Five-year follow-up of a posterior chamber phakic intraocular lens with a central hole for correction of myopia.

PURPOSE: To evaluate intermediate and long-term visual outcomes and safety of a phakic intraocular posterior chamber lens with a central hole (ICL V4c) for myopic eyes. METHODS: Retrospective, consecutive case study of patients that uneventfully received a ICL V4c for myopia correction, with a 5-year postoperative follow-up. Department of Ophthalmology, Goethe University Frankfurt, Germany. RESULTS: From 241 eyes that underwent ICL implantation, we included 45 eyes with a mean age at surgery of 33 years ± 6 (18-48 years), with a 5 years follow-up. CDVA improved from 0.05logMAR ± 0.15 CDVA preoperatively to - 0.00 ± 0,07 at 5 years and did not change significantly from 3 to 5 years' time (p = 0.266). The mean spherical equivalent (SE) improved from -10.13D ± 3.39 to - 0.45D ± 0.69. The change in endothelial cell count showed a mean decrease of 1.9% per year throughout the follow-up. Safety and efficacy index were 1.16 and 0.78, respectively. Cataract formation was seen in 2 of 241 eyes (0.8%), but in none of the 45 eyes that finished the 5-year follow-up. CONCLUSIONS: Our data show a good intermediate and long-term stability, efficiency, and safety of ICL V4c phakic lenses in myopic eyes comparable to other known literature.

Effect of the iridocorneal angle size on the diurnal pressure profile in a glaucoma suspect cohort and patients with glaucoma.

PURPOSE: To evaluate the impact of the iridocorneal angle size (ICAS) on the diurnal intraocular pressure (IOP) in patients with suspected glaucoma (SG). METHOD: Patients with any eye-pressure lowering medication or previous ocular surgery were excluded. In a retrospective study set, diurnal IOP profiles of 120 patients (205 eyes) within a 48-h period were analysed by regression analysis. Of those eyes, 44 were diagnosed to have glaucoma. The remaining eyes were used as healthy control group (HCG). RESULTS: The overall mean IOP was 15.63 mmHg ± 2.72 mmHg and mean ICAS was 23.92° ± 4.74°. In the glaucoma cohort, mean IOP was 18.77 ± 1.86 mmHg and mean ICAS was 25.02° ± 4.96°. In the HCG, mean IOP was 14.77 ± 2.25 mmHg and mean ICAS was 23.62° ± 4.64°. In the total cohort, as well as in the subgroups (HCG or glaucoma), regression analysis showed no significant impact even of the minimum ICAS, which was larger than 10°, on average (P = 0.89), maximum (P = 0.88), and range of IOP (P = 0.49) within 48 h. The difference between glaucoma cohort and HCG cohort was significant in terms of IOP (P < 0.001), but not for minimum ICAS (P = 0.07). Chi-square test showed no increase in prevalence of IOP peaks of  > 21 mmHg within 48 h in eyes with an angle between 10° and 20° (P = 0.18). CONCLUSION: An ICAS of larger than 10° in HCG or glaucoma patients with an open-angle does not influence the minimum, average, maximum or range of IOP. Additionally, an angle size larger than 10° does not allow the prediction of IOP changes in these two cohorts.

Comparison of Visual and Refractive Outcome between Two Methods of Corneal Marking for Toric Implantable Collamer Lenses (TICL) in Phakic Eyes.

PURPOSE: To compare the efficacy of digital-assisted reference marking for toric implantable collamer lenses (Callisto Eye System) with manual marking technique using a slit lamp markeur. METHODS: This study included patients that underwent implantation of a toric implantable collamer lens (EVO Visian toric ICL, Staar Surgical). Patients were included if they had a myopia above -3 diopters (D) and regular corneal astigmatism of 0.75 diopters or higher. Between both groups a 1:2 matching regarding similar preoperative level of myopia and astigmatism was performed. Visual and refractive outcomes were evaluated. Vector analysis was performed to evaluate total astigmatic changes. RESULTS: This study comprised 57 eyes of 57 patients with 19 eyes in the digital group and 38 eyes in the manual marking group. Postoperatively there were no statistically significant differences between both groups in UDVA (p = 0.467), spherical equivalent (SE) (p = 0.864), sphere (p = 0.761) and cylinder (p = 0.878). Vector analysis showed a slightly more accurate postoperative refractive astigmatism in the manual group (0.26 D at 107° ± 0.50 D) compared to the digital marking group (0.31 D at 107° ± 0.45 D), nevertheless with no statistically significant differences between both groups. CONCLUSIONS: A digital tracking approach for toric ICL alignment was an efficient and safe method for toric marking with similar results regarding visual and refractive outcomes compared to a conventional corneal marking method. Nevertheless, image-guided surgery helped to streamline the workflow in refractive ICL surgery.

