In vivo imaging of CNS microglial activation/macrophage infiltration with combined [18F]DPA-714-PET and SPIO-MRI in a mouse model of relapsing remitting experimental autoimmune encephalomyelitis

Purpose

To evaluate the feasibility and sensitivity of multimodality PET/CT and MRI imaging for non-invasive characterization of brain microglial/macrophage activation occurring during the acute phase in a mouse model of relapsing remitting multiple sclerosis (RR-MS) using [¹⁸F]DPA-714, a selective radioligand for the 18-kDa translocator protein (TSPO), superparamagnetic iron oxide particles (SPIO), and ex vivo immunohistochemistry.

Methods

Experimental autoimmune encephalomyelitis (EAE) was induced in female SJL/J mice by immunization with PLP_139–151. Seven symptomatic EAE mice and five controls underwent both PET/CT and MRI studies between 11 and 14 days post-immunization. SPIO was injected i.v. in the same animals immediately after [¹⁸F]DPA-714 and MRI acquisition was performed after 24 h. Regional brain volumes were defined according to a mouse brain atlas on co-registered PET and SPIO-MRI images. [¹⁸F]DPA-714 standardized uptake value (SUV) ratios (SUVR), with unaffected neocortex as reference, and SPIO fractional volumes (SPIO-Vol) were generated. Both SUVR and SPIO-Vol values were correlated with the clinical score (CS) and among them. Five EAE and four control mice underwent immunohistochemical analysis with the aim of identifying activated microglia/macrophage and TSPO expressions.

Results

SUVR and SPIO-Vol values were significantly increased in EAE compared with controls in the hippocampus (p < 0.01; p < 0.02, respectively), thalamus (p < 0.02; p < 0.05, respectively), and cerebellum and brainstem (p < 0.02), while only SPIO-Vol was significantly increased in the caudate/putamen (p < 0.05). Both SUVR and SPIO-Vol values were positively significantly correlated with CS and among them in the same regions. TSPO/Iba1 and F4/80/Prussian blue staining immunohistochemistry suggests that increased activated microglia/macrophages underlay TSPO expression and SPIO uptake in symptomatic EAE mice.

Conclusions

These preliminary results suggest that both activated microglia and infiltrated macrophages are present in vulnerable brain regions during the acute phase of PLP-EAE and contribute to disease severity. Both [¹⁸F]DPA-714-PET and SPIO-MRI appear suitable modalities for preclinical study of neuroinflammation in MS mice models.

Combined Surgical Ablation and Intravitreal Triamcinolone Acetonide for Retinal Angiomatous Proliferation

Purpose

Neovascular age-related macular degeneration (ARMD) with retinal angiomatous proliferation (RAP) has a poor natural history and the efficacy of any treatment has not yet been established. The authors describe a combined surgical treatment.

Methods

A 76-year-old woman presented with a best-corrected visual acuity (BCVA) of 20/600 in the right eye and macula with stage 3 RAP as identified by fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). After a standard three-port pars plana core vitrectomy (PPV), endodiathermy of the arteriolar and venous feeder vessels of each lesion was performed, intraretinal RAP feeder vessels were cut with manual vertical intraocular scissors, and 0.1 mL of triamcinolone acetonide (TAAC) was injected intravitreally At 1 and 4 weeks and at the sixth month, the patient underwent a complete eye examination, FA, ICGA, and OCT to assess outcomes and complications.

Results

Six months later, BCVA was stable at 20/300, intraocular pressure was 15 mmHg, anterior segment and vitreous cavity were clear without evidence of TAAC granules, and retina was attached. FA and ICGA showed a complete occlusion of the RAP and absence of leakage or ischemia and OCT demonstrated decreased macular thickness with resolution of both intraretinal edema and pigment epithelium detachment, and the restoration of the normal macular profile. At the end of follow-up, the authors did not observe any ocular or systemic complication.

Conclusions

Surgical approach to RAP stage 3 with intravitreal injection of 4 mg of TAAC was safe and anatomically effective.

