Ocular Surface Microbiota in Naïve Keratoconus: A Multicenter Validation Study.

In the field of Ophthalmology, the mNGS 16S rRNA sequencing method of studying the microbiota and ocular microbiome is gaining more and more weight in the scientific community. This study aims to characterize the ocular microbiota of patients diagnosed with keratoconus who have not undergone any prior surgical treatment using the mNGS 16S rRNA sequencing method. Samples of naïve keratoconus patients were collected with an eNAT with 1 mL of Liquid Amies Medium (Copan Brescia, Italy), and DNA was extracted and analyzed with 16S NGS. The microbiota analysis showed a relative abundance of microorganisms at the phylum level in each sample collected from 38 patients with KC and 167 healthy controls. A comparison between healthy control and keratoconus samples identified two genera unique to keratoconus, Pelomonas and Ralstonia. Our findings suggest that alterations in the microbiota may play a role in the complex scenario of KC development.

Endodiathermal Tautening of Floppy or Irregular Iris in Endothelial Keratoplasty (Iridodiathermy).

ABSTRACT: Floppy or irregular irides may be seen during endothelial keratoplasty in complex cases or in eyes with damaged irides and may cause uneven air fill, retro-pupillary air escape, anterior bowing of iris, forward movement of lens-iris diaphragm, shallowing of anterior chamber (AC), bellowing and floppiness of iris, uneven AC depth, difficulty in inserting and opening graft, iris trauma, intraoperative bleeding, and iridodialysis. We present a technique of iridodiathermy for tautening and flattening such irides. With continuous irrigation using AC maintainer, the bipolar endodiathermy probe tip is applied in localized spots to midperipheral iris in the affected area with power and duration adjusted to induce mild localized shrinkage and tightening of iris stroma. Such iris tautening decreases its floppiness and prevents anterior bowing, excessive mobility, irido-corneal touch, and peripheral anterior synechiae formation. It provides a stable AC with regular depth and improved, uniform, and nonmigratory air fill, thus decreasing intraoperative challenges.

The Management of Dry Eye Disease: Proceedings of Italian Dry Eye Consensus Group Using the Delphi Method.

Dry eye disease (DED) is a highly prevalent, chronic and progressive condition that affects 5-33% of the world's adult population [...].

Transepithelial Enhanced Fluence Pulsed Light M Accelerated Crosslinking for Early Progressive Keratoconus with Chemically Enhanced Riboflavin Solutions and Air Room Oxygen.

PURPOSE: To assess the 3-year clinical results of the 18 mW 7 J/cm2 transepithelial enhanced fluence pulsed light M accelerated crosslinking in the treatment of progressive keratoconus (KC) with chemically enhanced hyper-concentrated riboflavin solutions without iontophoresis and with air-room oxygenation. SETTING: Siena Crosslinking Center, Siena, Italy. METHODS: Prospective pilot, open non-randomized interventional study including 40 eyes of 30 young adult patients over 21 years old (10 simultaneous bilateral) with early (Stage I and II) progressive KC undergoing TE-EFPL 18 mW/7 J/cm2 ACXL (EFPL M TECXL). The 12 min and 58 s pulsed light (1 s on/1 s off) UV-A exposure treatments were performed with a biphasic corneal soaking using Paracel I 0.25% for 4 min and Paracel II 0.22% for 6 min riboflavin solutions and New KXL I UV-A emitter (Glaukos-Avedro, Waltham, USA) at an air room of 21% oxygenation. All patients completed the 3-year follow-up. RESULTS: CDVA showed a statistically significant improvement in the third postoperative month (Δ + 0.17 d. e.) with a final gain of +0.22 d. eq. AK showed a statistically significant decrease in the sixth postoperative month (Δ - 1.15 diopters). K itmax showed a statistically significant decrease at 1-year follow-up (Δ - 1.3 diopters). The coma value improved significantly by the sixth month (Δ - 0.54 µm). MCT remained stable during the entire follow-up. No adverse events were recorded. Corneal OCT revealed a mean demarcation line depth at 282.6 ± 23.6 µm. CONCLUSIONS: Transepithelial enhanced fluence pulsed light M accelerated crosslinking with chemically enhanced riboflavin solution halted KC progression in young adult patients without iontophoresis and no intraoperative oxygen supplementation addressing the importance of increased fluence.