Determining the center of a keratoconus: Comparison of different tomographic parameters and impact of disease severity.

Purpose: There exists remarkable variation in definitions for the location of the center of a keratoconus. The objective of this study was to analyze deviations between locations obtained by different tomographic maps for that purpose. Furthermore, it was investigated whether these deviations are influenced by disease severity. Methods: In 162 eyes with keratoconus, corneal tomographic maps derived by Scheimpflug technology were retrospectively analyzed to determine the cone location with 5 different methods: maximum axial curvature of the front surface (Kmax), maximum tangential curvature of the front surface (tKmax), minimum pachymetry (Pachymin), maximum elevation of the front surface (ELEF), and maximum elevation of the back surface (ELEB). Distances between the locations were calculated and tested for a correlation with keratoconus severity and distance between cone and corneal vertex. Results: Cone locations derived from the curvature maps (Kmax, tKmax) showed the lowest agreement with the locations determined by pachymetry or elevation maps. The largest distances were found between Kmax and Pachymin [Median and Interquartile range: 1.19 mm (0.87, 1.60)], Kmax and ELEB [1.12 mm (0.79, 1.41)], and Kmax and ELEF [0.97 mm (0.64, 1.27)]. Low distances (<0.5 mm) were calculated between ELEB and ELEF, and ELEB and Pachymin. All of the calculated distances between the locations showed a significant negative correlation with keratoconus severity and most of them increased significantly with a more peripheral position of the cone (p < 0.05). Conclusions: There was low consistency between different methods for describing the location of a keratoconus. Curvature-based determinations of the cone center (Kmax, tKmax) showed the highest deviations and should not be used for that purpose. However, the discrepancies between different cone location methods diminished with increasing disease severity and more central position of the cone.

[Preliminary Examination Before Cataract Surgery]. / Voruntersuchung bei Kataraktoperation.

To plan and execute a successful and safe cataract surgery one must conduct a structured, goal- and patient-oriented examination. The medical history provides crucial information regarding the planning of the anesthetic procedure, lens selection and possible intraoperative complications. Visual acuity and refraction measurements are essential for both documentation and discussion of the selected target refraction. Multifocal lenses have various contraindications to which attention must be paid during slit lamp examination and other imaging diagnostics. These include epithelial basement membrane dystrophy, Fuchs' endothelial dystrophy, zonular weakness, and progressive retinal diseases such as progressive AMD. Tomography reveals corneal irregularities as well as possible refractive laser treatments that have been performed previously. Lens calculation is complicated in these cases. Additionally, an endothelial cell count, aberrometry to rule out higher order aberrations, pupillometry and an analysis of the tear film can provide further information. The patient must be informed verbally about the severity of the procedure and the risks relevant for him with sufficient distance to the surgery.

[Phototherapeutic keratectomy for recurrent corneal erosion of various epithelial origins: influence of depth of ablation on pachymetry and refraction]. / Phototherapeutische Keratektomie bei rezidivierenden Hornhauterosionen verschiedener epithelialer Genese: Einfluss der Ablationstiefe auf Pachymetrie und Refraktion.

