Enzo Maria Vingolo

Visual acuity and contrast sensitivity: AcrySof ReSTOR apodized diffractive versus AcrySof SA60AT monofocal intraocular lenses

PURPOSE: To compare the visual acuity and contrast sensitivity in eyes with the AcrySof ReSTOR multifocal intraocular lens (IOL) (Alcon) and eyes with the monofocal AcrySof SA60AT IOL. SETTING: Policlinico Umberto I, Department of Ophthalmology, Rome, and private clinical practice, Rome, Italy. METHODS: One hundred eyes had phacoemulsification cataract extraction and implantation of a ReSTOR multifocal IOL in the capsular bag. Inclusion criteria were corneal astigmatism less than 1.5 diopters (D), myopia less than 4.0 D, and no associated ocular disease. A complete ophthalmic examination, including uncorrected visual acuity, best spectacle‐corrected visual acuity, and contrast sensitivity, was performed 6 months postoperatively. Results were compared with those in 40 eyes with the AcrySof monofocal IOL single‐piece IOL. RESULTS: In the multifocal group, 90 eyes (90%) had an uncorrected distance visual acuity of 20/25 or better (logMAR <0.10) and an uncorrected near visual acuity at 35 cm of J3 or better (logMAR 0.14). The multifocal group and monofocal group had similar distance uncorrected and best corrected visual acuities; however, the multifocal group had significantly better near uncorrected acuity. The mean contrast sensitivity values were 18.28 dB (static program) and 17.95 dB (dynamic program) in the multifocal group and 19.18 dB (static program) and 21.2 dB (dynamic program) in the monofocal group. CONCLUSIONS: The ReSTOR multifocal IOL provided a satisfactory full range of vision; 92% of the patients achieved total spectacle independence. Contrast sensitivity was lower than with the SA60AT monofocal IOL.

BBS1 mutations in a wide spectrum of phenotypes ranging from nonsyndromic retinitis pigmentosa to Bardet-Biedl syndrome

OBJECTIVE To investigate the involvement of the Bardet-Biedl syndrome (BBS) gene BBS1 p.M390R variant in nonsyndromic autosomal recessive retinitis pigmentosa (RP). METHODS Homozygosity mapping of a patient with isolated RP was followed by BBS1 sequence analysis. We performed restriction fragment length polymorphism analysis of the p.M390R allele in 2007 patients with isolated RP or autosomal recessive RP and in 1824 ethnically matched controls. Patients with 2 BBS1 variants underwent extensive clinical and ophthalmologic assessment. RESULTS In an RP proband who did not fulfill the clinical criteria for BBS, we identified a large homozygous region encompassing the BBS1 gene, which carried the p.M390R variant. In addition, this variant was detected homozygously in 10 RP patients and 1 control, compound heterozygously in 3 patients, and heterozygously in 5 patients and 6 controls. The 14 patients with 2 BBS1 variants showed the entire clinical spectrum, from nonsyndromic RP to full-blown BBS. In 8 of 14 patients, visual acuity was significantly reduced. In patients with electroretinographic responses, a rod-cone pattern of photoreceptor degeneration was observed. CONCLUSIONS Variants in BBS1 are significantly associated with nonsyndromic autosomal recessive RP and relatively mild forms of BBS. As exemplified in this study by the identification of a homozygous p.M390R variant in a control individual and in unaffected parents of BBS patients in other studies, cis - or trans -acting modifiers may influence the disease phenotype. CLINICAL RELEVANCE It is important to monitor patients with an early diagnosis of mild BBS phenotypes for possible life-threatening conditions.

Plasma endothelin-1 concentrations in patients with retinal vein occlusions.

