Rosachiara Leaci

Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

Purpose To study the accommodation process in normal eyes using a commercially available clinical system based on swept‐source anterior segment optical coherence tomography (AS‐OCT). Setting Ophthalmology Department, University of Parma, Italy. Design Evaluation of diagnostic technology. Methods Right eyes were analyzed using swept‐source AS‐OCT (Casia SS‐1000). The optical vergence of the internal coaxial fixation target was adjusted during imaging to obtain monocular accommodation stimuli with different amplitudes (0, 3.0, 6.0, and 9.0 diopters [D]). Overlapping of real and conjugate OCT images enabled imaging of all the anterior segment optical surfaces in a single frame. Central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness were extracted from the OCT scans acquired at different static accommodation stimulus amplitudes. The crystalline lens was analyzed dynamically during accommodation and disaccommodation by acquiring sequential OCT images of the anterior segment at a rate of 8 frames per second. The lens thickness was extracted from the temporal sequence of OCT images and plotted as a function of time. Results The study analyzed 14 eyes of 14 subjects aged 18 to 46 years. During accommodation, the decrease in the ACD was statistically significant (P < .05), as were the increase in the lens thickness (P < .001) and the slight movement forward of the lens central point (P < .01). The CCT and anterior chamber width measurements did not change statistically significantly during accommodation. The lens thickness at 0 D was positively correlated with age (P < .01). Conclusion High‐resolution real‐time imaging and biometry of the accommodating anterior segment can be effectively performed using a commercially available swept‐source AS‐OCT clinical device. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Corneal thickness mapping by 3D swept-source anterior segment optical coherence tomography

Purpose:  To assess accuracy and repeatability of central corneal thickness (CCT) measurements obtained by swept‐source anterior segment optical coherence tomography (AS‐OCT), spectral‐domain retinal OCT with corneal module and ultrasound pachymetry (USP), and to assess repeatability of pachymetric mapping with AS‐OCT.

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

Purpose To study the characteristics of late‐onset capsular block syndrome (CBS) using swept‐source anterior segment optical coherence tomography (AS‐OCT) and assess morphometric variations after treatment with neodymium:YAG (Nd:YAG) laser posterior capsulotomy. Setting Ophthalmology, University of Parma, Parma, Italy. Design Case series. Methods Patients with late‐onset CBS had an ophthalmology evaluation, including slitlamp photography and AS‐OCT, before and 1 month after ND:YAG laser posterior capsulotomy. The diameter of the anterior capsulorhexis, the posterior displacement of the posterior capsule, and the anterior chamber depth (ACD) were measured using AS‐OCT. Measurements before and after Nd:YAG laser posterior capsulotomy were compared using the paired t test. Results The study evaluated 6 patients. Slitlamp examination showed accumulation between the intraocular lens (IOL) and the posterior capsule of milky‐white or particulate liquefied material that appeared hyperreflective on AS‐OCT and caused posterior displacement of the posterior capsule (mean 1.38 mm). The diameter of the anterior capsulorhexis (mean 4.5 mm) was smaller than the IOL optic in all cases. After uneventful Nd:YAG laser posterior capsulotomy, the corrected distance visual acuity improved in all patients (P<.01). The ACD (IOL position) and refraction did not change significantly after the capsulotomy (P=.15 and P=.36, respectively). Conclusions Anterior segment OCT allowed accurate imaging and measurement of anterior segment parameters in late‐onset CBS. No displacement of the IOL was found after treatment with Nd:YAG laser posterior capsulotomy. Neodymium:YAG laser posterior capsulotomy was an effective and safe therapy in the 6 late‐onset CBS cases. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Simultaneous Descemet stripping automated endothelial keratoplasty and aphakic iris-fixated intraocular lens implantation: a case series.

Purpose: To report 3 cases of simultaneous Descemet stripping automated endothelial keratoplasty (DSAEK) and aphakic iris-fixated intraocular lens (IOL) implantation in patients with aphakia and bullous keratopathy. Methods: We retrospectively documented the clinical characteristics of patients before and after simultaneous DSAEK and aphakic iris-fixated IOL implantation undergoing operation between November 2008 and September 2009. Results: None of the cases showed any intraoperative complications. During the postoperative period, the corneal lenticule was clear and well-attached, and the iris-fixated IOL was well-positioned. Conclusions: Simultaneous DSAEK and aphakic iris-fixated IOL implantation can be used successfully and simultaneously in patients with aphakia and bullous keratopathy.

Femtosecond laser assisted design of sutureless intrastromal graft as an alternative to partial thickness keratoplasty

Minimally invasive laser assisted surgery in ophthalmology is continuously developing in order to find new surgical approaches, preserve patient tissue and improve surgical results in terms of cut precision, restoration of visual acuity, and invasiveness. In order to achieve these goals, the current approach in corneal transplant is lamellar keratoplasty, where only the anterior or posterior part of the patient’s cornea is substituted depending on the lesion or pathology. In this work, we present a novel alternative approach: a case study of intrastromal sutureless transplant, where a portion of the anterior stroma of a donor cornea was inserted into the stroma of the recipient cornea, aiming to restore the correct thickness of the patient’s cornea. The patient cornea was paracentrally thin, as the result of a trophic ulcer due to ocular pemphigoid. A discoid corneal graft from the anterior stroma of a donor eye was prepared: a femtosecond laser cut with a trapezoidal profile (thickness was 300 μm, minor and major basis were 3.00 and 3.50 mm, respectively). In the recipient eye, an intrastromal cut was also performed with the femtosecond laser using a specifically designed mask; the cut position was 275 μm in depth. The graft was loaded into an injector and inserted as an intrastromal presbyopic implant. The postoperative analysis evidenced a clear and stable graft that selectively restored corneal thickness in the thinned area. Intrastromal corneal transplant surgery is a minimally invasive alternative to anterior or posterior lamellar keratoplasty in select cases. We believe that Sutureless Intrastromal Laser Keratoplasty (SILK) could open up new avenues in the field of corneal transplantation by fully utilizing the potential and precision of existing lasers.