Eleonora Favuzza

Astigmatism correction with toric intraocular lenses: wavefront aberrometry and quality of life

Background/aim To evaluate wavefront aberrations and subjective quality of life after toric intraocular lens (TIOL) implantation. Methods Three groups of subjects who underwent unilateral cataract surgery with intraocular lens (IOL) implantation were compared: (1) toric group (n=40): corneal astigmatism >1.50 D, implanted with Acrysof toric SN60TT IOL (Alcon Inc, Fort Worth, Texas, USA); (2) astigmatic SN60AT group (n=40): corneal astigmatism >1.50 D, implanted with Acrysof SN60AT IOL; and (3) control group (n=40): corneal astigmatism <1.00 D, implanted with Acrysof SN60AT IOL. Uncorrected distance visual acuity (UDVA), refraction, lower order astigmatism (Z22, Z−22), Strehl ratio and the modulation transfer function area ratio were evaluated over a 3 month follow-up period. A standardised quality of life test (National Eye Institute Refractive Error Quality of Life Instrument-42) was distributed to both astigmatic groups 3 months postoperatively. Results Postoperative UDVA and aberrometric values were significantly better (p<0.001) and mean postoperative spherical equivalent was significantly lower (p<0.05) in the toric and control groups compared with the astigmatic SN60AT group. The toric group had significantly better postoperative quality of life compared with the astigmatic SN60AT group (p<0.05). Conclusions Acrysof TIOL implantation resulted in better visual, refractive and aberrometric results than SN60AT spherical IOL implantation in astigmatic patients, similar to the control group. The better objective optical and retinal image quality resulted in better subjective quality of life after TIOL implantation.

Imaging Mass Spectrometry by Matrix-Assisted Laser Desorption/Ionization and Stress-Strain Measurements in Iontophoresis Transepithelial Corneal Collagen Cross-Linking

Purpose. To compare biomechanical effect, riboflavin penetration and distribution in transepithelial corneal collagen cross-linking with iontophoresis (I-CXL), with standard cross linking (S-CXL) and current transepithelial protocol (TE-CXL). Materials and Methods. The study was divided into two different sections, considering, respectively, rabbit and human cadaver corneas. In both sections corneas were divided according to imbibition protocols and irradiation power. Imaging mass spectrometry by matrix-assisted laser desorption/ionization (MALDI-IMS) and stress-strain measurements were used. Forty-eight rabbit and twelve human cadaver corneas were evaluated. Results. MALDI-IMS showed a deep riboflavin penetration throughout the corneal layers with I-CXL, with a roughly lower concentration in the deepest layers when compared to S-CXL, whereas with TE-CXL penetration was considerably less. In rabbits, there was a significant increase (by 71.9% and P = 0.05) in corneal rigidity after I-CXL, when compared to controls. In humans, corneal rigidity increase was not significantly different among the subgroups. Conclusions. In rabbits, I-CXL induced a significant increase in corneal stiffness as well as better riboflavin penetration when compared to controls and TE-CXL but not to S-CXL. Stress-strain in human corneas did not show significant differences among techniques, possibly because of the small sample size of groups. In conclusion, I-CXL could be a valid alternative to S-CXL for riboflavin delivery in CXL, preserving the epithelium.

Transepithelial Riboflavin/Ultraviolet. A Corneal Cross-linking in Keratoconus: Morphologic Studies on Human Corneas

