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Purpose To assess the clinical and microstructural results of accelerated 15 mW pulsed-light corneal crosslinking (CXL) to treat progressive keratoconus. Setting Siena Crosslinking Center, Siena, Italy. Design Prospective case series. Methods After epithelium removal (with Epi-Clear) and 10 minutes stromal soaking with riboflavin 0.1% hydroxypropyl methylcellulose solution, all eyes had 15 mW/cm2 pulsed-light epithelium-off accelerated CXL for 6 minutes of ultraviolet-A (UVA) irradiation (1 second on/1 second off), maintaining a total UVA exposure of 12 minutes at a fluence of 5.4 J/cm2. The 2-year follow-up examination included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, Scheimpflug tomography, in vivo confocal microscopy (IVCM), and spectral-domain optical coherence tomography (SD-OCT). Results The study comprised 132 eyes of 96 patients (mean age 23.7 years ± 4.3 [SD]) with stage II keratoconus. The change in UDVA and CDVA was statistically significant, from 0.51 ± 0.106 logarithm of the minimum angle of resolution (logMAR) at baseline to 0.309 ± 0.074 logMAR (P = .0001) and 0.271 ± 0.144 logMAR at baseline to 0.135 ± 0.100 logMAR (P = .0023), respectively. Coma values measured by Scheimpflug analysis showed a statistically significant improvement beginning with the first postoperative month (P = .0004). The IVCM scans documented basal epithelial healing occurring 72 hours after treatment associated with the presence of subepithelial nerves. The SD-OCT scans performed in the central 6.0 mm of corneal diameter documented a demarcation line at a mean depth of 280 ± 32 μm. Conclusion The 15 mW/cm2 pulsed-light epithelium-off accelerated CXL was effective and safe, stabilizing keratoconus progression through 2 years of follow-up.

Purpose Assessing the quality of the ocular surface by in vivo scanning laser confocal microscopy (IVCM) in primary open angle glaucoma (POAG) patients treated by Xen 45 Gel Stent, medical therapy and trabeculectomy. Methods Retrospective, single-center, single-masked, comparative study including 60 eyes of 30 patients (mean age 61.16 ± 10 years) affected by POAG. Eyes were divided into 3 groups: Group 1 eyes underwent the Xen 45 Gel Stent procedure, Group 2 eyes were under medical therapy, Group 3 eyes were surgically treated by trabeculectomy. All patients underwent HRT II IVCM analysis of cornea, limbus, conjunctiva, sub-tenionian space and sclera. Results The Xen 45 Gel stent, if properly positioned in the sub-conjunctival space preserves goblet cells and limits ocular surface inflammation. Regular corneal epithelial cells with micro-cysts, and normo-reflective sub-epithelial nerve plexus are documented by IVCM. In sub Tenon’s implants an alternative lamellar intra-scleral filtration is detectable. Combined surgical procedures show a noticeable number of inflammatory cells with rare micro-cysts. Post-trabeculectomy inflammatory reaction is more evident than Xen 45 Gel Stent associated surgical procedures, but less than medical therapy where a conspicuous presence of Langerhans cells, peri-neural infiltrates, marked loss of goblet cells and fibrosis is visible. Conclusion Ocular surface inflammation was more notable in topical therapy than after trabeculectomy, which itself causes more inflammation than XEN Gel stents.

The corneal sub-basal nerve (SBN) plexus is destroyed during photorefractive keratectomy (PRK) and its recovery is still a matter of debate. In vivo confocal microscopy (IVCM) was used to evaluate SBN plexus in 23 patients at a distance of 10-25 years (mean 15.6 years) from myopic PRK. Because 8 out of the 23 PRK patients underwent pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment, IVCM was also performed on those patients 6 months after PPV. Thirteen patients matched for age and myopia served as controls (non-PRK). SBN plexus was markedly reduced after PRK compared with non-PRK eyes and showed a slow, continuous but incomplete recovery up to the end of our follow-up (range 10-25 years). PRK and non-PRK eyes showed a marked reduction in SBN density 6 months after PPV, thus demonstrating a detrimental effect exerted by PPV on SBN plexus.