BACKGROUND: Phototherapeutic keratectomy (PTK) is an established treatment method for patients suffering from either genetic corneal dystrophy or recurrent corneal erosion (RCE) without underlying basement membrane dystrophy, often caused by trauma. OBJECTIVE: This study aimed to describe the changes in manifest subjective refraction and pachymetry after PTK treatment in patients suffering from epithelial basement membrane dystrophy (EBMD) and traumatic or atraumatic RCE without underlying EBMD. MATERIAL AND METHODS: This was a retrospective, single-center study performed at the Department of Ophthalmology of the Ludwig-Maximilians University (Munich). Patient data were retrospective collected using the smart-eye database of the Department of Ophthalmology including diagnostic data from an autorefractometer and from the Pentacam HR. All laser treatments were performed with an ablation depth of 10 µm for EBMD patients and 6 µm for RCE patients without EBMD. RESULTS: Both collectives showed a decrease in pachymetry larger than the calculated ablation depths after a follow-up interval of 126 days (95% CI 104-147 days). While the EBMD collective receiving an ablation of 10 µm showed a decrease of 25.8 µm (N = 74; 95% CI 21.2-30.3; p < 0.001), the non-EBMD collective receiving an ablation of 6 µm showed a decrease of 12.3 µm (N = 44, 95% CI 7.0-17.7; p < 0.001). Both, total corneal refractive power (TCRP) as well as spherical equivalent (SE) offered no significant change in preoperative and postoperative comparison for the EBMD collective. On the other hand, patients without underlying EBMD showed a significant myopic decrease in SE of 0.4 dpt (±0.7 dpt SD, p < 0.05). The mean follow-up interval was 126 days (95% CI 104-147 days). CONCLUSION: PTK treatment offers an effective method for patients suffering from either EBMD dystrophy or RCE syndrome without underlying EBMD. The final ablation based on pachymetry at the apex can be estimated at 2.3 to 2.6 times higher compared to the original ablation depth. The reasons for this are on the one hand the laser ablation itself and the influence of the reactive wound healing of the corneal epithelium.

Saving of Time Using a Software-Based versus a Manual Workflow for Toric Intraocular Lens Calculation and Implantation.

Background: To determine whether there is a significant saving of time when using a digital cataract workflow for digital data transfer compared to a manual approach of biometry assessment, data export, intraocular lens calculation, and surgery time. Methods: In total, 48 eyes of 24 patients were divided into two groups: 24 eyes were evaluated using a manual approach, whereas another 24 eyes underwent a full digital lens surgery workflow. The primary variables for comparison between both groups were the overall time as well as several time steps starting at optical biometry acquisition until the end of the surgical lens implantation. Other outcomes, such as toric intraocular lens misalignment, reduction of cylinder, surgically induced astigmatism, prediction error, and distance visual acuity were measured. Results: Overall, the total diagnostic and surgical time was reduced from 1364.1 ± 202.6 s in the manual group to 1125.8 ± 183.2 s in the digital group (p < 0.001). The complete time of surgery declined from 756.5 ± 82.3 s to 667.3 ± 56.3 (p < 0.0005). Compared to the manual approach of biometric data export and intraocular lens calculation (76.7 ± 12.3 s) as well as the manual export of the reference image to a portable external storage device (26.8 ± 5.5 s), a highly significant saving of time was achieved (p < 0.0001). Conclusions: Using a software-based digital approach to toric intraocular lens implantation is convenient, more efficient, and thus more economical than a manual workflow in surgery practice.

Novel surgical technique of sutureless artificial iris and intraocular lens scleral fixation using Yamane technique.

Purpose: To describe a novel surgical technique of a combined implantation of an artificial iris and a scleral fixated intraocular lens (IOL) using flanged IOL haptics ("Yamane" technique). Observations: The suturelessly implanted artificial iris-IOL-sandwich was stable with good functional as well as aesthetic results. However, our case showed a postoperative intraocular pressure rise. Conclusions: The presented case demonstrates that a visual as well as cosmetical rehabilitation seems to be possible even after severe, penetrating ocular trauma with profound iris defects. Importance: The sutureless IOL scleral fixation technique can also be used in combination with a sutureless artificial iris implantation. Further studies are needed to evaluate the long-term safety profile and rates of postoperative complications.

Impact of DMEK on visual quality in patients with Fuchs' endothelial dystrophy.

