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Purpose Dyslexia is a reading disorder with neurological deficit of the magnocellular pathway. The aim of our study was to evaluate the functionality of the magnocellular-Y (M-Y) retinal ganglion cells in adult dyslexic subjects using steady-state pattern electroretinogram and frequency doubling perimetry. Methods Ten patients with dyslexia (7 females and 3 males), mean age 28.7 ± 5.9 years, and 10 subjects without dyslexia (6 females and 4 males), mean age 27.8 ± 4.1 years, were enrolled in the study and underwent both steady-state pattern-electroretinogram examination and frequency doubling perimetry. Results There was a significant difference in the amplitude of the steady-state pattern electroretinogram of the dyslexic group and the healthy controls (0.610±0.110 μV vs 1.250±0.296 μV; p=0.0001). Furthermore, in the dyslexic group we found a significant difference between the right eye and the left eye (0.671±0.11 μV vs 0.559±0.15 μV; p=0.001). With frequency doubling perimetry, the pattern standard deviation index increased in dyslexic eyes compared to healthy controls (4.40±0.81 dB vs 2.99±0.35 dB; p=0.0001) and in the left eye versus the right eye of the dyslexic group (4.43±1.10 dB vs 3.66±0.96 dB; p=0.031). There was a correlation between the reduction in the wave amplitude of the pattern electroretinogram and the simultaneous increase in the pattern standard deviation values (r=0.80; p=0.001). This correlation was also found to be present in the left eye (r=0.93; p

Costantino Schiavi, Filippo Tassi, Alessandro Finzi, Ernesto Strobbe, Mauro Cellini Department of Experimental, Diagnostic, and Specialty Medicine, Ophthalmology Service, University ofBologna, Bologna, Italy Background: Steady-state pattern electroretinogram (PERG) and frequency doubling technology (FDT) perimetry can be used to selectively investigate the activity of the M-Y ganglion cells in adult anisometropic amblyopes. Methods: Fifteen normal subjects (mean 27.8±4.1 years) and 15 adults with anisometropic amblyopia (mean 28.7±5.9 years) were analyzed using steady-state PERG and FDT. Results: The amplitude of steady-state PERG was significantly different not only among the control group and both the amblyopic eye (P=0.0001) and the sound eye group (P=0.0001), but also between the latter two groups (P=0.006). The difference in FDT mean deviation was statistically significant not only between the control group and amblyopic eye group (P=0.0002), but also between the control group and the sound eye group (P=0.0009). The FDT pattern standard deviation was significantly higher in the control group rather than in the amblyopic eye (P=0.0001) or the sound eye group (P=0.0001). A correlation was found between the reduction in PERG amplitude and the increase in FDT-pattern standard deviation index not only in amblyopic (P=0.0025) and sound (P=0.0023) eyes, but also in the healthy control group (P=0.0001). Conclusion: These data demonstrate that in anisometropic amblyopia, there is an abnormal functionality of a subgroup of the magnocellular ganglion cells (M-Y), and the involvement of these cells, together with the parvocellular pathway, may play a key role in the clinical expression of the disease. Keywords: pattern electroretinogram, frequency doubling technology perimetry, retinogeniculate pathways, amblyopia

Corrado Gizzi, Mauro Cellini, Emilio C Campos Department of Experimental, Diagnostic and Speciality Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy Purpose: To investigate the biomechanical response of the cornea, lamina cribrosa (LC), and prelaminar tissue (PT) to an acute intraocular pressure (IOP) increase in patients with markedly asymmetrical glaucoma and in healthy controls.Patients and methods: A total of 24 eyes of 12 patients with markedly asymmetrical primary open-angle glaucoma (POAG) and 12 eyes of 12 healthy patients were examined with spectral-domain optical coherence tomography (SD-OCT) and ocular response analyzer (ORA) at baseline and during acute IOP elevation by means of an ophthalmodynamometer. The displacement of the LC and PT and the change in corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated.Results: Following a mean IOP increase of 12.3±2.4 mmHg, eyes with severe glaucoma demonstrated an overall mean anterior displacement of the LC (-6.58±26.09 µm) as opposed to the posterior laminar displacement in eyes with mild glaucoma (29.08±19.28 µm) and in healthy eyes (30.3±10.9; p≤0.001 and p=0.001, respectively). The PT displaced posteriorly during IOP elevation in all eyes. The CH decreased in eyes with severe glaucoma during IOP elevation (from 9.30±3.65 to 6.92±3.04 mmHg; p=0.012), whereas the CRF increased markedly in eyes with mild glaucoma (from 8.61±2.30 to 12.38±3.64; p=0.002) and in eyes with severe glaucoma (from 9.02±1.48 to 15.20±2.06; p=0.002). The increase in CRF correlated with the anterior displacement of the LC in eyes with severe glaucoma.Conclusion: Eyes with severe glaucoma exhibited a mean overall anterior displacement of the anterior laminar surface, while eyes with mild glaucoma and healthy eyes showed a posterior displacement of the LC during IOP elevation. The CH decreased significantly from baseline only in eyes with severe glaucoma, but the CRF increased significantly in all glaucomatous eyes. The CRF increase correlated with the anterior displacement of the LC in eyes with severe glaucoma. Keywords: glaucoma, lamina cribrosa, cornea, hysteresis, ophthalmodynamometer, biomechanics, asymmetry&nbsp

Stefano Sebastiani, Michela Fresina, Mauro Cellini, Emilio C Campos Department of Experimental, Diagnostic, and Specialty Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy Purpose: To evaluate early changes in multifocal electroretinogram (mfERG) and subclinical aqueous humor flare and cellularity in patients receiving hydroxychloroquine (HCQ) as treatment for rheumatoid arthritis.Methods: Ten patients receiving treatment with HCQ and no ophthalmic symptoms were enrolled. After complete ocular examination, mfERG and laser flare-cell photometry were performed. Patients were also divided into two subgroups with HCQ cumulative dose (CD) higher or lower than 500 g. Results obtained were compared with a control group of ten healthy subjects and statistical analysis was performed.Results: In patients receiving HCQ treatment, mfERG P1-wave in ring 2 showed a significant reduction in amplitude and a significant increase in latency compared to healthy control subjects, respectively resulting in 1.143 µV vs 1.316 µV (P=0.040) and 38.611 ms vs 36.334 ms (P=0.024). These changes are highly related to CD. Furthermore, when using the laser flare-cell photometry, a significant increase in aqueous humor flare and cellularity was shown in patients with CD higher than 500 g, resulting in a mean value of 14.4 ph/ms compared to 8.1 ph/ms in patients with CD lower than 500 g (P=0.0029). These reports appear highly related to CD (P=0.001). Receiver operating characteristic curve analysis showed mfERG P1-wave amplitude in ring 2 as the most sensitive value in detecting early HCQ-related retinopathy.Conclusion: MfERG was shown to be a very sensitive test in detecting early retinal toxicity and should be used for the screening of patients receiving HCQ treatment. Although less sensitive, laser flare-cell photometry can provide further information to evaluate early toxic retinal cell damage. Keywords: hydroxychloroquine, multifocal electroretinography, laser flare-cell photometry, rheumatoid arthritis

