VOLUME 75 - ISSUE 5

PURPOSE: Crotoxin is the major toxin of the venom of the South American rattlesnake Crotalus durissus terrificus, capable of causing a blockade of the neurotransmitters at the neuromuscular junction. The objective of this study was to appraise the action and effectiveness of the crotoxin induced paralysis of the extraocular muscle and to compare its effects with the botulinum toxin type A (BT-A). METHODS: The crotoxin, with LD50 of 1.5 µg, was injected into the superior rectus muscle in ten New Zealand rabbits. The concentration variance was 0.015 up to 150 µg. Two rabbits received 2 units of botulinum toxin type A for comparative analysis. The evaluation of the paralysis was performed using serial electromyography. After the functional recovery of the muscles, which occurred after two months, six rabbits were sacrificed for anatomopathology study. RESULTS: The animals did not show any evidence of systemic toxicity. Transitory ptosis was observed in almost every animal and remained up to fourteen days. These toxins caused immediate blockade of the electrical potentials. The recovery was gradual in the average of one month with regeneration signs evident on the electromyography. The paralysis effect of the crotoxin on the muscle was proportional to its concentration. The changes with 1.5 µg crotoxin were similar to those produced by the botulinum toxin type A. The histopathology findings were localized to the site of the injection. No signs of muscle fiber's necrosis were seen in any sample. The alterations induced by crotoxin were also proportional to the concentration and similar to botulinum toxin type A in concentration of 1.5 µg. CONCLUSION: Crotoxin was able to induce transitory paralysis of the superior rectus muscle. This effect was characterized by reduction of action potentials and non-specific signs of fibrillation. Crotoxin, in concentration of 1.5 µg was able to induce similar effects as botulinum toxin type A.

Keywords: Crotoxin; Crotalid venoms; Snakes; Botulinum toxins, type A; Cobra neurotoxin proteins; Ophthalmoplegia; Neuromuscular junction; Comparative study

PURPOSES: To describe and categorize retinal vascular changes in patients with sickle cell anemia, as well as to compare diagnostic methods (indirect ophthalmoscopy and fluorescein angiography). METHODS: Patients with sickle cell anemia over the age of seven were examined. Complete ophthalmologic examination with indirect ophthalmoscopy and angiography was performed in each patient. The fundoscopy results were grouped in 3 classes: normal; non-proliferative retinopathy, which includes vascular tortuosity, black sunburst, salmon-patch and peripheral closure/anastomoses; and proliferative retinopathy, related to neovascular proliferation. Angiography results were classified according to Goldberg classifications from stage I to V. RESULTS: Retinopathy related to sickle cell anemia was seen in 62.3% (38/61) of the eyes checked. Neovascularization was observed in one eye. The frequency of bilateral changes in angiography was high. Non-proliferative retinopathy was more common, especially vascular tortuosities (17/61), followed by arteriovenous anastomoses in the retinal periphery (15/61) and arterial occlusions (5/61). The mean age of retinopathy group was 14.4 years old, significantly lower than the mean age of non-retinopathy group, which was 17.4. The result was normal in16.4% (10/61) of the eyes in the fundoscopy exam, while angiography showed alterations. CONCLUSIONS: All the results pointed to the conclusion that the non-proliferative retinal vascular changes are frequent and precocious in patients with sickle cell anemia (SS genotype). Fluorescein angiography is more sensitive in the diagnosis of retinopathy when compared to indirect ophthalmoscopy.

Keywords: Anemia, sickle cell; Retina; Retinal diseases; Fluorescein angiography; Ophthalmoscopy

PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL) on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes) received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes) received ultraviolet and blue light filter (yellow tinted) IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD]) investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens) difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens) under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.

Keywords: Lenses, intraocular; Cataract extraction; Phacoemulsification; Glaucoma; Visual field tests; Visual fields; Lens implantation, intraocular; Contrast sensitivity

PURPOSE: To evaluate the reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness measurements in normal eyes and eyes with glaucoma using spectral domain optical coherence tomography (SDOCT). METHODS: One eye of 79 normal and 72 glaucoma patients was analyzed. All patients underwent a complete ophthalmological examination, including visual acuity testing; intraocular pressure, slit-lamp examination, indirect ophthalmoscopy; and the glaucoma group underwent achromatic perimetry with the 24-2 SITA Fast Humphrey Field Analyzer. All patients' eyes were scanned using the spectral domain optical coherence tomography - Spectralis® and one of them was chosen randomly. Three consecutive circular B-scan centered at the optic disc were performed in one visit. RESULTS: The intraclass correlation coefficient (ICC), coefficient of variation and test-retest variability for the mean retinal nerve fiber layer thickness were respectively: 0.94, 2.56% and 4.85 µm for the normal group and 0.93, 4.65% and 6.61 µm for the glaucomatous group. The intraclass correlation coefficient for retinal nerve fiber layer thickness in all quadrants were all excellent in both groups, with the superior quadrant having the highest ICCs (0.964) in glaucomatous eyes and nasal quadrant measurements having the lowest (0.800), but still excellent in eyes without glaucoma. The coefficient of variation was between 2.56% - 8.74% and between 4.65% - 11.44% in normal and glaucomatous group respectively. The test-retest variability was between 4.85 µm and 11.51 µm in the normal group and between 6.61 µm and 14.24 µm in the glaucomatous group. The measurements in glaucomatous eyes were more variable than normal eyes. CONCLUSIONS: Spectral domain optical coherence tomography showed excellent reproducibility with regard to retinal nerve fiber layer thickness measurements in normal and glaucomatous eyes.

