bluuebunny/crossref_metadata_2025 huggingface dataset:
Health economics issues
Authors: LEIVO T
Published: October 2007

Purpose: To evaluate the cost and cost‐effectiveness of the simultaneous bilateral cataract surgery compared to sequential bilateral cataract surgery.

Methods: Design: Helsinki Simultaneous Bilateral Cataract Surgery Study. Prospective randomized comparative trial.

Participants: 520 patients scheduled for bilateral cataract surgery were selected based on strict inclusion criteria to be operated in one session or sequentially one month apart. In both groups every second patient was included in the economic cost analysis.

Methods: The costs were evaluated from the societal perspective, taking into account health and non‐health care costs in both groups. The cost of surgery, complications, outpatient visits, medication, travel, patient's and care‐taker's time and possible home nurse visits were evaluated. The cost data was obtained from the participant questionnaires and phone interviews at 3 months, hospital cost data and public statistics. The effectiveness was evaluated based on VF‐7 and 15‐D scores.

Main Outcome Measures: The cost of simultaneous vs. sequential bilateral surgery per treated patient. The cost‐ effectiveness of simultaneous bilateral surgery compared to sequential bilateral cataract surgery. Economic sensitivity analysis was carried on all main results.

Results: The preliminary results show, that cost per treated patient was lower in the simultaneous bilateral cataract surgery group. The effectiveness was similar in both groups.

Conclusions: Simultaneous bilateral cataract surgery is cost‐ effective procedure. If additionally the treatment processes are tailored to simultaneous bilateral surgery, more cost savings can be achieved. The proportion of bilateral cataract patients operated in one session has a substantial effect on the use of health care and non‐health care resources in the society.
Mid term results in keratoconus treatment by Riboflavin – UVA corneal collagen Cross‐Linking. Siena eye cross project
Authors: CAPOROSSI A , BAIOCCHI S , MAZZOTTA C , CAPOROSSI T
Published: October 2007

Purpose: We present a mid term follow up analysis of 44 keratoconic eyes treated by combined Riboflavin UV‐A collagen cross‐linking.

Methods: Progressive keratoconic eyes of 44 patient were treated by combined Riboflavin UV‐A collagen cross linking. UV‐A exposure was delivered by the new CBM X linker 370 nm Led array‐CSO, Italy. Riboflavin 0,1% solution, Ricrolin Sooft, after corneal epithelium debridement in all cases was instilled 15 minutes before starting irradiation and every 5 minutes for 30 minutes. Eyes were dressed with a soft contact lens for 4 days and medicated with levofloxacin drops, flurbiprofen drops and lacrimal substitutes for 15 days.

Results: In all treated eyes no progression of keratoconus was detected. the control fellow eye progressed in 30 % of cases in one year follow up. Mean k value improved meanly 2 Diopters with a significative reduction of Comatic aberration, improving corneal simmetry and quality of vision.

Conclusions: Corneal crosslinking is indicated in progressive keratoconus particularly in young patients under 26 years. It can delaly or stop keratoconus worsening reducing necessity of donor corneal transplantations.
Full‐field ERG responses in fellow eyes after the monocular trauma: normal values variability and the classification of oculo‐ocular reactions
Authors: ZUEVA MV , TSAPENKO IV
Published: October 2007

Purpose: To determine the monocular trauma influence "normal" values of the ERGs in fellow eyes.

Methods: Archive data of 845 patients who undergone the ocular trauma were analyzed retrospectively. We tested also ERG responses in 79 fellow eyes in dynamics: during 1 year after the trauma or enucleation. The single‐flash (4.7 cd?s?m‐2) and flicker (1.8 cd?s?m‐2; 12‐40Hz) full field ERGs were elicited after 10 min dark adaptation. The glial index Kg was calculated as the ERG b‐wave/12Hz‐flicker ERG amplitudes ratio.

Results: Regularities of ERG alterations in fellow eyes were determined, which depended on a remoteness and severity of the first eye damage. The data suggest that some regularity in oculo‐ocular reactions (OOR) should be considered the reflection of general adaptation (stress‐) syndrome on the retina level. Between all groups, patients with posttraumatic uveitis and subatrophy showed more pronounced disturbances in the ERGs. Two types of b‐wave and Kg dynamics were found in the earlier period after an enucleation or trauma. The first one should be determined as the regular fellow eye reaction, and the second – as a pathological one. The more expressed alterations in Kg and the slower restoration period should be considered the signs of a higher risk of sympathetic ophthalmia in a remote post‐surgical period. The proposed classification of OOR may have application for the more accurate detection of normal and pathological fellow eye reactions for prescriptions in damaged eye removing.

Conclusions: The revealed regularities should be taken into account for greater clinical value of electroretinography in trauma and, possibly, in other monocular pathology.
Electrophysiology and autofluorescence imaging in differential diagnosis of retinal and optic nerve disease
Authors: HAWLINA M , JARC‐VIDMAR M , POPOVIC P , BRECELJ J
Published: October 2007

Purpose: Electrophysiological methods enable exact layer by layer diagnosis of the retina and help to answer frequent diagnostic ambiguities between macular and optic nerve diseases.

Methods: New multifocal techniques enable topographic representation of the retinal function and can provide accurate diagnosis of macular diseases in early stages. Current trends with emphasis on non‐invasive recording of EOG, ERG, pattern ERG, VEP and multifocal testing, with regards to conventional perimetry, microperimetry and scanning laser ophthalmoscope imaging including autofluorescence of the RPE will be reviewed in representative clinical cases. The importance of standardisation on the performing of all tests according to the recommendations of the International Society for Clinical Electrophysiology of Vision (ISCEV) is emphasised.

