VOLUME 79 - ISSUE 5

Purpose: To evaluate the central corneal thickness (CCT), corneal volume (CV), and anterior and posterior corneal surfaces using the Scheimpflug imaging system in patients diagnosed with tilted disc syndrome (TDS). Methods: The study group (Group 1) and the control group (Group 2) comprised 35 eyes of 35 age-, sex-, and refraction-matched cases. All cases underwent a full ophthalmic examination that included cycloplegic refraction, axial ocular length measurement, and Scheimpflug imaging. Results: The mean age was 34.68 ± 15.48 years in Group 1 and 34.11 ± 12.01 years in Group 2 (p=0.864). The gender distribution was 18 males and 17 females in Group 1 and 16 males and 19 females in Group 2 (p=0.618). All subjects were Caucasian. The spherical equivalent was 3.62 ± 1.75 D in Group 1 and 3.69 ± 1.51 D in Group 2 (p=0.850). There was no significant difference in age, sex, race, or spherical equivalent between groups. There was no significant difference in mean keratometric value and CV3 (the CV in the central 3 mm) between groups (p=0.232 and 0.172, respectively). There were statistically significant differences in CCT, CV5, and CV7 (CV in the central 5 and 7 mm3, respectively) and total CV between groups (p=0.008, 0.003, 0.023, and 0.019, respectively). The values of all parameters were lower in the study group than in the control group. There was also a statistically significant difference in the anterior elevation parameters of the cornea between groups (p<0.05). The mean values of Group 1 were higher than those of Group 2. There were statistically significant differences in the two parameters referring to the posterior elevation of the cornea between the two groups (p<0.05). Conclusion: The results of this study showed that eyes with TDS have thinner CCT, lower CV, and different anterior corneal curvature than normal eyes.

Keywords: Corneal topography; Cornea/pathology; Optic disk/abnormalities; Diagnostic techniques, ophthalmological

Purpose: To analyze epidemiological and microbiological aspects of microbial keratitis in children and adolescents. Methods: This retrospective cohort study was conducted at the Department of Ophthalmology and Visual Science, Escola Paulista de Medicina, Universidade Federal de São Paulo, between July 15, 1975, and December 31, 2010. We analyzed corneal samples from 859 patients with clinical suspicion of infectious keratitis, comparing epidemiological and microbiological characteristics of bacterial keratitis with those of non-bacterial and non-viral keratitis. We also compared Gram-positive and Gram-negative pathogens in patients with bacterial keratitis. We created a susceptibility profile of the bacterial microorganisms studied. Results: Of the 859 patients, 346 (40.3%) showed positive culture results for non-viral microorganisms. Teenagers (13-18 years) made up the group with the highest number of patients with keratitis (164, 47.4%). The most frequent risk factors for keratitis were trauma (33.5%) and previous ocular surgery (24.9%). Gram-positive bacteria (71.8%) were the most often isolated, with coagulase-negative Staphylococcus (23.8%) the most prevalent microorganism. Logistic regression analysis showed age (p=0.002), topical antimicrobial drug use (p=0.01), and trauma due to non-chemical burns (p=0.005) were risk factors for non-bacterial keratitis. Age (p=0.01) was also a risk factor for Gram-negative bacterial keratitis. Conclusion: Our study showed that in the age range studied, the prevalence of keratitis caused by Gram-negative bacteria or by the non-viral microorganisms evaluated increases with age. Previous use of topical antimicrobial drug and trauma due to non-chemical burns are associated with non-bacterial keratitis. Knowledge of the risk factors and the microorganisms involved may help improve treatment of keratitis in children and adolescents and minimize visual impairment.

Keywords: Keratitis/microbiology; Keratitis/epidemiology; Eye infections; Children; Adolescent