Retinitis pigmentosa (RP) is an inherited retinal disorder clinically characterized by a pale, waxy optic nerve head, attenuated retinal blood vessels, and bone spicule pigment in the retina. Hemodynamic studies have demonstrated that RP is associated with a reduction in the retinal and choroidal blood flow. Retinal hemodynamic impairment is also present in early stages of RP, and various hypotheses have been advanced as to the cause. The authors studied 20 patients, 12 males and 8 females, aged 26–42 years (mean 35.1 years) and affected by simplex RP. The patients had a visual acuity of 0.9 ± 0.1, visual field mean defect of –6.52 ± 3.58 dB, and b-wave electroretinogram amplitude of 260.08 ± 8.24 µV. An increase in plasma levels of endothelin-1 (ET-1) was found: 1.910 ± 0.317 pg/mL versus 1.180 ± 0.210 pg/mL in non-RP controls (p < 0.02). Moreover both an ocular and systemic vascular impairment was detected by means of color Doppler imaging and laser Doppler flowmetry performed during a cold pressor test. We found a correlation between the increase of ET-1 plasma levels in RP and the decrease of peak systolic velocity in the ophthalmic artery (p < 0.03) and in the posterior ciliary arteries (p < 0.006). It is thought that an increase of ET-1 and retinal oxygen levels in RP could lead to vasoconstriction and a decrease of the retinal blood flow, worsening the abiotrophic process.

We applied a specific cytochemical reaction to characterize the glycoconjugates produced by goblet and non-goblet epithelial cells of normal human conjunctiva. For this purpose we utilized the lectins, proteins of vegetal origin, which are extremely sensitive in binding glycosidic residues. In particular, we used WGA, PNA, SBA and ConA conjugated with colfoidal gold as ultrastructural marker for Transmission Electron Microscopy. This technique allowed us also to perform a quantitative analysis, by counting colloidal gold particles present on mucus granules. In this way we analyzed the content both of goblet and non-goblet epithelial cells. In the former, WGA, PNA, SBA and ConA receptors, here reported in decreasing density, were present. In the latter WGA was always positive, SBA and PNA sometimes were negative, ConA was always negative. We speculate the different contribution to mucus production by these two sources may be important in evaluating tear film stability alterations occurring in those diseases in which non-goblet epithelial cell vesicles increase.

The purpose of this study is to evaluate the intraocular inflammation at a sub clinical level, in patients suffering from Sjogren's syndrome (SS-I) and Rheumatoid Arthritis (RA), to relate it with the ocular surface status and to verify the diagnostic performance of the method. Twenty-eight patients suffering from SS-I, 31 patients suffering from RA and 31 normal subjects matched in age and gender were included in the study. A Kowa 500F laser cell flare meter was utilized to quantify the aqueous cells and flare in vivo, ocular surface inflammation was graded by conjunctival cytology and dosage of serum albumin in tears, eye dryness was scored with Tear Function Index. All data resulted significantly different in both SS-I and RA patients vs. control group and also different comparing SS-I vs. RA patients group, except for the Flare values. A blood-aqueous barrier breakdown occurs either in SS-I and RA patients; the degree of the damage is related with ocular surface inflammation and dryness. We recommend the aqueous flare be analysed in those rheumatic patients where an ocular surface inflammation has been documented.

Purpose To evaluate biomechanical properties in eyes of patients affected by primary open angle glaucoma (POAG) with marked asymmetrical defects by means of Ocular Response Analyzer (ORA) and Spectral Domain OCT with Enhanced Depth Imaging (EDI SD-OCT) function. Methods We studied 20 patients (mean age: 56 ± 12) with asymmetrical POAG. One eye was classified as mild glaucoma (MG) and the sound eye as severe glaucoma (SG) by visual field indexes: MD −4.21 ± 1.51 vs −16.56 ± 5.76 dB; p = 0.011 and PSD 3.54 ± 0.87 vs 10.95 ± 3.51 dB; p = 0.007. An EDI SD-OCT centered on the optic nerve head and an ORA examination were performed on each eye of every subject before and during a IOP increase of 12.5 ± 2.1 mm/Hg induced by a compression of the globe with an ophthalmodinamometer. Corneal histeresis (CH), corneal resistence factor (CRF) and laminar displacement (LD) were statistically analyzed by Wilcoxon's rank sum test and Spearman's correlation test considering significant a p

PURPOSE: To study in ocular hypertension (OH) the retinal nerve fibre layer (RNFL) with optical coherence tomography (OCT) and the neuronal function with frequency-doubling technology (FDT) to assess which of the two methods was more sensitive in detecting early glaucomatous damage. Furthermore, a colour Doppler imaging (CDI) of the optic nerve was carried out to highlight any correlation with RNFL thickness and FDT abnormality. MATERIALS AND METHODS: We enrolled 28 ocular hypertensive patients who underwent OCT of the RNFL and FDT. Moreover, we performed a CDI of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs). RESULTS: The patients with OH following OCT revealed a significant thinning in the RNFL as compared to the control group only in the inferior quadrant: 122.250+/-14.091 vs131.750+/-10.729 mum (P

ObjectiveTo evaluate the diagnostic performance of the tests included in primary Sjogren's syndrome (SS-I) diagnostic criteria (Schirmer I, break-up time, vital dye staining) and to compare them with other examinations related to the ocular surface status.MethodsClinical and cytological data were collected from 177 patients (62 SS-1, 56 non-SS autoimmune diseases, 59 Sicca syndrome). Tear tests included: a validated questionnaire on symptoms, Schirmer I, Jones test, Ferning test, BUT, corneal aesthesiometry, tear clearance test, lissamine green staining, impression conjunctival cytology. Data were statistically evaluated and sensitivity, specificity, likelihood ratio (LR+), receiver-operating characteristics (ROC) curves were calculated for each test.ResultsData showed a poor diagnostic performance of Schirmer test I (sensitivity 0.42; specificity 0.76; LR+1.75) and BUT (sensitivity 0.92; specificity 0.17; LR+1.11) (area under the curve in ROC analysis 0.70). Lissamine green staining exhibited the best performance (sensitivity 0.63; specificity 0.89; LR+5.72) but the result could be distorted by an incorporation bias.ConclusionsOur data suggest to implement the items for ocular signs and symptoms contained in many SS-I diagnostic criteria with the use of a validated questionnaire, performance of Jones test, corneal aesthesiometry measurement, and tear clearance rate evaluation.