Controversy still exists regarding the role of the TGF-β in neovascular age-related macular degeneration (nAMD), a major cause of severe visual loss in the elderly in developed countries. Here, we measured the concentrations of active TGF-β1, TGF-β2, and TGF-β3 by ELISA in the aqueous humor of 20 patients affected by nAMD, who received 3 consecutive monthly intravitreal injections of anti-VEGF-A antibody. Samples were collected at baseline (before the first injection), month 1 (before the second injection), and month 2 (before the third injection). The same samples were used in a luciferase-based reporter assay to test the TGF-β pathway activation. Active TGF-β1 concentrations in the aqueous humor were below the minimum detectable dose. Active TGF-β2 concentrations were significantly lower at baseline and at month 1, compared to controls. No significant differences in active TGF-β3 concentration were found among the sample groups. Moreover, TGF-β pathway activation was significantly lower at baseline compared to controls. Our data corroborate an anti-angiogenic role for TGF-β2 in nAMD. This should be considered from the perspective of a therapy using TGF-β inhibitors.

Riboflavin UV-A Corneal Crosslinking was developed in the 1990’s to treat progressive keratoconus. Its indication was rapidly extended to iatrogenic corneal ectasias. Conventional 3mW/cm2 CXL represents the gold standard therapy in multiple Countries around the World to halt the progression of early stages corneal ectasia demonstrating good long-term visual results and low complications. Early diagnosis, slowing the progression of keratoconus turning to native corneal crosslinking spirit: stabilizing ectasia progression preventing corneal shape modification, is the key. Conventional and Accelerated CXL protocols demonstrated a medium-long term improvement in visual and topo-aberrometric parameters. New conservative approaches such as topography-guided CXL and CXL-plus corneal reshaping techniques are under investigation for patients with poor spectacles corrected visual acuity and contact lenses intolerance before keratoplasty.

Purpose:To assess the 10-year follow-up efficacy and safety of riboflavin ultraviolet A–induced cross-linking (CXL) in a population of pediatric patients aged 18 years and younger with progressive keratoconus (KC).Methods:The prospective longitudinal cohort study included 62 eyes of 47 keratoconic p

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Purpose The purpose of this study was to evaluate the expression of high-temperature requirement A serine peptidase 1 (HTRA1), TGF-β1, bone morphogenetic protein 4 (BMP4), growth differentiation factor 6 (GDF6), and VEGFA proteins in the aqueous humor of patients with naive choroidal neovascularization (nCNV) secondary to AMD. Methods We measured by ELISA the concentrations of HTRA1, TGF-β1, BMP4, GDF6, and VEGFA in the aqueous humor of 23 patients affected by nCNV who received three consecutive monthly intravitreal injections of 0.5 mg ranibizumab. Samples were collected at baseline (before the first injection), month 1 (before the second injection), and month 2 (before the third injection). Twenty-three age-matched cataract patients served as controls. Results Bone morphogenetic protein 4 and GDF6 were not detectable in any samples. Baseline HTRA1 was higher than controls (P < 0.0001) and higher than both the month 1 (P < 0.0001) and the month 2 (P < 0.0001) values. Baseline VEGFA was higher than controls (P < 0.0001), not different from month 1 value (P = 0.0821), but higher than month 2 value (P < 0.0001). Baseline TGF-β1 was higher than controls (P = 0.0015) and not different from month 1 (P = 0.129) and month 2 values (P = 0.5529). No correlation was found in naive patients between concentrations of HTRA1 and TGF-β1, HTRA 1 and VEGFA, or TGF-β1 and VEGFA. Conclusions In nCNV patients, HTRA1 and TGF-β1 were significantly higher compared to controls. After treatment, TGF-β1 was persistently elevated, while HTRA1 returned to control levels, suggesting the involvement of TGF-β1 and HTRA1 in neovascular AMD and a VEGFA-independent role for TGF-β1.

