Stefano Baiocchi | University of Siena / Università di Siena (original) (raw)

Papers by Stefano Baiocchi

DOAJ (DOAJ: Directory of Open Access Journals), Feb 1, 2021

Essential iris atrophy represents one of the phenotypic expressions of irido-corneal-endothelial ... more Essential iris atrophy represents one of the phenotypic expressions of irido-corneal-endothelial syndrome (ICE-S). Despite some typical clinical features, differential diagnosis of the endothelial alteration at early stage of the disease is not easy also with a careful slit lamp examination, with different overlapping clinical aspects. We report differential diagnosis by in vivo confocal microscopy and anterior segment optical coherent tomography, between ICE-syndrome related endotheliopathy in a 62 year male patient and other pathologies involving corneal endothelium with different therapeutic and prognostic implications: Posterior polymorphous corneal dystrophy, cornea guttata and Fuch’s endothelial dystrophy. Even if the ICS-Syndrome is generally unilateral and non familial, a bilateral occurrence may be possible. The disease may progress leading to secondary glaucoma and corneal decompensation. In this contest, early diagnosis becomes fundamental to monitor corneal endothelial and stromal changes, IOP variation and pupil distortion in order to establish a correct therapeutic strategy. Differential analysis with posterior polymorphous corneal dystrophy, cornea guttata and Fuch’s endothelial dystrophy is necessary, especially in bilateral disease due to different prognosis and management of these pathologies. Indeed in this clinical case, despite the apparent absence of stromal modifications at biomicroscopic examination, in vivo confocal microscopy allowed us to detect the presence of a stromal sub-clinical edema, explaining patients visual fluctuations with a consequent customized therapeutic strategy and prognostic evaluation

European Journal of Ophthalmology, Apr 1, 2012

This was a qualitative investigation of corneal microstructural modifications in keratoconic pati... more This was a qualitative investigation of corneal microstructural modifications in keratoconic patients undergoing experimental transepithelial crosslinking (TE CXL). Ten patients with keratoconus intolerant to gas-permeable rigid contact lenses were enrolled. Corneal thickness was in the range 350-390 µm at the thinnest point measured by Visante AC optical coherence tomography system (Zeiss, Jena, Germany). All patients underwent TE CXL with 0.1% riboflavin-15% dextran solution supplemented with TRIS plus sodium EDTA (Ricrolin TE, Sooft Italia) according to Siena protocol. In vivo Heidelberg retinal tomograph II laser scanning confocal analysis (Rostock Cornea Module, Heidelberg, Germany) was performed with the following follow-up: preoperative and postoperative assessments at 1, 3, and 6 months. The following morphologic parameters were evaluated: epithelium, subepithelial, and anterior stroma nerve plexi, keratocytes apoptosis, stromal changes, and the endothelium. After TE CXL, epithelial cells showed apoptosis, with mosaic alterations gradually disappearing. Keratocytes apoptosis was variable, superficial, and uneven, with a maximum depth of penetration at about 140 µm, measured from the surface of epithelium. Treatment respected subepithelial and stromal nerves that did not disappear. No variation in cell count or endothelial mosaic was observed. In vivo confocal analysis of corneal modifications induced by TE CXL showed a limited apoptotic affect of this treatment, about one-third of classic epi-off crosslinking procedure. The TE CXL respected sub-basal and anterior stroma nerve fibers, resulting safe for corneal endothelium. According to limited penetration, its mid- to long-term efficacy needs to be determined in different clinical settings related to patient age and keratoconus progression.

