Taxane Induced Cystoid Macular Edema: Case Report and Integrated Pathogenic Theory.

PURPOSE: To report a case of a 73-year-old man who presented with decreased visual acuity due to bilateral macular edema after paclitaxel administration for prostate cancer. METHODS: The ophthalmic evaluation consisted of medical and ocular history, Best Corrected Visual Acuity, slit-lamp biomicroscopy and Spectral-domain optical coherence tomography / Fluorescein Angiography. RESULTS: Optical Coherence Tomography and Fluorescein Angiography revealed silent cystoid macular edema. After consulting with the oncologist, the cessation of paclitaxel therapy was decided. The patient presented a gradual but steady resumption of the retinal edema, with complete restoration of normal retinal morphology and function within two months. The pathogenesis of the silent Cystoid Macular Edema (CME) is still unclear. Based on our case and a critical review of the previous observations and published data, we propose that the underlying cause of Taxane induced CME is the functional failure of Aquaporin mediated water transport at the level of retinal Intermediate and Deep capillary plexuses, and at lesser extent at the level of the Retinal Pigment Epithelium. CONCLUSION: Taxane induced silent CME should be attributed to the action of Taxanes on the microtubule guided aquaporin vesicles transport to the cell membrane. In our case of Taxane induced silent CME, withdrawal of the taxane was enough for complete recovery, and no additional treatment was needed.

Dynamic light scattering study on phase separation of a protein-water mixture: application on cold cataract development in the ocular lens.

We present a detailed dynamic light scattering study of the phase separation in the ocular lens emerging during cold cataract development. Cold cataract is a phase separation effect that proceeds via spinodal decomposition of the lens cytoplasm with cooling. The intensity autocorrelation functions of the lens protein content are analyzed with the aid of two methods, providing information on the populations and dynamics of the scattering elements associated with cold cataract. It is found that the temperature dependence of many measurable parameters changes appreciably at the characteristic temperature approximately 16+/-1 degrees C which is associated with the onset of cold cataract. By extending the temperature range of this work to previously inaccessible regimes, i.e., well below the phase separation or coexistence curve at Tcc, we have been able to accurately determine the temperature dependence of the collective and self-diffusion coefficients of proteins near the spinodal. The analysis showed that the dynamics of proteins bears some resemblance to the dynamics of structural glasses, where the apparent activation energy for particle diffusion increases below Tcc, indicating a highly cooperative motion. Application of ideas developed for studying the critical dynamics of binary protein-solvent mixtures, as well as the use of a modified Arrhenius equation, enabled us to estimate the spinodal temperature Tsp of the lens nucleus. The applicability of dynamic light scattering as a noninvasive, early-diagnostic tool for ocular diseases is also demonstrated in light of the findings of the present paper.

Dynamics of proteins: light scattering study of dilute and dense colloidal suspensions of eye lens homogenates.

We report a dynamic light scattering study on protein suspensions of bovine lens homogenates at conditions (pH and ionic strength) similar to the physiological ones. Light scattering data were collected at two temperatures, 20 and 37 degrees C, over a wide range of concentrations from the very dilute limit up to the dense regime approaching the physiological lens concentration. A comparison with experimental data from intact bovine lenses was advanced, revealing differences between dispersions and lenses at similar concentrations. In the dilute regime, two scattering entities were detected and identified with the long-time self-diffusion modes of alpha-crystallins and their aggregates, which naturally exist in lens nucleus. Upon increasing protein concentration, significant changes in time correlation function were observed starting at approximately 75 mg ml(-1), where a new mode originating from collective diffusive motions becomes visible. Self-diffusion coefficients are temperature insensitive, whereas the collective diffusion coefficient depends strongly on temperature revealing a reduction of the net repulsive interparticle forces with decreasing temperature. While there are no rigorous theoretical approaches on particle diffusion properties for multicomponent, nonideal hard sphere polydispersed systems, as the suspensions studied here, a discussion of the volume fraction dependence of the long-time self-diffusion coefficient in the context of existing theoretical approaches was undertaken. This study is purported to provide some insight into the complex light scattering pattern of intact lenses and the interactions between the constituent proteins that are responsible for lens transparency. This would lead to understand basic mechanisms of specific protein interactions that lead to lens opacification (cataract) under pathological conditions.

[The effect of brimonidine on postoperative hypertonia after an extracapsular cataract extraction]. / L'effet de la brimonidine sur l'hypertonie postopératoire après une extraction extracapsulaire de la cataracte.