Keywords: Diagnostic techniques, ophthalmological; Glaucoma; Tomography, optical coherence; Retinal ganglion cells; Optic nerve; Nerve fibers; Reproducibility of results

PURPOSE: To evaluate the efficacy of radiotherapy (RT) with total dose of 20 Gy (RT 20 Gy) in the treatment of Graves' ophthalmopathy. METHODS: A systematic review and meta-analysis of randomized controlled trials was performed comparing RT 20 Gy with or without glucocorticoid to clinical treatments for Graves' ophthalmopathy. The MEDLINE, EMBASE, Cochrane Library databases and recent relevant journals were searched. Relevant reports were reviewed by two reviewers. Response to radiotherapy was defined as clinical success according to each trial. We also evaluated the quality of life and whether RT to produce fewer side effects than other treatments. RESULTS: A total of 8 randomized controlled trials (439 patients) were identified. In the subgroup analysis, the overall response to treatment rates was better for: RT 20 Gy plus glucocorticoid vs glucocorticoids alone, OR=17.5 (CI95% 1.85-250, p=0.04), RT 20 Gy vs sham RT, OR= 3.15 (CI95%1.59-6.23, p=0.003) and RT 20Gy plus intravenous glucocorticoid vs RT 20Gy plus oral glucocorticoid, OR=4.15(CI95% 1.34-12.87, p=0.01). There were no differences between RT 20 Gy versus other fractionations and RT 20 Gy versus glucocorticoid alone. RT 20 Gy with or without glucocorticoids showed an improvement in diplopia grade, visual acuity, optic neuropathy, lid width, proptosis and ocular motility. No difference was seen for costs, intraocular pressure and quality of life. CONCLUSION: Our data have shown that RT 20 Gy should be offered as a valid therapeutic option to patients with moderate to severe ophthalmopathy. The effectiveness of orbital radiotherapy can be increased by the synergistic interaction with glucocorticoids. Moreover, RT 20 Gy is useful to improve a lot of ocular symptoms, excluding intraocular pressure, without any difference in quality of life and costs.

Keywords: Graves ophthalmopathy; Exophthalmos; Radiotherapy; Meta-analysis, Review

PURPOSE: To report the incidence and causes of cataract surgery cancellations in a public hospital. METHODS: This is a retrospective study, which examined the number of cancellations of cataract surgery during 2009. We analyzed the type of procedure suspended (phacoemulsification or extracapsular extraction), type of anesthesia, gender, age, covenant (public/private) and the main reasons for suspension of the surgeries (clinical causes, institutional or personal). RESULTS: We analyzed 2,965 scheduled cataract surgeries, with 650 cancellations (21.92%). The main reason for the suspension of the procedure was clinical causes (86.90%). The winter months had the highest suspension rates of cataract surgery. CONCLUSION: The cancellation rate of cataract surgery in Brazilian public system seems to be the same as 10 years ago. The main cause of the suspension should be in clinical conditions (hypertension, diabetes, lack of exams, etc.).

Keywords: Cataract; Cataract extraction; Phacoemulsification; Blindness; Hospitals, public; Surgical procedures, elective; Efficiency, organizational; Patient dropouts