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].

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.

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 ectasia remains one of the most insidious complications encountered after refractive surgery including laser in situ keratomileusis (LASIK), radial keratotomy (RK) and phptprefractive keratectomy (PRK) and more recently small incision lenticule extraction (SMILE). Ectasia after refractive surgery is a progressive increase in myopic defect, with or without irregular astigmatism, associated with fast keratometric steeping and topographic asymmetric inferior corneal steeping. Over time, there can be associated thinning of the central and paracentral ectatic corneal tissue. Normally this it come to patient’s clinical attention when there is associated loss of uncorrect distance visual acuity (UDVC) [1, 2].

Keratoconus is an ectatic disease of the cornea characterized by biochemical and biomechanical instability of stromal collagen leading to a reduction of corneal thickness [1], variation in posterior and anterior corneal curvatures and progressive deterioration of visual acuity due to irregular astigmatism [1, 2]. The recent advent of corneal collagen cross-linking in the panorama of ophthalmology of the last decade [3, 4] has transformed the conventional therapy of keratoconus, including in the best case scenario, rigid contact lens wearing for a lifetime or, at worst, corneal transplant. Conservative treatment has improved and thus reduced the necessity of a lamellar and penetrating corneal graft. Riboflavin UV-A induced corneal collagen cross-linking (CXL) demonstrated its efficacy in the conservative treatment of progressive keratoconus [3, 4] and secondary corneal ectasia [5] due to its ability to increase biomechanical corneal resistance [3, 4] and intrinsic anti-collagenase activity [6]. The physiochemical basis of cross-linking lies in the photo-dynamic type I-II reactions [7], induced by the interaction between 0.1% riboflavin molecules absorbed in the corneal tissue, and UV-A rays delivered at 3 mW/cm2 for 30 min (5.4 J/cm2 energy dose) releasing reactive oxygen species (ROS) that mediate cross-link formation between and within collagen fibers [8, 9]. The conventional epithelium-off cross-linking procedure (CXL) demonstrated its long-term efficacy stabilizing progressive keratoconus and secondary ectasia in different clinical trials [10–14]. Conventional CXL requires a long treatment time (1 h) [15]. A novel approach called Accelerated cross-linking (ACXL), based on the physical concept of photochemical reactions stated in the Bunsen–Roscoe’s law of reciprocity [16–18], has been recently proposed to shorten treatment time while maintaining the same efficacy. This theory [16] demonstrated that the photochemical process behind cross-linking depends on the absorbed UV-A energy, and its biological effect is proportional to the total energy dose delivered in the tissue [16–19]. Indeed, according to the “equal-dose” [18, 19] physical principle, 9 mW/cm2 for 10 min, 30 mW/cm2 for 3 min, 18 mW/cm2 for 5 min, 45 mW/cm2 for 2 min, at a constant energy dose of 5.4 J/cm2, have the same photochemical impact of conventional 3 mW/cm2 for 30 min [18, 19]. Moreover, an energy dose of 7.2 J/cm2 was demonstrated to be effective both in terms of corneal strengthening and anti-enzyme activity compared with the standard dose of 5.4 J/cm2, respectively tested by biaxial corneal extensiometry and papain digestion [20]. Previous histological reports in literature on conventional and accelerated corneal cross-linking [20, 21] demonstrated keratocyte damage and repopulation of the corneal stroma by proliferating cells, and an increase in collagen fiber diameter. These modifications are the morphological correlate of the process leading to increased corneal biomechanical stability. These observations were confirmed by in vivo studies in humans provided by Mazzotta et al. with scanning laser confocal microscopy which demonstrated the reduction in anterior and intermediate stromal keratocytes followed by gradual repopulation [22]. Long term keratoconus stability after conventional cross-linking treatment was correlated in vivo to increased cross-links formation, synthesis of restructured collagen and new lamellar interconnections [23].