Exploring the Healthy Eye Microbiota Niche in a Multicenter Study.

PURPOSE: This study aims to explore and characterize healthy eye microbiota. METHODS: Healthy subjects older than 18 years were selected for this descriptive cross-sectional study. Samples were collected with an eSwab with 1 mL of Liquid Amies Medium (Copan Brescia, Italy). Following DNA extraction, libraries preparation, and amplification, PCR products were purified and end-repaired for barcode ligation. Libraries were pooled to a final concentration of 26 pM. Template preparation was performed with Ion Chef according to Ion 510, Ion 520, and Ion 530 Kit-Chef protocol. Sequencing of the amplicon libraries was carried out on a 520 or 530 chip using the Ion Torrent S5 system (Thermo Fisher; Waltham, MA, USA). Raw reads were analyzed with GAIA (v 2.02). RESULTS: Healthy eye microbiota is a low-diversity microbiome. The vast majority of the 137 analyzed samples were highly enriched with Staphylococcus, whereas only in a few of them, other genera such as Bacillus, Pseudomonas, and Corynebacterium predominate. We found an average of 88 genera with an average Shannon index of 0.65. CONCLUSION: We identified nine different ECSTs. A better understanding of healthy eye microbiota has the potential to improve disease diagnosis and personalized regimens to promote health.

Double safe suture during cataract surgery on post radial keratotomy patients using clear corneal incisions.

PURPOSE: the aim of this study is to find a safer surgical approach in cataract surgery on eyes previously treated with radial keratotomy using clear corneal incisions. SETTING: Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Ophthalmology Clinic, University of Messina, Messina, Italy. DESIGN: Prospective study. METHODS: A prospective study was conducted on a group of 20 patients, 21 eyes with 16 RK incisions were evaluated for cataract phacoemulsification. Samples were divided into two groups: Group 1 underwent surgery with pre-operative one corneal stitch along radial keratotomy incisions near the main access site whereas Group 2 underwent modified surgery with two corneal stitches. RESULTS: After surgery, visual acuity, corneal hysteresis and corneal strength was evaluated. In all cases, an increased visual acuity was observed. Group 1 showed an UCVA of logMAR 0.22 ± 0.14, while group 2 presented a logMAR of 0.1 ± 0.07. Data did not show a statistically significant difference in UCVA after surgery between the two groups (P = 0.133). Instead, a significant difference in corneal hysteresis (CH), respectively with values of 8.65 ± 1.6 mmHg in group 1 and 9.2 ± 1.8 in group 2 (P = 0.031), and a corneal resistance factor (CRF) with values of 7.87 ± 1.4 mmHg in the first group and 8.65 ± 1.6 mmHg in the second one (P = 0.039) was observed. CONCLUSIONS: Double safe suture technique offers better stabilization of corneal structure during surgery in patients preventively treated with 16 incisions RK.

Glasses-Assisted 3D Display System-Guided Descemet Membrane Endothelial Keratoplasty Tissue Preparation.