PURPOSE: To describe the implantation of the red reflex test in 30 cities in the area of Botucatu Medical School Clinical Hospital, (480,337 inhabitants) and the creation of a reference Center for children with red reflex changes, the Red reflex screening and another Center for treatment of childhood cataract. METHODS: The red reflex exam was released in 30 cities of the surrounding Botucatu area, lectures were done in the cities invited to participate by the Regional Department of Health.109 pen torch ophthalmoscopes were distributed to the hospital maternities and primary care units. The Red reflex screening attended cases of altered or doubtful red reflex and established the diagnosis. The Center for treatment of childhood cataract performed the preoperative examination, surgical treatment and follow-up of children with cataracts. RESULTS: After one year the Red reflex screening attended 29 children, 17 males and 12 females, mean age and pattern deviation (PD) of 10.09 ± 20.35 months (7 days - 98 months old). 16 patients were referred with altered red reflex, with a mean age and pattern deviation of 13.17 ± 24.14 months (7 days - 98 months old). The alteration was confirmed in all of these cases. 13 children had cataract. In 13 children with doubtful exam, with a mean age and PD of 6.29 ± 14.46 months (7 days - 54 months old), the alteration was not confirmed in any of these patients. The incidence of negative red reflex found among newborns was 9.2/10,000 and the incidence cataracts in this same group was 7.9/10,000. CONCLUSION: We described the implantation of the red reflex exam in the Botucatu area, and the creation of a reference Center for eye examination of children with changes in the red reflex, and the creation of a reference Center for treatment of childhood cataract and difficulties.

Keywords: Cataract; Cataract; Ophthalmoscopes; Reflex, pupillary; Child

PURPOSE: To determine the prevalence and causes of blindness in Piribebuy, Paraguay. METHODS: A population based study was conducted from September to November 2007 in Piribebuy, Paraguay. Based on the city map, seven clusters were randomly selected, containing 22 to 36 squares (423 to 578 houses) each, where all subjects > 40 years old who agreed to participate were included in the study. Presenting vision acuity (VA) was obtained for each eye, with 'E' Snellen charts 6 meters far from the patient with appropriate light. Eyes with VA<20/60 were also tested with the pinhole. Objective and subjective refraction was performed, followed by examination of anterior segment under the slit-lamp, Goldmann applanation tonometry, and pupil dilatation with 0.5% tropicamide plus 0.5% phenylephrine, followed by evaluation of the posterior pole. Best corrected visual acuity was used to classify the patients as follows: blindness was defined as visual acuity of the better eye <20/400, low vision as 20/400 RESULTS: 402 subjects received ophthalmological evaluation (92.2% of the original sample). Prevalence of blindness and low vision adjusted for gender and age was 1.0% (95% CI: 0.3-2.7) and 4.5% (95% CI: 2.8-7.1), respectively. Cataract was the only cause of blindness and the main cause of low vision (77.8% of the cases), followed by age-related macular degeneration (11.1%), pterygium (5.6%) and bilateral macular scar (5.6%). CONCLUSION: The prevalence of blindness in Piribebuy was 1% and the main cause was cataract.

Keywords: Cataract; Blindness; Blindness; Visual acuity; Epidemiologic studies; Paraguay

PURPOSE: To describe an outbreak of Pseudomonas aeruginosa endophthalmitis post cataract surgery. Clinical findings, treatment and outcome are discussed. METHODS: Clinical charts review of forty-five patients treated for endophthalmitis in a two-day period. The patients underwent primary vitrectomy, anterior chamber irrigation and intravitreous antibiotic injection. Cultures from vitreous and anterior chamber samples were performed in all patients. RESULTS: Forty-five patients (twenty-three men and twenty-two women) were identified. The average age was 71.2 years (range, 56-83 years). The right eye (62%) was affected more often than the left eye (38%). The median interval between surgery and endophthalmitis onset was 5.5 days (range, 5-6 days). The visual acuity at the diagnosis was better than 20/40 in one patient (2%), from 20/40 to 20/200 in one patient (2%), from 20/400 to counting fingers in two patients (4%), hand movements in eleven patients (24%), and light perception in thirty patients (68%). Pseudomonas aeruginosa was the isolated agent in twenty-six vitreous samples and in three anterior chamber samples. Overall, one patient (2%) achieved a final visual acuity better than 20/40; eight patients (18%) achieved a final visual acuity from 20/40 to 20/200; six patients (13%) achieved a final visual acuity from 20/400 to counting fingers; eleven patients (25%) achieved a final acuity of hand movements; thirteen patients (29%) achieved a final acuity of light perception and six (13%) patients had no light perception at the last examination. None of these eyes underwent evisceration or enucleation in a three-month follow-up period. CONCLUSION: Even with all the safety that cataract surgery has achieved, today, endophthalmitis remains a risk and a fearful complication of this procedure. In the present study, it was impossible to identify the source of the outbreak.