Intravitreal Triamcinolone Acetonide in Refractory Pseudophakic Cystoid Macular Edema: Functional and Anatomic Results

PURPOSE

To evaluate safety and efficacy of intravitreal triamcinolone acetonide (TAAC) injections in the treatment of refractory pseudophakic cystoid macular edema (CME).

METHODS

Seven eyes of six patients (age range: 50-74) with pseudophakic CME resistant to standard treatment received intravitreal injections of 4 mg of TAAC with all vehicle. Mean preinjection duration of CME was 18.3 months. A mean of 2.1+/-1.2 (range 1 to 4) treatments were performed in four eyes (57.1 %) when visual acuity deteriorated towards baseline levels. Visual acuity assessment, optical coherence tomography (OCT), and fluorescein angiography (FFA) were performed pre- and postoperatively to evaluate results of TAAC injections. Intraocular pressure (IOP) and complications related to treatment were assessed.

RESULTS

After 11.1+/-3.9 months, mean best-corrected visual acuity (BCVA) increased (p =0.019) from 20/132 to a best value of 20/38. Mean macular thickness decreased from 517.29+/-146.98 mm to a best value of 263.71+/-83.13 mm (p=0.0018). Area of fluorescein leakage decreased (p<0.0001) from 11.84+/-0.93 mm2 at baseline to a minimal value of 3.86+/-0.98 mm2. The anatomic and functional improvement appeared after 1 month from the intravitreal injection and persisted through at least 3 months of follow-up. At the end of follow-up BCVA, macular thickness, and area of fluorescein leakage did not differ from baseline. Four eyes (57.1 %) developed IOP values higher than 21 mmHg, controlled by topical treatment. Two patients developed an endophthalmitis-like reaction.

CONCLUSIONS

Intravitreal TAAC was relatively safe and effective in resistant cases of pseudophakic CME with a temporary beneficial effect on visual acuity and macular edema.

Macular Hole following Conventional Repair of Bullous Retinal Detachment Using Air Injection (D-ACE Procedure)

PURPOSE

Sequential drainage of subretinal fluid (D), injection of air (A), cryotherapy (C), and application of local explants (E) (D-ACE) sequence was introduced in order to overcome the problems encountered in managing superior bullous detachments from multiple large equatorial breaks. The authors recently observed the occurrence of a full-thickness macular hole in one patient developing the day after he underwent a D-ACE procedure.

METHODS

A 61-year-old man presented a bullous retinal detachment in the right eye extending from the 9:30 to the 2 o'clock position, and posteriorly to the vascular arcades two retinal tears were noted, at the equator at 11 o'clock, and anterior to the equator at 12 o'clock. The patient underwent a D-ACE procedure. Subretinal fluid was drained above the lateral rectus muscle at the equator. One and a half milliliters of air were injected 3.5 mm from the limbus midway between the superior and the medial rectus insertions. Cryotherapy was applied to the retinal breaks. A 240 encircling band was used in conjunction with a 276 tyre segment at the level of the tears.

RESULTS

One day after surgery, the retina was flat, but a full-thickness macular hole could be seen with a surrounding cuff of subretinal fluid.

CONCLUSIONS

The mechanisms proposed to explain the occurrence of full-thickness macular holes after D-ACE may involve the concurrence of scleral elongation and vitreofoveal traction by means of previous partial posterior vitreous detachment with persistent posterior attachments at the fovea.

Low-fluence photodynamic therapy in longstanding chronic central serous chorioretinopathy with foveal and gravitational atrophy

PURPOSE

To describe anatomic and functional outcomes in two patients with long-standing severe chronic central serous chorioretinopathy (CSC) with foveal and gravitational atrophy treated with low-fluence photodynamic therapy (PDT).