Background: Recent studies have shown how the topical application of nerve growth factor (NGF) has led to the repair of neurotrophic corneal ulcers with recovery of corneal surface sensitivity. The biological effect of NGF, at a corneal level, is mediated by the presence of specific receptors localized on the surfaces of the corneal and conjunctival cells. Objectives: To evaluate the efficacy of NGF to promote corneal wound healing after cataract surgery. Methods: Thirty patients were divided into two groups (groups A and B) and underwent cataract surgery. After surgery patients in group A received 1 drop of NGF solution (10 µg of NGF dissolved in 50 µl of saline solution, 0.9% of sodium chloride) in the conjunctival fornix every 2 h (from 6 a.m. to 12 p.m.) for 2 weeks and then 4 times a day for another week. The patients in group B received 1 drop of hyaluronic acid 0.2% eye drops in the conjunctival fornix every 2 h for 2 weeks and then 4 times a day for another week. With optical coherence tomography (OCT) we evaluated the corneal thickness at the side of the surgical wound, the endothelial cell count and the incision line in the stroma 1, 7 and 21 days after surgery. Results: Before surgery in group A and in group B, the endothelial cell count was 2,607.4 ± 261.0 versus 2,602.0 ± 266.6 (p < 0.991), and the temporal cornea edge thickness was 639.2 ± 24.7 versus 644.4 ± 31.9 µm (p < 0.605), respectively. At 24 h after surgery, the results were: 2,523.2 ± 280.5 versus 2,528.2 ± 235.7 (p < 0.988) and 804.4 ± 29.5 versus 802.6 ± 35.0 µm (p < 0.953). After 7 days the cell count values were: 2,511.4 ± 229.8 versus 2,490.0 ± 230.4 (p < 0.361) and corneal thickness 713.6 ± 16.5 versus 771.4 ± 36.5 µm (p < 0.047). Finally, 21 days after surgery, the number of endothelial cells was 2,540.2 ± 237.3 versus 2,503.4 ± 224.5 (p < 0.382) and corneal thickness 645.2 ± 22.6 versus 704.2 ± 11.8 µm (p < 0.002). In the patients treated with NGF, on day 21, we found with OCT a complete wound healing, and the stromal incision was not visible. Conclusions: This clinical experience shows that the topical administration of NGF is effective in accelerating the healing of surgical corneal wounds.

Trabecular meshwork (TM) cells are now considered to play an active role in the aqueous outflow mechanism, since they exhibit smooth muscle-like contractile properties. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, has been proposed to play a role in the local regulation of aqueous outflow and intra-ocular pressure control. We propose an in vitro culture model as a method in the study of ET-1-induced human trabecular meshwork (HTM) cell contractility. Experiments were performed on semi-confluent HTM cells (primary cultures established from normotensive human donor eyes) at the 2nd passage with PBS as control, ET-1, sarafotoxin 6c (a selective endothelin B receptor agonist) and Y-27632 (a selective inhibitor of rho-associated kinase). The contractile status of the cells was evaluated by a morphometric analysis of the cell area, assuming that HTM cells in culture are able to reduce their area as a consequence of cytoskeletal contraction rather than regulatory volume decrease. Our data indicate that image analysis of the HTM cell area can be a reliable method in the study of TM cell contractility, since it utilizes human cells and offers versatile opportunities for the pharmacological evaluation of drugs controlling HTM cell status.

Purpose. To assess endothelin-1 (ET-1) plasma levels, choroidal thickness, and aqueous flare in patients with early stage retinitis pigmentosa (RP) and to search for possible correlations.Methods. We compared 24 RP patients with 24 healthy controls. Choroidal thickness and aqueous flare were measured, respectively, by using a spectral domain optical coherence tomography and a laser flare-cell meter, whereas plasma samples were obtained from each patient to evaluate ET-1 plasma levels.Results. Notably, RP subjects showed significantly increased ET-1 plasma levels and reduced choroidal thickness compared with controls:2.143±0.258versus1.219±0.236 pg/mL,P<0.002, and226.75±76.37versus303.9±39.87 μm,P<0.03, respectively. Higher aqueous flare values were also demonstrated in RP compared to controls: in detail,10.51±3.97versus5.66±1.29photon counts/ms,P<0.0001. Spearman’s correlation test highlighted that the increase of ET-1 plasma levels was related with the decrease of choroidal thickness (r=-0.702;P<0.023) and the increase of aqueous flare (r=0.580;P<0.007).Conclusions. Early stage RP patients show a breakdown of blood-ocular barrier and increased ET-1 plasma levels and these findings may contribute to the reduction of choroidal thickness.

Alessandro Finzi, Ernesto Strobbe, Filippo Tassi, Michela Fresina, Mauro Cellini Department of Specialized, Diagnosticand Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy Background: To assess the sensitivity and specificity of hemifield pattern electroretinogram (HF-PERG) for detecting early retinal ganglion cell (RGC) damage in ocular hypertensive (OH) patients.Methods: Fifty-two OH patients (mean age 56±9.6 years) with an intraocular pressure (IOP) >21 mmHg were assessed. All subjects underwent HF-PERG, optical coherence tomography (OCT), and frequency doubling technology (FDT) visual field.Results: OH patients showed a significant increase of peak-time of the N95 (P=0.027) compared to controls. The amplitude of the N95 of the lower and upper HF-PERG showed significant differences (P=0.037 and P=0.023, respectively) between the two groups. A significant intraocular (P=0.006) and interocular (P=0.018) asymmetry of N95 amplitude was found. Receiver operating characteristic (ROC) curve analysis revealed a sensitivity of 93% for the N95 of the lower HF-PERG, whereas full-field pattern electroretinogram (PERG) N95 peak-time had a sensitivity of 88%. In OH patients, we found a thinning of OCT - retinal nerve fiber layer (RNFL), especially in the superior and inferior quadrant, although not statistically significant, and a significantly higher FDT pattern standard deviation (FDT-PSD; P=0.001). In the OCT-RNFL inferior quadrant, a sensitivity of 82% was recorded. Finally, the sensitivity of the FDT-PSD was 92%.Conclusion: Our study shows that HF-PERG is a very sensitive test for detecting early damage of the RGC. Keywords: ocular hypertension, hemifield pattern electroretinogram, optical coherence tomography, frequency doubling technology&nbsp

