[Angioid streaks]

Angioid streaks represent breaks in Bruch's membrane, appearing as dark or reddish radial streaks eminating from the optic disc. Usually asymptomatic, these streaks may develop neovascularisation and lead to a maculopathy with marked loss of vision. Some associations with systemic disease are classically described, especially pseudoxanthoma elasticum. This condition may involve cardiovascular complications. A mutation has been found in the ABCC6 gene, which encodes for a membrane transport protein involved in the synthesis of the extracellular matrix. Imaging allows for visualization of the extent of the streaks, and autofluorescence is particularly informative. Spectral domain OCT may also demonstrate early breaks in Bruch's membrane. Neovascular complications, previously responsible for inevitable visual impairment at some point after their occurrence, are now managed by intravitreal injections of anti-VEGFs with clear efficacity. The ophthalmologist must be aware of this condition, in order to guide the patient towards a systemic work-up if necessary, and also to insure quick and targeted treatment in the case of neovascular complications.

[New therapeutic approach of keratoconus with intracorneal ring segments aided by femtosecond laser (Tecnolas Perfect Vision): indications, operating technique and results]

OBJECTIVE

To assess the results of intracorneal ring segment implantation assisted by the Tecnolas Perfect Vision(®) femtosecond laser (Heidelberg, Germany).

SETTINGS

Retrospective observational study.

METHODS

The patients were operated on with the Tecnolas Perfect Vision(®) femtosecond laser. The following parameters were evaluated before and after surgery: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal topography, wavefront analysis, and central corneal thickness. The Wilcoxon test was used for statistical analysis.

RESULTS

Seventeen eyes of 15 patients were included. The mean follow-up was 6.9±0.71 months. Significant improvement of UCVA and BCVA was observed in 82.35% (P=0.027) and 94.12% (P=0.003) of the eyes, respectively. The subjective refraction showed a significant decrease of the sphere from -10.29±5.54 to -6.5±5.03D (P=0.002). The subjective cylinder significantly decreased from 5.43±3.20 to 3.69±2.30D (P=0.026). The SAI also decreased significantly (P=0.011).

CONCLUSION

Femtosecond-assisted intracorneal ring segment implantation is an effective treatment for corneal ectasia. Further studies are needed to improve surgical parameters and outcomes.

[New approach for determining the damage level of biological tissues using femtosecond laser: advantages and application to corneal surgery]

INTRODUCTION

Optimization of femtosecond laser characteristics in corneal surgery is still needed to improve clinical results. In this study, we describe an original characterization technique able to measure laser damage of corneal tissues precisely and to provide complementary physical results on the laser-matter interaction.

METHOD

A femtosecond laser was used to damage corneas not suitable for graft. The epithelium and the Bowman layer are exposed to a set of different single-shot fixed laser fluences. Optical microscopy can determine the probability of laser damage on the corneal surface. The high damage threshold (minimum fluence systematically damaging the cornea) roughly fixes the operating laser fluence conditions, while the low damage threshold sets the maximum laser fluence level preserving tissue integrity (safety level).

RESULTS

We precisely evaluate the damage fluence threshold of a tissue, using a statistical approach coupled with optical microscopy analysis. This technique gives essential information on laser-tissue interaction with a high rate of confidence. For corneal epithelium and the Bowman layer, we determine the maximum laser fluence level preserving tissue integrity (safety level) and the minimum fluence level systematically damaging the tissue. High and low threshold fluences of epithelium and the Bowman layers are (5.6 ± 0.4 J/cm(2); 2.7 ± 0.1 J/cm(2)), and (7.1 ± 1.1 J/cm(2); 3.4 ± 0.1 J/cm(2)), respectively.

CONCLUSION

These data constitute determinant parameters for clinical applications, since they determine a working window providing the minimal effective irradiation dose that is mandatory for the development of high-quality laser-cutting surgery processes with minimized side effects.

[Anterior segment analysis using OCT3]

PURPOSE

Optical coherence tomography has been used for many years, in particular in the field of the retinal imaging, and is a promising technique in the analysis of the anterior segment, providing a similar resolution to histology for ocular tissue.