METHODS

Two patients with a history of over 10 years of chronic CSC and development of gravitational tracts, with best-corrected visual acuity <or=20/200, were treated with PDT guided by indocyanine green angiography (ICGA) with a fluence of 25 J/cm2 at an irradiance of 300 mW. Follow-up examinations 1 and 9 months after therapy included measurement of near and far best-corrected visual acuity, fundus biomicroscopy, fluorescein angiography and ICGA, optical coherence tomography, and microperimetry.

RESULTS

At 1 and 9 months after low-fluence PDT, complete resolution of subretinal, intraretinal, and under retinal pigment epithelium fluid was observed in both patients. Far and near visual acuity improved in both eyes. Improvement of sensitivity and fixation stability were demonstrated by microperimetry. No treatment-related side effects were seen.

CONCLUSIONS

ICGA-guided low-fluence PDT seems effective and safe for treating long-standing chronic CSC.

[Pelvic lymphadenectomy as an alternative to adjuvant radiotherapy in early stage endometrial cancer at high risk of recurrent lymphatic metastases (stage I)]

AIM

The aim of this study was to evaluate if the surgical approach without pelvic lymphadenectomy and with adjuvant radiotherapy in the patients suffering from endometrioid adenocarcinoma type at high risk (of lymphatic metastasis) in early stage can be substituted by only surgery with pelvic lymphadenectomy (with or without para-aortic lymphadenectomy).

METHODS

A retrospective study was carried out on 56 patients who underwent surgery with eventual adjuvant radiotherapy and were attended during the follow-up in the Operative Unit of Gynecology and Obstetrics from 1997 to 2004. The patients were divided into two groups: the low risk group and the high risk group. The cancer grading (G) was defined before the surgery with an hystological exam on endometrial biopsies. The follow-up had a medium duration of 30 months (range: 9-44 months) and consisted of the evaluation of: cancer related survival (CRS); recurrence free survival (RFS). Both were evaluated according to age, risk type, and therapy adopted.

RESULTS

Four patients (7.1%) showed relapse during the period of study in a medium time of 24 months (range: 12-36): 2 of these patients (C and D cases; 36%) had a relapse both locally (pelvic wall) and distantly; the other two (A and B cases; 36%) had only a distant relapse. None of the patients at the stage IA had a relapse, but it occurred in the 8.7% of the cases (N.=2) IB and in the 10.5 % of the patients IC (N.=2). One patient of the low risk group (3.8%) (case A) had a distant relapse (lungs) 12 months after the surgery and died 6 months after the appearance of the relapse without any additional treatment, because of age and of concomitant pathologies which suggested another illness. Three patients of the high risk group (10%) had a local and /or distant relapse (one only distant, two both distant and local). One of them with distant relapse (36 months after the primary treatment) (case B) is still alive, even though she has got a controlled cancer, 8 months after the rescue treatment (chemotherapy), whereas two of them died in a medium time of 14 months (range 13-15 months) from the rescue treatment (C and D cases). One of the three patients of the high risk group underwent the standard surgical treatment with lympho-adenectomy (case B) whereas the other two underwent the standard surgical treatment with aiding radiotherapy (C and D cases). The CRS and the RFS were 96.2% and 96.2% in the low risk group, 93.3% and 90% in the high risk group, respectively.

CONCLUSIONS

The standard surgery offers a good prognosis to the low risk group patients. To the high risk group the CRS and the RFS were better with standard surgery with lymphadenectomy than with standard surgery with adjuvant radiotherapy. The degree of differentiation of the cancer is the most important prognostic factor in relation to the survival free from relapse (RFS).

ncx1, ncx2, and ncx3 gene product expression and function in neuronal anoxia and brain ischemia