PURPOSE To evaluate histologic and molecular changes in human keratoconic corneas after the procedure of transepithelial collagen cross-linking (CXL), without the removal of corneal epithelium. DESIGN Experimental laboratory investigation. METHODS Thirty corneal buttons were examined, 18 of which were from patients affected by severe keratoconus and submitted to penetrating keratoplasty (PK). Among these, 8 were analyzed without any treatment, 4 were treated with transepithelial CXL 2 hours before PK, and 6 were treated with transepithelial CXL 3 months before PK. Twelve normal corneal buttons from healthy donors were used as controls. The corneal buttons were then evaluated by hematoxylin-eosin staining and by immunostaining with markers of epithelial junction proteins (ß-catenin and connexin 43), of stromal keratocytes (CD34), of apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL] assay), and of collagen type I fibers. RESULTS The analysis of epithelial markers showed a clear defective expression in keratoconic corneas before and soon after the transepithelial CXL treatment, returning to normal in corneas analyzed 3 months after transepithelial CXL. The analysis of stroma components indicated a loss of keratocytes in the upper stroma of keratoconic corneas and a trend toward a normal situation 3 months after transepithelial CXL; similarly, collagen fibers appeared disorganized in keratoconus, while their pattern appears to be close to normal 3 months after treatment. CONCLUSIONS Histologic and immunohistochemical findings on human keratoconic corneas showed the presence of biochemical and morphologic alterations in the epithelium and the upper stroma that are significantly improved 3 months after transepithelial CXL. However, further studies are necessary to assess to what extent these results correlate with measurable biomechanical effects.

Effect of a hyaluronic acid and carboxymethylcellulose ophthalmic solution on ocular comfort and tear-film instability after cataract surgery

Purpose To evaluate the efficacy and safety of using sodium hyaluronate 0.1% and carboxymethylcellulose 0.5% artificial tears for ocular discomfort and tear‐film stability in eyes after cataract surgery. Setting Twenty ophthalmic centers in Italy. Design Prospective randomized case series. Methods This study enrolled patients scheduled for unilateral cataract surgery. After surgery, patients received artificial tears and a topical steroid–antibiotic (study group) or topical steroid–antibiotic alone (control group) and were assessed postoperatively at 1 and 5 weeks. Outcome measures were tear breakup time (TBUT), ocular surface disease index (OSDI), frequency of dry‐eye symptoms evaluated using a visual analog scale (VAS), and corneal fluorescein staining. Results The study comprised 282 patients. At 5 weeks, the mean TBUT was statistically significantly higher in the study group than in the control group (P = .0003). The mean OSDI score statistically significantly improved in both groups from 1 to 5 weeks (P < .0001 for both groups); however, there was no statistically significant difference between the groups at these timepoints. The artificial tears statistically significantly improved VAS‐assessed dry‐eye symptoms in the study group compared with the control group at 5 weeks (P < .001). The mean corneal fluorescein staining was significantly reduced in the study group compared with the control group at 5 weeks (P = .002 versus P = .05, respectively). No treatment‐related adverse events were reported. Conclusion Sodium hyaluronate 0.1% and carboxymethylcellulose 0.5% ophthalmic solution was effective and well tolerated in reducing dry‐eye disease symptoms and improving the clinical outcome after cataract surgery. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Clinical outcomes and rotational stability of a 4-haptic toric intraocular lens in myopic eyes

Purpose To evaluate the refractive outcomes and rotational stability of a 4‐haptic toric intraocular lens (IOL) in myopic eyes and the correlations between IOL rotation and refractive sphere, axial length (AL), and white‐to‐white (WTW) diameter. Setting Eye Clinic, Careggi Hospital, Florence, Italy. Design Prospective case series. Methods Phacoemulsification cataract extraction and implantation of an AT Torbi 709M IOL were performed. Corneal astigmatism was 1.50 diopters (D) or greater and the AL between 25.0 mm and 27.0 mm in all eyes. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and IOL axis were evaluated preoperatively and postoperatively up to 6 months. Results The study enrolled 20 eyes (20 patients). The UDVA and CDVA improved significantly postoperatively (P < .001). The mean refractive spherical equivalent decreased significantly from −7.10 D ± 1.78 (SD) preoperatively to −0.55 ± 0.25 D 1 day postoperatively (P < .001) and remained stable thereafter. Vector analysis showed that 90% and 85% of the eyes were within ±0.25 D for J0 and J45, respectively. At 3 months and 6 months, the mean IOL rotation was 2.66 ± 1.53 degrees and 3.00 ± 1.69 degrees, respectively (P < .001), with 95% of eyes and 90% of eyes, respectively, within ±5 degrees. A positive correlation was found between IOL rotation and preoperative sphere; none was found with AL and WTW. Conclusions Implantation of the 4‐haptic toric IOL in myopic eyes was effective and safe. The IOL showed no significant rotation over the 6‐month follow‐up. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

CoQ10-containing eye drops prevent UVB-induced cornea cell damage and increase cornea wound healing by preserving mitochondrial function.

