Leonardo Mastropasqua

Reliability of nerve fiber layer thickness measurements using optical coherence tomography in normal and glaucomatous eyes

OBJECTIVE To evaluate the reliability of nerve fiber layer (NFL) thickness measurements by optical coherence tomography (OCT) in normal and glaucomatous eyes. DESIGN Prospective, comparative, observational case series and instrument validation study. PARTICIPANTS Twenty-four glaucomatous patients were compared with 24 gender- and age-matched normal subjects. METHODS Each individual underwent OCT measurements of NFL thickness. Five repetitions of a series of scans on five separate occasions within a 0.5-month period were performed. Each eye was scanned at three different nerve head programs (1.5 radius [R], R = 1.73 mm, 2.0 R). For each option (1.5 R, R = 1.73 mm, and 2.0R) and region (superior, inferior, temporal, nasal, and overall mean), variance components and intraclass correlation coefficients were determined using repeated measures regression. In these models, NFL thickness, as measured by OCT, was assumed to have three variance components: intersubject, intervisit (within-subject between-dates), and intravisit (within-subject within-date). The intraclass correlation coefficient (intersubject variance/total variance) was used as a measure of reliability. MAIN OUTCOME MEASURES Measurements of NFL thickness using OCT were performed. RESULTS Reliability values, as measured by intraclass correlation coefficients, resulted as follows: 1.5 R, 0.54/0.52 (normal/glaucoma); R = 1.73 mm, 0.50/0.50; 2.0 R, 0.49/0.50. CONCLUSIONS Our results indicate that the recent commercially available OCT provides reliable NFL thickness measurements in both healthy and glaucomatous eyes with each circle radius tested. The greatest amount of variability can be attributed to intersubject differences.

Femtosecond Laser Arcuate Keratotomy for the Correction of High Astigmatism after Keratoplasty

PURPOSE To determine the feasibility and initial outcomes of using a femtosecond laser to perform arcuate keratotomies to correct high post-keratoplasty astigmatism. DESIGN Prospective noncomparative interventional case series. PARTICIPANTS Twelve eyes of 12 consecutive patients (mean age 44.9+/-9.5 years) who presented with a high degree of astigmatism, noncorrectable with spectacles or contact lenses (10 post-penetrating keratoplasty, 2 post-deep lamellar keratoplasty), and were candidates for relaxing incisional corneal surgery. METHODS The Femtec (20/10 Perfect Vision, GmbH, Heidelberg, Germany) femtosecond laser performed paired 90-degree angled arcuate incisions on the graft button. The incision sites and depths were programmed at 1.00 mm inside the graft edge and at 90% of the corresponding local graft thickness, whereas the angular lengths of the cuts were determined by analyzing the locations and extents of the steepest meridians in the topographic map. MAIN OUTCOME MEASURES Changes in uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), mean subjective and topographically determined astigmatism; imaging of incisions by anterior segment optical coherence tomography (AS-OCT); and wound healing by in vivo confocal microscopy (IVCM). RESULTS Postoperative follow-up extended to 6 months. Mean uncorrected logarithm of the minimum angle of resolution (logMAR) BSCVA and UCVA improved from preoperative values of 0.25+/-0.16 and 1.05+/-0.18 to 6-month values of 0.11+/-0.12 (standard deviation) and 0.55+/-0.34, respectively (P<0.05). Mean subjective astigmatism was 7.16+/-3.07 diopters (D) preoperatively and 2.23+/-1.55 D at 1 month after surgery (P = 0.002) and remained stable to the end of follow-up. Anterior segment optical coherence tomography image analysis showed that the depth and location of the incisions were consistent with the preoperative surgical plan. In vivo confocal microscopy showed mild edema and keratocyte activation along the incision edges, together with initial epithelial ingrowth inside the wound, followed by subsequent moderate fibrotic scarring. CONCLUSIONS Arcuate keratotomies performed with the femtosecond laser were effective in reducing post-keratoplasty astigmatism. Laser-generated incisions within the graft button presented precise geometry and reliable depth of incision, with a wound healing pattern characterized by epithelial ingrowth and mild fibrosis. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Clinical study of the 1CU accommodating intraocular lens.