PURPOSE: We conducted a prospective study to determine the effect of topical administration of brimonidine tartrate 0.2% on postoperative intraocular pressure (IOP) spikes during the first 24 hours after an extracapsular cataract extraction. MATERIAL AND METHODS: In a placebo-controlled study, we randomized 40 consecutive normotensive eyes undergoing extracapsular cataract surgery into two treatment modalities. Twenty eyes (group A) received placebo and 20 eyes (group B) were given brimonidine tartate 0.2% drops twice the day before and twice on the day of the operation. IOP was measured at baseline (prior to surgery) and then 4, 6, 12 and 24 hours postoperatively. RESULTS: Mean postoperative IOP was higher in the placebo group than in the brimonidine group at every time point studied. In both groups, peak elevation of mean IOP was recorded 6 hours after surgery. At that time, mean IOP was significantly higher in the placebo group (36.2+/-4.0 mmHg) than in the brimonidine group (24.7+/-3.8 mmHg) (p<0.001). A gradual reduction in IOP followed, yet with significantly higher values than those found preoperatively, even 12 hours after surgery (p<0.001). It was only the brimonidine group that achieved a near-to-normal mean IOP 24 hours after surgery (p>0.05). Four of the placebo group patients compared to 1 of the brimonidine group patients had an IOP higher than 40 mmHg 6 hours after surgery and therefore received additional therapy. CONCLUSION: Prophylactic treatment with brimonidine tartrate 0.2% drops twice a day for 2 days is effective in reducing IOP spikes throughout the first 24 hours after an extracapsular cataract extraction.

[Idiopathic polypoidal choroidal vasculopathy associated with central retinal vein occlusion]. / Vasculopathie choroïdienne polypoïdale idiopathique associée à une occlusion de la veine centrale de la rétine.

We present the case of a 54-year-old man with a previous history of central retinal vein occlusion in the right eye, who developed an idiopathic polypoidal choroidal vasculopathy in the right eye and an epiretinal membrane in the left eye. The patient's medical history disclosed arterial hypertension controlled with medical treatment. Although idiopathic polypoidal choroidal vasculopathy has been associated with several conditions, this is the first time that this entity has been described in the literature in association with central retinal vein occlusion.

Does identification of the causal organism of corneal ulcers influence the outcome?

PURPOSE: To investigate whether identification of the causal organism in corneal ulcers influences their outcome. METHODS: We retrospectively studied 114 patients, 72 males and 42 females aged 6-89 years, admitted to this eye clinic during the years 1994-2000 on account of an infectious corneal ulcer. Their examination included a detailed history, visual acuity measurement, and biomicroscopy in everyday follow-up. The ulcers were classified according to their severity and outcome. We assessed the cases where cultures had been done, reviewed the results, and searched for a possible correlation between the outcome and the fact of culturing the ulcer and identifying the causal organism. RESULTS: Of the 114 corneal ulcers studied, 23 were mild, 49 moderate, and 42 severe. Fifty (44%) had not been cultured, but 64 ulcers (56%) had been cultured, with a positive result in 37 cases (58%), Staphylococcus and Pseudomonas species being the most common organisms found. In moderate and severe ulcers, there was a tendency to a higher proportion of successful outcome for cultured ulcers, but with no significant correlation. CONCLUSIONS: Despite a tendency towards favorable results in culture-positive corneal ulcers, the influence of the detection of the organism on their outcome has not been proved. The role of the initial broad-spectrum antibiotic therapy remains important.

Corneal complications following abuse of topical anesthetics.

PURPOSE: To describe corneal complications in three patients following abuse of topical anesthetics. MATERIALS AND METHODS: We describe one case with bilateral corneal perforation, another with unilateral corneal perforation and a third case of chronic keratitis following excessive use of topical anesthetics. RESULTS: Two patients continued to instill topical anesthetic drops despite all recommendations to stop. The result was a bilateral corneal perforation in the first case and a large unilateral descemetocele in the second. The third patient who had chronic toxic keratitis discontinued the anesthetic drops and after the appropriate treatment the cornea returned to normal. Corneal grafting and conjunctival flaps were used to seal the corneal perforation but the long-term anatomical and functional results were very poor. CONCLUSIONS: The initial presentation of this rare clinical entity creates difficulties in reaching a correct diagnosis. A presumed acanthamoeba keratitis is the first choice among many similar conditions. Thus abuse of topical ocular anesthetic drops should be included in the differential diagnosis of cases of chronic keratitis as it may masquerade as acanthamoeba keratitis. A current or past history of psychiatric and mental disorders or psychoactive substance abuse is important in the diagnosis. Functional and anatomical results after appropriate treatment are usually poor. Psychiatric counselling is extremely helpful and is in fact mandatory in the management of these patients.