Journal of Cataract and Refractive Surgery, Aug 1, 2013

.Purpose: To evaluate the effectiveness of transepithelial cornea impregnation with riboflavin 0... more .Purpose: To evaluate the effectiveness of transepithelial cornea impregnation with riboflavin 0.1% by iontophoresis for collagen cross‐linking.Material and methods: Transepithelial collagen cross‐linking by iontophoresis of riboflavin was performed in a series of 22 eyes of 19 patients with progressive keratoconus I–II of Amsler classification. The riboflavin solution was administered by iontophoresis for 10 min in total, after which standard surface UVA irradiation (370 nm, 3 mW/cm2) was performed at a 5‐cm distance for 30 min.Results: The riboflavin/UVA treatment resulted in a decrease in the average keratometry level from 46.47 ± 1.03 to 44.12 ± 1.12 D 1 year after the procedure. Corneal astigmatism decreased from 3.44 ± 0.48 to 2.95 ± 0.23 D. Uncorrected distance visual acuity improved from 0.61 ± 0.44 up to 0.48 ± 0.41 (LogMAR). Preoperative and postoperative endothelial cell density remained unchanged at 2765 ± 21.15 cells/mm2.Conclusion: Transepithelial collagen cross‐linking by iontophoresis might become an effective method for riboflavin impregnation of the corneal stroma reducing the duration of the procedure and being more comfortable for the patients. Further long‐term studies are necessary to complete the evaluation of the efficacy and risk spectrum of the modified cross‐linking technique.

American Journal of Ophthalmology, Apr 1, 2010

Results.dKeratoconus stability was detected in 44 eyes after 48 months of minimum follow-up; fell... more Results.dKeratoconus stability was detected in 44 eyes after 48 months of minimum follow-up; fellow eyes showed a mean progression of 1.5 diopters in more than 65% after 24 months, then were treated. The mean K value was reduced by a mean of 2 diopters, and coma aberration reduction with corneal symmetry improvement was observed in more than 85%. The mean best spectacle-corrected visual acuity improved by 1.9 Snellen lines, and the uncorrected visual acuity improved by 2.7 Snellen lines. Conclusions.dThe results of the Siena Eye Cross Study showed a longterm stability of keratoconus after cross-linking without relevant side effects. The uncorrected visual acuity and best spectacle-corrected visual acuity improvements were supported by clinical, topographic, and wavefront modifications induced by the treatment. : Collagen cross-linking is an exciting potential treatment for keratoconus. Unlike all other treatments for this condition, cross-linking works to strengthen the cornea to induce and maintain stability for this condition and potentially reverse corneal steepening/ectasia. Unfortunately, most of us in the United States have limited to no experience with this treatment, and we look to our colleagues elsewhere for insight.

Journal of the Siena Academy of Sciences, Nov 30, 2010

Purpose: evaluation of riboflavin stromal concentrations by HPLC assay to ensure the efficacy and... more Purpose: evaluation of riboflavin stromal concentrations by HPLC assay to ensure the efficacy and safety of corneal cross-linking by the standard and trans-epithelial procedures. Methods: 14 keratoconic patients enrolled for penetrating keratoplasty were selectioned as in vivo samples donors and 16 warm-stored ex vivo sclerocorneal rings unsuitable for transplant were used. In vivo samples were immediately exposed to sterile 0.1% riboflavin solution. 7 of the 14 specimens were debrided and the other 7 were left with the epithelium in situ. One of the latter and one of the debrided samples were not exposed with riboflavin (control groups). In 7 sclerocorneal rings epithelium was removed and in 9 was left in situ. Debrided and not debrided samples were soaked with 0.1% riboflavin solution, instilled every 2 minutes for 5 min, 15 min and 30 min in both in vivo and ex vivo groups. Riboflavin concentrations were determined by HPLC. Results: Control samples did not show any riboflavin emission peak. In samples exposed with epithelium, riboflavin concentrations were 2.54 μg/g after 5 min and 3.88 μg/g after 15 min of exposure, whereas in the debrided samples they were 96.28 μg/g after 5 min and 98.92 μg/g after 15 min exposure. Conclusion: HPLC quantitative study shows that stromal concentrations of riboflavin increase with exposure time only if the epithelium is removed. A safe and effective riboflavin concentration (>15 μg/g tissue) can be obtained for UVA-induced corneal cross-linking only removing the epithelium. and after at least 10 min exposure, applying riboflavin every 2 minutes.