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.

Introduction: Keratoconus is an ectatic disease of the cornea characterized by biomechanical instability of stromal collagen leading to reduction of corneal thickness, variation in posterior and anterior corneal curvatures with associated progressive deterioration of visual acuity mainly due to a secondary irregular astigmatism. Corneal collagen crosslinking (CXL) is a new approach to increase the mechanical strength and biochemical stability of the corneal stromal tissue affected from primary or secondary ectasia. A novel pharmacological series of riboflavin formulations from Avedro, Inc. (Waltham, Massachusetts, MA, USA), were recently granted orphan drug designation by the Food and Drug Administration for the treatment of keratoconus and secondary corneal ectasia. Areas covered: This report reviews the basic concepts concerning the role of riboflavin in crosslinking treatment in order to understand the potentiality of the new VibeX™ and VibeX Rapid™ solutions for riboflavin UVA-induced CXL. The treatme...

Previtrectomy cataract surgery was associated with less extensive postoperative posterior synechia, however, its final functional and anatomical outcomes were not significantly different from those of combined phacovitrectomy. Both approaches were efficacious., 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, early- and 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 posterior synechia in Group 1. There was no significant difference in fibrin, number of patients with posterior synechia, final intraocular pressure, retinal redetachment rate, final retinal status, or final best-corrected visual acuity. Conclusion: Preemptive cataract surgery was associated with less extensive postoperative posterior synechia, however, its final functional and anatomical outcomes were not significantly different from those of phacovitrectomy. Both approaches were efficacious.

PURPOSE To assess the efficacy of riboflavin ultraviolet A (UV-A) corneal collagen cross-linking in the management of keratoconic corneal ectasia exacerbated by radial keratotomy (RK). METHODS A patient with progressive corneal ectasia and hyperopic shift, occurring 10 years after RK performed in the left eye, was treated with riboflavin UV-A corneal collagen cross-linking according to the Siena protocol: Pilocarpin 0.1% drop (1 hour before), lidocaine 4% drops 15 minutes before, mechanical scraping of epithelium (9-mm-diameter area), preirradiation stromal soaking for 10 minutes in riboflavin 0.1%-dextrane 20% (Ricrolin; Sooft Italy) applied every 2 minutes, and 30 minutes of total exposure (6 steps of 5 minutes) to solid-state UV-A illuminator (Caporossi, Baiocchi, Mazzotta Vega X linker; CSO Opthalmics, Florence, Italy), energy delivered 3 mW/cm, and irradiated area 9 mm in diameter. RESULTS After the operation, uncorrected visual acuity and best spectacle-corrected visual acuity improved from 0.2 to 0.6 and from 0.3 to 0.8 Snellen lines, respectively, in a 12-month follow-up. Improved topographical K readings and corneal symmetry index were also recorded starting from the first postoperative month and continuing thereafter. No adverse effects were recorded after treatment. CONCLUSIONS Riboflavin UV-A-induced corneal cross-linking seems to be a promising surgical option in the management of unstable corneal ectasia exacerbated by RK, particularly in eyes with preexisting keratoconus. A large cohort and longer follow-up are needed to determine its long-term efficacy in this clinical setting.

We present a case of keratoconus in which the association with posterior polymorphous corneal dystrophy was established by confocal microscopy. Confocal microscopy enable us to assess the differential diagnosis between posterior corneal dystrophies, essential for a prognosis and therapeutic decision.

