Ultraviolet radiation at Mediterranean latitudes and protection efficacy of intraocular lenses.

PURPOSE: After determining the mean intensity of ultraviolet radiation to which the human eye is exposed at Mediterranean latitudes, this data is used to evaluate the efficacy of the ultraviolet filters incorporated into various intraocular lenses. METHODS: Ultraviolet radiation measured at Mediterranean latitudes was used as a reference for the theoretical calculation of the amount of radiation to which the human eye is exposed. The spectral transmission curve from 290 to 380 nm was measured for 10 IOLs using a UV/VIS Perkins-Elmer Lambda 800 spectrometer. RESULTS: At Mediterranean latitudes, at sea level, with a mean annual solar irradiation of 50 j/cm(2), the human eye receives a quantity of UVA and UVB that is lower than the threshold toxic dose for the rabbit crystalline lens (93 j/cm(2) for UVA and 6.45 j/cm(2) for UVB). However, at higher altitudes and with albedo approaching 0.9 (fresh snow), the amount of radiation increases, with duration of exposure potentially playing a significant role. The UV filters incorporated into the IOLs studied are, in general, protective against such levels of radiation. CONCLUSION: At Mediterranean latitudes, at sea level, the amount of UV radiation to which our eyes are exposed is insufficient to damage the crystalline lens; however, at higher altitudes, the risk of such damage exists. UV filters incorporated into intraocular lenses are generally effective, since they filter all radiation with wavelengths under 380 nm.

Optic nerve alterations in P27(Kip1) knockout mice.

PURPOSE: To study the morphologic characteristics of the optic nerve (ON) by using an experimental model of knockout mice for the expression of the P27(Kip1) gene, mainly involved in cell cycle arrest, apoptosis control, and retinoblastoma protein phosphorylation. METHODS: Eyeballs with the retrobulbar ON attached were obtained from 26-week-old mice. By using morphologic and morphometric techniques, light and electron transmission microscopy, the ON characteristics were determined in two groups of mice: 1) wild type mice as the control group (n=15), 2) homozygous knockout mice (-/-) for the P27(Kip1) gene as the knockout group (n=15). Glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) were studied using Western blot and immunoblotting approaches. RESULTS: The ON cross-sectional area was significantly larger in the P27(Kip1) knockout mice group than in the control group (p<0.001). The axon sizes in knockout animals were much larger than in wild-type mice (p<0.001). Higher number of axons forming the ON, intra-axonal degeneration, myelin sheath, and axoplasm density alterations were found in P27(Kip1) knockout mice when compared with control group (p<0.001). Analysis of lysates of optic nerves by Western blot showed less expression of myelin basic protein and GFAP in P27(Kip1) knockout mice as compared to wild type mice (p<0.005, p<0.01, respectively). CONCLUSIONS: The morphologic and morphometric results suggest that homozygous P27(Kip1) knock-out mice had hypertrophic, hyperplastic, and dystrophic ON.

[Atypical ophthalmic findings in Susac syndrome]. / Síndrome de Susac de presentación ocular atípica.

CASE REPORT: A 25-year-old woman with encephalopathy and sensorineural hearing loss was referred to us in order to confirm Susac syndrome, due to bilateral visual loss. Funduscopic examination revealed peripheral retinal microangiopathy. DISCUSSION: Susac syndrome is typically characterized by the clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss. In our case, ophthalmic findings were atypical. Interrupted vessels and microaneurisms accumulation in the peripheral retina of both eyes were observed.