Purpose: To compare the near functional capacities of patients with an accommodating intraocular lens (IOL) with those of patients with a conventional monofocal IOL. Setting: Department of Ophthalmology, University of Chieti, Chieti, Italy. Methods: This prospective double‐blind case‐control study comprised 42 eyes that had phacoemulsification and implantation of 1 of 2 types of IOLs: HumanOptics accommodating 1CU® (study group) and Eurocrystal IFP 3G 6.00 (control group). The main outcome measures were subjective refraction, uncorrected distance acuity, best corrected distance acuity, distance corrected near acuity at 40 cm, best corrected near acuity at 40 cm, and subjective amplitude of accommodation. Patients were examined 7, 30, 90, and 180 days after surgery. Results: Postoperatively, both groups had excellent uncorrected distance acuity, best corrected distance acuity, and best corrected near acuity. In the study group, the mean distance corrected near acuity (Jaeger) was 5.43 ± 0.98 (SD) (range 4 to 7) at 7 days, 2.33 ± 0.48 (range 2 to 3) at 1 and 3 months, and 3.66 ± 2.12 (range 2 to 7) at 6 months. In the control group, the mean distance corrected near acuity was 7.43 ± 0.50 (range 7 to 8) during the entire follow‐up. The differences between the groups was statistically significant (P<.001). The mean amplitude of accommodation was 0.00 diopter (D) in the control group and 1.14 ± 0.44 D (range 0.75 to 2.00 D) in the study group at 7 days, 2.36 ± 0.28 D (range 2.00 to 2.75 D) at 30 and 90 days, and 1.90 ± 0.77 D (range 0.75 to 2.75 D) at 6 months. Conclusions: The 1CU accommodating IOL provided better useful spectacle‐free near visual acuity than the conventional monofocal IOL. However, the accommodating mechanism can play a role in capsule fibrosis.

Corneal cross-linking: intrastromal riboflavin concentration in iontophoresis-assisted imbibition versus traditional and transepithelial techniques.

PURPOSE To determine differences in riboflavin concentration in the anterior, intermediate, and posterior stroma after 3 corneal cross-linking imbibition techniques (standard epithelial [epi]-off, epi-on, and iontophoresis-assisted administration) of 0.1% riboflavin. DESIGN Experimental laboratory investigation of human cadaver corneas not suitable for transplantation. METHODS Ten corneas underwent imbibition with epi-on (n = 3), epi-off (n = 3), iontophoresis (n = 3), and saline exposure (control; n = 1). Femtosecond laser was used to produce 3 8-mm discs of the superficial (0-150 μm), intermediate (150-300 μm), and deep stroma (>300 μm). Riboflavin concentration was measured with high-performance liquid chromatography. The main outcome measure was riboflavin concentration at the 3 evaluated depths. RESULTS The overall stromal concentration of riboflavin was 34.1 ± 7.1 μg/g in epi-off, 7.2 ± 3.7 μg/g in epi-on, and 15.0 ± 5.1 μg/g in iontophoresis. The mean riboflavin content in the superficial slice in the epi-off group was about 2-fold greater than that of the iontophoresis group (50.5 ± 5.3 μg/g and 23.6 ± 2.5 μg/g, respectively) and 4-fold greater than that of the epi-on group (11.7 ± 3.3 μg/g). Similar differences among the 3 groups were observed for the intermediate and posterior stromal slices, presenting an evident reduction of riboflavin concentration with increasing depth in all groups. Slice depth-dependent decrease in riboflavin concentration was statistically significant (general linear model (GLM); F1,6 = 62.265, P < .001), as was the group-dependent variation (GLM; F2,6 = 20.268, P = .002) and the slice depth group interaction (GLM; F2,6 = 18.004, P = .002). CONCLUSIONS Corneal cross-linking transepithelial iontophoresis imbibition yielded greater and deeper riboflavin saturation with respect to conventional epi-on, while maintaining the advantages of avoiding epithelial removal and shorter procedure time, but did not reach concentrations obtained with standard epi-off.

Visual performance and biocompatibility of 2 multifocal diffractive IOLs: six-month comparative study.

PURPOSE: To evaluate the distance and near functional capacity, wavefront error and biocompatibility in patients with 2 diffractive multifocal intraocular lenses (MIOLs). SETTING: Ophthalmology Department of Chieti‐Pescara University (Italy). METHODS: This prospective study comprised 28 eyes of 28 senile cataract patients having phacoemulsification and implantation of the Tecnis ZM900 MIOL (Group 1) and the AcrySof ReSTOR MIOL (Group 2). The main outcome measures, over a 6‐month follow‐up period, were spherical equivalent, distance visual acuity at high and low contrast, near visual acuity, and defocus curve. Wavefront error was evaluated in both groups. Capsule opacification was also assessed. RESULTS: The high and low contrast uncorrected and best corrected visual acuity for distance did not show statistically significant differences between the 2 groups. The distance corrected near visual acuity was 1.86 ± 1.66 in Group 1 and 1.93 ± 1.12 in Group 2. The depth of focus was 4.5 diopters in both groups. The root mean square of total aberration and of spherical and coma aberrations were significantly lower in Group 1 than in Group 2. A higher percentage of patients with Tecnis MIOLs showed a more severe grade of anterior fibrosis. Posterior opacification was minimal and not significantly different between the 2 groups. CONCLUSION: Diffractive MIOLs were effective in improving functional capacity for distance and near and provided a good quality of vision due to a significant reduction in spherical aberration, particularly in the Tecnis MIOLs. The higher capsular biocompatibility of the ReSTOR MIOL compared with the Tecnis MIOL could ensure long‐term stability.