PURPOSE: The aim of this study was to evaluate the feasibility of Descemet membrane endothelial keratoplasty (DMEK) tissue preparation using a glasses-assisted 3-dimensional (3D) display system and to compare it with a conventional surgical microscope. METHODS: Healthy pairs of human corneas suitable for penetrating keratoplasty surgery were selected for this study. The tissues were randomly divided into 2 groups. Each pair of corneas had 1 cornea (group 1) prepared with NGENUITY (Alcon) with a 5-second staining time with vision blue, and the fellow cornea (group 2) was prepared using a OPMI Lumera 700 surgical microscope (Carl Zeiss Meditec, Jena, Germany) with a 30-second staining time. DMEK graft preparation time, speed of stripping, graft width, and endothelial cell loss were evaluated. RESULTS: Twenty-eight pairs of corneas were included in this study. The graft preparation time was significantly higher in the 3D group than in the conventional group (498 ± 147 vs. 418 ± 85 seconds, P value = 0.031). The mean speed of stripping was 0.59 ± 0.081 mm/s in group 1 and 0.089 ± 0.005 mm/s in group 2 ( P value = 0.024). The mean endothelial cell density in group 1 and group 2 before tissue preparation was 2162 ± 115.21 and 2153 ± 122.45, respectively ( P value > 0.1). After tissue preparation, the endothelial cell density reduced to 1911 ± 150.72 in group 1 and 1998 ± 90.72 in group 2 ( P value = P value > 0.05). The graft width was 5.05 ± 0.71 mm in group 1 and 4.92 ± 0.23 mm in group 2 ( P value > 0.05). CONCLUSIONS: DMEK tissue preparation with 3D display system NGENUITY is feasible with a slightly increased preparation time. The improved visualization allows a reduced staining time that could be beneficial for eye banks because it may reduce the toxic effect of staining colorants.

Tips, Tricks, and Guides in Descemet Membrane Endothelial Keratoplasty Learning Curve.

Lamellar keratoplasty is fast becoming the most popular form of corneal transplantation. The adoption of Descemet membrane endothelial keratoplasty (DMEK) in the management of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy is partly responsible for this shift in the paradigm of management of corneal pathology. The learning curve of DMEK, however, has been proven to be much steeper than previous endothelial keratoplasty procedures. To ease the procedure, experts have proposed multiple innovative techniques from tissue preparation to graft unfolding to aid the more novice surgeon. Here, we collate and share tips and tricks from our collective experiences to support the learning curve and outcomes in DMEK for both the novice and more experienced corneal transplant surgeons.

Clinical Validation of the Automated Characterization of Cone Size and Center in Keratoconic Corneas.

PURPOSE: To evaluate an automated method for detecting the cone shape characteristics and to assess the cornea specialists' subjective variability of these measures using different maps. METHODS: Topographic images of the anterior and posterior surface of each eye were presented to 12 clinicians in two different types of map: tangential curvature and relative elevation to the best-fit sphere. They were asked to mark the cone center and its boundaries in the two maps without knowing that they belonged to the same patient. The results between the maps were compared to assess the subjective variability dependent on the map type and the automated method was compared against both estimations to assess its accuracy. RESULTS: Considering the results of anterior and posterior surfaces, there was low agreement between the cone center estimations using different types of maps for 10 of the 12 cases (P < .05), whereas the comparison between the automated method and the two map estimations did not show differences in 11 of the 12 cases (P > .05). There was high variability, up to 55%, among clinicians' estimations of the cone area. The results of the automated method were within the range of the expert's estimations. CONCLUSIONS: An objective, mathematically derived method of determining morphological dimensions of the cone was consistent with clinicians' evaluations. Although there was high variability among the experts' subjective estimates, which were highly influenced by the type of map, the objective method provided a reliable evaluation of the keratoconus shape independent of maps or color scale. [J Refract Surg. 2021;37(6):414-421.].

The cold eye irrigation BSS solution used during phacoemulsification reduces post-surgery patients discomfort preventing the inflammation.