Síndrome de Susac de presentación ocular atípica / Atypical Ophtalmic Findings in Susac Syndrome

Caso clínico: Mujer de 25 años de edad afecta de encefalopatía y pérdida auditiva neurosensorial, remitida a nuestro servicio para confirmar un síndrome de Susac por presentar una disminución de agudeza visual bilateral. En la exploración funduscópica se apreció una microangiopatía retiniana periférica. Discusión: El síndrome de Susac se caracteriza típicamente por la tríada encefalopatía, perdida auditiva neurosensorial, y oclusiones de ramas arteriales retinianas. En nuestro caso las alteraciones oculares eran atípicas, apreciándose amputación de vasos terminales con cúmulo de microaneurismas en retina periférica de ambos ojos (AU)

Case report: A 25-year-old woman with encephalopathy and sensorineural hearing loss was referred to us in order to confirm Susac syndrome, due to bilateral visual loss. Funduscopic examination revealed peripheral retinal microangiopathy. Discussion: Susac syndrome is typically characterized by the clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss. In our case, ophthalmic findings were atypical. Interrupted vessels and microaneurisms accumulation in the peripheral retina of both eyes were observed (AU)

Optic nerve alterations in PTEN +/- mice.

PURPOSE: To study the morphologic characteristics of the optic nerve (ON) by using an experimental model of knockout mice for the expression of the PTEN gene, mainly involved in cell cycle arrest, apoptosis control, and cell size regulation. METHODS: The eyeballs with the retrobulbar ON attached were obtained from 26-week-old mice. By using morphologic and morphometric techniques, light and electron transmission microscopy, the ON characteristics were determined in two groups of mice: 1) 'wild type' mice as the control group (C-G; n=15), 2) heterozygous knockout mice (+/-) for the PTEN gene (PTEN-G; n=15). Glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) were studied using Western blot and immunoblotting approaches. RESULTS: The ON cross-sectional area was significantly higher in the PTEN-G than in the C-G (p<0.001). The axon sizes in mutant animals were much larger than in wild-type mice (p<0.001). No significant differences were noticed between those groups regarding the number of axons forming the ON and the presence of intra-axonal degeneration, myelin sheath alterations, or axoplasm density. No differences were detected in developmental marker protein expression. CONCLUSIONS: The morphologic and morphometric results suggest that heterozygous PTEN knockout mice had hypertrophic ON without ultrastructural alterations.

Optic nerve alterations in PTEN +/- mice.

PURPOSE: To study the morphologic characteristics of the optic nerve (ON) by using an experimental model of knockout mice for the expression of the PTEN gene, mainly involved in cell cycle arrest, apoptosis control, and cell size regulation. METHODS: The eyeballs with the retrobulbar ON attached were obtained from 26-week-old mice. By using morphologic and morphometric techniques, light and electron transmission microscopy, the ON characteristics were determined in two groups of mice: 1) 'wild type' mice as the control group (C-G; n=15), 2) heterozygous knockout mice (+/-) for the PTEN gene (PTEN-G; n=15). Glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) were studied using Western blot and immunoblotting approaches. RESULTS: The ON cross-sectional area was significantly higher in the PTEN-G than in the C-G (p<0.001). The axon sizes in mutant animals were much larger than in wild-type mice (p<0.001). No significant differences were noticed between those groups regarding the number of axons forming the ON and the presence of intra-axonal degeneration, myelin sheath alterations, or axoplasm density. No differences were detected in developmental marker protein expression. CONCLUSIONS: The morphologic and morphometric results suggest that heterozygous PTEN knockout mice had hypertrophic ON without ultrastructural alterations.

[Contrast sensitivity to intraocular lens TECNIS Z-9000]. / Sensibilidad al contraste en las lentes TECNIS Z-9000.

PURPOSE: To evaluate the increase in contrast sensitivity to intraocular lens TECNIS Z-9000 (Pfizer) compared with other intraocular lenses. METHOD: We implanted a TECNIS Z-9000 lens in 18 patients who had another type of intraocular lens implanted in their other eye. We then tested contrast sensitivity under both mesopic and photopic conditions using the VCTS (Vision Contrast Test System) provided by Vistech Consultants Inc. RESULTS: There was an improved contrast sensitivity at low and medium frequencies, following TECNIS-Z 9000 lens implantation, however this improvement did not reach statistical significance. There were significant differences at high frequencies, which are directly related to the quality of visual function. CONCLUSIONS: TECNIS Z-9000 lens implantation (with a modified anterior surface) achieves a significant improvement in contrast sensitivity, meaning in practice an increase in the quality of visual function.