PURPOSE: To investigate short-term (3 months follow-up) changes in visual quality following Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy (FED). METHODS: In this prospective institutional case series, 51 patients that underwent DMEK for FED were included. Assessment included the Quality of Vision (QoV) questionnaire preoperatively, at 1 month, and 3 months after surgery. Secondary outcome measures were anterior segment parameters acquired by Scheimpflug imaging, corrected distance visual acuity (CDVA), and endothelial cell density (ECD). RESULTS: Glare, hazy vision, blurred vision, and daily fluctuation in vision were the symptoms mostly reported preoperatively. All symptoms demonstrated a significant reduction of item scores for severity, frequency, and bothersome in the course after DMEK (P < 0.01). Glare and fluctuation in vision remained to some extent during the follow-up period (median score = 1). Preoperatively, corneal densitometry correlated moderately to weakly with severity of hazy vision (rs = 0.39; P = 0.03) and frequency (rs = 0.26; P = 0.02) as well as severity (rs = 0.27; P = 0.03) of blurry vision. CDVA and central corneal thickness (CCT) did not correlate with visual complains. CONCLUSIONS: Following DMEK for FED, patient-reported visual symptoms assessed by the QoV questionnaire represent a useful tool providing valuable information on the impact of DMEK on visual quality that cannot be directly estimated by morphological parameters and visual acuity only.

OCT- versus Scheimpflug-based Total Corneal Power Measurements Changes in Myopic Astigmatic SMILE Procedures.

PURPOSE: To evaluate the value of total keratometry (TK) to estimate corneal power in eyes that underwent SMILE for treatment of myopia or myopic astigmatism in subgroups of low and high astigmatism. METHODS: The difference between preoperative and postoperative measurements of corneal power (ΔTCRP, ΔTK) was compared with the surgically induced refractive change at the corneal plane (ΔSEco) by Pearson correlation. Vector analysis of TCRP- and TK-derived astigmatism was performed to evaluate the corneal astigmatism. Single-angle plots were generated with the AstigMATIC tool for standard astigmatism vector analysis. RESULTS: Paired t-test revealed statistically significant differences in preoperative (p = .02) and postoperative (p = .0455) measurements between TK and TCRP in the group of high-level astigmatism and the postoperative low astigmatism group (p < .01). No significant differences were found in preoperative data in the group of low-level astigmatism (p = .60). The correlation of ΔSEco and TK (low astigmatism, R2 = 0.978; high astigmatism R2 = 0.980) was stronger than the correlation of TCRP 4.0 mm and ΔSEco (low astigmatism, R2 = 0.743; high astigmatism R2 = 0.959) in both astigmatic groups. The vector analysis demonstrated nearly identical results concerning the correction index (CI) for TK and TCRP. Comparing the difference vector (DV) between both parameters, TK-derived results were closer to the optimum. CONCLUSIONS: The findings endorse TK as a reliable measure of corneal power after SMILE in patients with low and high astigmatism.

Femtosecond laser-assisted descemetorhexis for Descemet membrane endothelial keratoplasty: cell-based and tissue-based ex vivo analysis of precision and safety.

PURPOSE: To analyze precision and safety of femtosecond laser-assisted descemetorhexis and postoperative corneal wound healing in human ex vivo specimens. SETTING: Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany. DESIGN: Experimental ex vivo study. METHODS: 4 donor corneas underwent femtosecond laser-assisted descemetorhexis. The descemetorhexis was performed using the LDV Z8 femtosecond laser, followed by live/dead staining, phase contrast microscopy, and scanning electron microscopy. The descemetorhexis parameters were set using a modified optical coherence tomography image capturing of 8 segments within a focus of 100 µm at the posterior corneal stroma (reversed capsulotomy program). RESULTS: Live/dead sample staining analysis demonstrated that the femtosecond laser had minimal impact on the vitality of surrounding endothelial cells. Phase contrast microscopy and scanning electron microscopy evaluation showed that the laser produced precise, clear-cut edges, leaving no stromal tissue bridges. CONCLUSIONS: Femtosecond laser-assisted descemetorhexis could serve as a safe and precise technique with only minimal endothelial cell damage. To minimize stromal damage, further laser energy profile adjustments are necessary to optimize corneal treatment within different stages of corneal tissue swelling.

Electron microscopy analysis of femtosecond laser-assisted capsulotomy before and after lens fragmentation.

Studying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with "valleys and mountains " as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.

Reliability of Corneal, Epithelial, and Stromal Thickness Mapping for a 9-mm Zone Using Spectral-Domain Optical Coherence Tomography.

