[The cornea in high axial myopia]. / Cornée et myopie axile forte.

PURPOSE: To compare corneal characteristics of eyes with high myopia with those of eyes with no spherical ametropia using Orbscan and ultrasonic pachymetry. METHODS: Orbscan and ultrasonic pachymetry values were prospectively recorded in a study group of 105 patients with high myopia (i.e., axial length greater than 26mm in both eyes) and in a control group of 105 patients with no spherical ametropia (absolute value of spherical equivalent less than 1.25D regardless of cylinder value). Astigmatism data were expressed by rectangular coordinates in a dioptric plane. Axis was decomposed in 2 components (WTR/ATR and oblique) which were analyzed by Cos2axis and Sin2axis trigonometric functions. Enantiomorphism (mirror-image symmetry) between fellow eyes was quantified by a Euclidean distance for the location of the thinnest point and by the difference (in absolute value) between 180° and the sum of both axes for astigmatism. RESULTS: In the study group, the mean axial length and subjective spherical equivalent were, respectively, 27.82±2.14mm (26.00 to 34.06) and -9.00±3.46D (-4.71 to -19.82). The mean corneal astigmatism was +0.92D×91.3° in the study group and +0.65D×89.3° in the control group. The mean corneal cylinder was higher in the study group (1.44D versus 0.91D; P<0.001) whereas axis showed no significant differences between both groups. The mean maximal keratometry was steeper in the study group (44.53D versus 44.13D; P=0.03) whereas the mean keratometry and minimal keratometry displayed no significant differences between both groups. No significant differences in central corneal thickness (540.2µm versus 546.9µm; P=0.10), peripheral corneal thickness, corneal diameter, corneal irregularity, asphericity, and irregular astigmatism were found between both groups. There were no significant differences in enantiomorphism parameters between both groups. In the study group, correlation with axial length was significant only for spherical equivalent (r=-0.86; P<0.001) and corneal cylinder (r=0.16; P=0.04). CONCLUSION: High myopia exhibits corneal characteristics similar to corneas of eyes with no spherical ametropia, except for toricity. While the posterior segment elongates, development of high myopia appears not to affect corneal characteristics. Corneal toricity may be associated with evolution toward high myopia by perturbing mechanisms of emmetropization.

Prognostic factors associated with the need for surgical treatments in acanthamoeba keratitis.

PURPOSE: The objective of this study was to assess the factors associated with anatomical and visual outcomes in patients presenting with Acanthamoeba keratitis (AK). METHODS: This is a retrospective noncomparative interventional case series study comprising 44 eyes from 42 patients presenting with AK, treated with topical hexamidine diisethionate and topical polyhexamethylene biguanide, monitored between 2004 and 2008. AK was confirmed by polymerase chain reaction or direct microscopic examination. Correlation between clinical presentation and prognosis was assessed. Anatomical outcome was assessed according to the percentage of eyes requiring at least 1 surgical procedure in addition to topical treatment. Visual outcome was assessed by the best-corrected visual acuity at the end of follow-up. RESULTS: Polymerase chain reaction results were positive for Acanthamoeba in 40 of the 44 eyes (91%) and in 16 of the 44 eyes (36%) by direct microscopic examination. Confocal microscopy suggested the presence of Acanthamoeba in 12 of 19 eyes (63%). Amniotic membrane transplantation was performed in 8 eyes, penetrating keratoplasty in 4 eyes, and evisceration in 2 eyes. The average follow-up time was 10 months. Surgical treatment was significantly associated (P < 0.05) with time from symptom onset to diagnosis of >30 days, an initial visual acuity of ≤20/200, an infiltrate size of >3 mm, preperforating infiltrates, and corneal neovascularization. The average final visual acuity was 20/48 in eyes that did not require surgical treatment (n = 34) and 20/1702 in eyes that required at least 1 surgical procedure (n = 10; P < 0.0001). CONCLUSIONS: Late diagnosis, low initial visual acuity, corneal neovascularization, large infiltrates, and preperforated infiltrates were associated with surgical treatment in patients presenting with AK. Surgical intervention was associated with worse visual outcome.