PURPOSE: The aim of this study was to assess whether the intraoperative use of the cold eye irrigation balanced salt solution (BSS) could have a protective effect in preventing the anterior chamber flare and conjunctival hyperemia and, thus, in reducing patients discomfort after phacoemulsification. MATERIALS AND METHODS: About 214 patients were enrolled and randomly divided into: patients whose eye were irrigated with BSS at ~ 20°C (Group 1) and patients whose eye were irrigated with BSS at 2.7°C (Group 2). Anterior chamber flare, visual analogue score and conjunctival hyperemia were evaluated at 1, 3, 5, and 30 days after surgery. RESULTS: In patients of Group 2 the anterior chamber flare, the visual analogue score and the conjunctival hyperemia, used as parameters to evaluated clinical inflammation, at 1 day after surgery were significantly lower than those in Group 1 who received BSS solution at operating room temperature (p < 0.001), while at day 3, 5, and 30 there were not any significant differences. CONCLUSION: Our study provided evidence supporting the efficacy of the treatment with cold irrigation solution on reduction of anterior chamber flare, pain and conjunctival hyperemia already at 1 day after phacoemulsification, suggesting that cooling procedure was fully effective at controlling early post-operative inflammation.

Transepithelial photorefractive keratectomy for the management of hyperopic regression after conductive keratoplasty.

Several refractive techniques are available for the treatment of hyperopia. Conductive keratoplasty (CK) is a safe and non-ablative procedure suitable for the treatment of low hyperopia and presbyopia. Due to the high rate of regression, it is not a commonly used technique. There is minimal literature about the use of refractive procedures for the treatment of hyperopic regression after CK. We report a case of a 49-year-old man who had undergone bilateral CK 15 years before for the correction of his hyperopia. He experienced a regression, with sph +2.75 cyl -0.50(20) in the right eye and sph +2.50 cyl -0.75(170) in the left eye. Transepithelial photorefractive keratectomy (tPRK) was performed with Schwind Amaris 750 s. After 12 months, his best-corrected visual acuity was 20/20, with -0.25 sph in both eyes. To the best of our knowledge, this is the first reported case of tPRK performed after CK.

Selective transepithelial ablation with simultaneous accelerated corneal crosslinking for corneal regularization of keratoconus: STARE-X protocol.

PURPOSE: To evaluate the changes in refractive outcomes and corneal aberrations in central and paracentral keratoconus after selective transepithelial topography-guided photorefractive keratectomy combined with accelerated corneal crosslinking (STARE-X). SETTINGS: Centro Polispecialistico Mediterraneo, Siena Crosslinking Center, and University of Messina, Italy. DESIGN: Prospective, interventional, multicentric study. METHODS: Patients were subdivided into 2 groups: Group 1 with cone located within the central 3 mm zone (50 eyes) and Group 2 (50 eyes) with cone located outside the central 3 mm zone. Follow-up was 2 years at least for all eyes. Outcome parameters included uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). Corneal tomography and corneal wavefront aberrations were assessed and compared before and 2 years after the treatment. RESULTS: 100 eyes of 100 patients underwent STARE-X protocol. At 2 years, UDVA and CDVA improved, and sphere, cylinder, and Kmax reduced after treatment in both groups (P < .001, respectively). Moreover, a statistically significant reduction was observed of total higher-order aberrations root main square (RMS), coma RMS, and spherical aberration RMS in both groups (P < .001, respectively). However, CDVA improved more in Group 1 than in Group 2 (P < .02). CONCLUSIONS: The STARE-X protocol demonstrated effective results in halting keratoconus progression and improving corneal regularity with a safe and effective profile. STARE-X improved both visual acuity and corneal aberration at 2 years. Longer follow-up studies are warranted to observe further long-term CXL flattening effect on the cone.

Topography/wavefront-guided photorefractive keratectomy combined with crosslinking for the treatment of keratoconus: preliminary results.

