Alessandra Mastropasqua

Scanning electron microscopy evaluation of capsulorhexis in femtosecond laser–assisted cataract surgery

Purpose To use scanning electron microscopy (SEM) to evaluate capsulorhexis‐cut quality obtained during femtosecond laser–assisted cataract surgery at different energy settings and evaluate whether there are differences between this technique and a standard manual technique. Setting Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D’Annunzio Chieti‐Pescara, Chieti, Italy. Design Prospective nonrandomized single blinded study. Methods Sixty capsulorhexes obtained using the conventional manual technique and the femtosecond laser with different laser energy settings were divided into 5 groups as follows: Group 1 (12 capsulorhexes) obtained with the manual technique and Groups 2 to 5 (each with 12 capsulorhexes) obtained with the femtosecond laser at 7.0 &mgr;J, 13.5 &mgr;J, 14.0 &mgr;J, and 15.0 &mgr;J, respectively. All samples were evaluated using SEM to compare the thickness along the capsulorhexis edge and the overall irregularity of the cut surface. Results Capsulorhexes obtained with the femtosecond laser at all energy settings were perfectly circular with negligible deformation. Group 1 and Group 2 had a significantly higher thickness and lower thickness, respectively, of the capsulorhexis edge than the other 3 groups (P<.001). There was also a statistically significant correlation between the degree of irregularity and increasing energy (P<.001). Conclusions The use of the femtosecond laser in cataract surgery resulted in better capsulorhexis geometry and circularity than the manual capsulorhexis. The cut surface was smoother in the manual group. In the femtosecond laser groups, the degree of irregularity was higher at increasing energy settings. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Corneal Changes in Neurosurgically Induced Neurotrophic Keratitis

IMPORTANCE Neurotrophic keratitis (NK) represents a sight-threatening complication after trigeminal impairment. To our knowledge, the duration for which trigeminal injury may affect corneal structures and function has not been investigated previously. OBJECTIVE To describe the long-term clinical, morphological, and functional outcomes of NK after neurosurgical trigeminal damage. DESIGN, SETTING, AND PARTICIPANTS Observational case series performed at a corneal and ocular surface diseases referral center in 2010. Eight consecutive patients with monolateral NK from 1 to 19 years after neurosurgery and 20 age- and sex-matched healthy participants were included. MAIN OUTCOMES AND MEASURES Complete eye examination, tear film function tests, corneal staining, and Cochet-Bonnet esthesiometry were performed. The number and density of corneal nerves, number of hyperreflective keratocytes, and corneal epithelial, endothelial, and keratocyte cell densities were evaluated by in vivo slit scanning confocal microscopy. Clinical and morphological data were compared with the contralateral unaffected eyes and with the eyes of healthy control participants. RESULTS All patients showed superficial punctate keratitis and dry eye in the NK eye and a healthy contralateral eye. Decreased corneal sensitivity was observed in all affected eyes (mean [SD], 2.0 [1.9] mm in the affected eyes vs 5.8 [0.3] mm in the contralateral unaffected eyes; P = .01) and was related to decreased subbasal nerve length (P = .04; R = 0.895). Corneal epithelial and endothelial cell densities were significantly decreased and the number of hyperreflective keratocytes was significantly increased in NK eyes compared with contralateral unaffected eyes and with the eyes of healthy participants. A longer duration of NK was associated with lower endothelial cell density (P = .046; R = -0.715). CONCLUSIONS AND RELEVANCE Corneal morphology and function were impaired even years after neurosurgical trigeminal damage, suggesting that assessment of tear film and corneal sensitivity as well as in vivo confocal microscopy examination should be performed in all patients with trigeminal impairment.

Structural modifications and tissue response after standard epi-off and iontophoretic corneal crosslinking with different irradiation procedures.

