Giancarlo Iarossi

Comparison of wavefront aberration changes in the anterior corneal surface after laser-assisted subepithelial keratectomy and laser in situ keratomileusis : Preliminary study

Purpose: To compare changes in anterior corneal wavefront aberrations after myopic laser‐assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Setting: Institute of Ophthalmology, Catholic University, Rome, Italy. Methods: This prospective study included 36 eyes of 25 myopic patients: 18 eyes of 12 patients had LASEK and 18 eyes of 13 patients, LASIK. The topography data (CSO EyeMap, version 6.2) were used to calculate corneal aberrations with 3.0 mm and 7.0 mm pupils before and 3 months after surgery. Results: Total corneal aberrations increased similarly after LASEK and LASIK with the 7.0 mm pupil but did not change with the 3.0 mm pupil. Coma‐like and spherical‐like aberrations changed similarly after both procedures, but spherical‐like aberrations increased after LASEK with the 3.0 mm pupil (P<.05, independent t test). With the 7.0 mm pupil, the amount of achieved correction was positively correlated with changes in total corneal aberrations after LASIK (P = .007) and with spherical‐like aberrations after LASEK (P = .03) and LASIK (P<.003). Although there was no significant difference between LASEK and LASIK (P>.05, independent t test), in individual eyes with an achieved correction less than 7.50 diopters (D), spherical‐like aberrations increased more after LASEK than after LASIK. Conclusions: In this preliminary study, myopic LASEK and LASIK changed total and higher‐order corneal aberrations. In both procedures, changes in spherical‐like aberrations were dependent on the achieved correction. However, in individual eyes, spherical‐like aberrations increased more after LASEK than after LASIK for low‐moderate achieved correction, suggesting that these procedures may induce the same optical changes in the anterior corneal surface in different ways.

Focal electroretinograms and fundus appearance in nonexudative age-related macular degeneration. Quantitative relationship between retinal morphology and function.

Abstract · Background: The aim of this study was to evaluate the focal electroretinogram (FERG), an objective indicator of outer retinal function, in nonexudative age-related macular degeneration (NE-AMD), and to compare FERG results with morphological lesions assessed by stereoscopic fundus photographs and fluorescein angiograms. · Methods: Twenty-five patients (25 eyes) with bilateral NE-AMD (visual acuity of the study eyes ≥0.4) as well as 10 age- and sex-matched control subjects (10 eyes) were evaluated. FERGs were recorded from the macular region (9°) in response to sinusoidal stimuli flickered at 32 Hz. Amplitude and phase angle of the Fourier-analyzed FERG fundamental component were measured. Fundus lesions were graded from color slides according to the Wisconsin age-related maculopathy grading system [15]. Fluorescein angiograms were evaluated by an image analysis technique to compute the area with pathological hyperfluorescence (associated with drusen and/or retinal pigment epithelial atrophy) within the macular (approximately 9°×9°) region. · Results: Compared to control eyes, NE-AMD eyes had a reduction in the mean FERG amplitude (57% loss, P<0.001) with no phase changes. Amplitudes of individual affected eyes were negatively correlated with either the Wisconsin grading score (r=–0.63, P<0.001) or the percentage area of pathological hyperfluorescence (r=–0.70, P<0.01). Eyes with minimal NE-AMD lesions (Wisconsin score ≤6) and normal acuity had a lower mean amplitude (47% loss, P<0.05) than that of control eyes. · Conclusions: The results indicate that, in NE-AMD, the FERG is altered in parallel with the extent and severity of fundus lesions. However, a functional impairment of outer macular layers, which is detected by FERG losses, could precede morphological changes typical of more advanced disease.

A fast visual evoked potential method for functional assessment and follow-up of childhood optic gliomas

OBJECTIVE To evaluate a fast technique of visual evoked potentials (VEPs) recording, in response to steady-state luminance stimuli (SS-LVEPs), for functional assessment and follow-up of childhood optic gliomas (OGs). METHODS Eighteen OG patients (age range: 3.5-18 years), with different degrees of optic pathway damage severity, were examined. Sixteen age-matched normal subjects served as controls. Ten of the 18 OG patients were re-tested 1-3 months after the first examination. SS-LVEPs were elicited by a sinusoidally-modulated flickering (8 Hz) uniform field, generated by a light emitting diode (LED)-array and presented monocularly in a mini-ganzfeld. Amplitude and phase of the Fourier-analyzed response fundamental (1F) and second harmonic (2F) were measured. The full VEP protocol had a median duration of 6 min (range: 4-12). RESULTS When compared to normal control values, median 1F and 2F SS-LVEP amplitudes of OG patients were reduced (P<0.01), with a borderline increase in 2F phase lag (P<0.05). In 11 OG patients with asymmetric optic pathway damage in between-eye comparisons, median 1F amplitude losses were greater (P<0.01) in fellow eyes with more severe damage. No significant interocular difference was observed in control subjects. Median test-retest changes of 1F and 2F component were <20% and 30 degrees for amplitude and phase, respectively. In individual OG patients, 1F and 2F amplitudes were positively correlated (P<0.01) with visual acuity. 1F amplitude losses were correlated (P=0.01) with the severity of optic disc atrophy. Considering both 1F and 2F abnormalities, diagnostic sensitivity of SS-LVEP in detecting OG-induced optic pathways damage was 83.3%. CONCLUSIONS The present findings support the use of this technique, as an alternative to pattern VEPs, for functional assessment and follow-up of OG in uncooperative children.