[Bilateral peripheral retinal neovascularization in a patient with multiple sclerosis]. / Néovascularisation rétinienne périphérique bilatérale chez un malade de sclérose multiple.

We present the case of a 32-year-old man suffering from multiple sclerosis who had developed bilateral peripheral neovascularization of the retina. The main disease had been diagnosed 10 years before, whereas in his ophthalmic history the patient reported an incident of retrobulbar optic neuritis in his left eye occurring 3 years before. The patient was referred to our clinic in order to investigate the cause of a sudden loss of vision in his left eye. Ophthalmic examination and fluorescein angiography revealed the presence of a bilateral peripheral retinal neovascularization with an intravitreous hemorrhage in the left eye. Systemic clinical and laboratory investigation were negative for other causes of retinal neovascularization except multiple sclerosis, which is associated with periphlebitis in 10% of cases. Chronic retinal ischemia may lead to retinal neovascularization.

Keratoconjunctivitis sicca and chronic HCV infection.

BACKGROUND: The aim of this study was to determine the prevalence of keratoconjunctivitis sicca (KCS) in Greek patients with chronic hepatitis C virus (HCV) infection and its association with HCV genotypes and liver histology. PATIENTS AND METHODS: 93 HCVAb (+) patients underwent lacrimal function testing (Schirmer-1 test, break-up time test and Rose-Bengal staining test) and estimation of serum cryoglobulins and autoantibodies. 80 healthy volunteers were included in the study as controls. RESULTS: 34 out of 93 HCV patients (36.6%) and eight out of 80 healthy subjects (10%) had at least two abnormal lacrimal function tests suggestive of KCS (p < 0.001), cryoglobulinemia was evident in 20 patients (21.5%), rheumatoid factor (RF) in 43 (46.2%), antinuclear antibodies (ANA) in 19 (20.4%), antinuclear antigens (anti-SS-A and anti-SS-B) in one (1.1%) and two (2.2%) patients, respectively. Reduced prevalence of KCS was found in patients with genotype 3a compared to those with other genotypes (5/30, 16.7% vs 20/42, 47.6%, p = 0.007), probably because of their younger age. In patients with KCS a higher staging score was noted in liver biopsy compared to those without KCS (4.50 +/- 1.65 vs 3.06 +/- 1.88, p = 0.005). CONCLUSION: Greek patients with chronic HCV infection have a high prevalence of KCS (36.6%). The low frequency of anti-SS-A and anti-SS-B antibodies in these patients denotes different pathogenetic associations from primary Sjogren's syndrome.

Evaluating the management of diabetic retinopathy in a teaching center.

PURPOSE: To evaluate the efficacy of the management of diabetic retinopathy (DR) in the teaching center of the University Eye Clinic of Patras in Greece. METHODS: From 1989 to 1999, 302 patients with type I (5.3%) and type II (94.7%) diabetes mellitus (DM) were examined. Standard examination and treatment protocols were employed. Examinations and laser treatment were done by trainee specialists, under the supervision of the head physician (N.Ph), during their rotation in the retina and vitreous disorders outpatient department. RESULTS: At baseline examination, 17.9% of the eyes had no DR, 71.7% had nonproliferative DR, and 10.4% had proliferative DR. In 34.4%, no laser treatment followed. The other 65.6% underwent focal and/or grid laser and/or panretinal photocoagulation and/or vitrectomy. At the final examination, DR was still the same in 63.1% of the eyes, progression had occurred in 34.1%, and regression in 2.8%. Type I DM patients' eyes had a higher prevalence of proliferative DR at the final examination than type II DM eyes. There was also a significant correlation between progression of DR and duration of DM, insulin treatment for DM, and elevated glycosylated hemoglobin (HbA1c). CONCLUSIONS: Having applied standard examination and treatment protocols, the efficacy of the management of our diabetic patients was consistent with international standards, even though patients were treated mostly by doctors in training.

[Effect of squatting on sub-foveal blood flow defect in pseudophakic eyes operated by cerclage]. / Effet du squatting sur le débit sanguin sous-fovéolaire dans les yeux pseudophaques opérés par cerclage.