Over the last few years, although extensive studies have focused on the relevant function played by the sodium-calcium exchanger (NCX) during focal ischemia, a thorough understanding of its role still remains a controversial issue. We explored the consequences of the pharmacological inhibition of this antiporter with conventional pharmacological approach, with the synthetic inhibitory peptide, XIP, or with an antisense strategy on the extent of brain damage induced by the permanent occlusion of middle cerebral artery (pMCAO) in rats. Collectively, the results of these studies suggest that ncx1 and ncx3 genes could be play a major role to limit the severity of ischemic damage probably as they act to dampen [Na+]i and [Ca2+]i overload. This mechanism seems to be normally activated in the ischemic brain as we found a selective upregulation of NCX1 and NCX3 mRNA levels in regions of the brain surviving to an ischemic insult. Despite this transcript increase, NCX1, NCX2, and NCX3 proteins undergo an extensive proteolytic degradation in the ipsilateral cerebral hemisphere. All together these results suggest that a rescue program centered on an increase NCX function and expression could halt the progression of the ischemic damage. On the basis of this evidence we directed our attention to the understanding of the transductional and transcriptional pathways responsible for NCX upregulation. To this aim, we are studying whether the brain isoform of Akt, Akt1, which is a downstream effector of neurotrophic factors, such as NGF can, in addition to affecting the other prosurvival cascades, also exert its neuroprotective effect by modulating the expression and activity of ncx1, ncx2, and ncx3 gene products.

Up-regulation and increased activity of KV3.4 channels and their accessory subunit MinK-related peptide 2 induced by amyloid peptide are involved in apoptotic neuronal death

The aim of the present study was to investigate whether K(V)3.4 channel subunits are involved in neuronal death induced by neurotoxic beta-amyloid peptides (Abeta). In particular, to test this hypothesis, three main questions were addressed: 1) whether the Abeta peptide can up-regulate both the transcription/translation and activity of K(V)3.4 channel subunit and its accessory subunit, MinK-related peptide 2 (MIRP2); 2) whether the increase in K(V)3.4 expression and activity can be mediated by the nuclear factor-kappaB (NF-kappaB) family of transcriptional factors; and 3) whether the specific inhibition of K(V)3.4 channel subunit reverts the Abeta peptide-induced neurodegeneration in hippocampal neurons and nerve growth factor (NGF)-differentiated PC-12 cells. We found that Abeta(1-42) treatment induced an increase in K(V)3.4 and MIRP2 transcripts and proteins, detected by reverse transcription-polymerase chain reaction and Western blot analysis, respectively, in NGF-differentiated PC-12 cells and hippocampal neurons. Patch-clamp experiments performed in whole-cell configuration revealed that the Abeta peptide caused an increase in I(A) current amplitude carried by K(V)3.4 channel subunits, as revealed by their specific blockade with blood depressing substance-I (BDS-I) in both hippocampal neurons and NGF-differentiated PC-12 cells. The inhibition of NF-kappaB nuclear translocation with the cell membrane-permeable peptide SN-50 prevented the increase in K(V)3.4 protein and transcript expression. In addition, the SN-50 peptide was able to block Abeta(1-42)-induced increase in K(V)3.4 K(+) currents and to prevent cell death caused by Abeta(1-42) exposure. Finally, BDS-I produced a similar neuroprotective effect by inhibiting the increase in K(V)3.4 expression. As a whole, our data indicate that K(V)3.4 channels could be a novel target for Alzheimer's disease pharmacological therapy.

VARIABLE OUTCOME OF PHOTODYNAMIC THERAPY FOR CHOROIDAL NEOVASCULARIZATION ASSOCIATED WITH CHOROIDAL NEVUS

PURPOSE

To report five cases of classic choroidal neovascularization (CNV) associated with choroidal nevus treated with photodynamic therapy (PDT) with verteporfin.

METHODS

The patients underwent an ophthalmologic evaluation, including fluorescein angiography and indocyanine green angiography. Clinical and angiographic data were retrospectively analyzed to evaluate visual acuity outcomes and both clinical evolution and angiographic evolution.

RESULTS

Two patients presented with subfoveal CNV, and three had juxtafoveal CNV. The mean follow-up was 25.8 months. Visual outcomes were extremely variable. Indeed, best-corrected visual acuity decreased in three eyes, stabilized in one case, and improved in the other case. The number of PDT sessions necessary to obtain CNV stabilization with cessation of fluorescein leakage varied from one to six.