AIMS To investigate whether plasma levels of endothelin-1 (ET-1), a potent vasoconstricting peptide that is crucial in regulating retinal blood flow, were elevated in patients with retinal vein occlusion (RVO). METHODS ET-1 plasma concentrations were determined by radioimmunoassays in a double blind fashion in a group of 18 selected patients with RVO, in 20 healthy age matched non-smoking, normoglycaemic, normotensive control subjects, and in 15 patients with uncomplicated essential hypertension in the same age range. RESULTS Patients with RVO had significantly increased ET-1 plasma levels (14.22 (SD 4.6) pg/ml) compared with both normal subjects (7.90 (1.6) pg/ml; p < 0.05) and hypertensive patients (8.50 (2.9) pg/ml; p <0.05). The highest concentrations of circulating ET-1 were found in patients with RVO of the ischaemic type (16.97 (3.5) pg/ml; p < 0.01; n = 7). Systemic hypertension alone did not account for the observed increase in plasma ET-1 concentrations. CONCLUSIONS These findings raise the possibility that the increased circulating ET-1 levels in patients with RVO may be a marker of the occlusive event, thereby suggesting that ET-1 homeostasis may be relevant to RVO pathogenesis and retinal ischaemic manifestations.

Autosomal dominant simple microphthalmos.

Congenital bilateral microphthalmos is a rare malformation of the eye, which ranges from extreme to mild reduction of total axial length. Microphthalmos may occur as an isolated ocular abnormality or as part of a systemic disorder, and different classifications of the condition have been attempted. We describe a large pedigree with 14 persons in four generations affected with bilateral microphthalmos without other ocular or systemic signs. An autosomal dominant trait with complete penetrance is proposed. Five subjects underwent a complete ophthalmological evaluation. The total axial length was measured by A scan ultrasonography in all persons. Ultrasonography showed a reduction of the total axial length (range 18.4-19.7 mm) and a reduced vitreous cavity length (range 11.4-13.5 mm) in all investigated patients. All the patients had microcornea (range 8-9.7 mm). No other ocular anomalies or associated systemic malformations were found. A review of published reports also suggests that simple, partial, posterior, pure microphthalmos and nanophthalmos are similar clinical entities sharing total axial length and vitreous cavity length reduction. Therefore, the term simple microphthalmos is proposed to identify these clinical conditions.

Correlation between Goldmann perimetry and maximal electroretinogram response in retinitis pigmentosa

To evaluate the relationship between Goldmann perimetry and maximal electroretinographic responses in patients with retinitis pigmentosa, analyses were performed on 220 affected subjects and separately on two subgroups with autosomal dominant (n = 35) and autosomal recessive (n = 29) inheritance. Electroretinograms were recorded averaging 100 iterations elicited with a 20-lux/s, 0.5-Hz white flash ganzfeld stimulation. The peripheral isopters of the visual fields were delimited with I4e, IIIe and V4e targets, measured on conventional perimetry charts with a light pen and expressed in square centimeters. Unlike most previously published reports, this investigation showed a definite correlation (p = 0.0001) between maximal electroretinographic response amplitude and visual field areas. This correlation was more evident for I4e and IIIe isopters (r = 0.89 and 0.87, respectively) than for V4e isopter (r = 0.69). This phenomenon appears to be related to distortion occurring on standard isometric charts and to spatial summation effects in the peripheral field. Such correlations held for both the autosomal dominant and autosomal recessive subgroups. It appears that, if enough accuracy is provided, maximal electroretinographic responses and Goldmann visual fields are both good measures of the remaining functioning retina in nonsyndromic retinitis pigmentosa, irrespective of inheritance models and dystrophic patterns.

Does hyperbaric oxygen (HBO) delivery rescue retinal photoreceptors in retinitis pigmentosa