Sensibilidad al contraste en las lentes TECNIS Z-9000 / Contrast sensitivity to intraocular lens TECNIS Z-9000

Objetivo: Evaluar el incremento en la sensibilidad al contraste de las lentes TECNIS Z-9000 (Pfizer) respecto a otras lentes.Método: Se implantó la lente TECNIS Z-9000 en 18 pacientes que ya habían sido intervenidos de un ojo con otro tipo de lente intraocular. Se les midió la sensibilidad al contraste en condiciones fotópicas y mesópicas mediante el test VCTS (Vision Contrast Test System) de Vistech Consultants Inc.Resultados: Aunque la tendencia es hacia una mejoría de la sensibilidad al contraste en las frecuencias bajas y media, no existen diferencias significativas. Sí que demuestran de forma significativa la mayor sensibilidad al contraste en las frecuencias altas, que son las que están directamente relacionadas con la calidad de la función visual.Conclusiones: Las lentes TECNIS, mediante una modificación de su cara anterior, consiguen de manera significativa una mejoría de la sensibilidad al contraste, que se traduce en un incremento de la calidad de la función visual

Purpose: To evaluate the increase in contrast sensitivity to intraocular lens TECNIS Z-9000 (Pfizer) compared with other intraocular lenses. Method: We implanted a TECNIS Z-9000 lens in 18 patients who had another type of intraocular lens implanted in their other eye. We then tested contrast sensitivity under both mesopic and photopic conditions using the VCTS (Vision Contrast Test System) provided by Vistech Consultants Inc. Results: There was an improved contrast sensitivity at low and medium frequencies, following TECNIS-Z 9000 lens implantation, however this improvement did not reach statistical significance. There were significant differences at high frequencies, which are directly related to the quality of visual function. Conclusions: TECNIS Z-9000 lens implantation (with a modified anterior surface) achieves a significant improvement in contrast sensitivity, meaning in practice an increase in the quality of visual function

Implantation of iris devices in congenital and traumatic aniridias: surgery solutions and complications.

PURPOSE: To show surgical solutions in patients with traumatic and congenital aniridia, to evaluate the clinical improvement of these patients when iris prosthesis are implanted, and to examine safety and complications of these implants in a long-term follow-up. METHODS: Eight patients were included in this retrospective noncomparative case series. Nine eyes had an artificial iris implantation for traumatic or congenital aniridia. Three eyes received a black diaphragm intraocular lens (IOL) in capsular bag after phacoemulsification. An aniridia prosthesis, sulcus sutured, in front of a previous IOL was implanted in two eyes. A black diaphragm IOL, sulcus sutured, in two eyes; two iris diaphragm rings, in front of the previous IOL, in one eye; and a sector iris prosthesis in front of an IOL in the last eye were implanted. Mean follow-up was 22.5 months (range 16 to 44 months). RESULTS: All patients had improved visual acuity (VA) and visual comfort after surgery. The glare disability was subjectively better in all cases. Two patients developed new ocular hypertension after surgery; one of them was controlled by medical treatment and the other needed cyclodiode. Two of the patients with glaucoma preoperatively also needed cyclodiode procedure and one of them an Ahmed valve. CONCLUSIONS: Several kinds of artificial iris implants are available. In all our patients with aniridia, iris artificial prostheses improved VA and diminished visual discomfort. Glaucoma is the most important complication after artificial iris implant. It is possible to implant the iris prosthesis in the capsular bag, but this requires a large capsulorrhexis and presents a surgical challenge.

Effect of prophylactic brimonidine on bleeding complications after cataract surgery.