Purpose: To evaluate visual acuity and transient pattern reversal (PR) visual evoked potentials (VEPs) in the fellow eyes of children with strabismic and/or anisometropic amblyopia. Methods: Children diagnosed with strabismic and/or anisometropic amblyopia were recruited for electrophysiological assessment by VEPs. Monocular grating and optotype acuity were measured using sweep-VEPs and an Early Treatment Diabetic Retinopathy Study chart, respectively. During the same visit, transient PR-VEPs of each eye were recorded using stimuli subtending with a visual angle of 60', 15', and 7.5'. Parameters of amplitude (in μV) and latency (in ms) were determined from VEP recordings. Results: A group of 40 strabismic and/or anisometropic amblyopic children (22 females: 55%, mean age= 8.7 ± 2.2 years, median= 8 years) was examined. A control group of 19 healthy children (13 females: 68.4%, mean age= 8.2 ± 2.6 years, median= 8 years) was also included. The fellow eyes of all amblyopes had significantly worse optotype acuity (p=0.021) than the control group, regardless of whether they were strabismic (p=0.040) or anisometropic (p=0.048). Overall, grating acuity was significantly worse in the fellow eyes of amblyopes (p=0.016) than in healthy controls. Statistically prolonged latency for visual angles of 15' and 7.5' (p=0.018 and 0.002, respectively) was found in the strabismic group when compared with the control group. For the smaller visual stimulus (7.5'), statistically prolonged latency was found among all fellow eyes of amblyopic children (p<0.001). Conclusions: The fellow eyes of amblyopic children showed worse optotype and grating acuity, with subtle abnormalities in the PR-VEP detected as prolonged latencies for smaller size stimuli when compared with eyes of healthy children. These findings show the deleterious effects of amblyopia in several distinct visual functions, mainly those related to spatial vision.

Keywords: Visual acuity; Evoked potentials, visual; Electrophysiology; Amblyopia; Refractive errors; Child

Purpose: To compare the effect of 20% sulfur hexafluoride (SF6) with that of air on graft detachment rates for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK). Methods: Forty-two eyes of patients who underwent DMEK by a single surgeon (A.S.J.) at Wilmer Eye Institute between January 2012 and 2014 were identified; 21 received air for intraocular tamponade and the next consecutive 21 received SF6. The main outcome measure was the graft detachment rate; univariate and multivariate analyses were performed. Results: The graft detachment rate was 67% in the air group and 19% in the SF6 group (p<0.05). No complete graft detachments occurred, and all partial detachments underwent intervention with injection of intraocular air. The percentages of eyes with 20/25 or better vision were not different between the groups (67% vs. 71%). Univariate analysis showed significantly higher detachment rates with air tamponade (OR, 8.50; p<0.005) and larger donor graft size (OR, 14.96; p<0.05). Multivariate analysis with gas but not graft size included showed that gas was an independent statistically significant predictor of outcome (OR, 6.65; p<0.05). When graft size was included as a covariate, gas was no longer a statistically significant predictor of detachment but maintained OR of 7.81 (p=0.063) similar to the results of univariate and multivariate analyses without graft size. Conclusion: In comparison with air, graft detachment rates for intraocular tamponade in DMEK were significantly reduced by 20% SF6.

Keywords: Descemet membrane; Descemet stripping endothelial keratoplasty/instrumentation; Sulfur hexafluoride/administration & dosage; Endotamponade; Visual acuity

Purpose: To investigate the contributions of transient pattern-reversal visual evoked potentials in the diagnosis of ocular malingering at a Brazilian university hospital. Methods: Adult patients with suspected malingering in one or both eyes were referred for visual evoked potential testing. Data from patients' medical records were reviewed and analyzed retrospectively. Data analysis included the distance optotype visual acuity based on a ETDRS retro-illuminated chart and the transient pattern-reversal visual evoked potential parameters of latency (milliseconds) and amplitude (microvolts) for the P100 component, using checkerboards with visual subtenses of 15' and 60'. Motivations for malingering were noted. Results: The 20 subjects included 11 (55%) women. Patient ages ranged from 21 to 61 years (mean= 45.05 ± 11.76 years; median= 49 years). In 8 patients (6 women), both eyes exhibited reduced visual acuity with normal pattern-reversal visually evoked potential parameters (pure malingerers). The remaining 12 patients (7 men) exhibited reduced vision in only 1 eye, with simulated reduced vision in the contralateral eye (exaggerators). Financial motivation was noted in 18 patients (9 men). Conclusion: Normal pattern-reversal visually evoked potential parameters with suspected ocular malingering were observed in a 20 patient cohort. This electrophysiological technique appeared to be useful as a measure of visual pathway integrity in this specific population.

