Emilio Pedrotti

Ultrasound biomicroscopic changes during accommodation in eyes with accommodating intraocular lenses: Pilot study and hypothesis for the mechanism of accommodation

Purpose: To document ciliary body constriction and movement with the Crystalens® AT‐45 intraocular lens (IOL) (eyeonics) using ultrasound biomicroscopy. Setting: Eye Clinic, Department of Neurological and Visual Sciences, University of Verona, Verona, Italy. Methods: Patients with no preexisting ocular conditions other than cataract who agreed to return for follow‐up were considered. Twenty eyes of 14 patients with a best corrected visual acuity of 5/10 or worse and a refractive error (spherical equivalent) of ±1.0 diopter (D) had implantation of a Crystalens AT‐45 accommodating IOL. Six patients had bilateral implantation. Ultrasound biomicroscopy was performed postoperatively at 1 and 6 months. Before and during accommodation, the anterior chamber depth (ACD) was measured to assess the endothelium–IOL distance and measure the scleral–ciliary process angle to determine whether there was anterior rotation of the ciliary body. The uncorrected distance acuity, best corrected distance acuity, uncorrected near acuity, distance corrected near acuity, best corrected near acuity, and accommodative amplitude were determined. Analysis was done to determine whether there was a correlation between the accommodative amplitude and the percentage variation in the ACD and scleral–ciliary process angle. Results: All surgical procedures were uneventful. The mean uncorrected distance acuity at 1 month was 0.8 ± 0.14 (SD) and remained stable at 6 months. Three of 20 eyes (15%) and 8 of 20 eyes (40%) had a Jaeger acuity of J1 and J3, respectively, without additional power correction. During accommodation, the mean reduction in ACD was 0.32 ± 0.16 mm at 1 month and 0.33 ± 0.25 mm at 6 months. The mean narrowing of the scleral–ciliary process angle was 4.32 ± 1.87 degrees at 1 month and 4.43 ± 1.85 degrees at 6 months. There was a correlation between accommodative amplitude and a decrease in the ACD (r = 0.404) and a decrease in scleral–ciliary process angle (r = 0.773). Conclusions: Anterior displacement of the Crystalens IOL and corresponding anterior rotation of the ciliary body occurred during near vision. The IOL displacement and rotation were proportional to the accommodation capacity.

Corneal cross-linking: intrastromal riboflavin concentration in iontophoresis-assisted imbibition versus traditional and transepithelial techniques.

PURPOSE To determine differences in riboflavin concentration in the anterior, intermediate, and posterior stroma after 3 corneal cross-linking imbibition techniques (standard epithelial [epi]-off, epi-on, and iontophoresis-assisted administration) of 0.1% riboflavin. DESIGN Experimental laboratory investigation of human cadaver corneas not suitable for transplantation. METHODS Ten corneas underwent imbibition with epi-on (n = 3), epi-off (n = 3), iontophoresis (n = 3), and saline exposure (control; n = 1). Femtosecond laser was used to produce 3 8-mm discs of the superficial (0-150 μm), intermediate (150-300 μm), and deep stroma (>300 μm). Riboflavin concentration was measured with high-performance liquid chromatography. The main outcome measure was riboflavin concentration at the 3 evaluated depths. RESULTS The overall stromal concentration of riboflavin was 34.1 ± 7.1 μg/g in epi-off, 7.2 ± 3.7 μg/g in epi-on, and 15.0 ± 5.1 μg/g in iontophoresis. The mean riboflavin content in the superficial slice in the epi-off group was about 2-fold greater than that of the iontophoresis group (50.5 ± 5.3 μg/g and 23.6 ± 2.5 μg/g, respectively) and 4-fold greater than that of the epi-on group (11.7 ± 3.3 μg/g). Similar differences among the 3 groups were observed for the intermediate and posterior stromal slices, presenting an evident reduction of riboflavin concentration with increasing depth in all groups. Slice depth-dependent decrease in riboflavin concentration was statistically significant (general linear model (GLM); F1,6 = 62.265, P < .001), as was the group-dependent variation (GLM; F2,6 = 20.268, P = .002) and the slice depth group interaction (GLM; F2,6 = 18.004, P = .002). CONCLUSIONS Corneal cross-linking transepithelial iontophoresis imbibition yielded greater and deeper riboflavin saturation with respect to conventional epi-on, while maintaining the advantages of avoiding epithelial removal and shorter procedure time, but did not reach concentrations obtained with standard epi-off.

Femtosecond laser versus manual clear corneal incision in cataract surgery.