PURPOSE: To evaluate the clinical outcomes of topography/wavefront-guided (TWFG) photorefractive keratectomy (PRK) using a new high-definition aberrometer combined with epithelium-off crosslinking (CXL-Plus). SETTING: Centro Oculistico Bresciano, Brescia, Italy. DESIGN: Prospective case series study. METHODS: Patients with grade I or II keratoconus, according to the Amsler-Krumeich classification, were included in this prospective case series. All cases underwent TWFG PRK using the VISX STAR S4 IR excimer laser and the new iDesign 2.0 system, followed by accelerated epithelium-off CXL. Visual, refractive, ocular aberrometric, and safety outcomes were evaluated during a 6-month follow-up. RESULTS: Thirty-five eyes of 19 patients were included. A significant improvement was observed in the uncorrected and corrected distance visual acuities (P < .001). Manifest sphere and cylinder were reduced significantly (P ≤ .001), with a total of 20 eyes (57%) and 30 eyes (86%) having a postoperative spherical equivalent within ±0.50 and ±1.00 diopter, respectively. Most corneal irregularity indexes and the level of ocular higher-order aberrations, primary coma, and trefoil (P < .05) were significantly reduced postoperatively. No significant corneal haze or safety issues were observed. CONCLUSIONS: TWFG PRK, using the iD2 system with simultaneous CXL, regularized the cornea by correcting the spherocylindrical error and minimizing the amount of higher-order aberrations in mild-to-moderate keratoconus.

Autologous platelet-rich plasma in the treatment of refractory corneal ulcers: A case report.

PURPOSE: To evaluate the efficacy of a low-cost preparation of platelet-rich plasma (PRP) eye drops in the treatment of persistent non-infectious corneal ulcer. OBSERVATIONS: A 67-year-old female presented to our clinic with a wide corneal ulcer and severe paracentral corneal thinning refractory to medical therapy with antibiotics, lubricant and contact lens bandage. The patient received a novel preparation of PRP solution. After 15 days of therapy, we observed complete resolution of the corneal ulcer with regrowth of the epithelium and a reduction in corneal opacity. CONCLUSION AND IMPORTANCE: Although the low-cost PRP preparation gives a lower platelet concentration than standard procedures, our work shows this preparation to be effective in the treatment of refractory non-infectious corneal ulcer.

Customized corneal crosslinking for treatment of progressive keratoconus: Clinical and OCT outcomes using a transepithelial approach with supplemental oxygen.

PURPOSE: To evaluate the outcomes of customized corneal crosslinking (CXL) for treatment of progressive keratoconus (KC) using a transepithelial approach with supplemental oxygen. SETTING: Siena Crosslinking Center, Siena, Italy. DESIGN: Prospective interventional case series. METHODS: Twenty-seven eyes of 24 patients (mean age 29.3 ± 7.3 years) with progressive KC underwent customized corneal CXL using a transepithelial approach with supplemental oxygen. Ultraviolet (UV)-A irradiation of 365 nm wavelength was delivered in an accelerated (30 mW/cm) pulsed-light UV light exposure in a 2-zone elliptical pattern. A total dose of 10 J/cm was delivered at the KC apex, surrounded by a broadbeam spot of 7.2 J/cm. After 0.25% riboflavin corneal soaking, the UV-A irradiation was initiated in the presence of additional oxygen (≥90% concentration) delivered through special goggles connected to an oxygen delivery system (flow-rate 2.5 liters per minute). Key outcome measures included corrected distance visual acuity (CDVA), keratometry (AK, K1, K2, and K-average), corneal higher-order aberrations, topographic and manifest cylinder, corneal optical coherence tomography (OCT) demarcation line, and endothelial cell count. RESULTS: Of the 27 eyes studied, a significant improvement of CDVA was recorded at 6-month follow-up visits, from baseline 0.19 ± 0.06 logarithm of the minimum angle of resolution (logMAR) to 0.11 ± 0.04 logMAR (P < .05). Significant flattening of steep keratometry (K2) was reported with mean change of -1.9 diopters (D) (P < .05), and coma values improved from 0.47 ± 0.28 µm to 0.28 ± 0.16 µm (P < .05). OCT revealed 2 demarcation lines at mean depths of 218.23 ± 43.32 µm and 325.71 ± 39.70 µm. CONCLUSIONS: In this series, customized CXL using a transepithelial approach with intraoperative supplemental oxygen resulted in clinically meaningful improvements in corneal curvature and CDVA without significant adverse events.