Results: Global retinal function is well assessed by flash evoked ERGs, but these may be normal in macular disease. PERG and multifocal ERG in combination with autofluorescence imaging may delineate macular diseases in very early stages. In such cases, visual loss may, due to the resulting delay in VEP, erroneously be attributed to optic nerve disease. On the other hand, optic nerve diseases usually do not affect multifocal ERG but can affect PERG, especially its N95 component. Combination of reduced N95 component and delay in VEP is strongly suggestive for optic nerve or ganglion cell disease in which autofluorescence imaging would usually be normal.

Conclusions: By judging the cause of visual loss, combination of morphological features by RPE autofluorescence with electrophysiological and psychophysical methods usually leads to correct diagnosis.
Clinical trial methodology in dry eye disease
Authors: SCHAUMBERG D
Published: October 2007

Purpose: Clinical trials in dry eye disease have often been challenging. This report will summarize some universal concepts with regard to the conduct of clinical trials, and will review other issues that specifically pertain to successful clinical trials of therapeutic interventions in dry eye disease.

Methods: The Dry Eye Workshop involved the deliberations of many contributors through an iterative process that ultimately produced a harmonized summary of current knowledge of dry eye disease (2007 Report of the International Dry Eye WorkShop; Ocul Surf 2007;5[2]:65‐206). The subcommitte on clinical trial methodology was given the task of performing an evidence‐based critical review and summary of the design and implementation of clinical trials in dry eye disease. The group systematically reviewed the medical literature, procedures, and concepts related to clinical trials in general, and considered special issues related to clinical trials involving therapeutic interventions in dry eye disease.

Results: The Dry Eye Workshop report makes some specific recommendations for the design and implementation of such trials, based on an assessment of the peculiarities of dry eye disease that complicate clinical trial design, such as the lack of correlation of signs and symptoms, as well as the likelihood of control interventions having a lubricant (placebo) effect. The group also points out potential advantages and disadvantage for conduct of trials in the context of a controlled adverse environment.

Conclusions: This report provides a summary of established principles of clinical trial design and implementation and makes suggestions for successful trials of therapeutic interventions in dry eye disease.
Deep sclerectomy in normal tension glaucoma
Authors: SUOMINEN S , HARJU M , IHANAMAKI T , VESTI E
Published: October 2007

Purpose: To study the effect of deep sclerectomy (DS) on intraocular pressure (IOP) in normal tension glaucoma (NTG) patients.

Methods: We retrospectively analysed 21 eyes of 18 consecutive NTG patients to whom DS was performed. A collagen implant was used (Aquaflow, Staar surgical, Nidau, Switzerland) in 20 of 21 operations. Mitomycin‐C (0.4 mg/ml for 3 minutes) was used in 20 of 21 operations. DS was combined with phacoemulsification in three eyes.

Results: Median follow‐up time at the last visit was 14 months (range 3 to 27 months). There was a significant reduction from the preoperative IOP (median, range; 16 mmHg, 11 to 22 mmHg) to the IOP at the last visit (10 mmHg, 4 to 20 mmHg; p<0,001). The median percentage of IOP change was ‐42% (‐81 to 19%). A 25% IOP reduction without medication was achieved in 15/21 eyes and 30% IOP reduction in 13/21 eyes. One year follow‐up was available for 13 eyes. In these, IOP was reduced from the preop‐erative 17 mmHg (14 to 22 mmHg) to 10 mmHg (4 to 20 mmHg; p=0,001) The median percentage of IOP change was ‐42% (‐81 to ‐9%). A 25% IOP reduction without medication was achieved in 11/13 eyes and 30% IOP reduction in 10/13 eyes. Goniopuncture had been done in 8/21 eyes until last visit and in 6/13 eyes until one year. Complications included tearing of conjunctiva (n=3), mi‐croperforation (1), flap avulsion (1), prominent subconjunctival bleeding (1), hyphema (1), re‐suturation of conjunctiva (3), dellen (1), loss of ≥2 Snellen lines (5), and later shunt operation (1). IOP was < 4 mmHg in 16/21 eyes on the first postoperative day, and in 2/21 at 4 weeks. None of these persisted.

Conclusions: Despite low preoperative IOP, clinically significant IOP reduction was achieved. DS seems to be effec‐tive and safe in reducing IOP in NTG patients.
Disk swelling ‐ differential diagnosis in orbital space occupying lesions
Authors: GUTHOFF RF
Published: October 2007

We frequently cannot decide with certainty whether a disk with blurred margins and slight elevation represents a pathologic condition or not. If unequivocal pathologic findings are lacking, it is up to the examiner to decide how far the diagnostic procedures should be carried out. It may be necessary to obtain neurologic consultation and to perform neuroradiologic investigations, including MRI and possibly angiographic techniques. On the other hand, after weighing the cost‐benefit ratio and the risk of some side effects, the investigator may rely on his clinical acumen and decide that the condition only represents a variant of the norm.

Main differential diagnosis are pseudopapilledema in hyperopia, disk drusen, ocular hypotony, posterior scleritis, optic neuritis, disk edema (due to increased intracranial pressure, due to compression of the orbital part of the optic nerve), optic nerve tumours (meningioma, glioma), metastatic carcinoma, blurred disk margins without echographically demonstrable changes, congenital disk anomalies , central vein occlusion and anterior ischemic optic neuropathy.
Microsurgery of canalicular stenosis
Authors: SERRA F
Published: October 2007

Purpose: To explain form the clinical finding which microsurgery of the canaliculi can be used to restore a spontaneous tear drainage in localised stenosis.

Methods: Design: Clinical and surgical cases demonstration.

