Posterior-chamber phakic implantable collamer lenses with a central port: a review.

We aimed to summarize the outcomes reported following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc) for myopia correction. A literature search in PubMed, Web of Science and Scopus was carried out to identify publications reporting clinical outcomes of patients who were implanted with the V4c ICL model and had a follow-up period of at least 6 months. A total of 35 clinical studies published between 2012 and 2020 were included in the present review. A comprehensive analysis of the available data was performed, focusing on visual and refractive outcomes at different time-points post-surgery. In addition, adverse events and other parameters such as endothelial cell density, intraocular pressure and vault measurements-which were evaluated in some of the studies-were also compared. This review encompassed a total of 2904 eyes. The outcomes reported in this review lead us to conclude that ICL V4c implantation for myopia correction is a safe and efficient procedure, with stable visual and refractive outcomes and low adverse event rates. The patient's anterior segment should be thoroughly characterized, and the ICL parameters should be carefully selected so as to achieve good outcomes and avoid complications.

Agreement of white-to-white measurements with swept-source OCT, Scheimpflug and color LED devices.

PURPOSE: To assess the interchangeability of different devices for measuring white-to-white (WTW) distance. METHODS: WTW distance was measured in 53 eyes of 53 patients using Anterion swept-source optical coherence topographer (SS-OCT), IOLMaster 700 SS-OCT, Pentacam HR Scheimpflug and Cassini color LED. Statistical analysis was done by means of the Friedman test and the post hoc Tukey test. The Bland-Altman analysis was applied to carry out pairwise comparisons with the average difference, 95% confidence interval of the average difference and limits of agreement 95% (LoA). RESULTS: WTW values obtained by the Anterion, IOLMaster 700, Pentacam HR and Cassini were: 11.84 ± 0.41 mm, 11.96 ± 0.41 mm, 11.68 ± 0.38 mm and 12.65 ± 0.52 mm, respectively. Statistically significant differences were found in all pairwise comparison (p < 0.001). The lowest mean difference was found between the Anterion and IOLMaster 700 (- 0.11 mm) and the highest between the Pentacam HR and Cassini (- 0.96 mm). The widest LoA ranges were those that compared any device with the Cassini. LoA ranges when the other three devices were compared among them were similar: Anterion versus IOLMaster 700, Anterion versus Pentacam HR and IOLMaster versus Pentacam HR (about 0.2 mm). CONCLUSIONS: Our results show that there were statistically significant differences in WTW measurement among the four devices, but under a clinical point of view, we believe that Anterion and IOLMaster 700 may be considered interchangeable and so Anterion and Pentacam HR, however, IOLMaster 700 and Pentacam HR may not and neither is Cassini with any of the other three devices.

Alport Syndrome and Femtosecond Laser-assisted Cataract Surgery.

We report the surgical management of a patient with bilateral anterior lenticonus due to Alport syndrome using femtosecond laser-assisted cataract surgery (FLACS) and the Optiwave Refractive Analysis (ORA) system. A 38-year-old man with Alport syndrome presented to our department with visual loss due to anterior lenticonus in both eyes. Adjustments during bilateral FLACS were performed with the software's calipers to manually delineate the anterior capsulotomy. Multifocal toric intraocular lenses (IOLs) were selected and placed in the posterior chamber with the aid of intraoperative aberrometry. The intended postoperative positioning parameters for the IOL as well as the planned visual acuity and refraction were achieved. The implementation of FLACS and intraoperative wavefront aberrometry is a safe and useful surgical approach for the management of cataract in challenging cases such as patients with anterior lenticonus due to Alport syndrome.

Femtosecond laser-assisted capsulotomy for treatment of bilateral anterior capsule contraction.