As previously reported in the literature, hyperbaric oxygen delivery seems to modify the natural course of retinitis pigmentosa. In order to evaluate these first encouraging data, 48 affected subjects were separately studied in two subgroups (cases and controls). All patients underwent yearly an ophthalmological examination completed by a maximum amplitude electroretinogram, conducted according to our ‘differential derivation’ system, a new recording technique specifically designed to enhance the signal-to-noise ratio. Oxygen delivery was provided regularly for 90 min daily (2.2 Absolute Atmosphere) in three cycles according to a standard protocol. In the cases, electroretinographic mean values were as follows: at TO (basal) 4.68 ± 3.81 μV; after one year (T1) 8.46 ± 5.71 μV; at two years (T2) 10.7 ± 7.6 μV; at the end of the study (T3) 14.4 ± 11.7 μV. In the controls, electroretinographic mean values were as follows: at T0 4.92 ± 3.05 μV; at T1 5.04 ± 3.07 μV; at T2 3.46 ± 2.77 μV; at T3 2.97 ± 3.61 μV. Amplitudes showed a remarkable (p<0.001) increase in the cases, while a slightly significant (p<0.02) decrease was evident at the end of the study in the controls. In our opinion, retinal oxygen availability may be critical in retinal degeneration and hyperbaric oxygen delivery, inducing hyperoxia, seems to be able to bring about the rescue of the retinal photoreceptors helping them in their metabolic requirements. Unfortunately, our study demonstrates an increase in electroretinographic responses only, which may not necessarily also mean an evident change in visual acuity.

Fourier-Domain Optical Coherence Tomography and Microperimetry Findings in Retinitis Pigmentosa

PURPOSE To investigate the relation between the optical coherence tomography (OCT) findings and retinal sensitivity in patients with retinitis pigmentosa (RP) by assessing the retinal thickness and retinal function using Fourier-domain OCT (FD-OCT) and microperimetry, respectively. DESIGN Observational case series. METHODS Fifty-nine patients (118 eyes) were enrolled, mean age 47 ± 14.8 years. Thirty-two healthy subjects (HS) were enrolled as a control group. Patients were assessed by means of FD-OCT and microperimetry. We analyzed the average foveal thickness (diameter of 1 mm centered on the point of fixation), the value of the retinal sensitivities corresponding to the 4 degrees centered on the fixation point, and logMAR visual acuity for regression analysis converted from Snellen chart. RESULTS We distinguished 4 groups of RP patients according to the macular pattern seen on OCT images. The first group of 36 eyes, mean age of 33.5 ± 7.4 years, had no macular changes, mean best-corrected visual acuity (BCVA) of 0.95 ± 0.07, mean foveal thickness of 256.3 ± 9.14 μm, and mean retinal sensitivities inside the central 4 degrees of 19.27 ± 0.87 dB (P > .05 for all the values). The second group of 28 eyes, mean age 35.4 ± 6.3 years, showed clinical macular edema (CME) on OCT images with mean BCVA of 0.72 ± 0.22, mean foveal thickness of 363.5 ± 93.45 μm, and mean retinal sensitivity inside the central 4 degrees of 15.94 ± 3.6 dB (P < .01 for all the values). The third group of 26 eyes, mean age 50.8 ± 8.7 years, showed macular vitreoretinal traction on OCT images with a mean BCVA of 0.5 ± 0.2, mean foveal thickness of 337.1 ± 71.7 μm, and mean retinal sensitivity inside the central 4 degrees of 11.78 ± 3.09 dB (P < .01 for all the values). The last group of 28 eyes, mean age 52.1 ± 13.6 years, showed macular retinal thinning on OCT images with mean BCVA of 0.36 ± 0.15, mean foveal thickness of 174.2 ± 24.40 μm, and mean retinal sensitivity inside the central 4 degrees of 10.22 ± 3.82 dB (P < .01 for all the values). CONCLUSIONS MP-1 and FD-OCT showed high sensitivity for identifying functional and structural macular abnormalities, respectively. Future studies should investigate the relationships among photoreceptor cell loss, retinal sensitivity, and fixation in patients with RP.

Subjective visual halos after sildenafil (Viagra) administration: Electroretinographic evaluation.

PURPOSE The ophthalmologic and electroretinographic (ERG) findings in one subject with subjective visual disturbances after sildenafil administration are described. DESIGN Interventional case report. METHODS A complete ophthalmologic examination was performed, including best-corrected visual acuity and ERG, repeated 1 and 2 hours after administration of 100 mg of sildenafil. MAIN OUTCOME MEASURES Rod responses were obtained over a range of retinal illuminances from those producing a minimum detectable response to those producing rod saturation. Intensity amplitude function was determined. RESULTS At 2 hours after 100 mg of oral sildenafil, we observed significant variations from baseline in parameters of best-fit Naka-Rushton function; V(max) was notably higher, and K was 0.14 log units lower than baseline. CONCLUSIONS Sildenafil administration resulted in a higher rod response to light stimuli and in a higher rod sensitivity. These findings are consistent with the weak PDE-6 inhibition induced by sildenafil.