The efficacy of voriconazole in 24 ocular Fusarium infections.

PURPOSE: We examined, retrospectively, the efficacy of voriconazole in Fusarium eye infections. METHODS: Voriconazole-treated patients with proven or probable keratitis or endophthalmitis from the voriconazole database (9 patients) and six French ophthalmology departments (15 patients) were included. Sociodemographic features, predisposing factors, history of corneal trauma, associated ocular conditions, other diseases and prior therapies were analysed. Investigator-determined success was defined as infection resolution with medical treatment. Failure was no response or persistent infection and required surgery. RESULTS: Most patients were Caucasian (83 %) and male (71 %). The infection was keratitis (63 %) or endophthalmitis (37 %) and proven in 23 (96 %). Prior therapy included topical and/or systemic amphotericin (46 %), fluconazole (17 %) or others (33 %), often in combination. Causative fungi were Fusarium solani (14, 58 %), Fusarium moniliforme (1), Fusarium oxysporum (1) and Fusarium spp. (8). Voriconazole was administered systemically, topically and/or by intraocular injection, and 16 patients (67 %) received salvage and eight primary therapy. The overall response was 67 % (73 % keratitis and 56 % endophthalmitis) but seven patients required adjunctive surgery. However, response was 63 % for eight primary therapy patients and 69 % for 16 salvage therapy patients. Response by species was Fusarium solani 64 % (9/14) and all others 80 % (8/10). In 13 patients (77 %), voriconazole was used in combination (response 69 vs. 64 % alone) with topical [amphotericin B 10/24 (42 %), caspofungin 5 (21 %), natamycin 1 (4 %)] and systemic agents [caspofungin 3 (13 %), amphotericin 2 (8 %)]. CONCLUSIONS: Topical and systemic voriconazole appears to be effective alone or in combination with other agents for treating severe Fusarium keratitis or endophthalmitis.

[Relationships between refractive parameters: sphere, cylinder and axis]. / Relations entre les paramètres de la réfraction : sphère, cylindre et axe.

PURPOSE: To analyze the relationships between refractive parameters as well as the relationship between fellow eyes in a normal population. METHODS: Both subjective refraction and auto-refractometry data of 500 patients were prospectively recorded. Refraction data were analyzed on three rectangular coordinates in a dioptric space. WTR/ATR ratio of axis was quantified by the Cos2axis function. Enantiomorphism (mirror-image symmetry) between fellow eye axes was quantified by the absolute value of the difference between 180° and the sum of both axes. RESULTS: Mean refraction and mean cylinder were -1.74D (+0.28D × 91.5°) and 0.81 ± 0.89D respectively. The spherical component had no significant influence on refractive astigmatism (r(s)≤ 0.07, P ≥ 0.07) except for high spherical ametropia. Eyes with spherical equivalent greater than 4D (in absolute value) demonstrated higher cylinder (1.15D vs 0.84D, P<0.001). Cylinder influenced the WTR/ATR ratio (r(s)=-0.25, P<0.001) and the enantiomorphism (r(s)=0.36, P<0.001). Age also influenced the WTR/ATR ratio (r(s)=0.27, P<0.001) and the enantiomorphism (r(s)=0.14, P<0.001). Axes were more likely WTR and enantiomorphic when the cylinder was high and the subject young. Oblique axes were less enantiomorphic (35.5° vs 20.6°, P<0.001) and were associated with lower cylinder (0.56D vs 0.98D, P<0.001). Correlation between fellow eyes was significant for cylinder (r(s)=0.66, P<0.001) and for spherical equivalent (r(s)=0.96, P<0.001). Gender had no significant influence on refraction (P>0.12) except for spherical equivalent (relative hyperopia of +0.17D, P=0.04 in females). CONCLUSION: The spherical component of the refraction appears to be independent of the refractive astigmatism except for high spherical ametropia. Cylinder influences somewhat the WTR/ATR ratio of axis and the enantiomorphism. Relationships between refractive parameters are weak in comparison to the fellow eye relationships.