PURPOSE To compare functional and morphological outcomes of femtosecond laser clear corneal incision (CCI) versus manual CCI during cataract surgery. METHODS Sixty eyes of 60 patients who underwent CCI during cataract surgery were randomized into two groups: femtosecond laser CCI (30 eyes) and manual CCI (30 eyes). RESULTS There were no significant between-group differences in uncorrected distance visual acuity, corrected distance visual acuity, surgically induced astigmatism, and corneal aberrations. Keratometric astigmatism was significantly lower in the femtosecond laser CCI group compared to the manual CCI group at 30 and 180 days (P < .05). Central endothelial cell count was significantly higher in the femtosecond laser CCI group compared to the manual CCI group at 7 and 30 days postoperatively (P < .05). A lower increase of corneal thickness at the incision site was observed at 30 and 180 days postoperatively in the femtosecond laser CCI group compared to the manual CCI group (P < .05). In addition, femtosecond laser CCI showed a better morphology (lower percentage of endothelial and epithelial gaping and endothelial misalignment) compared to manual CCI at different time points. Total phacoemulsification time was significantly lower in the femtosecond laser CCI group (P < .05). CONCLUSIONS The femtosecond laser procedure was safe, efficient, and less damaging, as evidenced by lower central endothelial cell loss, lower increase of corneal thickness at the incision site, and better tunnel morphology compared to the manual technique.

Circadian intraocular pressure patterns in healthy subjects, primary open angle and normal tension glaucoma patients with a contact lens sensor

To examine the circadian intraocular pressure (IOP) patterns in healthy subjects, in primary open angle and normal tension glaucoma (POAG; NTG) using a contact lens sensor (CLS; Sensimed Triggerfish, Lausanne, Switzerland).

Evaluation of ocular surface disorders: a new diagnostic tool based on impression cytology and confocal laser scanning microscopy

Aim To provide a new tool for the evaluation of altered ocular surfaces by using a combination of impression cytology, laser scanning confocal microscopy and advanced image analysis. Methods The expression of keratin 3 (K3), keratin 12 (K12), keratin 19 (K19) and mucin 1 (MUC1) was analysed by immunofluorescence on both histological sections of nine corneoscleral buttons from normal donors comprising conjunctiva, limbus and cornea and impression cytology specimens from six healthy normal subjects (12 eyes) and 12 patients with chronic ocular surface disorders. Levels of fluorescence expression of the different markers were quantified through quantitative fluorescence immunohistochemistry (Q-FIHC). Results Impression cytology specimens from normal and diseased ocular surfaces showed distinct expression patterns for K12 and MUC1. Healthy corneas expressed only K12 (but not MUC1), while conjunctivalised corneas from patients with limbal stem cell deficiency (LSCD) were characterised by the presence of MUC1 and the disappearance of K12. Similar clear-cut results were not seen with the K3/K19 markers, which showed lack of specificity and overlapping signals in cornea and conjunctiva impression cytology specimens. Conclusions The ability of K12 and of the antibody against MUC1 to discriminate clearly between limbus/cornea and conjunctiva in impression cytology specimens could become a valuable diagnostic tool for ophthalmologists in order to evaluate alterations of the ocular surface and the grading of LSCD.

Customized transepithelial photorefractive keratectomy for iatrogenic ametropia after penetrating or deep lamellar keratoplasty

PURPOSE: To evaluate the safety and efficacy of customized transepithelial photorefractive keratectomy (PRK) for the correction of iatrogenic ametropia after penetrating keratoplasty (PKP) or deep lamellar keratoplasty. SETTING: Eye Clinic, Department of Neurological and Visual Sciences, University of Verona, Verona, Italy. METHODS: This study comprised 9 patients who had irregular astigmatism from 2.0 to 8.0 diopters (D) after PKP or deep lamellar keratoplasty. The ametropia was corrected with customized transepithelial PRK and the Corneal Interactive Programmed Topographic Ablation (CIPTA) software program (LIGI). Complete ophthalmic examinations were performed before and after surgery. RESULTS: The mean age of the patients was 39.2 years (range 31 to 59 years). All patients gained at least 2 Snellen lines of uncorrected visual acuity; 2 patients had an increase of at least 5 lines, and 3 patients had an increase of 8 lines. The mean refractive spherical equivalent changed from −2.98 D ± 3.11 (SD) (range −7.25 to +3.00 D) before PRK to –0.58 ± 0.84 D (range 0 to −2.50 D) at the last follow‐up visit. One patient presented with grade 1 haze that did not improve with topical steroid therapy. No patient lost best spectacle‐corrected visual acuity. CONCLUSION: Customized transepithelial PRK with the CIPTA software was a safe and effective treatment for irregular astigmatism after PKP or deep lamellar keratoplasty.