Filtering Bleb Functionality: A Clinical, Anterior Segment Optical Coherence Tomography and In Vivo Confocal Microscopy Study

PurposeTo provide a microscopic and macroscopic analysis by a clinical, in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) assessment of filtering blebs after glaucoma surgery. Material and MethodsWe retrospectively analyzed 60 eyes of 48 glaucomatous patients by slit-lamp, IVCM, and AS-OCT examinations. Patients were divided into 2 groups: successful blebs (group 1, 16 patients, 27 eyes) were defined as a one-third reduction in preoperative intraocular pressure without antiglaucoma medications and failed blebs (group 2, 32 patients, 33 eyes) as a less than one-third reduction in preoperative intraocular pressure without therapy. The examinations were performed from 1 to 96 months postoperatively. ResultsDiffuse or cystic clinical patterns were indicative for good functionality whereas flat or encapsulation was indicative for poor functionality. When comparing successful with failed blebs, the IVCM analysis showed a greater number (P=0.014), density (P=0.009), and total area of epithelial microcysts (P=0.017) and a lower density of connective tissue (P=0.006). The AS-OCT analysis showed a lower degree of bleb wall reflectivity (P<0.001). A significant correlation was found between the clinical and AS-OCT parameters, particularly for the cystic (100%) and diffuse (74%) patterns. ConclusionsAll IVCM parameters did correlate well with the bleb functionality whereas, among the AS-OCT parameters, only the bleb wall reflectivity was significantly related to the filtering capability. Clinical and AS-OCT bleb classification showed a significant degree of concordance. As a consequence, simultaneous approach by clinical, microscopic, and tomographic assessment improves the clinicians ability in the postsurgery understanding and management of blebs.

Fundus microperimetry patterns of fixation in type 2 diabetic patients with diffuse macular edema.

Background: Recently developed fundus microperimetry (MP-1; Nidek Technologies, Srl. Vigonza PD, Italy) was used to evaluate fixation patterns and retinal sensitivity in patients who had clinically significant macular edema with a diffuse pattern and type 2 diabetes mellitus. Methods: In a prospective, observational case series study, 84 consecutive patients with type 2 diabetes (84 eyes) who had clinically significant macular edema with a diffuse pattern were studied by means of MP-1. Main outcome measures were fixation stability and position and mean retinal sensitivities within the central 2° and 8° areas. Logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) was evaluated by means of an Early Treatment of Diabetic Retinopathy Study chart. Foveal thickness was measured by Stratus optical coherence tomography (OCT; Carl Zeiss Meditec, Inc., Dublin, CA). Age, duration of diabetes, hemoglobin A1c (HbA1c) levels, duration of symptoms, history of panretinal photocoagulation, vitreomacular adhesion, and cystoid macular changes were documented. Patients were grouped according to both position of fixation (central or eccentric) and stability of fixation (stable or unstable). Statistical analyses included independent samples t-test, binomial test, Bonferroni correction for multiple comparisons, and generalized linear model univariate analysis. Results: Of 84 eyes, 44 (52.4%) had central fixation, and 40 (47.6%) had eccentric fixation. Of 84 eyes, 34 (40.5%) had stable fixation, and 50 (59.5%) had unstable fixation. In the whole sample, mean central 2° retinal sensitivity ± SD was 6.26 ± 3.19 dB (range, 0–14.80 dB), and mean central 8° retinal sensitivity ± SD was 7.62 ± 2.55 (range, 3.85–14.90 dB); logMAR BCVA ranged from 0.1 to 1.3 (mean ± SD, 0.6 ± 0.29). Mean OCT foveal thickness ± SD was 300.77 ± 66.93 m (range, 220–525 m). Both comparisons between groups (stable vs. unstable and central vs. eccentric) showed statistically significant differences in mean logMAR BCVA, mean central 2° and 8° retinal sensitivities, and mean OCT foveal thickness. Duration of symptoms was significantly longer and HbA1c levels were higher in the groups with deterioration of stability or centrality of fixation. The prevalence of cystoid macular changes was significantly higher in the groups with eccentric or unstable fixation (P < 0.001). Generalized linear model statistical analysis showed that logMAR BCVA was significantly associated with stability of fixation (P = 0.020), mean central 8° retinal sensitivity (P < 0.001), and mean OCT foveal thickness (P < 0.001). The interaction between stability of fixation and mean OCT foveal thickness showed a statistically significant association with logMAR BCVA (P = 0.003). Some eyes with eccentric fixation presented with stable fixation, especially in the presence of long-lasting symptoms, and had better visual acuity than eyes with central, but unstable fixation. Conclusion: Visual acuity, central retinal sensitivity, foveal thickness, duration of symptoms, HbA1c levels, and presence of cystoid macular changes were strongly associated with fixation impairment in type 2 diabetic patients who had clinically significant macular edema with a diffuse pattern. Stability of fixation and foveal thickness play a major role in conditioning BCVA.