Keywords: Phacoemulsification; Endophthalmitis; Pseudomonas aeruginosa; Vitrectomy; Pseudomonas, infections; Equipment contamination

PURPOSE: To study the results of cataract surgery in children with radiation-induced cataract after treatment for retinoblastoma. METHODS: Retrospective interventional case series. Six consecutive patients diagnosed with secondary cataracts due to radiation therapy for retinoblastoma. Intervention: Phacoemulsification and foldable acrylic intraocular lens implantation. Outcomes measu- red: Visual acuity, binocular indirect ophthalmoscopy and slit-lamp biomicroscopy. Aspirated lens material and aqueous humor samples were collected during surgery. RESULTS: Six uniocular children between 3 to 5 years of age at time of surgery were studied. The mean time interval between radiotherapy and cataract diagnosis was 22.3 months. The mean follow-up after surgery was 17.2 months (range: 12 to 23 months). All eyes achieved a clear visual axis after surgery allowing monitoring of the tumor status. None developed recurrence or retinoblastoma dissemination. Histopathological analysis of the aspired material showed no tumoral cells in all samples. All patients improved vision after cataract surgery. CONCLUSIONS: Phacoemulsification with acrylic intraocular lens implantation seems to be a safe, feasible, and effective method for the removal of radiation-induced cataracts in patients with treated retinoblastoma.

Keywords: Retinoblastoma; Retinoblastoma; Retinal neoplasms; Cataract; Eye enucleation; Radiation injuries; Radiotherapy; Lens implantation, intraocular; Humans; Child

PURPOSE: To describe the clinical and imaginological features of two families with Waardenburg syndrome: type I and II, with emphasis on ophthalmic manifestations, as well as the pattern of genetic inheritance. METHODS: We conducted a clinical study involving two families affected by Waardenburg syndrome, and through the pedigree, determined the present pattern of genetic inheritance. Analyses were performed including the measurement of visual acuity, the presence of dystopia cantorum (telecanthus), evaluation of iris color and retinal mapping, as well as dermatological and otological examinations. RESULTS: The pedigree of the family affected by the Waardenburg syndrome type I showed an autosomal dominant mode of transmission. The syndrome was present at 85.71% of patients. The dystopia cantorum was the most frequent feature, followed by the white streak on the skin of the forehead, hypopigmentation of the iris and retina and deafness. The Waardenburg syndrome family type II had 33.33% of family members affected by the syndrome. No member had dystopia cantorum and hypopigmentation of the iris. Three patients had sensorineural hearing loss (12.5%), associated with white forelock and achromatic spots confluent by the body. CONCLUSION: This study shows the importance of the ophthalmologist in aiding the diagnosis of this rare genetic condition, since it includes ocular disorders such as telecanthus, hypopigmentation of the iris and retina. The cantorum dystopia is the main diagnostic criterion to differentiate type I and II syndrome and should be done by a trained ophthalmologist. The families are in medical monitoring, receiving genetic guidelines and care related to eye protection.

Keywords: Waardenburg's syndrome; Iris diseases; Retinal diseases; Genetic counseling; Deafness; Eyelids; Nose; Case reports

Gelatinous drop-like corneal dystrophy is a rare disorder with few cases described in the present literature. The following report will show how difficult it is to diagnose this disease in early stages. Modern image exams, such as optical coherence tomography helps to diagnose and can be crucial to establish the best treatment. We will present the histopathological changes and clinical features in this unusual dystrophy.

Keywords: Corneal dystrophies, hereditary; Tomography, optical coherence; Corneal opacity; Case report; Humans; Child

A case of posterior scleritis associated with central retinal vein occlusion and cystoid macular edema is reported. With this case, we noticed how the disease can be aggressive and how the visual acuity can be compromised. However, the correct treatment can improve the ocular changes with visual improvement. We also alert to the care with the use of high doses of corticosteroids.

Keywords: Scleritis; Retinal vein occlusion; Macular edema; Uveitis; Fluorescein angiography; Methylprednisolone; Case report; Humans; Aged; Female

To report a case of extensive globe enlargement due to secondary glaucoma in a young adult suffering from ocular surface disorders related to hypohidrotic ectodermal dysplasia. To the best of our knowledge, this is the first report of buphthalmos in the adulthood.

Keywords: Hydrophthalmos; Ectodermal dysplasia 1, anhidrotic; Dry eye syndromes; Case report; Humans; Male; Adult

Rosacea is a prevalent chronic cutaneous disorder with variable presentation and severity. Although considered a skin disease, rosacea may evolve the eyes in 58-72% of the patients, causing eyelid and ocular surface inflammation. About one third of the patients develop potentially sight-threatening corneal involvement. Untreated rosacea may cause varying degrees of ocular morbidity. The importance of early diagnosis and adequate treatment cannot be overemphasized. There is not yet a diagnostic test for rosacea. The diagnosis of ocular rosacea relies on observation of clinical features, which can be challenging in up to 90% of patients in whom accompanying roseatic skin changes may be subtle or inexistent. In this review, we describe the pathophysiologic mechanisms proposed in the literature, clinical features, diagnosis and management of ocular rosacea, as well as discuss the need for a diagnostic test for the disease.

Keywords: Rosacea; Eye manifestations; Eye diseases; Rosacea; Doxycycline; Visual acuity