Keywords: Evoked potentials, visual/physiology; Malingering; Pattern recognition, visual; Vision disorders; Visual acuity

Purpose: To evaluate subfoveal choroidal thickness (SFCT) changes after intravitreal bevacizumab (IVB) therapy for central serous chorioretinopathy (CSC) using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Methods: In this retrospective study, we assessed the medical records of patients with CSC who received IVB (IVB group) or who were observed without intervention (control group). SFCT was measured using EDI-OCT. The main outcome measure was the change in SFCT. Results: Twenty-one eyes were included in the IVB group and 16 eyes were included in the control group. All patients showed resolution of neurosensory detachment and improvement in vision. In the IVB group, the mean SFCT was 315 μm at baseline, which decreased to 296 μm at the most recent visit. In the control group, the mean SFCT was 307 μm at baseline, which decreased to 266 μm at the most recent visit. Although there was a significant decrease in the mean SFCT for the control group, the decrease was not significant for the IVB group (41 vs 19 μm, p=0.003 vs p=0.071). Conclusions: SFCT decreased in both groups with remission of the disease. However, the decrease was significantly greater in the control group. In terms of anatomic and functional outcomes, IVB injection is not promising.

Keywords: Intravitreal injection; Bevacizumab; Central serous chorioretinopathy; Choroid; Optical coherence tomography

Purpose: To compare central corneal thickness (CCT) measurements of healthy individuals obtained with ultrasonic pachymetry (UP) and non-contact specular microscopy (NCSM). Method: In total, 148 eyes of 74 subjects with no ocular or systemic diseases were included in the study. Central corneal thickness measurements of all patients performed with UP and NCCM were compared. Results: A total of 74 subjects (38 females) were included in this study. The mean age was 45.2 ± 18.4 (range 12-85) years. The mean central corneal thickness of all 148 eyes was 546.9 ± 40 μm with UP and 510.8 ± 42 μm with NCSM. The mean central corneal thickness measured with NCSM was 35 μm thinner than that measured with UP (p<0.001). A high degree of agreement was found between the two methods (r=0.942, p<0.001). Conclusions: Our results suggest that NCSM measures thinner corneas than UP and that the correction formula we identified should be applied when comparing between these two devices.

Keywords: Cornea/pathology; Corneal pachymetry; Microscopy/methods; Cornea/anatomy & histology; Comparative study

Purpose: The aim of the present study was to use enhanced depth imaging optical coherence tomography (EDI-OCT) to investigate choroidal changes in patients with cone dystrophy (CD) and to correlate these findings with clinical and electroretinography (ERG) findings. Methods: This case-control study included 40 eyes of 20 patients with CD and 40 eyes of 40 age- and refraction-matched healthy individuals. Choroidal thickness (CT) measurements were obtained under the foveal center and at 500 and 1,500 μm from the nasal and temporal regions to the center of the fovea, respectively. EDI-OCT and ERG data were analyzed, and the correlations of CT with the best-corrected visual acuity (BCVA) and the central foveal thickness (CFT) were evaluated. Results: The mean subfoveal CTs in the CD and control groups were 240.70 ± 70.78 and 356.18 ± 48.55 μm, respectively. The subfoveal CT was significantly thinner in patients with CD than in the controls (p<0.001). The patients with CD also had significantly thinner choroids than the controls at each measurement location relative to the fovea (p<0.001). The subfoveal CT in the CD group correlated with CFT (p=0.012), but no significant correlation was found between the subfoveal CT and BCVA or photopic ERG responses. Conclusions: The present study demonstrated a significant thinning of the choroid in patients with CD. EDI-OCT is a useful technique for describing the choroidal changes occurring in CD. Future studies investigating the association between choroidal changes and outer retinal destruction or the disease stage may provide a better understanding of the pathophysiology of CD.

Keywords: Choroid; Fovea centralis; Retinal dystrophies; Retinal cone photoreceptor; Tomography, optical coherence; Electroretinography

Purpose: This study was conducted to evaluate the relationships of inner/outer segment (IS/OS) junction disruption, macular thickness, and epiretinal membrane (ERM) grade with best-corrected visual acuity (BCVA), as well as the relationship between IS/OS junction disruption and ERM grade. Methods: Fifty-four eyes of 54 patients with different grades of ERM were retrospectively reviewed. Patients were classified into three groups by ERM grade according to retinal striae and vessel distortion: grade/group 1, visible membranes without retinal striae or vessel distortion; grade/group 2, mild to moderate macular striae or vessel straightening; and grade/group 3, moderate to severe striae and vascular straightening. Correlations of BCVA with age, central retinal thickness, ERM grade, and IS/OS disruption as well as of IS/OS disruption, central macular thickness, and BCVA with ERM grade were evaluated. Results: Twenty-nine (53.7%) eyes exhibited IS/OS junction disruption. Groups 1 and 2 differed significantly with respect to BCVA (p=0.038), but groups 2 and 3 did not (p=0.070). Central macular thickness was significantly greater in group 2 than in group 1 (p=0.031) and in group 3 than in group 2 (p=0.033). Groups 1 and 2 differed significantly in terms of IS/OS disruption (p=0.000), but groups 2 and 3 did not (p=0.310). Conclusions: The IS/OS junction appears to be disrupted during the early stages of ERM. Grade 3 ERM is associated with a significantly higher incidence of IS/OS disruption.