Scleral pockets for an innovative technique of intrascleral fixation of intraocular lens.

The aim of this article is to report the results of an innovative technique for a scleral fixation of a posterior chamber intraocular lens using our new modified technique. We retrospectively reviewed the medical records of 15 eyes of 15 patients who underwent sutureless intrascleral intraocular lens fixation using our modified technique. We used a 23-gauge knife to perform sclerotomy and create two parallel scleral pockets for the haptics. The mean follow-up period was 3 years (3 ± 1). No complications were detected during the follow-up period. The creation of two parallel scleral pockets, parallel to the limbus, greatly simplifies the introduction of intraocular lens haptics.

Triphasic polymeric corneal coating gel versus a balanced salt solution irrigation during cataract surgery: A postoperative anterior segment optical coherence tomography analysis and confocal microscopy evaluation.

PURPOSE: To investigate the safety and efficacy of the intraoperative use of a triphasic polymeric gel as corneal coating during cataract surgery and its effect on postoperative ocular comfort. SETTING: Eye Clinic, University of Florence, Italy. DESIGN: Longitudinal observational retrospective study. METHODS: Data on patients who received an application of a polysaccharide blend of hydroxypropyl methylcellulose, xanthan gum, and carrageenan (EyeDRO) on the corneal surface and data on patients who received a balanced salt solution during phacoemulsification surgery were analyzed. The central corneal thickness (CCT) and epithelial thickness were examined using anterior segment optical coherence tomography, and the corneal basal epithelial cell (BEC) and Langerhans cell densities by in vivo confocal microscopy. The ocular surface disease index (OSDI) score, tear breakup time (TBUT), and Schirmer test I values were evaluated. RESULTS: The study comprised data on 28 patients in the coating gel group and 26 patients in the balanced salt solution group. In the coating gel group, the CCT and epithelial thickness values returned to the baseline value within 5 and 15 postoperative days, respectively; the BEC and Langerhans cell densities returned to baseline levels within 15 and 30 postoperative days. In the balanced salt solution group, the mean BEC and Langerhans cell densities were significantly different from the preoperative values at all follow-up assessments. The TBUT returned to the preoperative level at day 5 in the coating gel group. The OSDI scores returned to the preoperative values after 15 days in the coating gel group and 30 days in the balanced salt solution group. CONCLUSIONS: The use of a tripolymeric gel as a corneal coating during cataract surgery played a protective role on the corneal surface and reduced postoperative discomfort symptoms.

The Use of a Double Suture and Conjunctival Cuts in the Lateral Tarsal Strip: A New Approach to Involutional Ectropion.

PURPOSE: To describe the use of a double suture and conjunctival cuts in the lateral tarsal strip (LTS) and to evaluate postsurgical outcome in patients with severe involutional ectropion. METHODS: A prospective randomized study was conducted on 16 eyelids of 8 patients with symptomatic severe involutional ectropion. The 8 patients were between 62 and 79 years. They were distributed into 2 groups consisting of 4 patients each. The control group was treated with a conventional lateral tarsal strip (C-LTS), the second group underwent a modified lateral tarsal strip (M-LTS). The mean follow-up was 18 months. Success was defined as relief in lid laxity. The recurrence rate was also evaluated. RESULTS: Patients treated with M-LTS showed lower horizontal laxity (3.5 ±â€Š0.2) than patients treated with C-LTS (5.7 ±â€Š0.2). During the 18-month follow-up, a statistically significant difference was found between the 2 groups with P value <0.05. CONCLUSIONS: The use of a double suture and conjunctival cuts in the lateral tarsal strip proposed by Meduri showed a reduction of postsurgical ectropion's grade and postsurgical recurrences. This technique could be used for the treatment of patients with a severe ectropion.