Eye, Feb 27, 2015

Purpose To evaluate the clinical outcomes, safety, and efficacy of cataract surgery with the impl... more Purpose To evaluate the clinical outcomes, safety, and efficacy of cataract surgery with the implantation of a toric intraocular lens (IOL) in eyes with stable pellucid marginal degeneration (PMD). Methods Eleven eyes (eight patients) diagnosed as stable PMD and cataract underwent mini-incision 2.2 mm cataract surgery followed by the implantation of hydrophobic toric aspheric IOL (AcrySof IQ Toric IOL, Alcon, Fort Worth, TX, USA). Perioperative variables of interest included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, and corneal topography. Paired samples t-tests were used to analyze preoperative and postoperative visual acuity, astigmatism, and spherical equivalent (SE) parameters. Follow-up was 6 months. Results The mean CDVA was 0.62 ± 0.26 logMAR preoperatively and 0.07 ± 0.07 logMAR postoperatively. The mean preoperative sphere and cylinder was − 3.14 ± 3.58D and − 4.84 ± 2.02D, respectively. The mean postoperative manifest refractive sphere and cylinder was − 0.30 ± 0.51D and − 0.81 ± 1.51D, respectively. There was a significant reduction in refractive astigmatism after toric IOL implantation (Po0.002). The toric IOL axis rotation was o5°in all cases at the final follow-up. Conclusions Implantation of hydrophobic toric IOL was a safe and effective surgical procedure to correct mild to moderate stable PMD.

Advances in Science, Technology & Innovation, 2022

Journal of Cataract and Refractive Surgery, 2007

IOL edge. The second reason was the eagerness of manufacturers to switch sales from royalty-laden... more IOL edge. The second reason was the eagerness of manufacturers to switch sales from royalty-laden plano-convex ridge IOLs to royalty-free biconvex IOLs (without a ridge). Thiswas promoted on the proposition that a poly(methyl methacrylate) (PMMA) biconvex IOL was optically superior (which is not the case) and that a biconvex IOL could not be made with a ridge, especially of silicone, because the ridge would be damaged on injection. This was proved to be untrue by the commercially available Coburn PMMA biconvex ridge IOLs (implanted successfully for several years) and theAMOsilicone ridge IOL injection study. However, by then the manufacturers’ marketing skills led to the demise of the use of ridge IOLs until the patent expired. Later, the concept resurfaced without crediting the invention.

Purpose: To assess the impact of phacoemulsification performed one week before pars plana vitrect... more Purpose: To assess the impact of phacoemulsification performed one week before pars plana vitrectomy versus combined phacovitrectomy on postoperative anterior segment status and final functional and anatomical outcomes in phakic patients affected by complex rhegmatogenous retinal detachment. Methods: The authors retrospectively reviewed the records of 59 phakic patients affected by complex rhegmatogenous retinal detachment. Twenty-nine patients underwent cataract surgery 7 days before vitrectomy (preemptive cataract surgery—Group 1), whereas 30 patients underwent combined phacovitrectomy (Group 2). Preoperative, intraoperative, earlyand late-postoperative outcomes were measured and compared. Results: Numbers of previous retinal surgical procedures, nuclear sclerosis grade, proliferative vitreoretinopathy grade, eyes with inferior breaks, surgical time, and ratio of silicone oil/gas tamponade were all similar between the two groups. After surgery, there was less extension of posterio...

Revista Cubana de Oftalmología, Jun 21, 2020

Copyright © 2011 Aldo Caporossi et al. This is an open access article distributed under the Creat... more Copyright © 2011 Aldo Caporossi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To report a comparative prospective long-term functional analysis after Riboflavin UV A corneal cross-linking (CXL) in three different age groups of patients affected by progressive keratoconus (KC). Methods. Functional analysis comprised paediatric patients (≤18 years) included 152 eyes (29.5%); intermediate group (19–26 years) 286 eyes (55.4%), and adults (≥27 years) 78 eyes (15.1%). CXL was performed according to the Siena protocol by using the Vega CBM (Caporossi-Baiocchi-Mazzotta) X linker (CSO, Florence, Italy) at Siena University by the same authors. Pre- and post-op examinations included UCVA, BSCVA, corneal topography, and surface aberrometry (CSO Eye Top, Florence, Italy), at 48 months followup. Results. At 48 mont...