UNLABELLED: ZIEL: To investigate the relationship between velocity (Velch), blood volume (Volch) and blood flow (Fch), and the mean ocular perfusion pressure (PPm) in the foveal region, and to determine how the regulatory capacity of the choroidal circulation is affected after an encircling buckle procedure. METHODS: We investigated both pseudophakic eyes of 6 patients (age range 56-79 years) in a masked study. Subjects presenting eye diseases (glaucoma, uveitis, diabetic retinopathy) as well as systemic diseases were excluded from the study. All subjects had in one eye a successful management of retinal detachment with an encircling buckling; the second eye was considered as control. Measurements of Velch, Volch and Fch were obtained by Laser Doppler Flowmetry (LDF) at baseline and during isometric exercise (squatting). RESULTS: In the operated eyes, Velch and Fch increased significantly (ANOVA, p < 0.05) during the PPm raise, which was not the case for Volch (ANOVA, p > 0.05). In the control eyes, all hemodynamic parameters remained unaffected by the PPm increase (ANOVA, p > 0.05). The response of Velch and Fch was significantly different (ANCOVA, p < 0.002) between operated and control eyes. CONCLUSION: These results suggest that encircling buckle does affect subfoveal choroidal blood flow regulation, which may explain a possible macular dysfunction in the operated eyes.

[Value of indocyanine green angiography in detection of central serous chorioretinopathy]. / Apport de l'angiographie au vert d'indocyanine à la détection des lésions de choriorétinopathie séreuse centrale.

INTRODUCTION: Central serous chorioretinopathy (CSC) is a relatively common and self-limited disease affecting more commonly young adult males who are likely to have a type A personality. The aim of our study was to analyze indocyanine green (ICG) angiographic findings in CSC and correlate them with the biomicroscopical and Fluoresceine angiography (FA) findings in the affected and non affected eyes. PATIENTS AND METHODS: Our study included 19 consecutive patients, that were affected by CSC. The mean age of the patients was 44 years (range 35-50 years). In thirteen patients, in one eye typical acute lesions were observed, and in six patients presented chorioretinal inactive lesions. Angiographic ICG and FA findings of both eyes were compared. RESULTS: In 13 eyes (68%) presenting with the active form of CSC a classic focal leak with a smokestack phenomenon was seen in FA. The leaking point was identified in both FA and ICG, in 9 out of 13 eyes (70%). Surrounding the FA leaking point, an hyperfluorescent plaque in ICG was associated in 12 out of 13 (92%) eyes with active lesions. In 8 out of 13 (62%) controlateral eyes of this group, hyperfluorescent plaques in ICG were also observed. All eyes with inactive FA lesions (6 out of 6), expressed an hyperfluorescent plaque in ICG. DISCUSSION: ICG hyperfluorescence appears in the affected and the fellow eyes in areas where no clinical or FA signs of active disease were present. The persistence of abnormal ICG findings in all the cases of inactive disease suggest that CSC could be not a recurrent but a chronic disease.

Contrast sensitivity after extracapsular and intracapsular cataract extraction.

Contrast sensitivity function after cataract extraction and intraocular lens implantation has been mainly correlated to the type or the material of the intraocular lens. Our purpose was to identify other possible factors, like posterior capsule, to contrast sensitivity alterations after cataract surgery, comparing patients operated for cataract by techniques that mainly differed on the posterior capsule's integrity. The intraocular lens implanted was either a posterior or an anterior chamber one, always monofocal and made of PMMA. We measured contrast sensitivity function at four spatial frequencies in two groups of operated individuals (group A and B) and in one group of healthy control individuals. Each group consisted of 42 eyes. Group A comprised eyes with intact, clear posterior capsule and posterior chamber monofocal intraocular lens. Group B comprised eyes with ruptured or removed posterior capsule and anterior chamber monofocal intraocular lens. Control group comprised healthy control eyes. A pair matched design was used to compare contrast sensitivity values among the individuals of the three groups. No statistically significant differences in contrast sensitivity values were found when group B patients were compared to healthy controls (p >0.05). Patients of group A exhibited contrast sensitivity function impairment at intermediate and high spatial frequencies when compared to patients of group B (p <0.05) and to controls (p <0.01). It seems that intact posterior capsule provides inferior visual function, in spite of relatively good visual acuity and apparently satisfactory results.

Correlation study of two methods for evaluating corneal endothelial damage in vitro: the Janus green photometry technique versus cell counting.

Counting of endothelial cells after vital staining is a time-consuming method which, in addition, requires considerable experience and does not normally allow for the study of the entire endothelial cell surface. However, the Janus green photometry technique (JGPT) is an objective, time- and personnel-saving procedure which also has the advantage of allowing for the evaluation of the whole endothelial cell surface. A comparative simultaneous experimental study of the two methods had not been reported. Freshly excised pig corneas (n = 58) were preserved in MK storage medium for 4, 7, 14 and 20 days at 4 degrees C. All corneas were stained with Janus green and alizarin red. A 7-mm corneal button corresponding to an endothelial surface of 38.46 mm2 was punched out. The percentage of damaged cells was determined with cell counting (CC) and with JGPT, and the results were statistically compared. Two methods for CC were used. Cells were counted either directly under the microscope or in photomicrographs. The overall correlation between the results of CC and JGPT was R = 0.98. However, when endothelial cell damage was higher than 30%, CC became an estimation by approximation, since necrotic areas were confluent, whereas with JGPT the results were usable even when the damage was 100%. Thus it appears that although the two methods can be used interchangeably, JGPT may in some instances be the method of choice.