Purpose To assess which is the most sensitive and specific exam for detecting an early retinal ganglion cells (RGC) damage between hemifield test pattern electroretinogram (PERG HF) and the posterior pole asymmetry analysis with optical coherence tomography (OCT-PPAA) in ocular hypertensive patients (OH). Methods Forty-two OH patients (mean age of 56.0±5.6 yrs.) with an intraocular pressure (IOP)>21mmHg and forty healthy controls (mean age of 55.2±6.4 yrs.) with IOP

PURPOSE: The aim of this study was to assess corneal hysteresis (CH) and corneal resistance factor (CRF) in healthy subjects, to evaluate the relationship with age, and to investigate possible associations with other ocular factors. METHODS: Four hundred Italian subjects (male-to-female ratio, 168:232; mean age, 58.8 ± 17.2 years) were included and divided into 5 subgroups based on age. CH, CRF, and central corneal thickness (CCT) were measured by using the Ocular Response Analyzer and the integrated handheld pachymeter, and their relationship with gender, age, and ocular factors was evaluated. RESULTS: The mean CH, CRF, and CCT values were 10 ± 1.6 mm Hg, 10.5 ± 1.7 mm Hg, and 532.2 μm, respectively. Women had a lower mean CH (9.9 vs. 10.2 mm Hg; P = 0.04) and CRF (10.3 vs. 10.8 mm Hg; P = 0.03) than did men. The youngest subjects had the highest CH (11.2 ± 1.5 mm Hg), whereas the oldest patients had the lowest CH values (9 ± 1.1 mm Hg). No significant differences in CRF were observed between age groups. CH and CRF showed a positive correlation (r = 0.58; P < 0.001), and both had a positive association with CCT (r = 0.27; P < 0.001 and r = 0.57; P < 0.001, respectively). The strongest correlations were observed between Goldmann-correlated intraocular pressure (IOP) and corneal-compensated IOP (r = 0.68; P < 0.001) and between Goldmann-correlated IOP and Goldmann applanation tonometry (r = 0.88; P < 0.001). CONCLUSIONS: Gender and advancing age may influence corneal biomechanical properties. In our population, CH decreased with aging, and men demonstrated a higher CH and CRF than women did. Further, CH, CRF, and CCT were significantly related.

Objective To evaluate the efficacy of subconjunctival interferon-α for the treatment of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma. Design Small, noncomparative, interventional case series. Participants Five patients with histologically proven conjunctival MALT lymphoma were studied prospectively. Methods Patients were given 1,500,000 international units (IU) of interferon-α (IFN-α) (Roferon-A) subconjunctivally inside the lesion, three times a week for four weeks. If there was even a minimal response, a further cycle of 1,000,000 IU three times a week for four weeks was administered. Patients received a maintenance dose of 1 million IU, every 15 days for 4 times, after clinical resolution of the lesion. Main outcome measures Patients were followed clinically, with slit lamp examination, for evidence of tumor disappearance or recurrence. Results Complete response was obtained in all patients. The lesion resolved completely by the eighth week. Four patients did not show any local recurrence with a median follow-up of 21 months (12–36 months). One patient presented with a recurrence after 11 months, in association with systemic lymphoma progression. Conclusions Local chemotherapy with IFN-α seems to be an effective treatment modality, alternative to radiotherapy, for conjunctival MALT lymphomas.

Purpose: To report the diagnostic and therapeutic data obtained from 1,200 patients suffering from dry eye symptoms not due to Sjögren’s syndrome or other auto-immune diseases. Methods: Schirmer test I, ferning test, breakup time, vital dye staining, brush and imprint cytology were performed; data were grouped into diagnostic profiles, and the therapy was prescribed according to these. Results: Eight diagnostic profiles were identified. Dry eye was diagnosed in 57.1% of patients; the remaining 42.9% were found to suffer from eye discomfort or conjunctivitis of different aetiologies. Conclusions: Subjective symptoms of dryness can hide diseases other than dry eye; combined clinical and laboratory tests are requested to make a diagnosis. Our experience indicates that a therapy prescribed on the basis of diagnostic profiles provides relief in 79.1% of cases.

Purpose: To investigate the interactions occurring at the interface between some currently used vitreous tamponading substances and the ocular tissues, in an early follow-up after surgery. Methods: Adult albino rabbit eyes underwent vitrectomy and were injected intravitreally with silicone oils at 1,000 or 3,000 cSt, fluorosilicone oil and perfluorodecalin. Different morphological techniques (light microscopy, scanning and electron microscopy, immunohistochemistry) were applied. Results: All the tested materials, although non-toxic, penetrate the ocular tissues also at the anterior segment level, and in the long-term follow-up this can yield functional impairment. No massive inflammation has been detected in the zones in contact with the materials, but immunoglobulins and complement fractions are anyway present in the stroma of various tissues and around the droplets of emulsified materials, suggesting a local immune reaction. Conclusions: Data from this study confirmed that a permanent vitreous substitute, showing a perfect biocompatibility, still does not exist. The indication to remove the tamponading substance within 2 months after the surgery emerges from this investigation, confirming previous studies. Despite some negative features, silicone oil still appears the most biocompatible material for vitreous replacement.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelin cells There are reports in the literature that ET-1 plasma levels are raised in low tension glaucoma (LTG). ET-1 plasma concentration and Color Doppler Imaging (CDI) evaluation in ophthalmic and posterior ciliary arteries were measured in 15 LTG patients and in 15 healthy subjects. The blood flow index recorded for the ophthalmic artery in normal subjects was a PSV of 36.646 +/- 6.611 cm/sec with RI of 0.717 +/- 0.019 while in the LTG patients it was 32.961 +/- 3.045 cm/sec (p < 0.003) with RI of 0.789 +/- 0.018 (p < 0.001). For the posterior ciliary arteries in the same two groups, we obtained a PSV of 13.878 +/- 4.149 cm/sec vs 8.720 +/- 1.645 cm/sec (p < 0.001) and an RI of 0.679 +/- 0.039 vs 0.722 +/- 0.024 (p < 0.001). The plasma ET-1 level in normal subjects was 1.720 +/- 0.174 pg while in LTG patients it was 2.947 +/- 0.217 pg (p < 0.001). On the basis of our experience, we think that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self-regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.