PURPOSE The aim of this study is to investigate modifications in human cadaver corneas after different crosslinking procedures, including standard epi-off treatment, iontophoresis imbibition, and different exposure to ultraviolet A (UVA) sources (30 minutes at 3 mW and 9 minutes at 10 mW). METHODS A total of 12 human cadaver corneas was examined and divided as follows: 3 served as control (group 1), 3 were treated with a standard epi-off procedure (group 2), 6 underwent iontophoresis imbibition for 5 minutes, and then 3 were irradiated for 30 minutes with 3 mW UVA (group 3), and 3 for 9 minutes at 10 mW UVA (group 4). Deformation amplitude index was measured before and after the corneas underwent treatment. After treatment, corneas were prepared for hematoxylin-eosin and immunohistochemistry evaluation. The expression of TUNEL, matrix metalloproteinase-1 (MMP-1), collagen type I, and CD34 was investigate in all samples. RESULTS The deformation amplitude index decreased in all groups, in particular in group 4, indicating an improvement of corneal biomechanical properties. Immunohistochemical staining showed a significant stromal alteration in group 2, mild damage in group 3, and no modifications in corneal morphology in group 4. The TUNEL (P < 0.001) and MMP-1 (P = 0.002) positivity was more evident in group 4. Collagen type I positivity significantly increased in groups 3 (P = 0.002) and 4 (P = 0.002). The CD34 expression was more evident in groups 2 (P = 0.003) and 3 (P = 0.003). CONCLUSIONS Iontophoresis imbibition followed by UVA irradiation for 9 minutes at 10 mW determined less tissue damage and better stromal remodeling.

Optical coherence tomography and 3-dimensional confocal structured imaging system–guided femtosecond laser capsulotomy versus manual continuous curvilinear capsulorhexis

Purpose To compare the features of capsulotomy obtained during femtosecond laser–assisted cataract surgery with those of continuous curvilinear capsulorhexis (CCC) obtained using a standard manual technique. Setting Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D’Annunzio Chieti‐Pescara, Chieti, Italy. Design Prospective randomized clinical study. Methods Candidates for cataract extraction were randomized into 1 of 3 groups as follows: Lensx femtosecond laser–assisted cataract surgery capsulotomy (laser group 1), Lensar femtosecond laser–assisted cataract surgery capsulotomy (laser group 2), and manual CCC (manual group). Results Each group comprised 30 eyes (30 patients). The capsulotomies in laser group 1 and laser group 2 showed significantly better circularity than the manual CCCs at 7 days (P<.001). There was a significant correlation between the intended versus achieved capsulotomy size in the 2 laser groups. Both laser groups had better intraocular lens (IOL) centration than the manual group at all timepoints (P<.001). Between‐group differences in uncorrected and corrected distance visual acuities were not statistically significant. The residual spherical equivalent and mean absolute error were statistically significantly smaller in the 2 laser groups than in the manual group (P=.038) and increased significantly over time in all the groups (P<.001). Conclusions Femtosecond laser capsulotomies showed better circularity with more predictable size than manual CCCs. In addition, IOL centration was better immediately after surgery and over time with better refractive results in the 2 laser groups. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Reproducibility and Repeatability of Cirrus™ HD-OCT Peripapillary Retinal Nerve Fibre Layer Thickness Measurements in Young Normal Subjects