A 51-year-old woman developed severe fibrosis and occlusion of the visual axis in 1 eye, maintaining a pinhole aperture in the fellow eye, 2 months after uneventful cataract surgery and implantation of a hydrophilic trifocal intraocular lens in the capsular bag. She had not exhibited any risk factor for anterior capsule contraction preoperatively. Femtosecond laser-assisted capsulotomy with a fluid-filled interface system was used to perform a simultaneous anterior capsulotomy in both eyes. Preoperative calculations of the incision depth of the capsulotomy were performed using optical coherence tomography (OCT) and adjusted intraoperatively with the OCT system of the femtosecond laser. The energy level used in the first eye was increased for the second eye (4 µJ to 6 µJ) because of severe capsulotomy tags that had to be cut with scissors. Despite the increase in energy, a free-floating capsulotomy could not be achieved in the second eye.

Effect of the Femtosecond Laser on an Intracorneal Inlay for Surgical Compensation of Presbyopia during Cataract Surgery: Scanning Electron Microscope Imaging.

PURPOSE: To investigate the effect of the femtosecond laser-assisted cataract surgery (FLACS) on porcine eyes implanted with a Kamra corneal inlay and to describe how the inlay may change the effect of the femtosecond laser on the lens. METHODS: FLACS was performed on six porcine eyes and a Kamra corneal inlay had been implanted, exploring the lens under the surgical microscope. Another Kamra corneal inlay was attached to the upper part of the transparent hemisphere used for calibration of the femtosecond laser. Capsulorhexis, arcuate incisions, and phacofragmentation were carried out. The Kamra corneal inlay was compared with a nontreated one using a scanning electron microscope (SEM), and the hemisphere was analyzed with a surgical microscope. RESULTS: Capsulorhexis and phacofragmentation were completed in all the porcine eyes, although accuracy to determine the exact effect on the lens was not possible to achieve. The effect of the femtosecond laser on the PMMA hemisphere through the Kamra corneal inlay showed the capsulorhexis was placed outside the outer margin of the inlay and a sharply sculpted fragmentation pattern with a three-dimensional (donut-shaped) annulus untreated beneath it. SEM images of the nontreated and the treated inlays were comparable. No ultrastructural changes were found in the treated Kamra corneal inlay. CONCLUSIONS: FLACS can be performed with a Kamra corneal inlay for surgical compensation of presbyopia without the risk of damaging the inlay. The Kamra corneal inlay acts as a screen that avoids the laser to reach the areas beneath its shadow, but not the exposed areas of the lens.

Porcine Model to Evaluate Real-Time Intraocular Pressure During Femtosecond Laser Cataract Surgery.

PURPOSE: To investigate the changes in intraocular pressure (IOP) in porcine eyes during femtosecond laser-assisted cataract surgery using a liquid-optic interface system. MATERIALS AND METHODS: Femtosecond laser cataract surgery with the Catalys™ was performed on freshly enucleated porcine eyes in Oftalvist Moncloa, Madrid, Spain. Capsulorhexis and lens fragmentation were completed in all the eyes without complications. IOP was measured with a reusable blood pressure transducer connected by direct cannulation to the anterior chamber, recording data before suction (basal), at the beginning of the suction phase, every five seconds during femtosecond procedure and after the removal of the suction ring from the eye. RESULTS: Nine porcine eyes were used in this study. Basal IOP before suction was 5.67 ± 2.39 mmHg, rising to 20.33 ± 4.18 mmHg at the beginning of the suction phase (p < 0.001). During femtosecond procedure, pressure reached a value of 19.74 ± 4.31 mmHg, remaining stable during the entire process. The IOP recorded prior to removal of the suction ring was 21.00 ± 6.93 mmHg, returning to basal values in all the eyes after the suction ring was removed, with no statistical differences between basal and post-suction IOPs. Total femtosecond procedure time was 125.9 ± 15.9 s. CONCLUSIONS: Real-time IOP can be measured during surgery using a transducer connected to the anterior chamber. The results showed a significant increase in IOP during the procedure due to the pressure exerted by the suction ring but not by the effect of the femtosecond laser.

Corneal erosion and Kindler syndrome.