Methods: we will describe the different types of punctoplasty, the surgical repair of the stenosis located close to the puncti that can be reached by the direct approach and those close the lacrimal sac that reaquire an approach via the common canaliculus

Results: The goal of this surgery is to recreate the continutiy of the lacrimal mucosa in order to allow a spontaneous tear flow
Improvement of S‐cone mediated visual fields and rod function after correction of vitamin A deficiency
Authors: HAYASHI T , TAKEUCHI T , GEKKA T , KUBO A , NAKANO T , TSUNEOKA H
Published: October 2007

Purpose: To evaluate visual sensitivities mediated via short wavelength sensitive (SWS) cones and retinal function electrophysiologically in a patient with vitamin A deficiency.

Methods: This is an interventional case report. Ophthalmological examinations were performed. Full‐field electroretinograms (ERGs) were recorded. Mean deviation (MD), a global index that reflects the overall depression in visual fields, was evaluated using Humphrey standard automated perimetry (SAP) and short wavelength automated perimetry (SWAP).

Results: A 65‐year‐old Japanese female, who was diagnosed with primary sclerosing cholangitis, complained of night blindness. Her visual acuity was 1.2 in both eyes. The ERGs showed no rod b‐waves, reduced rod‐plus‐cone responses (negative type) and normal cone and 30‐Hz flicker responses. Plasma vitamin A concentration was 18 IU/dL (normal range 97‐316 IU/dL). The SAP MD was ‐1.09 dB (OD) and ‐0.97 dB (OS), whereas the SWAP MD was ‐10.10 dB (OD) and ‐10.50 dB (OS). The rate of sensitivity decreased in increasing eccentricity in SWAP. The ERG responses were normalized 4 months after oral administration of vitamin A. The SWAP MD was greatly improved to ‐3.47 dB (OD) and ‐4.10 dB (OS) compared with the changes to the SAP MD (OD: +0.67 dB, OS: +0.41 dB).

Conclusions: Rod dysfunction and impaired SWS cone mediated pathways were preferentially observed and were subsequently reversed after the treatment. The findings suggest that rods and SWS cones are more susceptible to vitamin A deficiency than long/middle wavelength sensitive cones in the patient.
Effect of induced myopia on scleral mechanics and myofibroblast populations
Authors: BACKHOUSE S , BUMSTED O'BRIEN K , PHILLIPS JR
Published: October 2007

Purpose: Determine the effect of induced refractive error on a) ocular compliance and b) scleral contractile cell populations in guinea pig.

Methods: One week old guinea pigs (n = 29) were monocularly deprived of form vision (MD) for 14 days. Cycloplegic refractive error was measured with an IR Optometer. Ocular compliance (change in length/mmHg change in IOP) of MD and control eyes was compared by raising the IOP to 50 mmHg for one hour in 8 anaesthetised animals. A‐scan ultrasound measures of axial length were taken every 10 minutes with raised IOP, and after returning IOP to 15 mmHg. Antibodies to DAPI and α‐smooth muscle actin (α‐SMA) were used to determine the total cell population and cell contractile potential respectively in MD and control sclera.

Results: MD induced ‐4.06 ± 1.88 D of myopia, which was correlated with 169 ± 267 μm of vitreous chamber depth (VCD) elongation (n = 29; R2 = 0.37). Both deprived and control eyes showed negative creep compliance (eye shortening) over one hour of raised IOP, equivalent to 1.44 μm shortening per minute. On returning the IOP to 15 mmHg the VCD of the control eye was shorter than baseline by 92.86 ± 88 μm while the deprived eye remained 83.48 ± 37 μm longer than baseline (± SEM; n = 8). These differences were not statistically significant (p = 0.173). There was however an increase of 6% in the percentage of the total cell population positive for α‐SMA in myopic versus control sclera (p = 0.015; n = 7).

Conclusions: Myopic and control eyes show similar negative creep compliance in vivo with raised IOP, and no difference in their elastic compliance response. However the α‐SMA positive cell population is increased in myopic sclera, suggesting a role in scleral remodelling.
Oxidative stress in the trabecular meshwork – Preventive effects of Prostaglandin analogues
Authors: WELGE‐LUSSEN U , YU AL , KAMPIK A
Published: October 2007

Purpose: The trabecular meshwork (TM) of primary open angle glaucoma (POAG) is characterized by an increased accumulation of extracellular matrix, cellular senescence, and the loss of TM cells. One factor in the pathogenesis of POAG is oxidative stress. The goal of this study was to determine whether oxidative stress is able to trigger these POAG specific changes in cultured human TM cells and whether these changes could be reduced or prevented by the application of prostaglandin analogues (PA).

Methods: Cultured human TM cells were stressed with hydrogen peroxide (H2O2) for 1 hour. Levels of fibronectin and MMP‐9 mRNA were analyzed by RT‐PCR. Senescence‐associated beta‐galactosidase (SA‐ß‐gal) activity was detected by histochemical staining. Cell loss was investigated by live dead assay. The effects of PA and benzalkonium chloride (BAC) on POAG typical TM changes were investigated by pre‐incubation with solutions of bimatoprost, travoprost and latanprost or its corresponding BAC concentrations of the either non stimulated or H2O2‐treated cells.

Results: H202 markedly influenced the mRNA expression of fibronectin (1.8 fold), MMP‐9 (0.4 fold) and increased SA‐ß‐gal activity to 12 fold. Incubation with 600 μM H2O2 for induced 50% of dead cells. Pretreatment with BAC alone induced POAG typical TM changes in non‐stimulated and H2O2‐treated cells. These effects were reduced by preincubation with PA in H2O2‐treated cells and to a lesser extent in non stimulated cells.