The authors investigated the effect of ketanserin 0.5% eye drops on intraocular pressure and orbital blood flow in some healthy volunteers. Ketanserin is a selective antagonist of serotonin S2 receptors; moreover, it produces an α1-blocking effect. It causes a systemic reduction of blood pressure and capillary vasodilatation. Three hours after topical administration of ketanserin 0.5%, the intraocular pressure was decreased by about 14% from the baseline. At the same time, we observed by color Doppler imaging that the mean percent increase in the peak systolic velocity in the ophthalmic artery (OA) was 5.18% (p < 0.161) and 23.18% (p < 0.001) in the posterior ciliary arteries (PCAs). The mean resistance index of the OA was in contrast reduced by 1.16% (p < 0.669) and by 32.14% (p < 0.003) in the PCAs. These data show that ketanserin 0.5% eye drops may be useful not only to decrease intraocular pressure but also to improve blood flow in the PCAs that supply the optic nerve head.

Discomfort eye syndrome (DES) comprises a series of ‘minor’ subjective symptoms in patients where no relevant clinical signs are observed suggesting ocular disease. Our study includes 100 DES patients, excluding video terminal users, selected from the First Aid Service of our Department over two peak periods in both winter and summer time. The Schirmer test I, ferning test, breakup time and conjunctival cytology (scraping and imprint) were performed and data were related to sex, age and air pollution indexes, recorded in the patients’ living zones. Our results demonstrate that: (i) the ocular surface cytology and the analysis of tear film changes provide significant information in those patients where no other clinical signs are evident; (ii) DES symptoms are more frequent in women than in men (ratio about 2:1), both with ages over 51 years; (iii) DES is significantly associated with ocular surface inflammation, as detected by cytological methods, and (iv) ocular surface subclinical inflammation and ocular dryness are related to high concentrations of atmospheric polluters, in both sexes.

Purpose To assess which is the most sensitive and specific exam for detecting early glaucomatous damage in ocular hypertensive patients (OH) among hemifield test pattern electroretinogram (PERG HF), frequency doubling technology (FDT) and optical coherence tomography retinal nerve fiber layer (OCT RNFL). Methods Fifty-two OH patients (mean age of 56±9.6 yrs) with an intraocular pressure (IOP)>21mmHg and 52 healthy controls (mean age of 54.8±10.4 yrs) with IOP

Purpose: The aim of this study was to assess (i) whether pupil dilation with tropicamide influences subfoveal choroidal blood flow, as assessed by continuous laser Doppler flowmetry (LDF) and (ii) if this is the case, whether the effect is due to a haemodynamic response of the drug-induced dilation. Methods: Following the instillation of one drop of 1% tropicamide in one eye of 18 healthy, nonsmoking volunteers (age 20–25 years), the subfoveal choroidal LDF parameters (Vel, Vol and ChBF) were recorded during 30 min, at 3-min intervals under two paradigms: through an artificial pupil (4 mm diameter) placed in front of the cornea (P1) and without this artificial pupil (P2). Results: Tropicamide increased the pupil diameter from 3.3 ± 0.4 mm (mean ± SD) to 8.3 ± 0.4 mm. Full dilation was reached at ∼24 min. During this period of time, linear regression analysis demonstrated that none of the LDF parameters varied significantly (p > 0.05), either under P1 or P2. Based on a group of 12 subjects, the smallest (%) change in the mean value of ChBF (ChBFm) that would be detectable (sensitivity of the method, S) was found to be 2% for P1 and 6% for P2. The average coefficient of variation of ChBFm based on eight measurements during dilation was greater for P2 than for P1 by a factor of approximately 2. Conclusion: Tropicamide had no significant influence on the subfoveal choroidal LDF parameters measured by continuous LDF during pupil dilation. Furthermore, pupil dilation did not affect ChBFm by more than the calculated minimum percentage change of 6% detectable with our method.

To investigate the status of the blood-aqueous barrier and to evaluate the subfoveal choroidal thickness (SCT) in patients with asymptomatic untreated chronic hepatitis C virus (HCV) infection without any anterior or posterior ocular involvement and to search for possible correlations.Observational case-control study.A total of 80 eyes of 20 HCV-positive patients (male-to-female ratio, 12:8; mean age, 46.9±7.23 years) and 20 healthy controls (male-to-female ratio, 10:10; mean age, 48.2±8.71 years) were examined.Participants underwent a complete ophthalmologic examination. Aqueous flare was quantified objectively by using the noninvasive laser flare cell meter FC-500 (Kowa Company Ltd, Tokyo, Japan), whereas SCT was evaluated by using enhanced depth imaging optical coherence tomography (Spectralis OCT; Heidelberg Engineering GmbH, Heidelberg, Germany). A Wilcoxon rank-sum test was performed to compare ocular findings between HCV patients and controls, and correlations were assessed by using the Spearman rank test.Retinal and choroidal thickness and anterior chamber inflammation of HCV patients and healthy controls.Patients with HCV showed significantly higher aqueous flare values (8.37±2.25 photon counts/ms vs. 4.56±1.45 photon counts/ms; P0.0001) and a significantly increased SCT (362.7±46.5 μm vs. 320.25±32.82 μm; P0.0001) than healthy controls. Moreover, subjects with liver fibrosis had higher flare values than those with no significant hepatic fibrosis (9.62±1.99 photon counts/ms vs. 6.97±2.19 photon counts/ms; P = 0.0003) and thicker choroids (379.15±44.75 μm vs. 346.3±43.27 μm; P = 0.024). Statistical analysis revealed that there was a positive correlation between aqueous flare values and SCT in HCV patients (r = 0.69; P0.0001) and between flare and the degree of liver fibrosis (r = 0.67; P = 0.0001).This study showed that impairment of the blood-aqueous barrier and thickened choroids are features of asymptomatic HCV patients, and that choroidal thickness increases as the degree of subclinical inflammation of the anterior chamber increases. Patients with significant liver fibrosis have the highest flare values and the thickest choroids.

Purpose To assess corneal hysteresis (CH) and corneal resistance factor (CRF) in keratoconic eyes before and after corneal cross-linking (CXL) with riboflavin/ultraviolet-A and to evaluate the correlation between these biomechanics values and central corneal thickness (CCT). Methods 22 eyes of 12 patients (mean age 25.3±5.9) were evaluated before and 1, 6 and 12 months after CXL. At each visit best corrected visual acuity (BCVA), CCT , CH and CRF using ocular response analyzer-ORA (Reichert Ophthalmic Instruments, Buffalo, NY) were assessed. Data were analyzed using Friedman and Spearman tests. Results BCVA, expressed in LogMAR, significantly improved 1 year after CXL (0.31±0.05 vs 0.27±0.04, p