CONCLUSION

Bearing in mind that both the natural history and the post-PDT outcome may be extremely variable, further studies are needed to assess the real benefit of PDT for classic CNV secondary to choroidal nevus.

Segregation of two endocannabinoid-hydrolyzing enzymes into pre- and postsynaptic compartments in the rat hippocampus, cerebellum and amygdala

Fatty acid amide hydrolase (FAAH) and monoglyceride lipase (MGL) catalyse the hydrolysis of the endocannabinoids anandamide and 2-arachidonoyl glycerol. We investigated their ultrastructural distribution in brain areas where the localization and effects of cannabinoid receptor activation are known. In the hippocampus, FAAH was present in somata and dendrites of principal cells, but not in interneurons. It was located mostly on the membrane surface of intracellular organelles known to store Ca(2+) (e.g. mitochondria, smooth endoplasmic reticulum), less frequently on the somatic or dendritic plasma membrane. MGL immunoreactivity was found in axon terminals of granule cells, CA3 pyramidal cells and some interneurons. In the cerebellum, Purkinje cells and their dendrites are intensively immunoreactive for FAAH, together with a sparse axon plexus at the border of the Purkinje cell/granule cell layers. Immunostaining for MGL was complementary, the axons in the molecular layer were intensively labelled leaving the Purkinje cell dendrites blank. FAAH distribution in the amygdala was similar to that of the CB(1) cannabinoid receptor: evident signal in neuronal somata and proximal dendrites in the basolateral nucleus, and hardly any labelling in the central nucleus. MGL staining was restricted to axons in the neuropil, with similar relative signal intensities seen for FAAH in different nuclei. Thus, FAAH is primarily a postsynaptic enzyme, whereas MGL is presynaptic. FAAH is associated with membranes of cytoplasmic organelles. The differential compartmentalization of the two enzymes suggests that anandamide and 2-AG signalling may subserve functional roles that are spatially segregated at least at the stage of metabolism.

Luxated intraocular lens fixation using anterior chamber slipknot of the haptic to the sclera: a simple procedure to fixate intraocular lens to the sclera

PURPOSE

To describe a technique for suturing a luxated intraocular lens (IOL) in the vitreous cavity directly to the ciliary sulcus using intraocular slipknot without IOL extraction.

DESIGN

Noncomparative interventional case series.

MATERIALS AND METHODS

A three-port vitrectomy was performed in all cases. According to the Lewis procedure, two scleral flaps and relative sclerectomies were performed at 3 and 9 o'clock position. IOL was rescued from vitreous cavity by means of perfluorocarbon and stabilized in anterior chamber by intravitreal forceps. Corneal endothelium was preserved by a dispersive ophthalmic viscosurgical device coating. Double armed 10-0 polypropylene was introduced into the vitreous cavity through the 9 o'clock sclerotomy incision and both the needles were passed out of the eye by the 3-o'clock position sclerotomy, guided by a bent 27-gauge needle 1.5 mm from the limbus. Hooking the slipknot around the haptics of the IOL in the anterior chamber by means of vitreous forceps, the 10-0 polypropylene was pulled so that the IOL haptic was fixated onto the sulcus. The same procedure was used to fixate the opposite haptic to the ciliary sulcus at the opposite position.

RESULTS

In all four cases, the IOL fixated stably and remained well positioned. No significant intraoperative or postoperative complications occurred.

CONCLUSIONS

This technique enables secure fixation of the luxated IOL in the vitreous without extracting it.

Choroidal neovascularization secondary to vitrectomy for idiopathic epiretinal membrane: report of an unusual case

PURPOSE

Epiretinal membranes (ERM) are a common finding in old patients. Pars plana vitrectomy is effective for removing ERM from the macula, but some postoperative complications are relatively frequent. In the present report, we describe a 73-year-old man in whom extrafoveal choroidal neovascularization developed four months after surgery.