Keywords: Epiretinal membrane; Retinal photoreceptor cell inner segment; Diagnostic techniques, ophthalmologic; Tomography, optical coherence/methods

Purpose: To analyze the intrasession and intersession repeatability of contrast sensitivity (CS) measurements in patients with glaucoma, cataract, or age-related macular degeneration (AMD) and healthy controls. Methods: CS measurements were performed using the OPTEC-Functional Vision Analyzer (FVA), which uses a standardized and closed (view-in) system. Measurements for patients with glaucoma, cataract, or AMD and healthy controls were repeated within 30 minutes (intrasession) and during two sessions (intersession), separated by one week to one month. Test-retest reliability and correlation were measured using the intraclass correlation coefficient (ICC) and coefficient of repeatability (COR). Results: Ninety subjects (90 eyes) with visual acuity of 0.17 logMAR or higher in the cataract group or 0.00 logMAR in the other groups were included. During the first session, the ICC values were 0.87, 0.90, 0.76, and 0.69, and COR values were 0.24, 0.20, 0.38, and 0.25 for the control, glaucoma, cataract, and AMD groups, respectively. The reliability scores significantly improved during the second session, except in the glaucoma group. There was an acceptable floor effect and no ceiling effect at higher frequencies in the glaucoma and AMD groups. Conclusion: In subjects with good visual acuity, the FVA system is useful for evaluating CS and demonstrates good repeatability, as shown by ICC and COR. Because there is no ceiling effect, this system is beneficial for evaluation of early changes in CS, particularly in patients with glaucoma or AMD.

Keywords: Macular degeneration; Contrast sensitivity; Glaucoma; Age effect; Reproducibility of results

A 42-year-old woman was admitted to our clinic with a complaint of glare in both eyes. Biomicroscopic examination of both the eyes revealed iris and lens colobomas in the inferior quadrant. Fundus examination of the right eye revealed an oval and gray inferotemporal optic pit and two choroid colobomas in the inferior quadrant. In the left eye, two choroid colobomas were detected that were inferior to the optic nerve head. Furthermore, a 21-year-old man presented to our clinic for a routine ophthalmologic examination. Bilateral biomicroscopic examination was normal. Fundus examination of the left eye revealed an oval and gray inferotemporal optic pit and a choroid coloboma that was inferior to the optic nerve head. Here we describe optic pits co-occurring with iris, lens, and choroidal colobomas. On the basis of these cases, a defect in the closure of the embryonic fissure is the most plausible etiology of the optic pit.

Keywords: Coloboma; Eye abnormalities; Optic nerve abnormalities; Iris abnormalities; Choroid abnormalities; Lens, crystalline abnormalities

We present the case of a 31-year-old patient with toxic anterior segment syndrome (TASS) that developed after undergoing deep anterior lamellar keratoplasty (DALK). She had keratoconus, and despite wearing hard contact lenses for many years in the left eye, her vision had deteriorated; therefore, DALK was performed on this eye. The preoperative visual acuity (VA) was finger counting at 3 m. Routine DALK was performed using the "big-bubble" technique. The corneal entry incision was hydrated at the end of the surgery, which was terminated by air injection into the anterior chamber. On postoperative day 1, VA was at the level of hand movements, and the cornea was edematous. Topical high-dose dexamethasone and oral steroids were initiated considering the diagnosis of TASS. Subsequently, the patient's VA increased, and the corneal edema decreased. We believe that the use of re-sterilized cannulas may have been the likely cause of TASS. Although DALK can be performed without interfering with the anterior chamber, one should keep in mind that TASS may occur in response to the solution used to hydrate the incision site and the air injected into the anterior chamber.