PURPOSE We evaluated the potential protective effects of Coenzyme Q10 (CoQ10) on human corneal cells and rabbit eyes after ultraviolet B (UVB) exposure and a model of wound healing in rabbit eyes after corneal epithelium removal. METHODS Human corneal epithelium cells (HCE) were exposed to a source of UVB radiation (312 nM) in the presence of different CoQ10 concentrations or vehicle. The mitochondrial function and cell survival were evaluated by means of 3-(4,5-dimethylthiazole-2-yl)2,5-diphenyl-tetrazolium (MTT) reduction and lactic dehydrogenase (LDH) release. Furthermore, quantitation of oxygen consumption and mitochondrial membrane potential were conducted. In vivo rabbit models were adopted to evaluate the effect of CoQ10 on UVB-induced conjunctival vessel hyperemia and corneal recovery after ethanol induced corneal lesion. RESULTS In UVB-exposed HCE cells, CoQ10 addition led to an increased survival rate and mitochondrial function. Furthermore, oxygen consumption was maintained at control levels and adenosine triphosphate (ATP) decline was completely prevented in the CoQ10-treated cells. Interestingly, in an in vivo model, CoQ10 was able dose-dependently to reduce UVB-induced vessel hyperemia. Finally, in a model of corneal epithelium removal, 12 hours from surgery, animals treated with CoQ10 showed a reduction of damaged area in respect to vehicle controls, which lasted until 48 hours. CONCLUSIONS We demonstrated that CoQ10 reduces corneal damages after UVB exposure in vivo and in vitro by preserving mitochondrial function. Also, for the first time to our knowledge we showed that the administration of CoQ10 after corneal epithelium removal promotes corneal wound healing.

Azithromycin: assessment of intrinsic cytotoxic effects on corneal epithelial cell cultures

Purpose To compare the cytotoxic effects of preservative-free azithromycin on corneal epithelial cells in vivo with those of preservative-free netilmicin and levofloxacin, and the preservative benzalkonium chloride (BAK). Methods Rabbit corneal epithelial cells in vitro were incubated for 15 minutes or 6 hours with commercially available ophthalmic preservative-free netilmicin 0.3%, levofloxacin 0.3%, or azithromycin 1.5% preparations or different concentrations of unpreserved azithromycin and different concentrations of BAK. Qualitative analysis was undertaken using phase-contrast optics to examine the morphological aspects of cell cultures and quantitative analysis was undertaken by measuring the release of the cytoplasmic enzyme lactate dehydrogenase into the medium immediately and 24 hours after exposure to drugs. Finally, we observed the wound-healing rate of mechanically injured corneal epithelial cells exposed to each antibiotic ophthalmic preparation for 48 hours. Results Our results show that both the commercially available unpreserved mono-dose preparation of azithromycin and ophthalmic preparations of azithromycin up to a concentration of 1.5% were virtually devoid of harmful effects under our experimental conditions. This was not significantly different from the results obtained for the other antibiotic preparations (P > 0.05) tested, but was unlike the results obtained for BAK. Azithromycin 1.5% also showed good recovery properties after a mechanical wound test. Conclusion Under our experimental conditions, unpreserved azithromycin 1.5% showed a much lower toxicity than BAK and did not interfere with the wound-healing process.

Ocular surface temperature in patients with evaporative and aqueous-deficient dry eyes: a thermographic approach