Purpose To investigate the status of blood-aqueous barrier and to evaluate the subfoveal choroidal thickness (SCT) in patients with chronic never treated hepatitis C virus (HCV) infection without any anterior or posterior ocular disease. Methods A total of 80 eyes of 20 naive HCV patients (M:F=12:8; mean age: 46.9±7.23 years) and 20 healthy controls (M:F=10:10; mean age: 48.2±8.71) were examined. Partecipants underwent a complete ophthalmologic examination. Aqueous flare was objectively quantified by using the non-invasive laser flare cell meter FC 1000 (Kowa, Tokyo, Japan), while SCT was evaluated by using enhanced depth imaging optical coherence tomography (Spectralis OCT; Heidelberg Engineering GmbH). An unpaired t test with Welch correction was performed to compare flare values and SCT between HCV patients and controls, considering significance a p

Purpose We decided to investigate the effects of an acute induced IOP elevation on the prelaminar tissue and on the lamina cribrosa in glaucomatous eyes and in healthy eyes by means of an high resolution Spectral Domain (SD) OCT. Methods We enrolled 10 patients (mean age 70.2 years) affected by primary open angle glaucoma (POAG) and 10 healthy subjects (mean age 70.8 years) as controls. All the subjects were scanned with a SD-OCT with real-time eye tracking at baseline and in the same exact position during IOP elevation performed with an ophthalmodynamometer. The IOP was measured with a Tono-Pen at baseline and during IOP elevation. The SD-OCT images acquired were processed with a computer graphical suite to determine the prelaminar tissue displacement (PTD) and the laminar displacement in the two groups. An analysis of variance was used for evaluating group differences considering statistically significant a P < 0.05. Results Baseline IOP was significantly different in the two groups, with higher values in patients compared to controls: 18.9(4.3) vs. 15.7(2.6) mmHg (P

The measurement of blood flow in the ocular fundus is of scientific and clinical interest. Investigating ocular blood flow in the choroid may be important to understand the pathogenesis of numerous ocular diseases, such as glaucoma or agerelated macular degeneration (AMD). Laser Doppler flowmetry (LDF) was applied to measure relative velocity, volume and flux of red blood cells in the tissues of human eye. Its main application lies in the possibility of assessing alterations in blood flow early in the course of diseases. The purpose of the present study was to investigate the effect of pupil dilatation with one drop of 1% tropicamide on blood flow in the foveal region of the choroid of the human fundus. The blood flow parameters were measured in 24 eyes during 30 minutes (one measurement in every 3 minutes) after the application of the drop. Since the Doppler parameters depend on the scattering geometry, which may change as the pupil dilates; an artificial pupil of 4mm in diameter was placed directly in front the eye. Following the administration of tropicamide the mean pupil diameter was increased from 3.29 mm to 8.25 mm (P

AIMS: To assess the relationship between endothelial dysfunction, endothelin 1 (ET-1) plasma levels and subclinical inflammation in primary open angle glaucoma (POAG) patients. MAIN METHODS: We enrolled 40 POAG patients with progressive visual field damage, although well controlled intraocular pressure (IOP) and compared to age and sex matched healthxy subjects. Each patient underwent an ophthalmological examination, a standard achromatic perimetry (SAP), blood sampling to assess ET-1 plasma levels, an objective assessment of cellularity within the anterior chamber (FLARE) and measurement of flow mediated dilation (FMD) with high resolution 2-dimensional ultrasonographic imaging of the brachial artery. KEY FINDINGS: At baseline, POAG patients, compared to healthy controls, showed an increase of ET-1 plasma levels: 2.83 ± 0.28 pg/ml vs. 1.75 ± 0.25 pg/ml (p0.001). SIGNIFICANCE: The increase of ET-1 in POAG patients is related to vascular dysfunction (r=0.942; p=0.001) and vascular dysfunction is related to sub-clinical intraocular inflammation (r=0.968; p=0.001). Thus ET-1 and vascular dysfunction related to sub-clinical inflammation may play a key role in determining a progressive visual field damage in POAG patients who present a well-controlled IOP.

Phacoemulsification and the contemporary implantation of intraocular lens (IOL) within the capsular bag represent the standard of care in cataract surgery, but sometimes a primary IOL implant is not possible due to intraoperative complications or preexisting conditions so that a secondary implantation of IOL within the anterior or posterior chamber is necessary. The aim of our study was to assess the degree of inflammation due to a secondary implant of claw lenses, angle-supported IOLs, and scleral-fixated IOLs by means of an objective, repeatable, and noninvasive device, the laser flare cell meter, which evaluates aqueous flare and cells within the anterior chamber in vivo and to show the contribution of the single IOLs to the genesis of inflammation.

Background To assess which of three methods, namely, optical coherence tomography (OCT), pattern electroretinogram (PERG) or frequency-doubling technology (FDT), is the most sensitive and specific for detecting early glaucomatous damage in ocular hypertension (OH). Methods Fifty-two patients with OH (24 men and 28 women, mean age of 56 ± 9.6 years) with an intraocular pressure (IOP) > 21 mmHg and fifty-two control patients (25 men and 27 women, mean age of 54.8 ± 10.4 years) with IOP All subjects underwent OCT, FDT and PERG. Data were analyzed with unpaired t-tests, Chi-square test and Receiver Operating Characteristic (ROC) curve analyses. Results In patients with OH, OCT showed retinal nerve fiber layer (RNFL) thinner than in control group in the superior quadrant (130.16 ± 10.02 vs 135.18 ± 9.27 μm, respectively; p Conclusions FDT is the most sensitive and specific method for detecting early glaucomatous damage in eyes with OH, and together with OCT, can be useful in identifying those patients who may develop glaucoma. Trial registration ISRCT number: ISRCTN70295497

Purpose To evaluate the effect of subtenon injection of natural leucocytic interferon-α (IFN-α) on visual acuity (VA), macular thickness (MT) and membrane size in patients affected by type II age-related choroidal neovascularization (CNV) refractory to intravitreal injection of bevacizumab Methods 20 patients (male:female=8:12; mean age: 77.7±6.6) were evaluated, including best-corrected visual acuity (BCVA), fluorescein angiography, indocianin angiography and SD-OCT, preoperatively and after 1 month and 4 months following the last injection. Patients received a parabulbar subtenonian injection of IFN-α (1x106 UL/ml, Alfaferone, AlfaWassermann) 3 times a week for 4 consecutive weeks. Results BCVA, expressed in LogMAR, significantly improved after the first month (0.88±0.49vs0.65±0.52; p