Purpose To assess the effectiveness of riboflavin–ultraviolet type A rays induced cross-linking of corneal collagen in reducing progression of keratoconus and in improving visual acuity in patients with progressive keratoconus. Setting Department of Ophthalmology, Siena University, Siena, Italy. Methods This was a second-phase prospective nonrandomized open study. Starting in September 2004, 10 eyes of 10 patients (mean age 31.4 years) with bilateral keratoconus were treated by combined riboflavin–ultraviolet type A rays (UVA) collagen cross-linking. Radiant energy was 3 mW/cm 2 or 5.4 joule/cm 2 for a 30-minute exposure at 1 cm from the corneal apex. A complete ophthalmologic examination (uncorrected visual acuity [UCVA], sphere spectacles corrected visual acuity (SSCVA), best spectacle-corrected visual acuity [BSCVA]) was performed. Patients had corneal computerized topographic examination, linear scan optical tomography, endothelial cell count, ultrasound pachometry, intraocular pressure (IOP) evaluation, and HRT II system confocal microscopy at 1, 2, 3, and 6 months. After treatment, eyes were medicated and dressed with a soft contact lens. Results Comparative preoperative and postoperative results showed increases of 3.6 lines for UCVA ( P = .0000112), 1.85 lines for SSCVA ( P = .00065), and 1.66 lines for BSCVA ( P = .00071). Topographic analysis showed a mean K reduction of 2.1 ± 0.13 diopters (D) in the central 3.0 mm. Statistical analysis of IOP and endothelial cell count did not show significant differences. Topo-aberrometric analysis findings of corneal symmetry showed a trend toward increasing corneal symmetry with a major reduction in asymmetry between vertical hemimeridians. Conclusions Refractive results showed a reduction of about 2.5 D in the mean spherical equivalent, topographically confirmed by the reduction in mean K. Results of surface aberrometric analysis showed improvement in morphologic symmetry with a significant reduction in comatic aberrations.

To evaluate the occurrence of late-onset corneal haze (LOCH) after vitrectomy for rhegmatogenous retinal detachment (RRD) in photorefractive keratectomy (PRK)-treated eyes. This observational cohort study comprised 13 eyes of 13 patients who underwent vitrectomy for RRD and who had been subjected to PRK years earlier. The occurrence of LOCH was evaluated together with all the preoperative, intraoperative, and postoperative factors that could affect final corneal status. LOCH developed in 2 eyes. Both patients had undergone PRK for high myopia—one 3 years and the other 9 years prior to RRD. Both patients presented with RRD due to giant retinal tear and were subjected to scleral buckle, 20-gauge vitrectomy, and silicone oil tamponade. Three months after vitrectomy and 1 month after silicone oil removal they both developed LOCH. During vitreoretinal surgery neither of the 2 patients needed mechanical epithelial debridement. Intraoperative epithelial debridement was performed in 2 of the other patients of the series, who had undergone previous PRK for high myopia and had clear corneas at presentation; in 1 of them this manoeuvre hampered intraoperative visualization. Follow-up after retinal detachment surgery ranged from 6 to 156 months (mean, 37.5 months). Subepithelial corneal scarring may be reactivated many years after PRK. In our series this happened after vitrectomy.

A 42-year-old man had uneventful bilateral nonsimultaneous photorefractive keratectomy (PRK) for severe myopia. Thirty-nine months after the procedure, the patient presented with a retinal detachment (RD) in the right eye. Cerclage, vitrectomy, endolaser, and intravitreal silicone oil tamponade were performed, and the RD was successfully repaired. Three months after vitrectomy and 42 months after PRK, the patient complained of visual impairment in the right eye and photophobia. On slitlamp examination, marked reticular scarring of the central anterior cornea was observed. The occurrence of late-onset corneal haze highlights the need for special attention to patients who have vitrectomy after PRK.