PURPOSE: To evaluate the reliability of spectral-domain optical coherence tomography (SD-OCT; RTVue XR; Optovue, Inc., Fremont, CA, USA) for thickness mapping of the entire cornea (CT), corneal epithelium (ET). and corneal stroma (ST) over a 9-mm zone in healthy eyes. We sought to develop reference values for different age groups and elucidate potential sex- and age-dependent characteristics of corneal sublayer pachymetry maps. METHODS: Three consecutive SD-OCT scans were obtained in 166 healthy right eyes (mean age = 50 ± 20 years). The thickness maps contain 25 sectors over a 9-mm diameter zone. To test measurement reliability, intraclass correlation coefficients (ICC), coefficients of variation (CoV), and within-subject standard deviations (WSSD) were calculated. RESULTS: CT, ET, and ST ICCs ranged from 0.961 to 0.998, 0.896 to 0.945, and 0.955 to 0.998, respectively. CoV values for CT, ET, and ST ranged between 0.3 and 1.5%, 1.6 and 4.2%, and 0.4 and 1.7%, respectively. WSSD ranged from 6 to 41, 4 to 8, and 7 to 46 µm, respectively. A negative correlation was found between age and ET (p < 0.05) but not between age and ST or CT. No gender-related differences in CT, ET, or ST were detected. CoV of CT, ET, and ST measurements showed a positive correlation with age in 28, 64, and 28% of the sectors, respectively. CONCLUSION: SD-OCT is a rapid and noninvasive technique that provides excellent reliability for corneal sublayer thickness measurements over a 9-mm zone. The reliability of the ET measurement seems to be negatively affected by age. Peripheral CT and global ET thin with age.

Effects of the First COVID-19 Lockdown on Ophthalmological Patient Care.

PURPOSE: To determine the effect of lockdown on medical care, with the example of ophthalmology. METHODS: Patients in a period during the first lockdown were compared to a non-lockdown period, with a total of 12 259 patients included in an observational study. Changes in different areas (elective, emergency, inpatients, surgeries) and eye care subspecialties were compared. Emergency patients were analyzed according to severity and urgency. Patients showing hints requiring treatment for urgent cardiovascular diseases were determined. Differences in patients who would have suffered severe vision loss without treatment were identified and the QALY (quality-adjusted life years) loss was determined accordingly. A model to prioritize patient visits after the end of lockdown or in future lockdown scenarios was developed. Data were collected at the University Eye Hospital LMU Munich and patient files were reviewed individually by ophthalmologists. RESULTS: The average patient number decreased by - 59.4% (p < 0.001), with a significant loss in all areas (elective, emergency, inpatients, surgeries; p < 0.001). There was a decline of - 39.6% for patients at high risk/high severity. Patients with indications of a risk factor of future stroke declined significantly (p = 0.003). QALY loss at the university eye hospital was 171, which was estimated to be 3160 - 24 143 for all of Germany. Working up high losses of outpatients during these 8 weeks of projected lockdown in Germany would take 7 - 23 weeks under normal circumstances, depending on ophthalmologist density. The prioritization model can reduce morbidity by up to 78%. CONCLUSION: There was marked loss of emergency cases and patients with chronic diseases. Making up for the losses in examinations and treatments will theoretically take weeks to months. To reduce the risk of morbidity, we recommend a prioritization model for rescheduling and future lockdown scenarios.

Impact of Pseudoexfoliative Syndrome on Effective Lens Position, Anterior Chamber Depth Changes, and Visual Outcome After Cataract Surgery.

PURPOSE: To compare the effective lens position (ELP), anterior chamber depth (ACD) changes, and visual outcomes in patients with and without pseudoexfoliation syndrome (PEX) after cataract surgery. DESIGN: Prospective, randomized, fellow-eye controlled clinical case series. METHODS: This prospective comparative case series enrolled 56 eyes of 56 consecutive patients with (n = 28) or without PEX (n = 28) and clinically significant cataract who underwent standard phacoemulsification and were implanted with single-piece acrylic posterior chamber intraocular lenses (IOLs). The primary outcome parameters were the ACD referring to the distance between the corneal anterior surface and the lens anterior surface, which is an indicator of the postoperative axial position of the IOL (the so-called ELP) and distance corrected visual acuity (DCVA). RESULTS: Before surgery, the ACD was 2.54 ± 0.42 mm in the PEX group and 2.53 ± 0.38 mm in the control group (p = 0.941). Postoperatively, the ACD was 4.29 ± 0.71 mm in the PEX group and 4.33 ± 0.72 mm in the normal group, respectively (p = 0.533). There was no significant difference in ACD changes between groups (PEX group: 1.75 ± 0.74 mm, control group: 1.81 ± 0.61 mm, p = 0.806) and DCVA pre- (p = 0.469) and postoperatively (PEX group: 0.11 ± 0.13 logMAR, control group: 0.09 ± 0.17 logMAR, p = 0.245) between groups. CONCLUSION: Preoperative and postoperative ACD, as an indicator of ELP, between PEX eyes and healthy eyes after cataract surgery showed no significant difference. Phacoemulsification induced similar changes in eyes with PEX compared to healthy eyes.