Purpose To report the effect of subtenon injection of natural leucocytic interferon-α (IFN-α) on visual acuity (VA) and macular thickness (MT) in diabetic macular edema (DME). Methods 3 patients affected by diabetic macular edema refractory to intravitreal injection of bevacizumab received a complete ophthalmic examination including best-corrected visual acuity (BCVA )and spectral domain ocular coherence tomography (SD-OCT) before and after 1 week, 1 month and 4 months of a cycle of 3 parabulbar subtenonian injections in a week of IFN-α (1x106 UL/ml, Alfaferone, AlfaWassermann). Results BCVA and MT significantly improved after a week in patient 2 (male, age 66): 20/50 vs 20/30 and 498μm vs 237μm. The result was stable during the third and fourth visits (299μm and 254 μm). BCVA and MT improved after a week in patient 1 (male, age 64): 20/40 vs 20/32 and 467μm vs 244μm, respectively; BCVA was stable during the follow up period, but MT increased significantly (610 μm and 603μm during the third and fourth visits). BCVA improved in patient 3 (female, age 75) after one week (20/50 vs 20/32) and was stable during the follow up period, but she had only a little improvement in MT (533μm, 483μm, 498μm and 493μm during the 4 visits). Conclusion BCVA improved in all the patients, and was stable after 4 months. MT greatly improved in two patients after 1 week but only in one patient was the result stable. IFN-α, with its immunomodulatory, antiproliferative and antiangiogenic actions, was effective in improving VA and reducing macular thickness in DME. Randomized controlled studies will be useful to understand how long the effect of IFN-α lasts, how many injections are needed and which patients might have the best results.

Laser Doppler flowmetry (LDF) is a technique used to measure relative average velocity, number and flux (number times velocity) of red blood cells in vessels or capillaries. In this study, the effect of topical timolol on the choroidal circulation was investigated in 12 healthy subjects. Maximum velocity of red blood cells and volumetric blood flow rate in sub-foveal choroids are determined in each eye just before instillation of drops and then every 30 min upto 2 hours. Average intraocular pressure (IOP) decreased significantly in the timolol-treated eyes compared to that of placebo-treated eyes. Nevertheless no significant differences in choroidal blood hemodynamic between timolol and placebo-treated eyes were observed.

Purpose To compare the corneal hysteresis (CH) and the corneal resistance was increase force (CRF) of patients with age-related macular degeneration (ARMD) and control subjects. Methods The CH and the CRF were compared among 20 patients with ARMD (ARMD group: 10 with neovascular and 10 with non-neovascular ARMD) aged from 54 yrs to 78 yrs (68.9±15.9 yrs) and 20 age-matched control patients (control group). In ARMD and control group the eye's axial length was: 23.14 ±0.95 mm vs. 23.04 ±1.16 mm (p

Purpose To assess the expressibility of the meibomian gland we proposed a new diagnostic tool. We evaluated the use of the instrument by assessing the time of the meibomian gland expressibility and the intraocular pressure change in two groups of healthy patients. Methods We selected two groups of patients divided according to age. The first group consisted of 45 subjects aged between 20 and 30 years (mean 28 ±4.5 yrs) and a second group (group B) of 45 subjects aged between 40 and 50 years (mean 46±3.8 yrs). Meibomian gland evaluations were performed using a standardized technique with an evolved new diagnostic instrument patented in Italy. The instrument has a rectangular contact surface area of 40.57 mm2. The head surface is covered with a plastic film that is changed at each examination. The instrument exerts a constant pressure of 1.2 gr/mm2 under piezoelectric control. We evaluated the time to onset of fluid at the orifices of the meibomian glands and changes of intraocular pressure (IOP) after compression of the lower eyelid with applanation tonometry. Results In the group A and in group B the time to onset the fluid was 3.69±1.22 vs. 6.62±1.39 sec. (p

Retinitis pigmentosa (RP) is an inherited retinal disorder clinically characterized by a pale, waxy optic nerve head, attenuated retinal blood vessels, and bone spicule pigment in the retina. Hemodynamic studies have demonstrated that RP is associated with a reduction in the retinal and choroidal blood flow. Retinal hemodynamic impairment is also present in early stages of RP, and various hypotheses have been advanced as to the cause. The authors studied 20 patients, 12 males and 8 females, aged 26-42 years (mean 35.1 years) and affected by simplex RP. The patients had a visual acuity of 0.9 +/- 0.1, visual field mean defect of -6.52 +/- 3.58 dB, and b-wave electroretinogram amplitude of 260.08 +/- 8.24 microV. An increase in plasma levels of endothelin-1 (ET-1) was found: 1.910 +/- 0.317 pg/mL versus 1.180 +/- 0.210 pg/mL in non-RP controls (p0.02). Moreover both an ocular and systemic vascular impairment was detected by means of color Doppler imaging and laser Doppler flowmetry performed during a cold pressor test. We found a correlation between the increase of ET-1 plasma levels in RP and the decrease of peak systolic velocity in the ophthalmic artery (p0.03) and in the posterior ciliary arteries (p0.006). It is thought that an increase of ET-1 and retinal oxygen levels in RP could lead to vasoconstriction and a decrease of the retinal blood flow, worsening the abiotrophic process.

Many drugs, including quinolone antibiotics, have been implicated in the aetiology of pseudotumour cerebri. We here report the case of an 18-year-old male of high body mass index who developed pseudotumour cerebri after treatment with oral levofloxacin for broncho-pneumonia. After 5 days of treatment, his general condition improved but he started to complain of headache, intermittent vomiting, tinnitus in the left ear, blurred vision, photophobia, and intermittent horizontal diplopia. The fundus oculi examination revealed bilateral papilloedema. All the symptoms resolved within 2 weeks after levofloxacin withdrawal. This case raises the possibility that quinolone antibiotics can cause pseudotumour cerebri.

Purpose To assess peripheral vascular endothelial function and IOP in patients with ocular hypertension (OH), before and after the use of Palmitoylethanolamide per os, using non-invasive dependent flow mediated vasodilation (FMD). Methods We studied 20 OH patients (12 females and 8 males) aged from 34 to 64 (mean 56.8+8.1 yrs). The diagnostic criteria for OH were: IOP exceeded 22 mm/hg, open anterior chamber angle, cup/disc ratio

Introduction: Mooren's ulcer is a rare disorder of unknown etiology that is refractory to treatment. It can affect not just the cornea but also the scleral tissue and can involve both eyes. Case presentation: We report a case of a 74-year-old man with a history of bilateral and malignant Mooren's ulcer. The patient had undergone an exenteratio bulbi of the left eye because of the perforation of a Mooren's corneal ulcer. The perforated Mooren's corneal ulcer also presented in the right eye and involved the adjacent scleral tissue. It was decided to perform a corneal-scleral graft to preserve the anatomical integrity of the eye. Conclusion: This report highlights how a corneal-scleral graft followed by systemic and local immunosuppressive treatment should be considered in monocular patients with malignant Mooren's ulcer where there is serious damage to the corneal and scleral tissue. © 2009 Cellini et al; licensee BioMed Central Ltd.