Conclusions: Oxidative stress is able to induce several characteristic POAG TM changes in vitro and these oxidative stress‐induced TM changes can be minimized by the use of PA. Thus, prevention of oxidative stress exposure to the TM may help to reduce the progression of POAG.
Local and multifocal ERG in age‐related macular degeneratıon.
Authors: ZOLNIKOVA IV , AHMEDZHANOVA EV , KARLOVA IZ , SHAMSHINOVA AM
Published: October 2007

Purpose: To assess the macular ERG responses in different forms of AMD with OCT‐visualisation.

Methods: 60 patients (120 eyes) wıth AMD, aged 57‐82, were examined. The groups were formed based on clinical examination, OCT and fluorescein angiography data. Local ERG (L‐ERG) to a red and green stımulus was recorded wıth MBN ERG system (Russıa). Multıfocal ERG was recorded wıth RETIscan system (Roland Consult, Germany).

Results: In group 1 wıth hard drusen (18 eyes) ERG responses were in normal range. In group 2 with soft confluent drusen (18 eyes) a‐wave implicit tıme (IT) was prolonged (p=0,007);N1 of mfERG in normal range. b‐wave amplitude of L‐ERG to red stimulus was reduced (p=0,014), P1 of mf‐ERG reduced in fovea and parafovea (р<0,001). In a group 3а (31 eyes) wıth focal RPE atrophy,a‐wave IT of M‐ERG prolonged (p=0,002), P1 reduced in fovea (p=0,04). In a group 3b (16 eyes) with focal RPE atrophy and hyperpigmentation (VA 0,4‐0,1) a‐ and b‐wave reduced (p<0,001),P1 reduced in fovea and parafovea (р<0,05), N1 in foveal hexagone (p=0,04). In a group 4a with CNV with CMO foveal and parafoveal b‐wave amplitude reduced (p<0,05), P1 and N1 reduced (р<0,001). P1 in paramacular ring was reduced (р<0,05). In group 4b with RPE‐detachment a‐wave prolonged, a‐and b‐wave reduced, P1 and N1 reduced (р<0,001).

Conclusions: The most sensitive indicators of macular dysfunction in AMD are the implicit time of a‐wave to a red stimulus local ERG and P1 response density of mf ERG in foveal hexagone. Normal amplitude and implicit time of N1 in soft drusen and early RPE‐atrophy in eyes with prolonged a‐wave of local ERG provides the evidence of smaller contibution of cones to N1 of FOK of mf ERG.
Prevention of hypoxia/reoxygenation‐, H2O2‐ and TGF‐β2‐mediated increase of alphaB‐crystallin and Hsp27 by the use of antioxidants
Authors: YU AL
Published: October 2007

Purpose: Reactive astrocytes in glaucomatous optic nerve changes are characterized by an increased expression of alphaB‐crystallin and heat shock protein 27 (Hsp27). Previously, we could show that hypoxia/reoxygenation (H/R), hydrogen peroxide (H2O2) and transforming growth factor beta 2 (TGF‐β2) induced the expression of both Hsps. Our goal was to determine the ability of various antioxidants to prevent H/R‐, H2O2‐ and TGF‐β2‐mediated increase of alphaB‐crystallin and Hsp27 in cultured human astrocytes.

Methods: Cultured astrocytes were incubated under hypoxic conditions (1% O2 for 4 hours) with subsequent reoxygenation (12 to 48 hours). Additionally, cells were treated with 400‐800 μM H2O2 or with 1.0 ng/ml TGF‐β2 for 12 to 48 hours. Expression of alphaB‐crystallin and Hsp27 was examined by real‐time PCR and western blotting. To evaluate the effect of vitamin B1, B12, E, C, alpha lipoic acid and anthocyanin, cells were preincubated with physiological concentrations before stress exposure.

Results: H/R, oxidative stress and TGF‐β2 treatment markedly increased the expression of alphaB‐crystallin and Hsp27. This effect of H/R, oxidative stress and TGF‐β2 was diminished when cells were preincubated with 100 μM alpha lipoic acid and 100 μM anthocyanin. In contrast, preincubation of cells with vitamin B5, B12, C and E could not reduce the stress‐induced increase of both Hsps.

Conclusions: The antioxidants alpha lipoic acid and anthocyanin are capable to reduce the H/R‐, oxidative stress‐ and TGF‐β2‐mediated increase of alphaB‐crystallin and Hsp27 in cultured human astrocytes. Therefore, the use of these antioxidants in glaucomatous patients may help to lower the incidence of characteristic changes in the optic nerve.
Combination of structural and functional methods for the diagnosis and follow‐up of glaucoma:results of a two‐year‐study
Authors: SKORKOVSKA SS , MICHALEK JM
Published: October 2007

Purpose: To determine, whether an appropriate combination of the structural and the functional examination methods can improve the diagnosis and follow‐up of glaucoma

Methods: One randomly selected eye of 40 patients with primary open angle glaucoma (POAG) with none or early glaucomatous visual field loss and 40 age‐matched healthy persons were included in the prospective longitudinal study. Structural evaluations were conducted using Heidelberg Retina Tomograph (HRT) and retinal nerve fiber layer (RNFL) loss scoring according to Airaksinen method. Functional parameters were reviewed by means of standard white‐on white (W/W) and blue‐on yellow (B/Y) perimetry. To assess the diagnostic value of different data sets machine learning classifiers , linear discriminant analysis and classification trees were applied. The accuracy of discrimination was described and visualized by the Receiver Operating Characteristic Curves (ROC), and the results of the first and second year of study were compared.

Results: There were statistically significant differences between the healthy and glaucomatous group in the scoring of RNFL loss, HRT parameters (CA,CD,RD,RV,CSM) and mean defect of W/W perimetry. Parameters with the highest diagnostic ability obtained by ROC curves were scoring of RNFL loss, HRT analysis of the optic nerve head and W/W perimetry.