Management of Early Progressive Corneal Ectasia, 2017

Crosslinking Results and Literature Overview 2.1 Conventional Crosslinking 2.1.1 The Standard "Dr... more Crosslinking Results and Literature Overview 2.1 Conventional Crosslinking 2.1.1 The Standard "Dresden Protocol" Corneal crosslinking (CXL) is performed in an outpatient setting. Thirty minutes in advance, a systemic analgosedation can be administered. Some surgeons use Pilocarpin 2% eye drops in order to reduce potential thermal and photochemical effects of UVA-radiation on the retina and the lens. The procedure is performed under sterile conditions in an operating room. After topical anesthesia, an eye lid retractor is inserted and the epithelium is removed with a diameter of 8 mm so that riboflavin can penetrate into the corneal stroma leading to a high UVA-absorption. Riboflavin 0.1% is a photosensitizer which is installed every 2 min for 30 min, ensuring maximum penetration into the cornea. During this riboflavin application is the eyelid retractor removed. Before UV-irradiation, the surgeon checks the appearance of riboflavin in the anterior chamber via slit lamp with blue filter. Corneal thickness is measured (ultrasonic pachymetry) immediately after the epithelium removal (in order to decide which kind of riboflavin solution should be used: isoosmolar or hypoosmolar) and before irradiation in order to ensure that the corneal thickness is above 400 μm and endothelium remains protected from UV-light. A special UV-sensor is used in order to detect intensity of irradiation in advance of the procedure. An area of 8 mm of central cornea is irradiated with UV-light of a wave length of 370 nm and intensity of 3 mW/cm 2. The irradiation lasts 30 min and riboflavin is applied every 5 min. Local antibiotics and lubricants are applied after the CXL and a soft contact lens is inserted till the epithelium is fully restored. The systemic use of painkillers is possible. After epithelial closure, topical steroids are prescribed for a duration of 3 weeks. Patients are followed-up every day till the re-epithelialization process is completed and after 1, 3, 6, 12 months and every year. Fitting of new rigid contact lenses is recommended about 6-8 months after the procedure [1, 2].

We introduce and explore an empirical index of increase that works in both deterministic and rand... more We introduce and explore an empirical index of increase that works in both deterministic and random environments, thus allowing to assess monotonicity of functions that are prone to random measurement-errors. We prove consistency of the index and show how its rate of convergence is influenced by deterministic and random parts of the data. In particular, the obtained results suggest a frequency at which observations should be taken in order to reach any pre-specified level of estimation precision. We illustrate the index using data arising from purely deterministic and error-contaminated functions, which may or may not be monotonic.

Modern keratoconus (KC) therapeutic strategy should be based on its clinical stage depending on c... more Modern keratoconus (KC) therapeutic strategy should be based on its clinical stage depending on corneal apex and posterior elevation location (central 2 mm), curvatures, thickness, high-order aberrations, documented clinical (UCVA, BSCVA) and instrumental (topographic, pachymetric and/or aberrometric) progression [1]. Therapeutic approach must be also strongly connected to patient’s age according to different progression rate, faster in paediatric patients 18 years and under and among young people between 19 and 26 years [2].

Corneal cross-linking was in experimental setting introduced by Seiler and Spoerl in 1997 in Dres... more Corneal cross-linking was in experimental setting introduced by Seiler and Spoerl in 1997 in Dresden and the first clinical pilot study was conducted and published by Wollensak et al. in 2003 also in Dresden [1, 2]. A standardized protocol that we refer to as a “Dresden protocol” involves abrasion of the corneal epithelium, followed by riboflavin application for 30 min as a photosensitizer and subsequent UVA illumination of 3 mW/cm2 of its intensity applied to a 9-mm zone in the cornea for another 30 min. This corresponds to a total energy dose of 3.4 J or a radiant exposure of 5.4 J/cm2 [3].

$Research paper thumbnail of Refractive Crosslinking: ACXL Plus$

Keratoconus is a degenerative non-inflammatory ectatic disease of the cornea characterized by bio... more Keratoconus is a degenerative non-inflammatory ectatic disease of the cornea characterized by biomechanical instability of stromal collagen leading to a reduction in corneal thickness, a variation in posterior and anterior corneal curvature, fluctuation and loss of visual acuity attributable to irregular astigmatism with or without a reduction in corneal transparency.

Annali di ottalmologia e clinica oculistica, 1990

In this paper the Authors relate one case of posterior capsular tear happened during surgery with... more In this paper the Authors relate one case of posterior capsular tear happened during surgery with phaco emulsification technique in patient with polar posterior cataract and they analyse the possible correlations between polar posterior cataract and posterior capsular tear