PURPOSE: To describe a very common corneal pathology in a patient with Kindler syndrome. CASE REPORT: We report the case of a 21-year-old woman, who presented to the Ophthalmology Department as an emergency presentation because of ocular pain in the left eye that radiated to other areas of the face and neck. After an exhaustive clinical interview, it was determined that the patient had a rare disease (Kindler syndrome). Ophthalmologic examination revealed corneal erosion on the left eye. No other significant conditions were found. After the application of conventional treatment, the corneal integrity was completely restored. CONCLUSIONS: We describe a very rare syndrome. Although conventional treatment restored corneal integrity, it is important to remember that ocular signs and symptoms are often associated with systemic pathologies.

The influence of age on the refractive index of the human corneal stroma resected using a mechanical microkeratome.

PURPOSE: To measure the refractive index (RI) of the human corneal stroma in vivo using an objective Abbé refractometer (VCH-1) and to determine if RI of the stroma is related to age. METHODS: The VCH-1 was calibrated against a standard subjective Abbé refractometer using 7 randomly selected turbid semiliquid media. VCH-1 was used to measure RI at the central midstroma immediately after lifting the flap in neophyte patients preselected for laser-assisted in situ keratomileusis. Surgical procedures continued as preplanned after measuring the RI; in binocular cases, measurements were taken from the right eye only. Flaps were created using a mechanical microkeratome. RESULTS: The VCH-1 was capable of measuring the RIs of all 7 turbid semiliquid media. The average RMS difference between RI estimates according to the VCH-1 and standard subjective Abbé refractometer was 0.003. The mean RI (± SD) of the stroma was 1.369 (± 0.008; range, 1.356-1.390), and the mean age (± SD) of the subjects was 33.7 years (± 8.86; range, 18-56 years). A significant linear correlation was found between age and RI. Least squares regression lines equating RI with age (x, years) was of the form: RI = 1.35711 + 0.00034x (r = +0.383, n = 36, P = 0.011). CONCLUSIONS: RI of the stroma in vivo has a tendency to be increased in older patients when the stroma is resected using a mechanical microkeratome.

Factors influencing corneal biomechanical changes after microincision cataract surgery and standard coaxial phacoemulsification.

PURPOSE: To determine the factors affecting corneal biomechanics using biomechanical waveform analysis after microincision cataract surgery (MICS) and standard coaxial phacoemulsification with different incision sizes. SETTING: Vissum-Instituto Oftalmologico de Alicante, Alicante, Spain. METHODS: This prospective nonrandomized study comprised eyes with significant cataract that had MICS (sub-1.8 mm incision) or coaxial phacoemulsification (2.75 mm incision). Corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured by biomechanical waveform analysis (Ocular Response Analyzer) preoperatively, immediately postoperatively, and at 1 month. Results were analyzed and compared between groups. RESULTS: In the MICS group (n = 30), there was a significant increase in Goldmann-correlated intraocular pressure (IOP) and corneal-compensated IOP, although CH decreased in the immediate postoperative period (P<.05). At 1 month, all parameters in the MICS group returned to normal. The coaxial group (n = 30) had an increase in Goldmann-correlated IOP and corneal-compensated IOP, both of which were higher than normal at 1 month. Backward multiple regression analysis showed significant correlations between CH and preoperative Goldmann-correlated IOP and preoperative CRF (r(2) = 0.631, P<.05); between age, axial length (AL), and preoperative CRF (r(2) = 0.418, P<.05); and between the change in CH and AL, total incision length, and preoperative CH (r(2) = 0.429, P<.05). CONCLUSIONS: Cataract surgery with MICS and coaxial phacoemulsification significantly altered corneal biomechanics. Corneal hysteresis was inversely correlated with Goldmann-correlated IOP; CRF was inversely correlated with age and AL. The MICS technique provided more stable corneal biomechanical properties than standard coaxial phacoemulsification 1 month postoperatively.

Effect of suction ring application during LASIK on goblet cell density.