OBJECTIVE In recent decades infrared thermography (IRT) has facilitated accurate quantitative measurements of the ocular surface temperature (OST), applying a non-invasive procedure. The objective of this work was to develop a procedure based on IRT, which allows characterizing of the cooling of the ocular surface of patients suffering from dry eye syndrome, and distinguishing among patients suffering from aqueous deficient dry eye (ADDE) and evaporative dry eyes (EDE). APPROACH All patients examined (34 females and 4 males, 23-84 years) were divided into two groups according to their Schirmer I result (⩽ 7 mm for ADDE and  >  7 mm for EDE), and the OST was recorded for 7 s at 30 Hz. For each acquisition, the temperatures of the central cornea (CC) as well as those of both temporal and nasal canthi were investigated. MAIN RESULTS Findings showed that the maximum temperature variation (up to 0.75  ±  0.29 °C) was at the CC for both groups. Furthermore, patients suffering from EDE tended to have a higher initial OST than those with ADDE, explained by the greater quantity of the tear film, evenly distributed over the entire ocular surface, keeping the OST higher initially. Results also showed that EDE patients had an average cooling rate higher than those suffering from ADDE, confirming the excessive evaporation of the tear film. SIGNIFICANCE Ocular thermography paves the way to become an effective tool for differentiating between the two different etiologies of dry eye syndrome.

Square-edge intraocular lenses and epithelial lens cell proliferation: implications on posterior capsule opacification in an in vitro model.

BackgroundTo evaluate lens epithelial cell (LEC) proliferation with two different designs (one-piece or three-piece) of hydrophobic acrylic IOLs with 360° square optic edge using an in vitro culture model of posterior capsule opacification (PCO).MethodsThis experimental study was conducted at the Department of NEUROFARBA, Section of Pharmacology, University of Florence, Italy. Human LECs were seeded and cultured in transwell cell culture inserts coated with a type-IV collagen membrane on which an IOL (one-piece Tecnis-1 or three-piece AR40E, Abbott Medical Optics Inc.) had been previously placed. As control, cells were plated on the insert membrane without an IOL. At day six (cells confluent in controls) IOLs were removed and cell counting, viability and cell density under and outside the IOLs were evaluated.ResultsNo statistically significant difference in the number of cells (p > 0.05) between inserts with the one-piece and three-piece IOLs was found. Cell density in the area under each IOL was significantly lower than in the area outside of it (p < 0.05), or in the control insert. (p < 0.05). Cell density under the single-piece IOL was not significantly different from that under the three-piece IOL (p > 0.05).ConclusionsA 360° sharp-edge played a crucial role in avoiding LEC migration under the IOL and preventing the formation of PCO after cataract surgery. Long term clinical evaluation is necessary to estimate functional results.

Assessment of the tolerability profile of an ophthalmic solution of 5% glycyrrhizin and copolymer PEG/PPG on healthy volunteers and evaluation of its efficacy in the treatment of moderate to severe blepharitis

Purpose To evaluate the tolerability on healthy volunteers and the efficacy on subjects affected by chronic moderate/severe blepharitis of a 5% glycyrrhizin and copolymer poly(ethylene glycol)/poly(propylene glycol)(PEG/PPG) ophthalmic solution. Methods The study was a randomized, controlled, open label, intra-patient monocentric study. It consisted of two different phases, the assessment of tolerability phase on 20 healthy volunteers, and the evaluation of the efficacy on 21 subjects affected by chronic moderate/severe blepharitis; the treatment period was 2 weeks, followed by 1-week of follow-up. In the efficacy phase, in both eyes, eyelid hygiene was also performed. At day 0, 3, 7, 14, and 21 a complete ophthalmological examination was performed. In the tolerability phase, signs of clinical toxicity were recorded and subject-reported symptoms were collected using a questionnaire. In the efficacy phase, global signs and symptoms of blepharitis scores were collected using standardized photographic scales and questionnaire. The statistical analysis was performed using the Wilcoxon signed-rank test. Results No ocular signs of drug toxicity were reported. During the treatment period for tolerability phase, there were statistically significant higher scores of tearing and ocular discomfort in the tolerability study group versus the tolerability control group. In the efficacy phase, differences between global scores of the two groups were statistically significant at day 0 (score of the efficacy study group was higher than the efficacy control group; P = 0.005) and at day 21 (score of the efficacy study group was lower than the efficacy control group (P ≤ 0.001).The difference of global scores at day 3, 7, 14, and 21 versus day 0 was statistically significant in both groups. No serious adverse events occurred. Conclusion The 5% glycyrrhizin ophthalmic solution was well tolerated in healthy volunteers and in patients with chronic moderate/severe blepharitis, and in association with eyelid hygiene showed good clinical anti-inflammatory activity that lasted after instillation suspension.