Purpose: To assess qualitative micro-morphological corneal changes by confocal microscopy and corneal OCT after accelerated corneal crosslinking (A-CXL) in keratoconic patients. Study design: Prospective non-randomized pilot study. Methods: 20 eyes of 20 patients, aged between 13 and 26 years (mean 22.6 years) underwent A-CXL by the KXL UV-A source (Avedro Inc. Waltham MA, USA). Patients were divided into 4 groups according to different riboflavin solutions and UV A powers.15 patients underwent epithelium-off A-CXL: 5 (Group 1) by riboflavin 0.1% plus dextran 20% at 12 mW/cm2 for 10 min; 5 (Group 2) at 30 mW/cm2 for 4 min; 5 (Group 3) by dextran-free riboflavin 0.1% plus HPMC at 30 mW/cm2 for 4 min and 5 (Group 4) by riboflavin 0.25% plus EDTA, BAK, TRIS epithelium-on A-CXL for 2 min and 40 sec. Micro-morphological analysis was assessed by in vivo HRT II confocal microscopy and corneal OCT. Results: Epithelium regenerated into 3 days. Sub-epithelial nerves disappeared after treatment regenerating into 6 months. Epithelium off A-CXL penetration, measured evaluating keratocytes loss at confocal microscopy and demarcation lines at corneal OCT, resulted at 180 μm on average in the Group 1, 160 μm in the Group 2, 150 μm in the Group 3. Epithelium-on A-CXL (Group 4) revealed a penetration at 80 μm on average. No endothelial damage was recorded in all groups. Conclusion: A-CXL shortened conventional CXL procedure under 20 minutes, being well tolerated. Its clinical efficacy needs to be determined in the mid-long term follow-up and in a large cohort of patients.

This study compared how well two sodium hyaluronate viscoelastics maintained the anterior chamber during cataract surgery in eyes at risk for high vitreous pressure. Patients were divided into two groups based on the sodium hyaluronate used: Healon® or Healon GV©. Qualitative data were obtained with a digital slide gauge attached to the operating microscope. After capsulorhexis, mean anterior chamber depth (distance of the corneal apex to the iris plane) was significantly greater in the Healon GV group ( P = .0012). Subjective intraoperative evaluation by surgeons also favored Healon GV. There was no difference between the groups in postoperative inflammation, corneal edema, intraocular pressure, or visual acuity. Therefore, although the two viscoelastics are equally safe, Healon GV maintains the anterior chamber better during cataract surgery.

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.

Evaluation of stability and functional response after riboflavin-UVA–induced cross-linking in a population of patients younger than 18 years with progressive keratoconus after 36 months of follow-up.Prospective nonrandomized phase II open trial conducted at the Department of Ophthalmology, Siena University, Italy. The "Siena CXL Pediatrics" trial involved 152 patients aged 18 years or younger (10–18 years) with clinical and instrumental evidence of keratoconus progression. The population was divided into 2 groups according to corneal thickness (450 and450 μm) at the time of enrollment. The riboflavin-UVA–induced corneal cross-linking was performed in all patients according to the standard epi-off protocol. Parameters recorded preoperatively and postoperatively were as follows: uncorrected visual acuity, best spectacle–corrected visual acuity, corneal topography and surface aberrometry (CSO Eye Top topographer; Florence, Italy), optical pachometry (Visante OCT; Zeiss Meditec, Jena, Germany), and HRT II confocal microscopy (Rostock Cornea Module, Heidelberg, Germany).Functional data at 36 months showed an increase of +0.18 and +0.16 Snellen lines for uncorrected visual acuity and best spectacle-corrected visual acuity, respectively, in the thicker group (corneal thickness450 μm) and +0.14 and +0.15 Snellen lines, respectively, in the thinner group (corneal thickness450 μm). Patients in the latter group already showed a better and faster functional recovery than the thicker group at 3-month follow-up. Topographic results showed statistically significant improvement in K readings and asymmetry index values. Coma reduction was also statistically significant.The study demonstrated significant and rapid functional improvement in pediatric patients younger than 18 years with progressive keratoconus, undergoing riboflavin-UVA–induced cross-linking. In pediatric age, a good functional response and keratoconus stability was obtained after corneal cross-linking in a 36-month follow-up.