PURPOSE: To evaluate the effect of prophylactic brimonidine on bleeding complications after cataract surgery. METHODS: The authors performed a prospective, double-masked, two-surgeon study of 137 patients (137 eyes) who underwent phacoemulsification and intraocular lens implantation with or without prophylactic brimonidine before cataract surgery. The authors also compared the effect of brimonidine among patients with systemic diseases such as diabetes mellitus (types I and II), hypertension, and anticoagulant or antiplatelet treatment. RESULTS: Subconjunctival hemorrhage was observed in 73.70% of the patients not treated with brimonidine before surgery and in only 23.75% of the patients who were given prophylactic brimonidine (p<0.001, chi2). The grade of hemorrhage was also statistically significant (p<0.001, Mann-Whitney). No statistically significant difference with regard to the presence of hemorrhage in diabetic patients or in the anticoagulant or antiplatelet treatment group was observed. However, a statistically significant difference (p<0.027, chi2) was found between hypertensive patients treated and not treated with prophylactic brimonidine before cataract surgery. CONCLUSIONS: This study suggests that brimonidine administered before cataract surgery may significantly reduce subconjunctival hemorrhage in the general population. It has been shown to be beneficial in hypertensive patients. A strong statistical trend, but not significance has been found in diabetic patients or in patients treated with antiplatelet or anticoagulant drugs, but further studies are needed to reach conclusive results.

Optic nerve alterations in apolipoprotein E deficient mice.

PURPOSE: To study the morphologic characteristics of the optic nerve (ON) by using an experimental model of knockout mice for expression of the ApoE gene. METHODS: Eyeballs with the retrobulbar ON attached were obtained from 24-week-old mice. Using morphologic and morphometric techniques and light and transmission electron microscopy, the ON characteristics were determined in three groups of mice: 1) wild type mice as the controls (CG; n = 15), 2) knockout mice for the ApoE gene (ApoE-G; n = 15), and 3) knockout mice for the ApoE gene that were fed a cholesterol-supplemented diet (ApoED-G; n = 15). RESULTS: The ON cross-sectional area was significantly higher in the ApoE-G than in the CG (p < 0.001) mice, whereas no significant changes were noticed between the ApoE-G and ApoED-G mice. Significant differences were noticed between those groups regarding the myelination index. Higher density of intra-axonal degeneration and myelin sheath alterations were found in both ApoE groups in respect to the CG. CONCLUSIONS: These results suggest that ApoE knockout mice have changes in ON morphology and myelination.

Macular phototrauma after cataract extraction and multifocal lens implantation: case report.

PURPOSE: To report a patient who developed photic injury after cataract surgery and multifocal MF4 lens implantation METHODS: A 41-year-old caucasian woman without antecedents of interest was subjected to left catarct surgery involving phacoemulsification with capsular sac implantation of a new type of multifocal lens. A coaxial light microscope was used for surgery. The operation was filmed and anterior pole photographs were obtained. RESULTS: Two days after the operation, the patient noted a paracentral scotoma and hand movement visual acuity in the left eye. Indirect ophthalmoscopy revealed an oval, hyperpigmented macular lesion compatible with phototoxic maculopathy. CONCLUSIONS: Phototoxic injury to the macula may occur after cataract extraction. Implantation of an intraocular lens is an important factor in the producion of maculopathy, on account of its light-focusing effect on the retina. This effect was probably increased in our patient by the use of a new autofocus multifocal lens.

[Terson syndrome associated with a carotid-ophthalmic giant aneurysm]. / Síndrome de Terson asociado a aneurisma carótido-oftálmica gigante.

UNLABELLED: PURPOSE/MATERIAL AND METHOD: A case of a 42 year-old woman presenting headache, vomiting and loss of consciousness of sudden onset. Upon testing right eye presented amaurosis while left eye showed a visual acuity of 20/50. RESULTS/CONCLUSION: Brain angiography showed a right sided giant carotid aneurysm at the ophthalmic artery area. Globe fundus in left eye showed vitreal and intra-retinal hemorrhage appearing in retinal posterior pole and periphery of the retina. Subarachnoidal hemorrhage accompanied by intra-vitreal bleeding is known as Terson's Syndrome. Peculiarities of this clinical case are discussed in this paper.

[Conjunctival microbiological study in corneo-schleral prosthesis users]. / Estudio microbiológico de la conjuntiva en portadores de prótesis esclero-corneales.