MATERIAL AND METHODS

We present a collection of images obtained with the OCT3 (Carl Zeiss Meditec, Dublin, CA), with parameters set to obtain good-quality images of the iris and corneal structures.

RESULTS

The OCT provides detailed analysis of the cornea, precise assessment of the dimensions and locations of corneal lesions - in the anterior-posterior plane as well as transversally or obliquely - with 10-microm precision, and the study of the iridocorneal angle and its dynamics.

DISCUSSION

Using the highly precise OCT3 for retinal imaging, it is possible to obtain good-quality anterior segment imaging, which makes the device highly versatile and thus increases reasons for acquiring this type of apparatus.

CONCLUSIONS

OCT3 users should not neglect this potential of the device, already in wide use for examining the retina.

Kératoplastie lamellaire antérieure assistée par laser femtoseconde

INTRODUCTION

Automated lamellar keratoplasty remains a challenging surgical technique because of surgical difficulties and is associated with a high rate of complications. The precision of the corneal cut at any corneal depth with the femtosecond laser is an important improvement in this technique. We report the first case of femtosecond-assisted anterior lamellar keratoplasty.

MATERIAL AND METHODS

A 63-year-old woman with anterior stromal dystrophy underwent femtosecond laser-assisted ALTK on the left eye. A donor lenticula was prepared from a corneoscleral rim utilizing the Femtec 20/10 Perfectvision femtosecond laser device and an artificial anterior chamber (Moria, Antony, France). The anterior lamellar cut was also performed on the patient's eye with the femtosecond laser.

RESULTS

Postoperative examinations showed a well-adapted graft with a clear interface. OCT III (Carl Zeiss Meditech, Dublin) measurements showed a corneal pachymetry of 713 microm associated with a regular posterior bed and a central thickness of 132 microm.

DISCUSSION

Femtosecond laser corneal cutting may offer greater safety, reproducibility, predictability, and flexibility. The risks of irregular cutting and microperforation are reduced. A better graft congruence can limit the risk of secondary displacement and the smooth interface should improve visual results.

CONCLUSION

Donor lenticulae and corneal cuttings performed with the Femtec 20/10 Perfectvision( femtosecond laser device can be used in the successful management of eyes requiring anterior lamellar keratoplasty. Further studies are needed to evaluate outcomes of this procedure.

Traitement médical de l’œdème maculaire

Macular edema was first described more than a century ago, and its medical treatment has made great progress thanks to recent pharmacological advances. Administration is topical, local (peri- or intraocular), or systemic. Nonsteroidal anti-inflammatory agents and corticosteroids are the mainstay therapy when inflammation is involved, as well as acetazolamide in many cases. More recently, molecules such as protein kinase-C- beta inhibitors and anti-VEGF agents are already or will soon be available, to add to our therapeutic armamentarium. Perhaps combination therapy will become popular, as is the case with age-related macular degeneration.

Identification of novel mutations in WFS1 and genotype-phenotype correlation in Wolfram syndrome

Mutations in the WFS1 gene have been reported in Wolfram syndrome (WS), an autosomal recessive disorder defined by early onset of diabetes mellitus (DM) and progressive optic atrophy. Because of the low prevalence of this syndrome and the recent identification of the WFS1 gene, few data are available concerning the relationships between clinical and molecular aspects of the disease. Here, we describe 12 patients from 11 families with WS. We report on eight novel (A214fsX285, L293fsX303, P346L, I427S, V503fsX517, R558C, S605fsX711, P838L) and seven previously reported mutations. We also looked for genotype-phenotype correlation both in patients included in this study and 19 additional WS patients that were previously reported. Subsequently, we performed a systematic review and meta-analysis of five published clinical and molecular studies of WFS1 for genotype-phenotype correlation, combined with our current French patient group for a total of 96 patients. The presence of two inactivating mutations was shown to predispose to an earlier age of onset of both DM and optic atrophy. Moreover, the clinical expression of WS was more complete and occurred earlier in patients harboring no missense mutation.