METHODS

Choroidal neovascularization was treated by argon laser photocoagulation.

RESULTS

Six months after treatment, the choroidal neovascularization was obliterated, with no recurrence of ERM.

CONCLUSIONS

Choroidal neovascularization can be an unusual complication of ERM surgery, and should be suspected in case of poor visual outcome or recurrence of symptoms.

Corneal interactive programmed topographic ablation customized photorefractive keratectomy for correction of postkeratoplasty astigmatism

OBJECTIVE

This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation [CIPTA], LIGI, Taranto, Italy), which, by transferring programmed ablation from the corneal topograph to a flying-spot excimer laser, provides customized laser ablation for correction of postkeratoplasty astigmatism.

DESIGN

Noncomparative consecutive interventional case series.

PARTICIPANTS

Ten eyes of 10 patients with a mean age of 41.4 years (range, 26-64) had CIPTA-guided photoastigmatic refractive keratectomy (PARK) at the Clinica Oculistica of Bari (Italy). Two patients were treated for hyperopic astigmatism and eight for myopic astigmatism. All the patients had irregular astigmatism after penetrating keratoplasty. OPERATION: Topography was acquired by a corneal topograph (Orbscan II, Orbtek, Inc., Salt Lake City, UT). This, together with refractive data, was processed to obtain a customized altimetric ablation profile that was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL).

MAIN OUTCOME MEASURES

Data on uncorrected (UCVA) and best-corrected (BCVA) visual acuity, predictability, stability of refraction, and any complications were analyzed.

RESULTS

Mean follow-up was 8.4 months (range, 6-12; SD 2.4). At the last postoperative examination, seven eyes (70%) had a UCVA superior to 20/40. Three eyes (30%) had a UCVA of 20/20. Five eyes (50%) were within 0.50 diopters (D) of attempted correction in the spherical equivalent, and eight eyes (80%) within 1 D. Index of success of astigmatic correction was 0.19. All the eyes (100%) gained Snellen lines of BCVA. We did not observe any decentration and/or haze after PARK treatment performed in this study.

CONCLUSIONS

The combination of topographic data with computer-controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism after penetrating keratoplasty.

Topography-driven excimer laser for the retreatment of decentralized myopic photorefractive keratectomy

OBJECTIVE

This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation, CIPTA, LIGI, Taranto, Italy), which, by transferring programmed ablation from the corneal topograph to a flying-spot excimer laser, provides customized laser ablation for correction of postmyopic photorefractive keratectomy (PRK) decentrations.

DESIGN

Noncomparative consecutive case series.

PARTICIPANTS

Thirty-two eyes of 32 subjects with a mean age of 35 years (range, 19-49; standard deviation [SD], 7.9) had CIPTA-guided PRK at the Clinica Oculistica of Bari University (Italy). All the subjects had irregular astigmatism after postmyopic PRK because of clinically significant, decentered treatments of more than 1 mm. OPERATION: Individual topographies were acquired by a corneal topograph (Orbscan II, Orbtek, Inc., Salt Lake City, UT). These, together with refractive data, were processed to obtain a customized altimetric ablation profile that was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL).

MAIN OUTCOME MEASURES

The topographic study of centration and data on uncorrected (UCVA) and best-corrected (BCVA) visual acuity, predictability, and stability of refraction, and any complications, were analyzed.

RESULTS

Mean follow-up was 10.3 months (range, 4-18 months; SD, 5.8). At the last postoperative examination, 29 eyes (90.6%) had a UCVA superior to 20/40. Nineteen eyes (59.4%) had a UCVA of 20/20. Twenty-two eyes (68.75%) were within 0.50 diopters (D) of attempted correction in the spherical equivalent and 28 eyes (87.5%) were within 1 D. The index of success of astigmatic correction was 0.15. No eye lost Snellen lines of BCVA, whereas 18 eyes (56.25%) gained Snellen lines. Postoperative topographies revealed well-centered treatments.