Conclusions: Combination of different diagnostic methods can enhance precision of early diagnosis and follow‐up of glaucoma. A limitation for a relationship between structure and function is the individual variability of the optic disc morphology and subjective variability of visual field testing.

Supported by IGA NR‐8371
Conjunctival melanoma & histone deacetylase inhibitors
Authors: MADIGAN MC , CUNNEEN TS , NAREYECK G , ANASTASSIOU G , CONWAY RM
Published: October 2007

Purpose: Conjunctival melanoma is a rare disease with a poor prognosis. Malignant conjunctival melanoma or primary acquired melanosis (PAM) with atypia are usually treated by surgical excision and cryotherapy. Topical mitomycin C (MMC) is also increasingly used for treating PAM with atypia. Histone deacetylase (HDAC) inhibitors can modify tumour growth and induce tumour cell death, and may be useful adjuvants for treating conjunctival melanoma. We examined the effects of HDAC inhibitors (sodium butyrate ‐ SB , Trichostatin A ‐ TSA) and MMC on the growth and survival of human conjunctival melanoma cells.

Methods: Two conjunctival melanoma cell lines (CRMM‐1 & CRMM‐2), and primary human melanocytes and fibroblasts, were treated with SB (0‐8mM), TSA (0‐1uM), and MMC (0‐20ug/ml) for up to 72 hrs. Viability was assessed using MTT assays and cell counts. Inverted and fluorescence microscopy was used to assess morphology and cell death (DNA stains).

Results: HDACs and MMC significantly decreased cell growth and viability in a concentration and time dependent manner for both conjunctival melanoma cell lines. Low concentration HDACs (<2mM SB; <0.1uM TSA) reduced melanoma cell growth, associated with morphological differentiation, particularly in CRMM‐1 cells. Melanocytes and fibroblasts remained viable with HDACs, although at maximal doses used (SB 8mM, TSA 1uM), some cell death was seen. At 48 hrs, MMC >5ug/ml killed >80% of CRMM‐1 & CRMM‐2 cells.

Conclusions: These observations suggest that HDACs do not affect melanocyte and fibroblast viability at doses which can inhibit growth and survival of conjunctival melanoma cells. As such, these compounds may be useful for controlling conjunctival melanoma growth, alone or combined with topical agents such as MMC.
A software system for automatic estimation of corneal epithelial cell density in confocal microscopy
Authors: RUGGERI A , GRISAN E
Published: October 2007

Purpose: The problem of reliable automatic estimation of density of corneal epithelial cells in images from confocal microscopy was addressed. The reliability of estimated densities should be comparable to that of manual cell count.

Methods: The spatial frequencies contained in epithelial images can be extracted with suitable mathematical techniques (2‐dimension Discrete Fourier Transform, DFT). An algorithm for reliably identifying the spatial frequency information and for deriving from it an estimate of the cell density has been developed. A preliminary entropy‐based pre‐processing was carried out to extract from the whole image the ROI (region of interest) where cells are visible. A prototype of the whole algorithm was implemented in the Matlab® language and run on a personal computer. A preliminary evaluation was performed on a data set containing 24 images from normal subjects (see e.g. enclosed image), acquired with a ConfoScan 3 confocal microscope (Nidek Technologies, Italy). Reference manual counts were performed on each image by an experienced optometrist.

Results: Mean percent difference of automatic densities vs. manual ones was ?1%, with std dev 10% and range [?17% ? +18%]. Mean percent absolute difference was 9%, with std dev 4% and range [+1% ? +18%]. Running times of the prototype were in the order of 40 seconds per image.

Conclusions: A new algorithm was developed for the automatic estimation of epithelial cell density. A preliminary evaluation of the proposed technique confirmed its capability of reliably estimating corneal epithelial cell density in confocal images of normal subjects. Implementation of the algorithm with a more efficient computer language, e.g. C++, will allow execution times in the order of 2‐3 seconds.
Patients with coronary heart disease show reduced dynamic retinal arterial reaction
Authors: LANZL IM , ALI M , SCHMIDT‐TRUCKSAESS A , HALLE M , PRESSLER A , KOTLIAR KE
Published: October 2007

Purpose: Coronary heart disease (CHD) and related vascular disorders are able to change vascular endothelial function. Whether the dynamic reaction to luminance flicker stimulation in retinal branch arteries and veins differs between healthy volunteers and patients suffering from CHD is investigated using the Dynamic Vessel Analyzer (DVA).

Methods: Retinal vessel reactions to flicker stimulation were examined in 21 CHD‐patients (57,9±6,9 years old) and in 21 age and gender matched healthy volunteers. Vessel diameters of retinal vessel segments were assessed with DVA. After baseline assessment for 1 min a monochromatic (530‐600nm) rectangular luminance flicker of 12.5 Hz was applied for 20 s for 3 consecutive times.

Results: In most volunteers a retinal arterial dilation in comparison to the baseline as well as an ensuing reactive arterial constriction were observed. In detail we found arterial reactions in % to baseline:

...............................CHD.......control...p‐value(U‐test)

mean maximal

arterial dilation........2,4±1,3*..3,9±2,3...0,02

mean maximal

venous dilation........3,4±2,1....4,5±1,7...0,08

mean maximal

arterial constriction.‐1,0±1,2..‐1,3±1,3...0,7

Conclusions: Functional retinal arterial vessel reaction to flicker stimulation differs between CHD‐patients and healthy subjects of the same age and gender. Maximal dilation as a response to the stimulus is not reached. This might be explained with a different basic vessel tonus as well as with possible endothelial dysfunction in CHD. Application of luminance monochromatic flicker stimulus to retinal vessels may represent a possible method to assess the state of impairment of regulatory reserve of vessels of the central circulation.
Optimal stimulus size maps in the primary visual cortex revealed by optical imaging in cats
Authors: CASANOVA C , VANNI M , VILLENEUVE MY
Published: October 2007

Purpose: It is well known that the responses of cells in the primary visual cortex depend on stimulus size. While the stimulus‐size dependency has been well documented at the cellular level, nothing is known about its consequences on global functional maps.