Effect of oral captopril (SQ 14225) on intraocular pressure in man

The effects of the angiotensin converting enzyme (ACE) inhibitor captopril (SQ 14225) on intraocular pressure (IOP) were studied. Four groups were analyzed: group A, ten control subjects; group B, ten hypertensive patients with normal IOP; group C, ten normotensive patients with primary open angle glaucoma (POAG); and group D, ten hypertensive patients with POAG. Systolic and diastolic blood pressure, heart rate, pupil diameter, IOP and total outflow facility were recorded at baseline and at 1-h intervals up to 3h after an oral dose of 25 mg captopril or placebo, given in a randomized, double-blind cross-over fashion. The alternative treatment was given a week later. Captopril significantly lowered IOP in all patients, with no effects on heart rate and pupil diameter. Blood pressure changed only in patients with hypertension (groups B and D). Total outflow facility, measured by conventional tonography, increased significantly in all groups. These findings indicate that oral captopril could represent a new antiglaucomatous compound.

Optical Coherence Tomography Angiography in Retinal Vascular Diseases and Choroidal Neovascularization

Purpose. To assess the ability of optical coherence tomography-angiography (OCT-A) to show and analyze retinal vascular patterns and the choroidal neovascularization (CNV) in retinal vascular diseases. Methods. Seven eyes of seven consecutive patients with retinal vascular diseases were examined. Two healthy subjects served as controls. All eyes were scanned with the SD-OCT XR Avanti (Optovue Inc, Fremont CA, USA). Split spectrum amplitude decorrelation angiography algorithm was used to identify the blood flow within the tissue. Fluorescein angiography (FA) and indocyanine green angiography (ICGA) with Spectralis HRA + OCT (Heidelberg Engineering GmbH) were performed. Results. In healthy subjects OCT-A visualized major macular vessels and detailed capillary networks around the foveal avascular zone. Patients were affected with myopic CNV (2 eyes), age-related macular degeneration related (2), branch retinal vein occlusion (BRVO) (2), and branch retinal artery occlusion (BRAO) (1). OCT-A images provided distinct vascular patterns, distinguishing perfused and nonperfused areas in BRVO and BRAO and recognizing the presence, location, and size of CNV. Conclusions. OCT-A provides detailed images of retinal vascular plexuses and quantitative data of pathologic structures. Further studies are warranted to define the role of OCT-A in the assessment of retinovascular diseases, with respect to conventional FA and ICG-A.

Prospective randomized comparison of wavefront-guided and conventional photorefractive keratectomy for myopia with the meditec MEL 70 laser

PURPOSE To study refractive results and aberrometric changes in myopic patients treated with wavefront-guided photorefractive keratectomy (PRK) in comparison with standard PRK. METHODS Sixty eyes of 60 patients with myopic astigmatism were randomly divided into two groups. Group 1 included 30 eyes (mean spherical equivalent refraction -4.39 +/- 1.31 D; range -2.50 to -6.50 D) treated with wavefront-guided PRK using the WASCA workstation and the Asclepion Meditec flying spot MEL 70 excimer laser. Group 2 had 30 eyes (mean spherical equivalent refraction -4.33 +/- 1.22 D; range -2.50 to -6.50 D) that underwent conventional PRK using the same laser, and served as the control group. Wavefront analysis of high order aberrations was performed before and 6 months after surgery. RESULTS Postoperatively, wavefront error increased in both groups (5.0-mm wavefront aperture diameter). Six months after surgery, the eyes that received the WASCA ablation had a smaller increase in root-mean-square (RMS; 70% of increment) compared to the conventional PRK group (139% of increment) (P<.001). In the standard PRK group, all aberrations notably increased; in the wavefront-guided PRK group there was a smaller increase of trefoil and spherical aberrations (P<.001) and a decrease of coma aberrations (P<.001). The smaller increase of wavefront error in the wavefront-guided PRK group compared to the standard PRK group was more evident when preoperative RMS values were higher than 0.4 microm (P<.01). The visual parameters (spherical equivalent refraction, uncorrected and best spectacle-corrected visual acuity) did not show significant differences between the two groups. CONCLUSION Wavefront-guided PRK induced a smaller increase of postoperative wavefront-error compared to conventional PRK, particularly in patients with higher preoperative higher order aberrations.