[Fungal keratitis caused by Cylindrocarpon lichenicola]. / Kératite fongique à Cylindrocarpon lichenicola.

We report a case of a 67-year-old woman with no significant past ocular history, who was referred for management of an unresponsive microbial keratitis resulting from trauma with a piece of clothing fabric 1 month previously in Portugal and worsening despite topical fortified antibiotics. On examination, visual acuity was limited to "light perception". Slit lamp examination revealed an 11×11mm full-thickness corneal infiltrate. Confocal images showed branching hyphae suggestive of a fungal infection. Fungal cultures of corneal scrapings revealed growth of Cylindrocarpon lichenicola, a saprophytic, filamentous fungus, which is an unusual cause of keratitis. Despite aggressive antifungal therapy with voriconazole and amphotericin B, she required penetrating keratoplasty for impending corneal perforation. Follow-up was uneventful, with no recurrence at 1 year. Fungal infections must be suspected in all corneal ulcers of traumatic etiology. Specific cultures and confocal microscopy must be performed early, so as to enable early treatment modification.

[Clinical, microbiological and therapeutic features of severe bacterial keratitis]. / Caractéristiques cliniques, microbiologiques et thérapeutiques d'une série de 111 kératites bactériennes sévères.

PURPOSE: To analyze risk factors and prognosis factors of severe bacterial keratitis. METHODS: Retrospective study of 111 eyes from 105 patients hospitalized from 2005 to 2006 for bacterial keratitis proven by microbiological assessment or suspected (favorable outcome after antibiotic treatment). RESULTS: The main risk factors were contact lens wear (39.6%), ocular surface diseases (36.9%), a history of ocular surgery (27.9%), and ocular trauma (11.7%). Gram-positive cocci were found in 46.8% of cases, Gram-negative bacilli in 19.8%, Gram-positive bacilli in 7.2%, Gram-negative cocci in 2.7%, and Gram-negative coccobacilli in 0.9%. No infectious agents were found in 22.5% of the cases. Two or more bacteria were found in 25.6%. The mean follow-up time was 6.5 months. Resolution of infection was obtained in 77.5% with only medical treatment and in 99.1% with further surgical treatment. Amniotic membrane transplantation was performed in 16.2% and emergency keratoplasty in 8.1%. The mean LogMAR visual acuity was 1.43 initially and 0.84 at the last examination. The final visual acuity was 1.03 for Gram-positive and 0.35 for Gram-negative organisms (p=0.03). CONCLUSION: Bacterial keratitis is a sight-threatening infection. Gram-positive keratitis is more frequent, except for contact lens wearers, and is also more severe.

[Fusobacterium nucleatum isolated from a patient presenting lachrymal canaliculitis]. / Fusobacterium nucleatum isolé chez un patient présentant une canaliculite.

A 68-year-old woman presented with a painless inflammation of the right superior eyelid that had started several weeks before. The clinical diagnosis concluded in canaliculitis and the solid concretions were surgically extracted from the superior canalicula. The anaerobic bacteria Fusobacterium nucleatum sp. nucleatum was isolated. Signs dramatically regressed two weeks after surgery followed by one course of oral amoxicillin and clavulanic acid associated with topical tobramycin. The clinical signs had disappeared two months later.

[Calculations of mean refraction and variation of refraction using a dioptric space]. / Réfraction moyenne et variation de réfraction calculées dans un espace dioptrique.