PURPOSE: To evaluate conjunctival bacterial flora in carrier patients of corneo-schleral prosthesis, both in the affected and fellow eye. MATERIAL AND METHOD: Samples were obtained from twenty-six corneo-schleral prosthesis carriers and smear from both eyes were cultured. Samples were taken from 24 patients as controls. RESULTS: Significant growth of potentially pathogen bacteria was observed in the corneo-schleral prosthesis and fellow eyes compared to controls. CONCLUSION: Conjunctival bacterial flora showed variations in the eyes of controls, corneo-schleral prosthesis and fellow eyes groups.

Estudio microbiológico de la conjuntiva en portadores de prótesis esclero-corneales / Conjunctival microbiological study in carriers of corneo-schleral prosthesis

Objetivo: Evaluar la flora bacteriana conjuntival en pacientes portadores de prótesis esclero-corneales, tanto en el ojo portador como en el contralateral. Métodos: Obtuvimos muestras de frotis conjuntivales para cultivo en veintiséis pacientes portadores de prótesis esclerocorneales, en sus ojos contralaterales y en veintiséis pacientes de una población control. Resultados: Tanto en el grupo de los ojos portadores de prótesis esclero-corneales como en el grupo formado por los ojos contralaterales existió un crecimiento significativo de gérmenes potencialmente patógenos, con respecto a los ojos del grupo control. Conclusiones: La flora bacteriana conjuntival varía entre los ojos control, los portadores de prótesis y los contralaterales a éstos (AU)

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Multilayer amniotic membrane transplantation in severe ocular graft versus host disease.

PURPOSE: To clarify the usefulness of multilayer amniotic membrane transplantation in an unusual case of calcareous corneal degeneration in a patient with graft-versus-host disease. METHODS: A 20-year-old Caucasian woman had bilateral calcareous corneal degeneration of one year of evolution, secondary to graft-versus-host disease. Treatment for both eyes with topical steroids and antibiotic ointment was not successful. Right eye had a spontaneous corneal perforation, and a three-layer circle amniotic membrane graft was applied to the whole cornea. RESULTS: During a follow-up period of 20 months we observed stability of the corneal epithelium and stroma. The amniotic membrane-covered area showed rapid epithelization, reduced inflammation and suppressed fibrosis formation. CONCLUSIONS: Multilayer amniotic membrane transplantation may be considered an alterantive for reconstructing the ocular surface in a patient with severe dry eyes and calcareous corneal degeneration, even with little perforation.

Posterior chamber phakic intraocular lenses to correct high myopia: a comparative study between Staar and Adatomed models.

PURPOSE: To determine the feasibility of using posterior chamber phakic intraocular lenses (PIOLs) to treat high myopia, comparing two different models, Staar and Adatomed. METHODS: Twenty-four eyes from 12 patients were studied prospectively. A phakic Staar IOL was implanted in one eye of each patient, and the other eye received a phakic Adatomed IOL. Patients with uveitis or ocular trauma prior to ocular surgery, diabetic retinopathy, or capsular pseudoexfoliation were excluded. The mean preoperative spherical equivalent refraction was -16.00 +/- 5.05 D for the Staar group and -15.39 +/- 2.83 D for the Adatomed group. Average follow-up was 32.4 months (range, 19 to 46 mo) for the Adatomed group and 18.3 months (range, 11 to 21 mo) for the Staar group and included evaluation of intraocular pressure, intraocular lens pigment deposits, lens decentration, anterior subcapsular cataract, and visual acuity. RESULTS: Spectacle-corrected and uncorrected visual acuity improved in all eyes in both groups. No statistically significant differences in visual acuity gain were observed with the two materials (Student t-test, P = .08 for the Staar group and P = .6 for the Adatomed group), although the gain in visual acuity was somewhat greater with the Staar PIOLs. The difference in mean intraocular pressure before surgery and at last follow-up was 1.5 mmHg for the Staar group and 2.3 mmHg for the Adatomed group (P = .36). The incidence of lens pigment deposits was the same in both groups (41.66%), with deposits in 5 of the 12 eyes in both groups. The incidence of lens decentration was higher in the Adatomed group (5/12; 41.66%) than in the Staar group (2/12; 16.7%). Anterior subcapsular cataract was higher in the Adatomed group (4/12; 33.3%) than in the Staar group (3/12; 25%). CONCLUSIONS: There was a higher incidence of lens decentration and anterior subcapsular cataract in the Adatomed group than in the Staar group.