CONCLUSIONS

The combination of topographic data with computer controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism after postmyopic PRK decentrations.

Protein oxidation and lens opacity in humans

PURPOSE

Oxidative damage to lens proteins is a major factor leading to cataract formation. It is of pathogenic importance to determine a threshold of protein oxidation over which opacification of the lens takes place.

METHODS

Sixty-two lenses extracted from patients affected by idiopathic senile, diabetic, or myopic cataract were studied. Clear lenses were obtained from subjects undergoing enucleation (n = 10) or vitrectomy for giant retinal tears (n = 9), and were age- and sex-matched to those with cataract. The content of carbonyls and sulfhydryls (P-SH) in proteins in the lens was assessed using spectrophotometric assay.

RESULTS

An age-associated inverse relation (P < 0.01) was noted in the content of P-SH, the concentrations of which were also inversely related (P < 0.03) to the content of protein carbonyls. These changes were more pronounced in cataracts than in clear lenses and in diabetic and myopic cataracts when compared with senile cataracts. The drop of P-SH concentration occurred earlier in diabetic and in myopic cataracts than in senile cataracts. The accumulation of protein carbonyls > 2 nmol/mg protein and the decrease of P-SH below 12 to 10 nmol/mg protein were always accompanied by lens opacification.

CONCLUSIONS

Idiopathic senile, diabetic, and myopic cataractogenesis appear to be dependent on oxidative damage to lens proteins. This damage occurs earlier in myopic and diabetic patients. Values of P-SH below and protein carbonyls above their specific threshold were found to be predictive for the presence of cataract. Because increased oxidation was observed in clear lenses removed from myopic and diabetic subjects, oxidation may be involved in the pathogenesis of these forms of human cataract.

Topography-driven photorefractive keratectomy: results of corneal interactive programmed topographic ablation software

OBJECTIVE

This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation (CIPTA) LIGI, Taranto, Italy) which, by transferring programmed ablation from the corneal topography to a flying-spot excimer laser, provides customized laser ablation.

DESIGN

Noncomparative consecutive case series.

PARTICIPANTS

Forty-two eyes of 34 subjects with a mean age of 33.9 (range, 20-54) had CIPTA at the Cattedra di Ottica Fisiopatologica of Bari (Italy). Twenty-eight eyes were treated for hyperopic astigmatism and 14 for myopic astigmatism. All the subjects had irregular astigmatism. OPERATION: Topography was acquired by a corneal topography mapping system (Orbscan, Orbtek, Inc., Salt Lake City, UT). These data were processed to obtain a customized altimetric ablation profile, which was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL).

MAIN OUTCOME MEASURES

Data on uncorrected (UCVA) and best-corrected visual acuity (BCVA), predictability, and stability of refraction and any complications were analyzed.

RESULTS

Mean follow-up was 13.2 months. At the last postoperative examination, 26 eyes (92.8%) in the hyperopic group and 12 eyes (85.7%) in the myopic group had an UCVA superior to 20/40. Twelve hyperopic eyes (42.8%) and five myopic eyes (35.7%) had a UCVA of 20/20. All patients fell between 1 diopter of attempted correction in the spherical equivalent. Only 1 (2.4%) of the 42 eyes, belonging to the hyperopic group, lost 1 Snellen line of BCVA. We did not observe any decentration and/or haze after photorefractive keratectomy treatment or any irregularity in the flap-stroma interface in the three laser in situ keratomileusis operations performed in this study.

CONCLUSIONS

The combination of topographic data with computer-controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism due to different causes.

