjectively there was a 50% improvement in negative dysphotopsia and no increase in photic phenomena. Conclusions: A diffractive trifocal secondary sulcus IOL can be used in series with an intracapsular diffractive trifocal lens. The success of this approach suggests that it may be used to both improve negative dysphotopsia and address postoperative refractive error. [ Journal of Refractive Surgery Case Reports. 2023;3(4):e53–e55.]

Accuracy of Intraocular Lens Power Estimation in Aphakic Eyes Filled with Silicone Oil

Purpose: To compare preoperative refractive power estimation and actual postoperative refraction after combined silicone oil removal and intraocular lens (IOL) sulcus implantation in silicone oil-filled aphakic eyes.Methods: Records of patients with silicone oil-filled aphakic eyes who received simultaneous silicone oil-removal and IOL sulcus implantation (Group1) and aphakic patients who received vitrectomy combined with IOL implantation (Group 2) were reviewed. Optical biometry including axial length measurements were obtained using IOL master&lt;sup&gt;®&lt;/sup&gt; 700 and predicted refractive errors, actual postoperative refractive errors were examined retrospectively.Results: Predicted refractive errors, calculated by subtracting 1 diopter (D) from myopic lens power closest to plano based on sulcus implantation, were 0.50 ± 0.12 D in Group 1, 0.45 ± 0.20 D in Group 2. Six months after operation, mean refractive errors measured -0.76 ± 0.49 D in Group 1, -0.23 ± 0.49 D in Group 2, showing significant myopic shift (&lt;i&gt;p&lt;/i&gt; &lt; 0.001, &lt;i&gt;p&lt;/i&gt; &lt;0.001). Group 1 showed larger significant myopic shift compared to Group 2 (&lt;i&gt;p&lt;/i&gt; = 0.001), especially in 3 eyes with insufficient filling of intravitreal silicone oil showing -1.5 D myopic shift.Conclusions: Ocular biometry of silicone oil-filled aphakic eyes undergoing simultaneous silicone oil removal and IOL sulcus implantation are difficult to measure, showing postoperative myopic shift compared to control. Incomplete intravitreal silicone oil filling showed larger refractive errors needing additional compensations.

Correlation between anterior chamber depth changes and post operative refractive error after phacoemulsification

: There is an increase in patient demands and satisfaction with post-operative visual recovery. There are numerous factors affecting post-operative visual outcomes. One of the factors is the change in anterior chamber depth post-operatively. The following study was planned to assess the changes in anterior chamber depth post- operatively and determine the correlation with post-operative refractive errors in patients who had cataracts and underwent phacoemulsification with intraocular lens (IOL) implantation. : This prospective cohort study was conducted in 120 eyes. The cases diagnosed with cataract underwent phacoemulsification. Preoperative and post-operative anterior chamber depths were obtained and post-operative spherical equivalent of refractive errors were noted at 4 weeks.: Smaller anterior chamber depths had a larger amount of deepening of the anterior chamber (ACD difference&amp;#62;1.22mm) after cataract surgery and vice versa (r= -0.46, p&amp;#60;0.01). Post-operative refractive error showed hyperopic shift when the change in AC depth was small (&amp;#60;1.22mm) and myopic shift when the change in AC depth was large (&amp;#62;=1.22mm). : There is a definite correlation between AC depth difference and post-operative spherical refractive error (r= -0.41, p&amp;#60;0.01).

Relationship Between Postoperative Residual Refractive Error and Preoperative Corneal Stiffness in Small Incision Lenticule Extraction.

To explore the relationship between postoperative residual refractive error and preoperative corneal stiffness after small incision lenticule extraction (SMILE). Hospital clinic. Retrospective cohort study. Corneal stiffness was evaluated using the stress-strain index (SSI). Associations between postoperative spherical equivalent (SE) and corneal stiffness were determined using longitudinal regression analysis after adjustment for sex, age, preoperative SE, and other variables. The cohort was divided into halves to compare risk ratios for residual refraction in corneas with different SSI values. Low SSI values were defined as having "less-stiff corneas" and others as having "stiffer corneas." 287 patients (287 eyes) were included. Greater undercorrection was found in less-stiff corneas across all follow-up time points (less-stiff corneas: 1 day: -0.36±0.45 D, 1 month: -0.22±0.36 D, 3 months: -0.13±0.15 D; stiffer corneas: -0.22±0.37 D, -0.14±0.35 D, -0.05±0.11 D, respectively). Postoperative refraction exhibited an average 0.05-D undercorrection for every 0.1-unit decrease in SSI after adjustment for variables. SSI accounted for nearly 10% of the variance in retractive outcomes. Less-stiff corneas increased the risk ratio of postoperative absolute SE >0 D and ≥0.25 D by 2.242 (95% confidence interval [CI]: 1.334, 3.768) and 3.023 (95% CI: 1.466, 6.233), respectively, compared to stiffer corneas. Postoperative residual refractive error was associated with preoperative corneal stiffness. Patients with less-stiff corneas had a 2-3-fold increased risk of residual refractive error post-SMILE. Preoperative analysis of corneal stiffness can help modify nomogram algorithms of surgery and improve the predictability of refractive outcomes.

Refractive outcomes of toric intra-ocular lens implantation in cases of high posterior corneal astigmatism.

To evaluate whether the toric intra-ocular lens (IOL) power calculation based on total corneal astigmatism (TCA) in eyes with high posterior corneal astigmatism (PCA) could result in a systematic over-correction or under-correction after operation. The present study included a mono-centric retrospective study design. The data were collected from 62 consecutive eyes during uncomplicated cataract surgery by a single surgeon with a measured PCA of 0.50 diopters (D) or higher. Toric IOL calculations were made using TCA measurements. The eyes were grouped as either "with-the-rule" (WTR) or "against-the-rule" (ATR) on the basis of the steep anterior corneal meridian. The post-operative refractive astigmatic prediction error was analyzed 1 month post-operatively using the vector analysis by the Alpins method and double-angle plots method. The correction indexes were 1.14 ± 0.29 in the ATR eyes and 1.25 ± 0.18 for the WTR eyes, indicating a tendency toward over-correction. The mean over-correction was 0.22 ± 0.52D in the ATR group and 0.65 ± 0.60D in the WTR group. The magnitude of error (ME) values were significantly different from the ideal value of zero in both groups (ATR: P = 0.03; WTR: P = 0.00). No significant difference in mean absolute error (MAE) in predicted residual astigmatism was found between ATR and WTR groups (0.61 ± 0.42 D versus 0.64 ± 0.39 D; P = 0.54). The ATR group yielded better results, with 48% <0.50D prediction error in the main analysis. The results suggested that in cases of high PCA, the toric IOL calculation, which was performed using TCA, may cause a potential over-correction in the ATR and WTR eyes. For ATR eyes, over-correction led to slight disruption of post-operative visual quality because of the "with-the-rule" residual astigmatism after operation. Therefore, we suggested using TCA for toric IOL calculation in ATR eyes.