Methods: Optical imaging of intrinsic signals in the primary visual cortex was carried out in anesthetized cats. Stimuli consisted of 0.75 to 0.1 cycles per degree square‐wave gratings drifting in 8 directions at 2 to 4 Hz and were presented monocularly. Responses were obtained for different stimulus diameters (3 to 50 deg, and a full screen condition).

Results: The minimal visual stimulation necessary to activate areas 17 and 18 was around 3 and 6 deg. in diameter respectively. The activation area of cortex (10‐30 mm2) was dependent of the eccentricity (0 to 30 deg). The pixelwise measure of the signal magnitude in this area showed a modular organisation uncorrelated with the orientation map and stable in time: Half of the pixels had a maximum activation for the full screen stimulation (full field facilitation) and the other half attained their maximum for diameters about 15 and 30 deg of diameter in area 17 and 18 respectively (full field suppression). The suppression by the full screen stimulation was around 30% in both areas.

Conclusions: Thus, the maximum activation revealed by optical imaging necessitates the stimulation of a much larger spatial area than that observed with single cells. This difference is likely due to the fact that this method reflects in‐ and out going signals and reveals activity of adjacent neurons being part of intra‐cortical and thalamo‐cortical circuits. Supp: NSERC and CIHR.
Decreased OCT measured central retinal thickness in patients with and without minimal diabetic retinopathy
Authors: KOK PHB , VAN DIJK HW , BIALLOSTERSKI C , VAN VELTHOVEN MEJ , VERBRAAK FD
Published: October 2007

Purpose: To evaluate OCT measured central retinal thickness (RT) in diabetes mellitus (DM) patients, with or without minimal diabetic retinopathy (DR).

Methods: DM patients with or without minimal DR on biomicroscopy, were included and underwent a full ophthalmologic examination, (redfree) fundus photography and OCT scanning of the macula using StratusOCT (Zeiss). Mean RT measurements of the fovea (A1), pericentral ring (A2‐A5) and the peripheral ring (A6‐A9) in the patients were compared with RT measurements in normal, sex and age‐matched subjects.

Results: One hundred DM patients were included in this study of which 50 type 1 and 50 type 2. Fundus photography showed either no abnormalities or only few microaneurysms in the posterior pole. The mean pericentral RT was significantly decreased in DM patients with and without minimal DR compared with the normal controls (n=100).

The predicted value of the mean pericentral RT calculated with a regression model, based on the normal subjects, was not significantly different from the truly measured mean pericentral RT.

Conclusions: In contrast with previous studies, we found that the pericentral RT in DM patients seems to be decreased compared to healthy subjects. This could be explained by the loss of intraretinal neurons in the earliest stage of DR. The use of a regression model suggests this neural tissue loss is not restricted to the pericentral region.
Minocycline is cytoprotective in human trabecular meshwork cells and optic nerve head astrocytes by increasing expression of XIAP, Survivin and Bcl‐2
Authors: KERNT M , NEUBAUER AS , YU AL , KAMPIK A , WELGE‐LUSSEN U
Published: October 2007

Purpose: Primary open‐angle glaucoma (POAG) is one of the leading cause for blindness. Activation of optic nerve head astrocytes (ONHA) and loss of trabecular meshwork cells (TMC) are pathognomonic for this disease. Oxidative stress (OS) and elevated levels of TGF‐beta play an important role in the pathogenesis of this neurodegenerative disease. This study investigates possible anti‐apoptotic and cytoprotective effects of Minocycline (M) on TMC and ONHA under OS and TGF‐beta.

Methods: TMC and ONHA were treated with 1μM to 150μM M. Possible toxic effects and IC50 were evaluated after 24h (MTT). To investigate possible protective effects of M on TMC and ONHA, cell proliferation and viability was examined. Expression of XIAP, Survivin as well as Bcl‐2 and their mRNA was assessed by RT‐PCR 24h after treatment with M alone, additional incubation with TGF‐beta‐2 and OS.

Results: M concentrations from 1μM to 75μM showed no toxic effects on TMC and ONHA. Under conditions of OS both TMC and ONHA showed an increase in viability and ability to proliferate when treated with 20‐40μM M. RT‐PCR yielded an overexpression of XIAP, Survivin and Bcl‐2, when TMC or ONHA cells were treated with 20‐40μM M for 24 hours, under OS and when additionally incubated with TGF‐beta2.

Conclusions: We could show that M does not have toxic effects on TMC and ONHA cells up to 75μM. The observed increase in viability and proliferation under OS and TGF‐beta2 and the overexpression of XIAP, Survivin and Bcl‐2 after treatment with 20‐40μM M might prevent apoptotic‐cell‐death in response to cellular stress and may be a protective pathway for TMC and ONHA to avoid progression of glaucomatous degeneration.
Human choroidal endothelial cell growth factor signalling in age‐related macular degeneration
Authors: STEWART EA , BROWING AC , AMOAKU WMK
Published: October 2007

Purpose: Age‐related macular degeneration (AMD) is the most common cause of irreversible visual loss in elderly populations in the western world[1]. As the population ages, the number of people with AMD will increase even further with marked economic implications. Neovascularisation by human choroidal endothelial cells (hCEC) causes wet AMD; however, the mechanisms responsible are not fully understood. In order to assist in the development of future treatments of AMD, further investigation is required into the intracellular mechanisms involved in the activation of hCECs.