Multicenter study of the Artisan phakic intraocular lens.

PURPOSE: To assess the Artisan intraocular lens to correct myopia in phakic eyes. SETTING: European multicenter study sponsored by Ophtec BV, Groningen, The Netherlands. METHODS: In this prospective multicenter clinical study, the Artisan lens was implanted in 518 eyes between September 1991 and October 1999. The power of the lenses ranged from -5.0 to -20.0 diopters (D). Follow-up examinations were performed at 6 months and 1, 2, and 3 years. Follow-up ranged from 6 months (n = 454) to 3 years (n = 249). The preoperative uncorrected visual acuity (UCVA) was not recorded but was estimated to be worse than 0.1. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.67 +/- 0.26 (SD). Endothelial cell counts were done at 6 months and 1, 2, and 3 years in a subgroup of 129 eyes. RESULTS: A UCVA of 20/40 or better was observed in 76.8% of eyes regardless of the postoperative goal. A BSCVA of 20/40 or better was observed in 93.9% of eyes and remained stable throughout the follow-up. Of the eyes with extremely high myopia (>-15.0 D), 63.3% gained 2 or more lines of BSCVA; of those with moderate myopia (-5.0 to -10.0 D), 23.5% gained 2 or more lines. The mean endothelial cell density change was 4.8% at 6 months, 2.4% at 1 year, 1.7% at 2 years, and 0.7% at 3 years. The incidence of persistent adverse events at 3 years was relatively low. Secondary surgical interventions included repositioning of the lens because of poor initial placement and lens exchange because of preoperative power calculation errors. Glare and halo effects during night driving were noted and were related to large pupils in young patients. CONCLUSION: The Artisan lens is a safe, stable, efficacious, and predictable method to correct -5.0 to -20.0 D of myopia. This study suggests that the corneal endothelial cell loss is stabilized to the physiologically normal level after 3 years.

Acute iridocyclitis in a patient with AIDS diagnosed as toxoplasmosis by PCR.

PURPOSE: To study the etiology of an acute iridocyclitis in a patient with AIDS using polymerase chain reaction (PCR) analysis of aqueous humor. METHODS: Case report describing a patient diagnosed with toxoplasmic retinochoroiditis in his left eye. He stopped his treatment after three weeks and subsequently developed an acute iridocyclitis without chorioretinitis in the fellow eye. Anterior chamber paracentesis was performed and aqueous humor was assayed by PCR. RESULTS: PCR of the aqueous humor showed positivity for Toxoplasma gondii. The iridocyclitis responded to topical dexamethasone and oral treatment with pyrimethamine and sulfadiazine. CONCLUSION: PCR is an effective method to diagnose toxoplasmic iridocyclitis in a patient with AIDS.

Branch retinal vein occlusion associated with the 20210 G-to-A prothrombin variant.

PURPOSE: To describe a case of branch retinal vein occlusion (BRVO) in a patient who tested positive for the 20210 A allele of the prothrombin (PT) gene. METHODS: A 48-year-old man had visual loss in the right eye secondary to BRVO confirmed by ophthalmoscopy and fluorescein angiography. His medical history was not remarkable for common risk factors for retinal occlusive diseases. RESULTS: Laboratory tests for hypercoagulability were positive for PT 20210 A variant. The patient's family tested negative for the PT variant. CONCLUSIONS: Laboratory tests for coagulopathy, including the PT 20210 A variant, should be added to the examination of patients with central or BRVO, especially if most common risk factors for thrombosis have been excluded.