Visual outcome after rhegmatogenous retinal detachment repair surgery in patients with multifocal vs monofocal intraocular lenses.

PURPOSE: To evaluate functional outcome after retinal detachment (RD) repair surgery in eyes with a multifocal intraocular lens (mIOL). SETTING: Ludwig-Maximilians-University, Munich, Germany. DESIGN: Single-center case control study. METHODS: 52 pseudophakic eyes with successful anatomical outcome after surgical RD repair were included. Retrospectively, 21 mIOL eyes were compared with a matched group of 21 monofocal eyes over 6 weeks. Prospectively, corrected distance visual acuity (CDVA) was evaluated over 12 months in these eyes. Furthermore, uncorrected distance, intermediate, and near visual acuity (UDVA, UIVA, and UNVA, respectively), defocus curves, and patient-reported outcomes were evaluated at 1 year in 24 mIOL eyes. RESULTS: 52 eyes of 48 patients comprised the study. The mean CDVA (logMAR) improved significantly from 1.35 ± 1.38 to 0.29 ± 0.37 at 6 weeks and remained stable at 12 months postoperatively in monofocal eyes (P = .001) and from 1.16 ± 1.2 to 0.37 ± 0.29 (6 weeks) and 0.20 ± 0.36 (12 months) in mIOL eyes (P = .001). Univariate factorial analysis of variance showed no statistically significant differences in CDVA at 6 weeks or 12 months postoperatively for IOL type or for preoperative macular status (P > .05). In the prospective cohort of 24 mIOL eyes, a mean CDVA of 0.13 ± 0.33 logMAR, UDVA of 0.21 ± 0.34 logMAR, UIVA of 0.17 ± 0.28 logMAR, and UNVA of 0.23 ± 0.32 logMAR was achieved. Macular status did not affect final outcome significantly (P > .05). Most patients stated they usually did not need spectacles; no patient wanted mIOL replacement. CONCLUSIONS: 1 year after successful anatomical repair after 23-gauge vitrectomy with gas tamponade, functionality of mIOL was restored, and CDVA was comparable with that of patients with monofocal IOL.

Predictability of Refractive Outcome of a Small-Aperture Intraocular Lens in Eyes With Irregular Corneal Astigmatism.

PURPOSE: To compare different new-generation biometric formulas and ray-tracing for small-aperture intraocular lens (IOL) (IC-8; Acufocus, Inc) implantation in patients undergoing cataract and refractive lens exchange surgery with highly irregular corneas. METHODS: This monocenter study included 17 eyes of 17 patients with highly irregular corneas of different genesis. Biometric and topographic corneal data were assessed using the IOLMaster 700 (Carl Zeiss Meditec) and Pentacam (Oculus Optkigeräte GmbH). Prediction and absolute error were compared after 3 months based on manifest refraction. Furthermore, change of total corneal refractive power in different corneal pathologies was also evaluated. For IOL power calculation, three fourth-generation IOL formulas were compared (Haigis, SRK-T, and Barrett Universal II). The dataset was then checked against ray-tracing and analyzed to improve prediction error in these highly irregular corneas. RESULTS: All patients showed an improvement in visual acuity postoperatively with a mean spherical equivalent of -1.22 ± 0.49 diopters (D). Overall comparison of the three formulas showed the Haigis formula to be superior in terms of the smallest deviation of predictive and absolute error. IOL calculations with ray-tracing were possible in all eyes, but showed inaccurate results with keratometric values of 48.00 D and greater. CONCLUSIONS: The IC-8 IOL is well suited for patients with lens exchange in highly irregular corneas. The Haigis formula seemed to be the most accurate in the patient group. Ray-tracing confirmed the results of biometric formulas up to a keratometric value of 48.00 D and should be compared with standard biometric formulas to address corneal irregularities and to minimize refractive surprises after surgery. A comparison with ray-tracing in eyes with a keratometric value of greater than 48.00 D should not be considered due to the inaccurate results. [J Refract Surg. 2021;37(5):312-317.].