Keywords: Keratoplasty; Anterior eye segment/pathology; Keratoconus; Corneal transplantation

Lacrimal sac tumors are rare with a clinical presentation that typically includes obstruction of the lacrimal drainage system and epiphora as the most frequent symptom. Cribriform adenoid cystic carcinoma (ACC) is the most common malignant epithelial tumor of the lacrimal gland and minor salivary glands; however, its occurrence in the lacrimal drainage apparatus is extremely rare. Given the rarity of ACC, definitive diagnosis is almost invariably late conferring a poor prognosis. Herein we report the case of a 41-year-old woman with primary ACC of the lacrimal sac and describe the ophthalmological examination, diagnosis, and multidisciplinary treatment of this rare type of tumor.

Keywords: Carcinoma; Adenoid cystic/diagnosis; Lacrimal apparatus diseases; Eye neoplasms

We report a case of bilateral acute angle-closure glaucoma in a patient with undiagnosed granulomatosis with polyangiitis (Wegener's). A 59-year-old man presented with a severe headache, ocular pain, blurred vision, shortness of breath, and mild fever. Clinical examination revealed conjunctival chemosis, corneal edema, and shallow anterior chambers. Closed angles were observed bilaterally on gonioscopy. The patient was treated with intravenous mannitol, oral acetazolamide, and anti-glaucomatous eye drops. Over the following two days, his vision improved and intraocular pressures decreased. Subsequently, laser iridotomies were performed bilaterally and the patient attended consultations with our departments of respiratory medicine, nephrology, and rheumatology and was subsequently diagnosed with granulomatosis with polyangiitis. Bilateral acute angle-closure glaucoma is a very rare ocular manifestation of granulomatosis with polyangiitis. The association of this clinical entity with Wegener's granulomatosis remains unknown.

Keywords: Glaucoma, angle-closure/diagnosis; Acute disease/diagnosis; Granulomatosis with polyangiitis/diagnosis; Vasculitis

The authors present a case of necrotizing scleritis after pterygium excision successfully treated with rituximab after attempts with high doses of corticosteroids and immunosuppressive drugs. A literature review revealed case reports and a phase I/II dose-ranging randomized clinical trial using rituximab for necrotizing scleritis with or without association with autoimmune disease. This is the only case report on rituximab treatment for necrotizing scleritis after pterygium surgery. In cases with refractoriness to immunosuppressive drugs, a CD20 antibody can be used.

Keywords: Scleritis; Pterygium/surgery; Rituximab/therapeutic use; Antibodies, monoclonal/administration and dosage

Herein, we report a case of nonarteritic anterior ischemic optic neuropathy (NAION) following uneventful pars plana vitrectomy for macular hole treatment. A 56-year-old previously healthy woman presented with a full-thickness macular hole in right eye (OD) and small cup-to-disc ratios in both eyes. Five days after surgery, she noticed sudden painless loss of vision in OD and was found to have an afferent pupillary defect and intraocular pressure of 29 mmHg. Fundus examination showed right optic disc edema and the resolution of a macular hole with an inferior altitudinal visual field defect. Erythrocyte sedimentation rate, C-reactive protein levels, and general physical examination findings were normal. She was treated with hypotensive eyedrops and oral prednisone, resulting in mild visual improvement and a pale optic disc. A combination of face-down position and increased intraocular pressure due to a small optic disc cup were considered as potential mechanisms underlying NAION in the present case. Vitreoretinal surgeons should be aware of NAION as a potentially serious complication and be able to recognize associated risk factors and clinical findings.

Keywords: Optic neuropathy, ischemic/diagnosis; Papilledema; Retinal perforations/therapy; Vitrectomy; Visual fields

Abnormalities in visual processing caused by visual deprivation or abnormal binocular interaction may induce amblyopia, which is characterized by reduced visual acuity. Occlusion therapy, the conventional treatment, requires special attention as occlusion of the fellow normal eye may reduce its visual acuity and impair binocular vision. Besides recovering visual acuity, some researchers have recommended restoration of stereoacuity and motor fusion and reverse suppression in order to prevent diplopia. Recent studies have documented that the amblyopic visual cortex has a normal complement of cells but reduced spatial resolution and a disordered topographical map. Changes occurring in the late sensitive period selectively impact the parvocellular pathway. Distinct morphophysiologic and psychophysical deficits may demand individualization of therapy, which might provide greater and longer-lasting residual plasticity in some children.

Keywords: Amblyopia; Visual acuity; Neural plasticity; Visual córtex