Oxidative retinal products and ocular damages in diabetic patients

Several evidences suggest a retinal participation to the genesis of diabetic eye complications by means of an increased free radical production at this level. However, no direct proof exists that this happens in humans in vivo. Therefore, the concentrations of malondialdehyde (MDA), carbonyl and sulfhydryl (P-SH) proteins, and vitamin E have been assessed in the subretinal fluid (SF) of patients affected by retinal detachment. Diabetic (n = 19) and nondiabetic (n = 21 ) subjects with comparable age, degree of myopia, and duration of the retinal detachment were considered. A control group of n = 7 subjects was included. The SF was collected after drainage during surgery. The concentrations of total proteins, P-SH, and carbonyl proteins were determined with spectrophotometric methods; the levels of MDA and vitamin E were measured by HPLC. The protein concentration in SF did not differ among groups. A higher concentration of MDA (p < .01) and carbonyl proteins (p < .02) were found in diabetic compared to nondiabetic subjects. Diabetic patients also showed a lower content of P-SH (p < .002) and vitamin E (p < .001) compared to nondiabetic subjects. All these parameters were more markedly altered in patients affected by proliferative diabetic retinopathy and significantly differed between patients and control subjects. In conclusion, oxidative events are associated with retinal detachment in humans. This evidence strongly suggests that the retina is a source of free radical production under certain conditions, such as diabetes.

Role of lipid peroxidation in the pathogenesis of myopic and senile cataract

AIMS/BACKGROUND

Increased production of free radicals, consumption of antioxidant, and oxidation of unsaturated lipids have been observed recently in cataractous lenses and active participation of the retina in human cataractogenesis has been proposed. To verify this hypothesis, the total (GSH) and oxidised (GSSG) glutathione concentrations were assayed in the lens and the malondialdehyde (MDA) levels assayed in the vitreous and in the lens of normal controls and patients with senile or myopic cataract.

METHODS

The study was conducted on 34 lenses (nucleus and epinucleus) (nine clear lenses, 14 lenses with idiopathic senile cataract, and 11 lenses affected by severe myopic cataract) and vitreous of 19 (seven non-myopic, seven myopic, and five control) subjects. Glutathione determination was performed following the method of Reed, while malondialdehyde was assayed using a modification of the method of Dahle.

RESULTS

Cataractous lenses showed a decreased content of GSH and increased concentration of GSSG compared with clear lenses. A higher oxidative consumption of GSH was found in myopic cataracts compared with senile ones. Also, increased levels of MDA were observed both in cataractous lenses and in the vitreous of myopic patients compared with the control and the senile ones.

CONCLUSION

The observed alterations strongly suggest that retinal lipid peroxidation might play a key role in human cataractogenesis, especially in the myopic type.

High doses of L-carnitine in acute myocardial infarction: metabolic and antiarrhythmic effects

Fatty acids accumulate in the muscle cells in some carnitine deficiency syndromes due to a variety of genetic defects in intermediary metabolism. L-Carnitine administration may relieve this excess by transporting acyl compounds out of the cell as acylcarnitine. Similar fatty acid accumulation occurs during myocardial ischaemia because of the decreased rate of beta-oxidation, and this has been put forward as a cause of ventricular arrhythmias. This study was carried out to investigate whether administration of high doses of i.v. L-carnitine in patients with acute myocardial infarction could increase urinary excretion of acylcarnitine and reduce early ventricular arrhythmias. Fifty-six patients suffering from acute myocardial infarction, admitted to the Coronary Unit between 3 and 12 h after the onset of symptoms, were included in the study. The design of the study was double blind, parallel and placebo controlled. Allocation of treatment to patients was done randomly after stratification (time from onset of pain and site of infarction). The first group (28 patients) received intravenous L-carnitine at a dose of 100 mg kg-1 b.w. every 12 h for 36 h while the second group (28 patients) received placebo intravenously. Immediately before starting treatment two blood samples were taken (at 5-min intervals) and a further 16 samples were taken at regular intervals over the following 48 h. Patients' urine was collected over the same period of time. Concentrations of free carnitine, short chain acylcarnitine esters and long chain acylcarnitine esters in serum and urine were measured.(ABSTRACT TRUNCATED AT 250 WORDS)