Anterior segment changes during accommodation in eyes with a monofocal intraocular lens: High-frequency ultrasound study

PURPOSE: To analyze anterior segment structure changes during accommodative stimuli after monofocal intraocular lens (IOL) implantation using 2 ultrasound biomicroscopy (UBM) systems. SETTING: Department of Ophthalmology, University of Verona, Verona, Italy. METHODS: Twenty‐six eyes (23 patients) with 1 of 4 monofocal IOL types were studied. Five to 9 months postoperatively, the patients were examined by high‐frequency UBM using the HiScan system (Optikon 2000 SpA) and UBM 840 system (Carl Zeiss Meditec). Anterior chamber depth (ACD), iris–zonule distance, anterior chamber angle (ACA), scleral–ciliary process angle, and iris–ciliary process angle were measured using both systems. The iris–ciliary process distance and scleral spur perpendicular–sulcus distance were measured with the UBM 840 system and the sulcus–sulcus distance and capsular bag–IOL position with respect to ciliary process apex, with the HiScan system. Two experienced examiners performed all measurements. RESULTS: All parameters except the horizontal iris–ciliary process distance and vertical ACA measured by the UBM 840 system and horizontal ACA by the HiScan system showed significant variation during accommodation. An anterior shift of the IOL–capsular bag ciliary processes–sulcus–zonular iris complex was observed. A simultaneous centripetal shift of ciliary bodies and processes, shown by a reduction in sulcus and capsular bag diameter, was also observed. CONCLUSION: Anterior segment structures demonstrated accommodative movement on UBM after implantation of standard monofocal IOLs.

Long-term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency due to chemical burns.

Background:  Chemical burns cause depletion of limbal stem cells and eventually lead to corneal opacity and visual loss. We investigated the long‐term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency.

Comparative Analysis of the Clinical Outcomes With a Monofocal and an Extended Range of Vision Intraocular Lens

PURPOSE To evaluate and compare the clinical outcomes with an aspheric monofocal intraocular lens (IOL) and an extended range of vision (ERV) IOL based on achromatic diffractive technology. METHODS This was a prospective comparative study including 80 eyes undergoing cataract surgery with implantation of the monofocal Tecnis ZCB00 IOL (Abbott Medical Optics Inc., Santa Ana, CA) (monofocal group: 30 eyes of 15 patients) or the ERV Tecnis Symfony IOL (Abbott Medical Optics, Inc.) (ERV group: 50 eyes of 25 patients). Visual, refractive, contrast sensitivity, defocus curve, ocular optical quality (Optical Quality Analysis System; Visiometrics SL, Terrassa, Spain), and quality of life (National Eye Institute Refractive Error Quality of Life Instrument 42 Questionnaire) outcomes were evaluated during a 3-month follow-up. RESULTS Significantly better postoperative uncorrected monocular and binocular distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuities were found in the ERV group (P ≥ .013). Postoperative spherical equivalent was within ±1.00 diopters in 94% and 100% of eyes in the ERV and the monofocal groups, respectively. Binocular UIVA and UNVA of 0.20 or better (Snellen 20/30) were observed in all cases in the ERV group and in 13.3% and 6.7% of eyes of the monofocal group, respectively. No significant differences among groups were observed in contrast sensitivity (P ≥ .156) or ocular optical quality parameters (P ≥ .084). In the monocular defocus curve, all visual acuities were better in the ERV group (P ≤ .002), except for the +0.50-diopter defocus level (P = .367). Significantly better scores were obtained for dependence on correction (P = .003) and suboptimal correction (P = .038) subscales in the ERV group. CONCLUSIONS The extended range of vision IOL provides better distance, intermediate, and near visual acuity than the aspheric monofocal IOL, while maintaining the same level of visual quality. [J Refract Surg. 2016;32(7):436-442.].

Comparison of two multifocal intraocular lens designs that differ only in near add.

PURPOSE To evaluate monocular functional outcomes after the implantation of the AcrySof ReSTOR SN6AD2 intraocular lens (IOL) (+2.5 diopters [D] near add) (Alcon Laboratories, Inc., Fort Worth, TX) and the AcrySof ReSTOR SN6AD1 IOL (+3.0 D near add) (Alcon Laboratories, Inc.). METHODS This prospective, comparative, nonrandomized single-blind observational study comprised 62 eyes of 62 patients that underwent phacoemulsification and implantation of a multifocal IOL: SN6AD2 (31 eyes) (+2.5 group) and SN6AD1 (31 eyes) (+3.0 group). Twelve months after surgery, monocular near (30 and 40 cm), intermediate (50, 60, and 70 cm), and distance (4 m) visual acuity were evaluated with the internal root mean square and modulation transfer function. Both parameters were evaluated at the 4- and 6-mm pupil sizes. RESULTS No statistical differences at 4 m were found between the groups. The +2.5 group obtained better performances at all intermediate distances (50 cm, 0.23 ± 0.14 vs 0.32 ± 0.13; 60 and 70 cm, 0.21 ± 0.10 vs 0.41 ± 0.14 and 0.24 ± 0.10 vs 0.53 ± 0.17, respectively), whereas the near visual acuity was better for the +3.0 group (30 and 40 cm, 0.36 ± 0.18 vs 0.14 ± 0.09 and 0.36 ± 0.19 vs 0.17 ± 0.07, respectively). The root mean square was lower for the +2.5 group compared to the +3.0 group, whereas the modulation transfer function showed overlapping results between the two models. CONCLUSIONS Both IOL models showed good results in distance vision; the +2.5 D IOL seemed to provide better intermediate vision than the +3.0 D IOL. For near vision, the +3.0 D model performed better than the +2.5 D model.