Methods: hCEC were isolated and cultured in EBM2‐MV medium as previously described. Cell proliferation after exposure to selected growth factors was measured using the WST‐1 assay, which was validated by manual cell counting. The effect of the growth factors on angiogenesis was assessed using a double layer Matrigel technique. The signalling involved was analysed by isolating phosphotyrosine proteins and 2D gel electrophoresis.

Results: A consistent pattern was seen between growth factors in all experiments. For example VEGF stimulated significant increases (180% and 160%) in both proliferation and angiogenesis, whilst IGF‐1 did not significantly increase either.

Conclusions: Several growth factors may have potent roles in AMD and this complicates its treatment. The identification of the specific signalling pathways involved in growth factor stimulation may allow more specifically targeted treatments of AMD in the future.
Orbscan evaluation of keratoconus
Authors: HERNANDEZ VERDEJO J , CANADAS SUAREZ P , MARINA C , GARCIA‐GONZALEZ M , TEUS MA
Published: October 2007

Purpose: To evaluate corneal structure in keratoconus eyes using “in vivo” laser confocal microscopy.

Methods: In this prospective study we evaluated 23 eyes of 12 consecutive patients with keratoconus [6 men and 6 women, mean aged 37,30 ± 9,93; range: 23‐52 years]. 23 eyes of normal patient were the control group. Keratoconus were classified in mild (<47D), moderate (entre 47‐55D) and severe (>55D).We evaluated using laser confocal microscopy the corneal epithelium, Bowman layer and anterior, intermediate and posterior stroma. We quantified the mean density per mm2 of basal epithelial cells, anterior stromal keratocites (50 μm down Bowman layer), intermediate and posterior (50 μm up endothelial cells). All measurements were done by the same masked examiner.

Results: Of the 23 eyes, 16 had mid keratoconus , 5 moderate keratoconus and 2 severe keratoconus.

Basal epithelial cells density was 5600,22 cél./mm2 ± 975,13. Keratocite density was 391,04 cél./mm2 ± 105,39 in anterior stroma, 353,83 cél./mm2 ± 53,28 in intermediate stroma and 349,43 cél./ mm2 ± 61,34 in posterior stroma. We found a reduction of cellular density in all measurements with a p<0,01 when compared with normal population.

Conclusions: Using laser confocal microscopy HRT2‐RCM is possible to measure the reduction of the keratocite population in keratoconus eyes. The clinical relevance and implications that this fact may have need further research.
Remodelling of collagen fibrils and proteoglycans in the zebrafish cornea during development
Authors: AKHTAR S , SCHONTHALER HB , BRON AJ , DAHM R
Published: October 2007

Purpose: Collagen fibrils and proteoglycans are the main components of the corneal extracellular matrix and corneal transparency depends crucially on their proper organisation. We investigated their formation and arrangement in the developing cornea of the zebrafish, a major model of vertebrate development and genetic disease.

Methods: We employed thin‐section electron microscopy to investigate the ultrastructure of the zebrafish cornea at different stages of development.

Results: Layering of the zebrafish cornea into an epithelium, Bowman’s layer, stroma and endothelium was observed by 72 hours post‐fertilization. At this stage, the stroma contained orthogonally arranged collagen fibrils and small proteoglycans. The density of proteoglycans increased gradually throughout subsequent development. In the stroma of 2 week old larvae, the collagen fibrils were organized into thin lamellae for the first time and were separated by very large, randomly distributed proteoglycans. At 4 weeks, a regular arrangement of proteoglycans around the collagen fibrils was observed for the first time and the lamellae also thickened.

Conclusions: This is the first report of collagen fibril and proteoglycan development in the zebrafish cornea and it directly correlates collagen fibril and proteoglycan organisation of the zebrafish cornea with that of the human cornea. The similarities between the two species, including the possession of a Bowman layer, suggest that the zebrafish could serve as a model for the genetics of human corneal development and inherited disease.
Lymphocyte activation marker analysis in patients with sight threatening uveitis
Authors: WILLERMAIN F , VEREERTBRUGGHEN H , SERVAIS G , BRUYNS C , CASPERS L , DUCHATEAU J
Published: October 2007

Purpose: To investigate the expression of CD69 on CD4 and CD8 lymphocytes of patients with autoimmune uveitis

Methods: Peripheral blood from 14 patients with severe autoimmune uveitis and 15 healthy controls was directly cultured in RPMI for 3 days. T lymphocytes were thereafter analysed by flow cytometry for the expression of CD25, CD69 or CD28, CD69 on CD4+ or CD8+ T cells respectively.

Results: The expression of CD69 by CD4+ lymphocytes of patients with uveitis was significantly higher than in control subjects (p=0.029). This difference was more pronounced when CD69 expression was analysed on CD4+CD25++ lymphocytes (p=0.016) and lost for CD4+CD25+ T cells. Besides, the number of CD4+CD25++ lymphocytes was increased in the uveitis group (p=0.01). However, we did not observed any correlation between the level of CD69 on CD4+ lymphocytes and the severity or aetiology of the disease. No differences were found when the expression of CD69 was studied on CD8+ lymphocytes.

Conclusions: Our results suggest that some patients with autoimmune uveitis have a spontaneous activation of their CD4+CD25 ++ lymphocytes.
Strampelli's osteo‐odonto‐keratoprosthesis
Authors: BARRAQUER J , TEMPRANO J , DE LA PAZ MF
Published: October 2007

Purpose: This presentation is meant for the keratoprosthesis session organized by Christopher Liu. The early technique for "osteo‐odonto‐keratoprosthesis" described first by Strampelli in 1963 is demonstrated converting the inclusion of an acrylic prosthesis into an "heterotopic autoplastic transplantation" for the management of chemical and thermal burns, autoimmune disease (Stevens‐Johnsons, Lyell), trachoma or pemphigoid scarring, etc.