Purpose: To assess the reproducibility and repeatability of peripapillary retinal nerve fibre layer (RNFL) thickness measurements using a spectral-domain optical coherence tomography (SD-OCT) device in healthy subjects. Methods: In this observational study, 68 young Caucasian healthy volunteers (68 eyes) were subjected to Cirrus™ high-definition (HD) OCT (Zeiss) peripapillary RNFL thickness measurements by two experienced examiners in two different sessions. Average, 4-quadrant and 12-clock-hour sector RNFL thicknesses were analysed. For each option, intra-observer, intrasession repeatability and interobserver, intersession reproducibility were tested. To assess the repeatability of measurements, the Bland and Altman plots were used and the coefficient of repeatability was calculated. Interobserver and intersession reproducibilities were analysed by means of concordance correlation coefficients (CCCs). Results: The sample age ranged from 21 to 39 years (mean 29.09, standard deviation ±5.21). The average RNFL thickness ranged from 90.97 to 91.46 and from 91.34 to 91.78 µm, for the first and the second operator, respectively. The highest repeatability and reproducibility were obtained for average RNFL thickness with coefficients of repeatability of 5.30 and 6.05 µm for the first and the second operator, interoperator CCCs of 0.95 and 0.96 for the first and the second session, and intersession CCCs of 0.96 and 0.97 for the first and the second operator, respectively. Conclusions: Cirrus OCT peripapillary average RNFL thickness measurement in young healthy subjects showed high interoperator and intersession reproducibility. Intrasession repeatability as tested by coefficient of repeatability was next to the device resolution, with very similar results between the two operators. When analysing quadrant and clock hour sector RNFL thickness measurements, both repeatability and reproducibility tend to decrease.

Systematic review of randomised clinical trials on topical ciclosporin A for the treatment of dry eye disease.

Aims Topical ciclosporin A (CsA) is a therapeutic option for dry eye disease (DED) to control ocular surface inflammation and improve tear function. The aim of this study is to systematically review data from randomised clinical trials (RCTs) evaluating efficacy and safety of topical CsA treatment for DED. Methods Articles published up to December 2012 were identified from Medline, Embase and the Cochrane Controlled Trials Register. A total of 18 RCTs that evaluated the efficacy and safety of different topical CsA formulations for the treatment of DED were selected according to the set criteria. The Jadad score was calculated to assess RCT quality. Results The mean Jadad score of the included RCTs was 2.8±0.6. All CsA formulations proved safe for the treatment of DED. Symptoms improved in 100% (9/9) RCTs, tear function improved in 72% (13/18) RCTs and ocular surface damage was ameliorated in 53% (9/17) RCTs in patients with DED. No improvements with CsA treatment versus control were observed in DED resulting from surgical procedures, contact lens use and thyroid orbitopathy. Statistical comparison of CsA efficacy through a meta-analysis of data was not possible due to a lack of standardised criteria and comparable outcomes among studies. Conclusions Although topical CsA appears to be a safe treatment for DED, evidence emerging from RCTs is limited, and this affects the strength of recommendations to healthcare providers and policymakers for optimal management. Standardised diagnostic criteria to assess the efficacy of topical CsA are recommended to improve the design of future RCTs in DED.

Evaluation of Corneal Biomechanical Properties Modification after Small Incision Lenticule Extraction Using Scheimpflug-Based Noncontact Tonometer

Purpose. To quantify the effect of small incision lenticule extraction (SMILE) on the corneal biomechanics using Scheimpflug noncontact tonometer (Corvis ST). Methods. Twenty eyes of twenty patients, evaluated as eligible for surgery, with high myopia and/or moderate myopic astigmatism, underwent small incision lenticule extraction (SMILE). All patients underwent Corvis ST preoperatively and postoperatively after 1 week, and 1 and 3 months to observe alterations of corneal biomechanical properties. The main outcome measures were Deformation Amplitude, 1st-AT, and 2nd-AT. The relationship between the amount of stroma removed and the percentage variation of the measured parameters from baseline was evaluated with generalized linear model from each time point. For completeness also intraocular pressure (IOP), central corneal thickness (CCT), and their variations after surgery were evaluated. Results. The ratio between the amount of removed refractive error and, respectively, changes of Deformation Amplitude, 1st-AT, and 2nd-AT were significantly modified at the 1st week after surgery (P = 0.005; P = 0.001; P = 0.024). At 1 and 3 months these values did not show statistically significant alterations. Intraocular pressure and central corneal thickness showed statistically significant changes during follow-up. Conclusions. No significant modifications in biomechanical properties were observed after SMILE so this procedure could induce only minimal transient alterations of corneal biomechanics.