Traitement endovasculaire de l'hypertension intracrânienne bénigne étiquetée « idiopathique ». Analyse de huit cas consécutifs

INTRODUCTION

Optic nerve sheath fenestration or ventricular shunting are classically proposed after failure of medical treatment. Idiopathic intracranial hypertension is caused by venous sinus obstruction in an unknown percentage of cases. Recently, endoluminal venous sinus stenting was proposed as an alternative treatment.

PATIENTS AND METHOD

Between September 2003 and December 2004, eight consecutive patients with a diagnosis of idiopathic intracranial hypertension underwent MRI venography and direct retrograde cerebral angiography.

RESULTS

There were five females and three males aged 22 to 55 years. All patients had vision disorders. The cerebrospinal fluid pressure ranged from 27 to 45 mmHg with normal composition. All patients presented at least one sinus stenosis. Endovascular stenting of the stenotic venous sinus was performed under intravenous heparin administration. Anti-platelet therapy was administered for 3 months post treatment. Intra-sinus pressures were invariably reduced by stenting. Mean follow-up was 18 months. All patients improved clinically. The cerebrospinal fluid pressure had normalized at 3-month follow-up in all patients. In all patients, multidetector row CT-angiography or MRI venography was performed at 3-, 6- and 12-month follow-up and demonstrated the patency of the stent.

DISCUSSION

The importance of venous sinus disease as a cause of idiopathic intracranial hypertension is probably underestimated. Patients with idiopathic intracranial hypertension should be evaluated with direct retrograde cerebral venography and manometry. In patients with venous sinus lesions, treatment by an endoluminal venous sinus stent is a safe and effective alternative for amenable lesions.

Oblitération de l’artère centrale de la rétine secondaire à une dissection de la carotide interne sur fibrodysplasie artérielle

INTRODUCTION

We report a case of a 66-year-old woman presenting a central retinal artery occlusion with no cardiovascular risk factor, with assessment using supra-aortic artery ultrasonography showing total internal carotid artery thrombosis.

OBSERVATION

When vascular thrombosis risk factors are absent, more in-depth assessment such as a supra-aortic artery angioscan can provide the diagnosis of arterial dissection on arterial fibromuscular dysplasia.

CONCLUSION

Central retinal artery occlusion is a rare but severe pathology. Therefore it is very important not to neglect the etiological assessment, because it can be the revealing element of a severe pathology.

[Bilateral corneal endothelial decompensation after postsepticemia coma]

We report a case of unexplained bilateral corneal endothelial decompensation after a coma. A 71-year-old man with no medical history presented with bilateral endothelial decompensation that required penetrating keratoplasty of the left eye combined with cataract surgery. This coma was caused by septicemia originally due to staphylococcus infection following catheter placement in preparation for a CT scan. Visual acuity of the left eye was 20/400 and 20/100 in the right eye when the patient awoke from the coma. After examination, we noted only stromal thickening and Descemet membrane folds causing corneal edema predominating OS. The rest of the exam was normal. Six months after surgery, visual acuity improved to 20/25. The most probable physiopathological mechanism of this decompensation is an iatrogenic complication from drugs administered during the patient's stay in intensive care (oxacillin), but we cannot rule out direct aggression of a bacterium or its toxin or the decompensation of a preexisting pathology.

Evaluation of the effect of JPEG and JPEG2000 image compression on the detection of diabetic retinopathy

AIMS

To compare the effect of classic Joint Photographic Experts Group (JPEG) and JPEG2000 compression algorithms on detection of diabetic retinopathy (DR) lesions.

METHODS

In total, 45 colour fundus photographs obtained with a digital nonmydriatic fundus camera were saved in uncompressed Tagged Interchanged Files Format (TIFF) format (1.26 MB). They were graded jointly by two retinal specialists at a 1 month interval for soft exudates, hard exudates, macular oedema, newvessels, intraretinal microvascular abnormalities (IRMA), and retinal haemorrhages and/or microaneurysms. They were compressed to 118, 58, 41, and 27 KB by both algorithms and 24 KB by classic JPEG, placed in random order and graded again jointly by the two retina specialists. Subjective image quality was graded, and sensitivity, specificity, positive and negative predictive values, and kappa statistic were calculated for all lesions at all compression ratios.