Purpose To evaluate intrastromal concentrations of riboflavin with and without epithelium to ensure the efficacy and safety of corneal crosslinking (CXL) by the standard and transepithelial procedures. Setting Department of Ophthalmology and Department of Pharmacology G. Segre, Siena University, Siena, Italy. Methods This study comprised keratoconic patients enrolled for penetrating keratoplasty (PKP) and warm-stored sclerocorneal rings unsuitable for transplantation. Half the PKP specimens were debrided, and half were left with the epithelium in situ. One of the latter and 1 debrided sample were not exposed to riboflavin (controls). Samples in both groups were soaked with 0.1% riboflavin–dextran 20% solution instilled every 2 minutes for 5, 15, and 30 minutes. Riboflavin concentrations were determined by high-performance liquid chromatography (HPLC). Results The study evaluated 14 PKP specimens and 16 sclerocorneal rings. Control samples did not show a riboflavin emission peak. In exposed samples with epithelium, the mean riboflavin concentration was 91.88 ng/g after 5 minutes of exposure, 95.60 ng/g after 15 minutes, and 94.92 ng/g after 30 minutes. In the debrided samples, the mean riboflavin concentration was 14.42 μg/g, 20.92 μg/g, and 24.06 μg/g, respectively. No differences were seen between the in vivo samples and the ex vivo samples. Conclusions The HPLC quantitative study showed that stromal concentrations of riboflavin increased with exposure time only if the epithelium was removed. A theoretically safe and effective riboflavin concentration of 15 μg/g was obtained for ultraviolet A-induced CXL only after the epithelium was removed and after at least 10 minutes of riboflavin application every 2 minutes.

Following retinal detachment, subretinal fluid (SRF) fills the neoformed space. Subsequently subretinal and preretinal strands of proliferative tissue begin to form. We have collected the subretinal fluid withdrawn during retinal detachment surgery. We have studied subretinal fluid cytologically to evaluate the number and the type of cells present in the fluid, and by means of transmission electron microscopy. The first cell type to be present in the fluid represented degenerated aspects of pigmented epithelial cells (PECs). Successively, other cell types appeared in the fluid as nerve cells (rods, cones and glial cells), macrophages and well preserved pigmented epithelial cells.

● PURPOSE: To assess early and late micromorphological modifications of cross-linked corneas in vivo by means of Heidelberg Retinal Tomography (HRT) II confocal microscopy. ● DESIGN: Prospective nonrandomized open trial. ● METHODS: Micromorphological examination of 44 cross-linked keratoconic corneas was performed in vivo by HRT II confocal laser scanning microscopy. Riboflavin ultraviolet (UV)-A‐induced corneal collagen crosslinking (CXL) was performed according to the Siena protocol: pilocarpin 1% drops 30 minutes before, topical anesthesia with lidocaine 4% drops 15 minutes before irradiation, mechanical scraping of epithelium (9-mmdiameter area), preirradiation soaking for 10 minutes in riboflavin solution 0.1% (Ricrolin, Sooft, Italy) applied every 2.5 minutes for 30 minutes, 30 minutes exposure to solid-state UVA illuminator (Caporossi; Baiocchi; Mazzotta, X-linker, CSO, Italy), 8-mm-diameter irradiated area, energy delivered 3 mW/cm 2 . All patients were examined by confocal scans preoperatively and at the following times after treatment: one, three, and six months, and one, two, and three years. ● RESULTS: No damage to the limbal region was observed. Epithelial regrowth was complete after four days of soft contact lens bandage. The anatomy of the subepithelial plexus was restored one year after the operation with full corneal sensitivity. Increased density of extracellular matrix in late postoperative period indicated cross-linked collagen to a depth of 340 m expressed by a late demarcation line. ● CONCLUSION: In vivo confocal microscopy showed early and late modification of corneal microstructure after the treatment. The three-year stability of CXL recorded could be related to increased cross-links formation, synthesis of well-structured collagen and new lamellar interconnections. (Am J Ophthalmol