PURPOSE: To study the effect of LASIK surgery on conjunctival goblet cells as one of the proposed mechanisms for dry eye occurring after LASIK. METHODS: This prospective study included 22 eyes (11 patients) that underwent LASIK for the correction of myopia. Three pairs of samples were taken from the bulbar conjunctiva of each eye. The first pair was taken preoperatively before application of the suction ring. The second and third pairs were taken from the same sites at 1 week and 1 month consecutively. The first site was at 12 o'clock and the second at the inferotemporal quadrant between 7 and 8 o'clock. Time of suction was recorded. RESULTS: Preoperatively, mean goblet cell density was 424 +/- 105 cells/mm2 (range: 284 to 630 cells/mm2). All postoperative samples showed a statistically significant decrease in goblet cell count: 216 +/- 81 cells/mm2 (range: 40 to 325 cells/mm2) at 1 week and 218 +/- 99 cells/mm2 (range: 50 to 396 cells/mm2) at 1 month. Other parameters of conjunctival impression cytology were normal. The difference between the samples in the inferior conjunctiva preoperatively and 1 week postoperatively was greater than that of the superior conjunctiva. Recovery rate in both sites was similar and the damage did not correlate with the duration of suction. CONCLUSIONS: The application of the microkeratome suction ring induced changes in the perilimbic conjunctiva. These changes contribute to the pathology of dry eye. Goblet cell count remains affected at 1 month postoperatively.

Human anterior lens capsule as a biologic substrate for the ex vivo expansion of limbal stem cells in ocular surface reconstruction.

PURPOSE: To study the potential use of human anterior lens capsule as a scaffold for stem cell transplantation in treatment of limbal cell deficiency. METHODS: Limbal biopsies and anterior lens capsules were obtained (same eye) from 30 patients during cataract surgery. Biopsies were suspended in Dulbecco modified Eagle medium under sterile conditions and stored at 4 degrees C. Capsules were treated in distilled water under strict asepsis for 2 hours to eliminate the crystalline epithelium and stored at 4 degrees C. After initial processing, the limbal biopsy was plated epithelial-side down (48 hours) on the capsular specimen in a 35-mm culture dish. Samples were sorted into 4 groups. Group 1 was made up of 10 samples in which limbal biopsies were allowed to grow on corresponding capsules from the same eye (autologous). Group 2 was 10 limbal biopsies that were allowed to grow on capsules of different eye (allogeneic). The remaining specimens were randomized into 2 groups. Group 3 included 10 capsules on which an ex vivo expanded cell line was allowed to grow. Group 4 harbored 10 limbal biopsies that were allowed to grow on polystyrene culture plates. All specimens were incubated for 2 weeks at 37 degrees C and 5% CO2. Cell density, viability, morphology, and adherence of the cell-capsule complex were evaluated at 1, 3, 7, and 14 days. RESULTS: Rate of cell growth and density in groups 1 and 2 were comparable to the control groups. Cell viability was 95% or superior in all groups, and desmosomes developed between growing cells. CONCLUSIONS: Human anterior lens capsule is a potential scaffold for ex vivo expansion of limbal epithelial cells, possibly providing a substrate for ocular surface reconstruction.

LASIK in myopic patients with dermatological keloids.

PURPOSE: To evaluate the visual and refractive out come of LASIK in myopic patients with a known history of dermatological keloid scar. METHODS: This retrospective case series included 10 eyes of 5 white patients with a known history of dermatological keloids. All patients had low to moderate myopia with no corneal or limbal keloid. All underwent uneventful bilateral LASIK. Postoperatively, visual outcomes, refractive outcomes, and complications were evaluated. Minimum 1-year follow-up was indicated for all patients in this study. RESULTS: Mean preoperative uncorrected visual acuity (UCVA) was 20/320 and 1 year postoperative 20/20. Mean preoperative best spectacle-corrected visual acuity (BSCVA) was 20/25 and 1 year postoperative was 20/20. The mean preoperative spherical equivalent refraction was -5.00 +/- 2.6 diopters (D) and +0.1 +/- 0.2 D 1 year postoperative. The safety index was 1.02 and the efficacy index was 1.02. None of the included in this study underwent retreatment for correction of residual error or regression up to 1 year postoperatively. No sight-threatening complications were reported. No patient reported postoperative haze, severe dry eye syndrome, or flap-related problems. CONCLUSIONS: LASIK is a safe, effective, and predictable technique for correcting low and moderate myopia in patients with dermatological keloids.