Methods: The surgery comprises three phases. Phase 1: Superficial keratectomy, cleaning and repair of the ocular surface and the fornices and transplantation of buccal mucosa from the internal lip onto the ocular surface. Phase 2: Removal of a superior canine surrounded by dentine and bone. After shaping an adequate lamina of tooth and bone a central trephination is performed to receive the optical PMMA cylinder which is glued into place with dental glue. Then the entire block is placed into the inferior orbital space for biointegration. Phase 3 consists in removal of the osteo‐odonto‐keratoprosthesis from the orbital socket, dissection of the buccal mucosa, central trephination of the

host cornea and fixation of the osteo‐odonto.keratoprosthesis into the corneo‐scleral bed.

Results: Some results and variations of the early technique are illustrated and discussed.

Conclusions: Although the technique was primitive and complicated, Strampelli's idea to use autoplastic tissue to incorporate the artificial prothesis into the ocular surface has to be coinsidered of great importance for the evolution of modern techniques of keratoprosthesis implantation.
Watch out if you tell it with flowers: Euphorbia latex keratitis
Authors: LANGMAN ME , DIGHIERO PL , GICQUEL JJ
Published: October 2007

Purpose: To report an unusual case of deep corneal ulceration due to the latex of Euphorbia.

Methods: A 76 year old woman presented in emergency to the ophthalmology department with a red, painful eye and blurred vision 2 days after ocular exposition to the sap of Euphorbia species.

Results: The best corrected visual acuity was 20/200. The examination in the slit lamp showed a deep central corneal ulceration, epithelial sloughing and Descemet’s folds. Cultures were sterile.

The patient underwent local treatment, ciprofloxacin and picloxydine dichlorhydrate 0, 05% for 10 days with a corneal ulceration healing. A punctuate keratitis remained which disappeared under vitamin A ointment. Regular controls were performed. The best corrected final visual acuity found 3 weeks later was 20/25. A review of the literature revealed that Euphorbia sap has an antineoplastic effect in rodents. This could be a cause of the delay in the corneal epithelial healing process.

Conclusions: To our knowledge, this is the first case reported of a corneal ulceration after eye contact with the latex of Euphorbiaceae. The clinical findings described in the literature varied from a mild keratoconjuntivitis to a severe keratitis with stromal edema, epithelial sloughing and anterior uveitis. We also encourage to wearing eye protection in those who work with this family of plants.
Nodular Degeneration
Authors: WOOD TO , WILLIAMS EE , HAMILTON DL
Published: October 2007

Purpose: Recent studies suggest that Salzman's Nodular Degeneration can be treated effectively using excimer laser phototherapeutic keratectomy (PTK). However, superficial keratectomy (SPK), a simple office procedure for removing the nodules, has shown similar post‐operative results. The purpose of the study is to describe this procedure and present post‐operative outcomes relative to improvement and/or stabilization of vision and relief of discomfort.

Methods: The study sample consisted of 36 eyes among 30 consecutive patients with symptomatic Nodular Degeneration. Twenty‐five were female. Twenty‐six eyes presented with decreased vision and discomfort, four with only decreased vision, and six with only irritation. All patients underwent removal of the nodules using the SPK procedure.

Results: Thirty‐three of the 36 eyes have follow‐up at the present time (average follow‐up, 1 year). Thirty‐two of the 33 eyes have had improvement in vision, discomfort, or both. One has had improvement in vision but occasionally experiences mild discomfort. Two patients with initial improvement through 9 and 13 months had asymptomatic recurrences as of 27 and 17 months. The second patient has keratoconus and wears a hard contact lens, creating the recurrence which was removed before symptoms developed. At 22 months, there was no recurrence.

Conclusions: In this series, Nodular Degeneration has been successfully treated by SPK without the addition of excimer laser therapy.
Oxygen gradients in the anterior segment of the eye
Authors: REITSAMER HAR
Published: October 2007

Purpose: To investigate the oxygen gradients in the anterior segment of the eye in anesthetized rabbits.

Methods: Mean arterial pressure (MAP) and intraocular pressure (IOP) were measured by direct cannulation of the central ear artery and the vitreous respectively. Laser Doppler flowmetry was used to measure ciliary blood flow (CilBF, n=5), oxygen tension was measured with two fluorescent probes at the corneal endothelium and the anterior surface of the lens. To change oxygen gradients the cornea was exposed to either nitrogen or room air.

Results: Baseline values: MAP 75.6±1.3 mmHg, IOP 15±1.5 mmHg, CilBF 53.8±4.2 P.U., oral mucosal oxygen saturation 89.9±0.7 %, pO2 Lens 20.8±3.3 mmHg, pO2 corneal endothelium 49.6±1.5 mmHg. Exposing the cornea to 100% N2 did not change MAP, IOP, CilBF or arterial O2 saturation. However, pO2 at the endothelial side of the cornea and the anterior lens surface dropped by 87% and 57% respectively (p<0.05). Topical brimonidine 0,2% was used to lower CilBF, which caused a significant reduction of oxygen tension in the posterior chamber by 34% and at the corneal endothelium by 8%.

Conclusions: Changes of oxygen gradients in response to all perturbations were observed. The cornea is an important source of oxygen in the anterior chamber, however, changing ciliary blood flow also impacts the oxygen levels at the cornea. Oxygen gradients in the anterior segment are very sensitive to local perturbations.