RESULTS

Compression to 118 KB showed no effect on image quality and kappa values were high (0.94-1). Image degradation became important at 27 KB for both algorithms. At high compression levels, IRMA and HMA detection were most affected with JPEG2000 performing slightly better than classic JPEG.

CONCLUSION

Performance of classic JPEG and JPEG2000 algorithms is equivalent when compressing digital images of DR lesions from 1.26 MB to 118 KB and 58 KB. Higher compression ratios show slightly better results with JPEG2000 compression, but may be insufficient for screening purposes.

Metabolic factors and the foveal avascular zone of the retina in diabetes mellitus

AIM

To study the foveal avascular zone (FAZ) of the central retina in diabetic patients with retinopathy having undergone metabolic evaluation.

METHODS

One hundred and ten digital fluorescein angiograms were chosen from our digital image bank after cross matching diabetic patient lists of the ophthalmology and endocrinology departments of our institution. The patients had undergone day visits with systemic, biological and ophthalmologic evaluation, including digital fluorescein angiography.

RESULTS

Sex ratio was M 62/F 48. Average age was 52.4 years (+/- 13.8) with 44 type 1 diabetics and 66 type 2. Retinopathy was present in all patients (54 background (BDR), 30 pre-proliferative (PPDR), 26 proliferative (PDR)). Age was positively correlated with FAZ grade (47.3 years +/- 13.2 for normal FAZ, 53.8 years +/- 13.7 for abnormal FAZ, P=0.03). Lipid profile showed a protective tendency of the Apo A1 fraction of cholesterol on macular vascularization (1.7 gr./l in normal FAZ patients vs 1.43 gr./l in abnormal FAZ patients, P=0.004). Body mass index was negatively correlated with macular ischemia (28.11 if FAZ not severely altered, 25.97 if FAZ severely altered, P=0.03).

CONCLUSIONS

We found possible relations between BMI and Apo A 1 cholesterol and macular vascularization which may warrant further investigation.

Foveal avascular zone in diabetic retinopathy: quantitative vs qualitative assessment

PURPOSE

To describe the relations between foveal avascular zone (FAZ) size and outline in patients presenting diabetic retinopathy.

METHODS

110 high-quality fluorescein angiograms from 110 diabetics were chosen from our digital retinal image databank. Patients with significant media opacities, macular scars, macular hard exsudates, high ametropia, and associated macular pathology were excluded. Both FAZ perimeter and surface area were measured with image analysis software. FAZ outline was graded according to ETDRS report Number 11 (from 0=normal to 4=capillary outline completely destroyed). Data were compared to that of 31 healthy controls. FAZ surface in diabetics was compared to that of controls and FAZ surface was compared to FAZ grade, FAZ perimeter and retinopathy stage in diabetics. Quantitative variables were compared using the U-test of Mann-Whitney or Kruskal-Wallis test and correlations between quantitative variables were estimated with the Spearmann coefficient.

RESULTS

All patients presented diabetic retinopathy (54 BDR, 30 PPDR, 26 PDR). FAZ size was larger in diabetics than controls (P<0.001). In diabetics, FAZ size increased with FAZ grade (P<or=0.006 except between grades 1 and 2=NS) and with retinopathy stage (P<or=0.024). As retinopathy advanced, there was a higher proportion of altered FAZ outlines (P=0.003).

CONCLUSIONS

This study confirms capillary alteration to be the cause of increase in FAZ size in diabetics and presents an alternative evaluation method of the FAZ to FAZ size measurement. No qualitative studies using the ETDRS FAZ grading scale have been performed to our knowledge.

[Quantitative and spatial analysis in image processing: study of drusen distribution from the foveal center in age-related macular degeneration]

Angiofluorograms were obtained from 58 patients presenting posterior pole drusen due to age-related macular degeneration. These frames underwent image processing by morphological mathematics algorithms. The detection sensitivity of this algorithm is 78%. We present a quantitative and spatial analysis of drusen distribution from the foveal center in the form of a graph. This technique may allow for multi-date comparisons, by using a graphic representation of this risk factor for age-related macular degeneration.