Purpose Glaucomatous optic neuropathy (GON) is related not only to elevated intraocular pressure (IOP) but also to an insufficient ocular blood supply related to a vascular dysregulation. We evaluated peripheral vascular endothelial function in primary open-angle glaucoma (POAG) with a non-invasive endothelium flow mediated vasodilatation (FMD). Methods We studied 20 POAG patients. The diagnostic criteria for POAG was an IOP exceeded 22 mm/hg before treatment, open anterior chamber angle, cup/disc ratio >0.7 and optic nerve related visual field loss (MD>6 dB, SF>2.5 dB and CPSD>3 dB). Patients with systemic diseases such hypertension, heart failure and diabetes mellitus were excluded. All patients and 20 normal controls underwent measurement of FMD with high-resolution 2-dimensional ultrasonographic imaging of the brachial artery by a Philips ENVISOR echographic machine. To induce iperemia a sphygmomanometer cuff was inflated to 250 mm/hg for 5 minutes. The cuff then was deflated rapidly and at 60 seconds after cuff deflation 2-D images of the brachial artery were recorded for 5 seconds. A statistical analysis was made of the FMD in POAG and in normal control patients using the Student “t” test for unpaired data and the Pearson correlation test to show the correlation between the endothelial dysfunction and the visual field indexes. Results Patients affected by POAG exhibit lower values of FMD compared with healthy people In POAG patients we found an FMD 4,28%±2,49 vs. 8,66%±3,02 (p

Background The aim of this study was to assess changes in metalloproteinases (MMP-2) and tissue inhibitor of metalloproteinases (TIMP-2) following selective laser trabeculoplasty (SLT) in patients with pseudoexfoliative glaucoma (PEXG). Methods We enrolled 15 patients with PEXG and cataracts (PEXG-C group) and good intraocular pressure (IOP) controlled with β-blockers and dorzolamide eye drops who were treated by cataract phacoemulsification and 15 patients with pseudoexfoliative glaucoma (PEXG-SLT group). The PEXG-SLT patients underwent a trabeculectomy for uncontrolled IOP in the eye that showed increased IOP despite the maximum drug treatment with β-blockers and dorzolamide eye drops and after ineffective selective laser trabeculoplasty (SLT). The control group consisted of 15 subjects with cataracts. Aqueous humor was aspirated during surgery from patients with PEXG-C, PEXG-SLT and from matched control patients with cataracts during cataract surgery or trabeculectomy. The concentrations of MMP-2 and TIMP-2 in the aqueous humor were assessed with commercially available ELISA kits. Results In PEXG-SLT group in the first 10 days after SLT treatment a significant reduction in IOP was observed: 25.8 ± 1.9 vs 18.1.0 ± 1.4 mm/Hg (p < 0.001), but after a mean time of 31.5 ± 7.6 days IOP increased and returned to pretreatment levels: 25.4 ± 1.6 mm/Hg (p < 0.591). Therefore a trabeculectomy was considered necessary. The MMP-2 in PEXG-C was 57.77 ± 9.25 μg/ml and in PEXG-SLT was 58.52 ± 9.66 μg/ml (p < 0.066). TIMP-2 was 105.19 ± 28.53 μg/ml in PEXG-C and 105.96 ± 27.65 μg/ml in PEXG-SLT (p < 0.202). The MMP-2/TIMP-2 ratio in the normal subjects was 1.11 ± 0.44. This ratio increase to 1.88 ± 0.65 in PEXG-C (p < 0.001) and to 1.87 ± 0.64 in PEXG-SLT (p < 0.001). There was no statistically significant difference between the PEXG-C and PEXG-SLT ratios (p < 0.671). Conclusion This case series suggest that IOP elevation after SLT can be a serious adverse event in some PEXG patients. The IOP increase in these cases would be correlated to the failure to decrease the TIMP-2/MMP-2 ratio. Trial registration Current Controlled Trials ISRCTN79745214

BACKGROUND: To assess the efficacy of the intravitreal (IVT) injection of Triamcinolone Acetonide (TA) as compared to posterior subtenon (SBT) capsule injection for the treatment of cystoid diabetic macular edema. METHODS: Fourteen patients with type II diabetes mellitus and on insulin treatment, presenting diffuse cystoid macular edema were recruited. Before TA injection all focal lakes were treated by laser photocoagulation. In the same patients one eye was assigned to 4 mg IVT injection of TA and the fellow eye was then treated with 40 mg SBT injection of TA. Before and one, three and six months after treatment we measured visual acuity with ETDRS chart as well as thickness of the macula with optical coherence tomography (OCT) and intraocular pressure (IOP). RESULTS: The eyes treated with an IVT injection displayed significant improvement in visual acuity, both after one (0.491 +/- 0.070; p < 0.001) and three months (0.500 +/- 0.089; p < 0.001) of treatment. Significant improvement was displayed also in eyes treated with an SBT injection, again after one (0.455 +/- 0.069; p < 0.001) and three months (0.427 +/- 0.065; p < 0.001). The difference between an IVT injection (0.809 +/- 0.083) and SBT injection (0.460 +/- 0.072) becomes significant six months after the treatment (p < 0.001).Macular thickness of the eyes treated with IVT injection was significantly reduced both after one (222.7 +/- 13.4 microm; p < 0.001) and after three months (228.1 +/- 10.6 microm; p < 0.001) of treatment. The eyes treated with SBT injection displayed significant improvement after one (220.1 +/- 15.1 microm; p < 0.001) and after three months (231.3 +/- 10.9 microm; p < 0.001). The difference between the eyes treated with IVT injection (385.2 +/- 11.3 microm) and those treated with SBT injection (235.4 +/- 8.7 microm) becomes significant six months after the treatment (p < 0.001).Intraocular pressure of the eyes treated with IVT injection significantly increased after one month (17.7 +/- 1.1 mm/Hg; p < 0.020), three (18.2 +/- 1.2 mm/Hg; p < 0.003) and six month (18.1 +/- 1.3 mm/Hg; p < 0.007) when compared to baseline value (16.1 +/- 1.402 mm/Hg). In the SBT injection eyes we didn't display a significant increase of intraocular pressure after one (16.4 +/- 1.2 mm/Hg; p < 0.450), three (16.3 +/- 1.1 mm/Hg; p < 0.630) and six months (16.2 +/- 1.1 mm/Hg; p < 0.720) when compared to baseline value (16.2 +/- 1.3 mm/Hg). CONCLUSION: The parabulbar subtenon approach can be considered a valid alternative to the intravitreal injection. TRIAL REGISTRATION: Current Controlled Trials ISRCTN67086909.