To assess ultrastructural stromal modifications after riboflavin-UVA-induced cross-linking of corneal collagen in patients with progressive keratoconus.This was a second-phase prospective nonrandomized open study in 10 patients with progressive keratoconus treated by riboflavin-UVA-induced cross-linking of corneal collagen and assessed by means of Heidelberg Retinal Tomograph II Rostock Corneal Module (HRT II-RCM) in vivo confocal microscopy. The eye in the worst clinical condition was treated for each patient. Treatment under topical anesthesia included corneal deepithelization (9-mm diameter) and instillation of 0.1% riboflavin phosphate-20% dextran T 500 solution at 5 minutes before UVA irradiation and every 5 minutes for a total of 30 minutes. UVA irradiation was 7 mm in diameter. Patients were assessed by HRT II-RCM confocal microscopy in vivo at 1, 3, and 6 months after treatment.Rarefaction of keratocytes in the anterior and intermediate stroma, associated with stromal edema, was observed immediately after treatment. The observation at 3 months after the operation detected keratocyte repopulation in the central treated area, whereas the edema had disappeared. Cell density increased progressively over the postoperative period. At approximately 6 months, keratocyte repopulation was complete, accompanied by increased density of stromal fibers. No endothelial damage was observed at any time.Reduction in anterior and intermediate stromal keratocytes followed by gradual repopulation has been confirmed directly in vivo in humans by HRT II-RCM confocal microscopy after riboflavin-UVA-induced corneal collagen cross-linking.

Purpose To assess the possible thermal damage to the cornea during combined riboflavin and ultraviolet-A crosslinking using in vivo surface thermographic analysis. Setting Department of Oto-Neuro-Ophthalmological Surgical Sciences, Eye Clinic, University of Florence, Florence, Italy. Methods Collagen crosslinking was performed on a day-surgery basis under aseptic conditions with traditional techniques. During the procedure, temperature measurements on the corneal surface were taken using an infrared thermocamera. The temperature values were detected in the area directly exposed to light irradiation, selecting it in the acquired thermographic image. Because the aim of the study was to consider the thermal damage that may be induced during the procedure, the maximum temperature value detected in the area studied was recorded and considered for successive analysis. Results Infrared thermocamera measurements of the corneal surface during crosslinking treatment showed that the temperature was constant during the entire procedure and remains under the threshold of thermal injury to corneal collagen. Conclusion Corneal collagen crosslinking was a safe procedure that did not cause thermal injury to the corneal surface.

The technique of corneal collagen cross-linking consists of photopolymerization of stromal fibres by the combined action of a photosensitizing substance (riboflavin or vitamin B2) and ultraviolet light from a solid state UVA source. Photopolymerization increases the rigidity of corneal collagen and its resistance to keratectasia. In this report we present two cases, studied through in vivo confocal microscopy, with stage III keratoconus that developed stromal haze after the cross-linking treatment.

Purpose: To evaluate the intraoperative and postoperative performance of the single-piece AcrySof® SA30AL intraocular lens (IOL) in a series of patients after cataract surgery and IOL implantation. Setting: Department of Ophthalmology and Neurosurgery, University of Siena, Siena, Italy. Methods: In this prospective study, 20 patients who had phacoemulsification and implantation of a single-piece AcrySof SA30AL lens from March to April 2000 were evaluated. Assessed were control of IOL folding, ease of IOL implantation, IOL centration, intraoperative and postoperative complications, visual acuity, and anterior (ACO) and posterior (PCO) capsule opacification. Results: In all cases, the IOL was easily folded, inserted, and unfolded. It remained well centered in the capsular bag, and there were no intraoperative or postoperative complications. The best corrected visual acuity after surgery was 20/40 or better in all patients. No eye developed ACO or phimosis. One eye had a well-demarcated, oval area of lens epithelial cell proliferation on the posterior capsule that did not impair visual acuity. Conclusions: Initial results indicate that the single-piece AcrySof SA30AL IOL has good biocompatibility, haptic flexibility and resistance, and stability in the capsular bag. The incidence of PCO in 1 eye could have been the result of several factors and requires further evaluation. An area of future study is the wide haptic of the lens, which may create a path for cells to proliferate as they travel from the equatorial capsule.