Advances in microincision cataract surgery intraocular lenses.

PURPOSE OF REVIEW: This paper reviews the recent developments in microincision cataract surgery intraocular lenses. RECENT FINDINGS: Seven intraocular lenses are currently available for implantation through sub-2.0-mm incision. From the intraocular lenses available, two microincision cataract surgery intraocular lenses were included in clinical studies and their results were reviewed. The available lenses were implanted through a clear corneal incision of 1.5-1.9 mm and showed excellent biocompatibility. The behavior of the microincision cataract surgery in vivo is similar to the conventional lenses in terms of optical quality and retinal image quality. The clinical results of microincision cataract surgery intraocular lenses such as Acri. Smart 48S showed that a certain degree of pseudoaccommodation could be achieved with this lens. SUMMARY: Cataract removal through sub-2.0 mm incision is possible with implantation of microincision cataract surgery intraocular lenses through the same undilated incision. The current technique allows cataract removal through 1.7 mm and the available microincision cataract surgery intraocular lenses showed optical quality and biocompatibility similar to conventional intraocular lenses.

Outcomes of microincision cataract surgery versus coaxial phacoemulsification.

PURPOSE: To compare outcomes of microincision cataract surgery (MICS) with coaxial phacoemulsification. DESIGN: Prospective randomized consecutive case series. PARTICIPANTS: One hundred eyes of 50 patients with nuclear or corticonuclear cataract (grades 2+ to 4) with Lens Opacities Classification System III. METHODS: One hundred eyes (50 patients) were randomly operated through clear corneal incisions using 2 techniques: coaxial phacoemulsification (50 eyes) and microincision cataract surgery (50 eyes). MAIN OUTCOME MEASURES: Mean phacoemulsification time, total phacoemulsification percent, effective phacoemulsification time (EPT) (calculated by multiplying total phacoemulsification time in seconds by the average power percent used), intraoperative total balanced salt solution (BSS) volume, visual outcome, vectorial astigmatic changes, corneal thickness, endothelial cell count, and anterior chamber flare and cells preoperatively and at 1 day, 1 month, and 3 months. RESULTS: Statistically significant differences were found between MICS and coaxial phacoemulsification regarding mean incision size, mean total phacoemulsification percent, and EPT. There were no significant differences between the techniques regarding the mean percent of endothelial cell loss, anterior chamber cell count and flare, mean phacoemulsification time, pachymetric measures or total BSS volume utilized, or visual outcome. The vectorial astigmatic changes in the MICS group showed a change of < or =0.25 diopters (D) in 35% of the eyes, 0.25 to 0.5 D in 50% of the eyes, and 0.5 to 1.0 D in 15% of the eyes. These changes were induced by the surgery. Vectorial astigmatic changes of >1 D were not observed. In the coaxial phacoemulsification group, vectorial astigmatic changes of <0.25 D were not observed either. Changes of 0.25 to 0.5 D were seen in 20% of the eyes, and changes of 0.5 to 1.0 D were seen in 30%. Fifty percent of the eyes showed changes of >1.0 D. Mean vectorial astigmatic changes were 0.36+/-0.23 D in the MICS group and 1.2+/-0.74 D in the coaxial phacoemulsification group (P<0.001). CONCLUSIONS: Microincision cataract surgery significantly lowered mean phacoemulsification time, mean total phacoemulsification percent, mean EPT, and surgically induced astigmatism when compared with coaxial phacoemulsification.

Visual outcome of microincision cataract surgery with implantation of an Acri. Smart lens.