In Vivo Confocal Microscopy of Conjunctiva-Associated Lymphoid Tissue in Healthy Humans

PURPOSE To investigate modifications with aging of the presence, distribution and morphologic features of conjunctiva-associated lymphoid tissue (CALT) in healthy human subjects using laser scanning in vivo confocal microscopy (IVCM). METHODS A total of 108 (age range, 17-75 years) subjects were enrolled. In vivo confocal microscopy of the tarsal and bulbar conjunctiva, and impression cytology (IC) with CD3 (intra-epithelial T-lymphocytes) and CD20 (intra-epithelial B-lymphocytes) antibody immunofluorescence staining were performed. The main outcomes were subepithelial lymphocyte density (LyD), follicular density (FD), and follicular area (FA). The secondary outcomes were follicular reflectivity (FR), and lymphocyte density (FLyD), and CD3 and CD20 positivity. RESULTS Conjunctiva-associated lymphoid tissue was observed in all subjects (97% only superior and 3% in both superior and inferior tarsum). Lymphocyte density ranged from 7.8 to 165.8 cells/mm(2) (46.42 [18.37]; mean [SD]), FD from 0.5 to 19.4 follicles/mm(2) (5.3 [3.6]), and FA from 1110 to 96,280 mm(2) (26,440 [26,280]). All three parameters showed a highly significant inverse cubic relationship with age (P < 0.001); that is, in the first and last parameters a steep decline up to 35 years and above 65 years of age, with a plateau phase between these ages, whereas FA had a gradually decreasing rate of loss over the studied age range. CD3 and CD20 IC were consistent with these results. CONCLUSIONS In vivo confocal microscopy was effective in revealing CALT and modifications these structures undergo with aging. Aging correlated with an involution of all parameters defining lymphoid structures. These modifications may account for the decrease of mucosal immune response and increase of ocular surface diseases in the elderly.

Astigmatism correction with toric IOL: analysis of visual performance, position, and wavefront error.

PURPOSE To evaluate astigmatism correction, visual performance, intraocular lens (IOL) position, and wavefront error after implantation of toric IOLs in patients with cataract. METHODS This prospective study comprised 30 eyes of 30 patients with cataract who were candidates for phacoemulsification and implantation of the AcrySof toric IOL (Alcon Laboratories, Inc., Fort Worth, TX). Mean preoperative corneal keratometric and subjective refractive cylinder were 2.10 ± 0.47 and 2.17 ± 0.41 diopters (D), respectively. RESULTS The refractive cylinder decreased significantly from 2.17 ± 0.41 to 0.73 ± 0.45 D (P = .001) at 180 days postoperatively. The difference between preoperative corneal astigmatism and postoperative refractive astigmatism was statistically significant (P < .05). At 180 days postoperatively, the uncorrected distance visual acuity was 0.20 logMAR (Snellen 20/32) in 100% of patients and 0.0 logMAR (Snellen 20/20) in 64% of patients. The root mean square of internal coma and trefoil aberrations showed a trend toward reduction; internal spherical aberration significantly decreased, whereas corneal trefoil aberration significantly increased (P < .05). A low amount of IOL decentration and tilt were detected at 30 and 180 days postoperatively, respectively. CONCLUSIONS Toric IOL implantation is an effective procedure for correction of preexisting corneal astigmatism, improving visual performance, and inducing a low amount of higher-order aberrations. Moreover, the toric IOLs is well positioned early after surgery and stable over time.

Spectral domain optical coherence tomography and in vivo confocal microscopy imaging of a case of Bietti's crystalline dystrophy.

The aim was to describe the morphology and localisation of crystals in a case of Biettis crystalline corneo‐retinal dystrophy (BCD) by means of spectral domain optical coherence tomography (SD‐OCT) and in vivo confocal microscopy (IVCM).