[Histologic study of corneal lesions caused by the slime-GLP glycolipoprotein of Pseudomonas aeruginosa]. / Etude histologique des lésions cornéennes créées par la glycolipoprotéine Slime-GLP du Pseudomonas aeruginosa.

The Pseudomonas aeruginosa slime-glycolipoprotein (GLP) is considered as one of the principal pathogenetical factors of the bacterium. A single dose of 100 micrograms of the P. aeruginosa slime-GLP was injected in rabbit corneas intrastromally. Light microscopy showed that 4 hours after the injection, polymorphonuclear leucocytes (PMNs) began to infiltrate the anterior stroma. 24 hours after the intrastromal injection, PMNs had infiltrated full corneal thickness followed by multiple absceses formation, loss of epithelial and endothelial cells, disorganisation of normal collagen fibres and hyperplasy of fibroblasts. These morphological observations are very similar to those observed during experimental P. aeruginosa keratitis and show that the P. aeruginosa slime-GLP is at least in part responsible for the characteristic liquefaction necrosis of the keratitis induced by the P. aeruginosa.

[A new in vitro test of endothelial viability. Vital staining using Janus green with spectrophotometric analysis of the color extract]. / Un nouveau test in vitro de la viabilité endothéliale. La coloration vitale au vert de Janus avec analyse spectrophotométrique du colorant extrait.

A new in vitro technique has been developed to measure by simple photometry the amount of Janus Green extracted with absolute alcohol from isolated corneas after vital staining. The amount of stain corresponds to the percentage of damaged endothelial cells and is a reliable parameter of endothelial viability. More rapid and easier to perform than the usual cell counting of devitalized cells this technique may be used to study the endothelial damage induced e.g. by experimental surgery, intraocular solutions, IOL material, cornea storage solutions.

[In vitro changes in the lens epithelium and corneal endothelium caused by the cytostatic drug daunomycin]. / In vitro Veränderungen des Linsenepithels und Hornhautendothels durch das Zytostatikum Daunomycin.

We evaluated the effects of the antiproliferative drug daunomycin on the viability and proliferation of cultured porcine lens epithelial cells. After a single short-term application, daunomycin penetrates the lens epithelial cells within 5 min. At a concentration of 2.5-7.5 mg/l, daunomycin has a low level of acute cytotoxicity and significantly suppresses the mitotic activity of the epithelial cells in culture. The daunomycin-induced endothelial lesions in freshly excised pig corneas were quantified with the Janus green photometry technique (n = 30) and studied with scanning electron microscopy (n = 9) in comparison to Ringer solution, which served as the control (n = 39). Whether the endothelial lesions were exposed to daunomycin or Ringer solution for 10 or 30 min seemed to make no significant difference. In addition, daunomycin did not seem to induce any morphological changes in the endothelial surface. These in vitro results confirm our clinical experience that daunomycin is apparently not harmful to the adult human corneal endothelium. Our results indicate that short-term endocapsular application of daunomycin during extracapsular cataract extraction, with or without IOL implantation, may prevent and/or delay the formation of capsular opacification.

[In vitro corneal endothelial damage caused by intraocular lenses of PMMA, silicone and polyhema]. / In vitro Hornhautendothelschädigung durch intraokulare Linsen aus PMMA, Silikon und Polyhema.

We compared the endothelial damage to freshly excised pig corneas (n = 156) as a result of contact with IOLs made of PMMA, silicone and polyhema. The contact time was 15 s, 1 min and 30 min. The endothelial damage was quantified with the Janus green vital staining photometric technique. Morphological changes were evaluated by scanning electron microscopy. The most damage was caused by PMMA (7.6%; 10.2%; 19.7%), followed by silicone (4.8%; 6.8%; 10.2%) and polyhema (4.6%; 5.9%; 8.3%). The degree of endothelial damage was statistically significant (P less than 0.01) in comparison with the control groups without any relationship to lens material or contact time. There was no significant difference between the damage caused by silicone and polyhema, but there was a significant difference between PMMA and silicone or polyhema.