PURPOSE: To evaluate visual and refractive outcome of microincision cataract surgery (MICS) with implantation of an Acri. Smart 48S intraocular lens (IOL) (Acri.Tech) through a sub-1.9 mm incision. SETTING: Vissum/Instituto Oftalmologico de Alicante and Ophthalmology Department, Miguel Hernandez University, Alicante, Spain. METHODS: In this consecutive prospective observational noncomparative clinical trial, 45 eyes were included. Microincision cataract surgery was performed through a 1.9 mm or smaller clear corneal incision using low ultrasound power MICS. The IOL was injected using a hydraulic cartridge and injector. The final size of the clear corneal incision, postoperative uncorrected and best corrected near and distance acuities, lens stability, ease of implantation, rate of posterior capsule opacification (PCO), and complications were reported up to 6 months. RESULTS: The Acri. Smart lens was inserted through mean incision of 1.5 mm +/- 0.3 (SD). The mean uncorrected distance visual acuity improved significantly from 20/100 (0.2 +/- 0.2 decimal value) preoperatively to 20/32 (0.7 +/- 0.3) by the end of 6 months postoperatively (P<.000). The best corrected distance visual acuity improved significantly from 20/50 (0.4 +/- 0.2) preoperatively to 20/25 (0.9 +/- 0.2) after 6 months (P<0.000). The uncorrected near visual acuity at the end of 6 months was 20/32 (0.6 +/- 0.2, P<.000). The mean postoperative spherical equivalent was -1.1 +/- 0.9 diopters (P<.947). The safety index was 2.5 for distance and 1.4 for near. There were no intraoperative or postoperative complications. No eye had a neodymium:YAG laser capsulotomy for PCO or reported undesirable complications at the end of 6 months. CONCLUSIONS: Results show that the Acri. Smart 48S IOL is a safe, effective, and stable lens that could be inserted through sub-1.9 mm incisions. It provided excellent surgical performance, predictability, and some degree of pseudoaccommodation.

Near vision restoration with refractive lens exchange and pseudoaccommodating and multifocal refractive and diffractive intraocular lenses: comparative clinical study.

PURPOSE: To evaluate near visual performance after implantation of a pseudoaccommodating intraocular lens (IOL) (Crystalens AT-45, eyeonics) or a multifocal IOL (refractive model, AMO Array; diffractive model, AcriTec TwinSet) after lens surgery. SETTINGS: Instituto Oftalmologico de Alicante, Miguel Hernandez University, Alicante, Spain. METHODS: Forty patients were included in this prospective clinical comparative study. The patients were divided into 3 groups according to the type of IOL implanted. Group 1 included 24 eyes (12 patients) implanted with the Crystalens IOL; Group 2, 32 eyes (16 patients) with the Array IOL, and Group 3, 24 eyes (12 patients) with the TwinSet IOL. Bilateral phacoemulsification and IOL implantation were performed in all patients, and the follow-up was 1 year. The postoperative main visual outcome evaluations were uncorrected and best corrected distance and near visual acuities, mean add for near, and best distance-corrected near acuity. RESULTS: In Group 1, the mean uncorrected near acuity was 20/40 preoperatively and 20/25 after 1 year. The mean preoperative best distance-corrected near acuity was 20/32 and 20/25 after 1 year. In Group 2, the mean uncorrected near acuity was 20/40 and 20/25, respectively. The mean preoperative best distance-corrected near acuity was 20/32 and 20/25 after 1 year. In Group 3, the mean uncorrected near acuity was 20/63 preoperatively; after 1 year, it was approximately 20/25. The mean best distance-corrected near acuity was 20/50 and 20/25, respectively. A neodymium:YAG laser capsulotomy was performed for posterior capsule opacification when required, with no change in the refractive outcome. CONCLUSIONS: Implantation of multifocal and pseudoaccommodating IOLs provides adequate near vision restoration. The TwinSet IOL provided faster recovery of near vision than the other 2 IOLs. The Crystalens IOL provided less postoperative visual phenomena with favorable near vision. The Array IOL achieved the most comfortable distance and near vision.