The first and second harmonics of the macular flicker electroretinogram: Differential effects of retinal diseases

We evaluated the effects of retinal diseases on the macular electroretinogram first and second harmonic components, which are dominated by outer and inner retinal activity, respectively. Macular electroretinograms in response to a uniform field (9° × 9°) flickering sinusoidally at either 32 or 8 Hz (peak frequencies of the first and second harmonics, respectively) were recorded in 14 patients with maculopathies involving photoreceptors (e.g., age-related macular degeneration), in 16 patients with postreceptoral macular diseases (e.g., branch occlusion of central retinal artery), and in 38 normal controls. Amplitude and phase of the first and second harmonic response components were evaluated by Fourier analysis. When compared to controls, patients with photoreceptor diseases had reduction in both first and second harmonic mean amplitudes and second harmonic phase delay; patients with postreceptoral diseases had normal first harmonic components but reduced and delayed second harmonic components. A discriminant analysis, by using first and second harmonic values, correctly classified 13 of 14 patients with photoreceptor diseases and 14 of 16 patients with postreceptoral disorders. These results indicate that combined evaluation of the macular electroretinogram first and second harmonic components is a useful test for identifying the site(s) of retinal dysfunction in patients with macular diseases.

Long-term decline of central cone function in retinitis pigmentosa evaluated by focal electroretinogram

PURPOSE We evaluated long-term changes of central cone-mediated function in retinitis pigmentosa (RP) patients by recording focal electroretinograms (fERG). METHODS A cohort of 43 RP patients was followed from 4 to 16 years (average follow-up 9.3 years, average 10 examinations/patient) by recording the fERG response to a flickering uniform red field overlaying the central 18° of visual field (VF). Statistical censoring led to a reduced dataset of 32 patients (autosomal dominant 9, recessive 5, sporadic 5, x-linked 1, Usher II 12), from which long-term decay rates were estimated by global fitting of individual fERG amplitude time-curves. RESULTS Long-term follow-up of central cone FERG amplitude showed two main features: short-term variability and long-term decline. fERG short-term variability range was 0.14 to 0.2 log units. Mean yearly decay rate of central fERG was 5.6% (95% confidence interval [CI] 4%-7%). Yearly decline depended on inheritance pattern, being significantly greater in autosomal recessive and sporadic compared to autosomal dominant RP. The degree of central cone fERG decline was unrelated to the size of the residual VF. CONCLUSIONS The decline of central cone function is significantly slower than global cone function decline in RP. Central cone fERG loss is independent of residual VF.

Morpho-functional follow-up of the optic nerve in treated ocular hypertension: disc morphometry and steady-state pattern electroretinogram.

Purpose: To examine longitudinally optic disc structure and inner retinal function in treated ocular hypertension (OHT). Materials and Methods: A morphometric (Heidelberg Retina Tomograph, HRT) and functional (steady-state pattern electroretinogram, PERG) evaluation of 27 OHT patients treated with topical beta-blockers and/or prostaglandin analogues and prospectively followed over a 24 ± 6 month period. Results: Compared with baseline, mean final PERG amplitude tended to increase (p < 0.01), while HRT was stable. Individual PERG amplitude increase was large (≥ 100%) in some patients (5/27), and unexplained by clinical parameters at baseline. Conclusions: In treated OHT, functional responses may improve while disc structure remains stable. The findings suggest that OHT-associated inner retinal dysfunction is at least in part reversible with therapeutic intraocular pressure control.

Erratum to: NGF eye-drops topical administration in patients with retinitis pigmentosa, a pilot study

The online version of the original article can be found under doi:10.1186/s12967-015-0750-3.

Corrigendum to “Genotype-Phenotype Characterization of Novel Variants in Six Italian Patients with Familial Exudative Vitreoretinopathy”

[This corrects the article DOI: 10.1155/2017/3080245.].

Contents Vol. 41, 2009

Anatomy, Pathology and Cell Biology A. Prescott, Dundee Biochemistry, Molecular Biology and Molecular Genetics J. Graw, Neuherberg Clinical and Epidemiological Research M. Kojima, Kahoku Clinical Retina P. Wiedemann, Leipzig Cornea and Ocular Surface C. Marfurt, Gary, Ind. Glaucoma C. Erb, Berlin Immunology and Microbiology U. Pleyer, Berlin Lens and Cataract S. Varma, Baltimore, Md. Miscellaneous U. Pleyer, Berlin Neuro-Ophthalmology and Vision Sciences P. Aydin, Ankara Ocular Oncology M. Jager, Leiden Physiology, Pharmacology and Toxicology A. Wegener, Bonn Retina and Retinal Cell Biology M. Boulton, Gainesville, Fla. P. Wiedemann, Leipzig Editorial Board