Polar notations (sphere, cylinder, and axis) of refraction perfectly characterize a single refraction but are not suitable for statistical analysis or graphic representation. While the spherical component of refraction can be easily analyzed by the spherical equivalent, statistical analysis of astigmatism requires non-polar expressions of refraction. Indeed, the cylinder and axis of astigmatism are not independent data. In addition, axis is a directional data including a non-trigonometric cycle. Refraction can be written in a non-polar notation by three rectangular coordinates (x, y, z), which can also represent the spherocylinder by one point in a dioptric space. These three coordinates constitute three independent (orthogonal) variables that correspond to a sphere-equivalent component and a pair of Jackson cross-cylinder components, oriented at 0°/90° (WTR/ATR astigmatism) and 45°/135° (oblique astigmatism). Statistical analysis and graphical representation become less complicated when using rectangular coordinates of refraction. Rectangular coordinates of the mean refraction are obtained by average rectangular coordinates. Similarly, rectangular coordinates of refraction change are obtained by a single subtraction of rectangular coordinates between the final and initial refractions. After statistical analysis, the rectangular coordinates obtained can be converted into a polar form for a more easily understood result. Finally, non-polar notations including rectangular coordinates are useful for statistical and graphical analysis, which would be difficult with only conventional polar notations of refraction.

[Polar and non polar notations of refraction]. / Les différentes expressions <> et <> de la réfraction.

Refraction can be expressed by four polar notations which correspond to four different combinations of spherical or cylindrical lenses. Conventional expressions of refraction (plus and minus cylinder notation) are described by sphere, cylinder, and axis. In the plus cylinder notation, the axis visualizes the most powerful meridian. The axis usually corresponds to the bow tie axis in curvature maps. Plus cylinder notation is also valuable for all relaxing procedures (i.e., selective suture ablation, arcuate keratotomy, etc.). In the cross-cylinder notation, two orthogonal cylinders can describe (without the sphere component) the actual refraction of both the principal meridians. This notation must be made before performing the vertex calculation. Using an association of a Jackson cross-cylinder and a spherical equivalent, refraction can be broken down into two pure components: astigmatism and sphere. All polar notations of refraction may perfectly characterize a single refraction but are not suitable for statistical analysis, which requires nonpolar expression. After doubling the axis, a rectangular projection breaks down the Jackson cross-cylinder, which has a polar axis, into two Jackson cross-cylinders on the 0 degrees /90 degrees and 45 degrees /135 degrees axis. This procedure results in the loss of the directional nature of the data. Refraction can be written in a nonpolar notation by three rectangular coordinates (x,y,z), which can also represent the spherocylinder by one point in a dioptric space. These three independent (orthogonal) variables have a concrete optical significance: a spherical component, a direct/inverse (WTR/ATR) component, and an oblique component of the astigmatism. Finally, nonpolar notations are useful for statistical analysis and graphical representation of refraction.

[Relevance of traditional hospitalizations in an ophthalmology department]. / Pertinence de l'hospitalisation traditionnelle dans un service d'ophtalmologie.

INTRODUCTION: Ophthalmological indications for traditional hospitalizations are not clearly established and should be updated with respect to both healthcare quality and economic considerations. We therefore analyzed the data of patients hospitalized in an ophthalmology department. PATIENTS AND METHOD: We prospectively analyzed the medical and socioeconomic charts of all patients hospitalized during a 2-month period (December 2006 and January 2007) in a single ophthalmology department. RESULTS: Over the 2 months, 349 patients were admitted (mean stay, 3 days), 324 of whom were operated. The main causes of admission were retinal detachments (n=103), injuries (n=33), endothelial cell failure (n=27), cataract (n=27), high ocular pressure (n=23), and corneal abscess (n=17). Admission was mainly guided by the surgeon's habits (n=135, 39%) and was not medically relevant but was generally motivated by financial considerations. Other hospital admissions were medically justified (intravenous injections, head positioning) but the hospitalization of patients living far from the hospital (n=46; 13%) could be limited by the development of housing made available to patients. CONCLUSION: Ophthalmological hospitalization is not always medically relevant and often is based on financial or housing constraints. More than half of the classical admissions should be switched to ambulatory patient care by adapting financial compensations to surgical costs or providing outpatient housing.