Comparison of changes in corneal volume and corneal thickness after myopia correction between LASIK and SMILE.

Myopia is the most common refractive error. Surgical correction with laser is possible. LASIK and SMILE are the techniques currently most used. Aim of the study was to compare changes in corneal volume and thickness after the respective laser treatment. 104 eyes of 52 patients were matched based on refractive error into two equally sized groups, either treated with LASIK or SMILE. Measurements were obtained from the Scheimpflug camera (Pentacam) preoperatively and at 3 and 12 months postoperatively. 3 months postoperatively, the flapless SMILE procedure resulted in a significant overall greater loss of corneal volume (P < 0.01) and corneal thickness (P < 0.01) compared to LASIK. No significant difference was found when comparing the 3 to 12-months values in each group. Within the currently used ranges of refractive error correction, loss in central corneal thickness and corneal volume with SMILE is higher in comparison to LASIK. As greater loss in corneal volume and thickness might contribute to higher level of corneal instability maximum ranges of refractive error correction with SMILE should not supersede those set currently for LASIK until more long-term results on corneal ectasia are available for SMILE.

Safety and Efficacy of Current Sclera Fixation Methods for Intraocular Lenses and Literature Overview. / Sicherheit und Effektivität von aktuellen Sklerafixationstechniken für intraokulare Linsen und Literaturübersicht.

BACKGROUND: Evaluation of the three currently most common techniques for intraocular lens (IOL) sclera fixation: (1) Prolene suture with Hoffman sclera pocket (2) four-point GoreTex suture technique (3) sutureless flanged intrascleral IOL fixation with double-needle ("Yamane") technique. MATERIAL AND METHODS: Retrospective, clinical case series (chart review) at the Department of Ophthalmology, Ludwig-Maximilians-University (LMU), Munich, Germany. Enrolled in the study were 51 patients with 55 eyes. Best-corrected visual acuity (BCVA); manifest refraction (OR); corneal tomography (central corneal thickness, CCT); biometry; central macular thickness (CMT) by optical coherence tomography (OCT); intraocular pressure (IOP); and IOL type and IOL power were recorded and compared prior to and 3 - 12 months post IOL sclera fixation surgery. Pre- and postsurgery difference analysis was performed by Wilcoxon rank sum testing (z). RESULTS: Intrascleral fixation by GoreTex suture was performed in 14 (25.5%) eyes, by Prolene suture in 19 (34.5%,) and by Yamane technique in 22 (40.0%) eyes. Within the 3 - 12 months follow-up post scleral fixation, a total of 2 (14.3%) eyes from the GoreTex, 3 (15.8%) from the Prolene and 1 (4.5%) eye from the Yamane group required refixation. Pre- and post-surgery analysis revealed a statistically significant difference in the total patient population BCVA (exact Wilcoxon test: z = - 3.202; p = 0.001; n = 55) and the Yamane subgroup (exact Wilcoxon test: z = - 2.068; p = 0.001; n = 22). The GoreTex (n = 14) and Prolene (n = 19) subgroups revealed no statistically significant differences versus preoperative baseline. Across groups, there was no statistically significant difference in IOP, CMT, and CCT. No retinal complications were observed, neither intraoperatively nor during follow-up. CONCLUSION: The volume of IOL revision surgery is increasing. Often, the only option left for visual rehabilitation is scleral IOL fixation. All three scleral fixation techniques studied demonstrated a good safety profile with no statistically significant impact on IOP, CMT, CCT, but with a notable revision rate. Visual rehabilitation to preoperative baseline levels (GoreTex [n = 14] and Prolene [n = 19]) and a statistically significant increase in visual acuity (total cohort [n = 55] and Yamane [n = 22]) seems possible. Unlike iris fixation, scleral fixation is surgically more complex and the surgeon must master a steeper learning curve.