Is acetazolamide effective in the treatment of diabetic macular edema? A pilot study

Aim: To investigate whether acetazolamide, already found to be helpful in decreasing cystoid macular edema in patients with retinitis pigmentosa, was also effective in the treatment of diabetic macular edema in nonproliferative retinopathy. Methods:Two randomized age- and sex-matched groups (cases and controls) of 12 diabetics (five Type 1 and seven Type 2) were selected for this pilot study and graded for retinopathy (Early Treatment of Diabetic Retinopathy Study – Airlie House Classification). Cases were treated with acetazolamide for three months according to a standard protocol. The Early Treatment of Diabetic Retinopathy Study chart was used for assessing far-best corrected visual-acuity, and fluorescein angiography was performed using the Heidelberg Retina Angiograph. The Amsler grid-test and computerized-perimetry (Octopus 2000R) were also performed. Results: Fluorescein-angiographic findings and perimetric data improved significantly (p < 0.01) in the acetazolamide-treated cases compared to the controls while visual-acuity varied only slightly (p > 0.01). The Amsler grid-test resulted insignificant in our study (p > 0.05). No adverse effects or significant variations in laboratory tests were recorded. Conclusion: Further clinical investigations involving larger numbers of patients and a longer follow-up are required to confirm these preliminary results. However, the present study seems to suggest that acetazolamide could be effective in reducing fluorescein-angiographic findings and improving perimetric data in diabetics with macular edema, even though the mechanism of action remains obscure. Visual-acuity varied only slightly.

Efficacy of intravitreal triamcinolone acetonide in long standing diabetic macular edema: a microperimetry and optical coherence tomography study.

Purpose: To investigate the efficacy of intravitreal triamcinolone acetonide in patients suffering from diffuse long standing diabetic macular edema, by the assessment of retinal thickness and retinal function by means of optical coherence tomography (OCT) and microperimetry-1. Methods: Twenty eyes received 8 mg in 0.2 mL preservative free intravitreal triamcinolone injection delivered through the pars plana. The best corrected visual acuity (BCVA), foveal thickness, and the average retinal sensitivity of the 45 stimuli were considered in our study. Patients were instructed to attend for OCT and microperimetry-1 follow-up at baseline, 1, 3, and 6. Results: At the baseline, mean macular thickness was 692&mgr; ± 70&mgr;; mean visual acuity was 0.13 ± 0.09. Mean macular sensitivity determined with the microperimetry-1 was 6.85 dB ± 2.1 dB. At the 1 month follow-up, mean OCT macular thickness decreased to 348.28&mgr; ± 132.10&mgr; (P = 0.0001); mean BCVA improved to 0.23 ± 0.15 (P = 0.019); mean retinal sensitivity improved to 8.71 dB ± 2.79 dB (P = 0.03). At the 3 months follow-up, mean OCT macular thickness changed to 363.7&mgr; ± 123.52&mgr; (P = 0.0002); mean BCVA was 0.23 ± 0.15 (P = 0.0024); mean retinal sensitivity 8.54 dB ± 2.78 dB (P = 0.048). Six months after the injection, mean OCT macular thickness was 460.61&mgr; ± 104.9&mgr; (P > 0.05); mean BCVA was 0.15 (P > 0.05); mean retinal sensitivity 7.54 dB ± 2.58 dB (P > 0.05). Conclusion: In our study, we found intravitreal effective in improving BCVA, macular thickness, and retinal sensitivities during the first 3 months. At 6 months, follow-up of the data were not dissimilar to those obtained at baseline. Further investigation is warranted to asses the correlation among daily life visual performance, retinal sensitivities, and macular thickness.