VOLUME 77 - ISSUE 4

Purpose: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. Methods: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. Results: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). Conclusions: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn.

Keywords: Corneal neovascularization/chemically induced; Vascular endothelial growth factor A; Angiogenesis inhibitors/administration and dosage; Injections; Disease models, animal; Corneal diseases; Animals; Rats

Purposes: To validate a teleophthalmology mobile system aimed at improving and providing eye urgency screenings in remote and poor area settings in Brazil. The system enables one or more ophthalmologists to remotely examine a patient's condition and submit a decision describing the gravity of the case. If necessary, the patient can be forwarded to a hospital for further consultation. Methods: A cellphone (Nexus One model, with a 5 megapixel camera) was used to collect data and pictures from 100 randomly selected patients at the Ophthalmology Emergency Room located at the General Hospital of the Federal University of São Paulo (UNIFESP). Data was then sent remotely to an online recording system to be reviewed by an ophthalmologist who provided feedback regarding the state of ocular urgency. Results were then compared to the gold standard diagnosis provided at the hospital. Results: The diagnosis of urgency was given by two ophthalmologists: one in the hospital (gold standard) and one remotely. When we compared both diagnoses we obtained results of 81.94% specificity, 92.85% sensitivity, and 85% accuracy, with a negative predictive value of 96.72%. This work also included a processing time analysis, resulting in an average time of 8.6 min per patient for remote consultations. Conclusions: This study is the first that has used only a cellphone for diagnosing the urgency of ocular cases. Based on our results, the system can provide a reliable distinction between urgent and non-urgent situations and can offer a viable alternative for the servicing of underprivileged areas. In screening techniques, the most important outcome is to identify urgent cases with a high level of sensitivity and predictive negative value. Thus, our results demonstrate that this tool is robust and we suggest that a major study aimed to verify its efficiency in resource-poor areas should be initiated.

Keywords: Telemedicine; Remote consultation; Ophthalmology; Diffusion of innovation; Triage; Eye diseases/diagnosis

Purpose: In this study, we examined the spectral domain optical coherence tomography (OCT) findings of ocular Behçet's disease (OB) in patients with inactive uveitis. Specifically, we analyzed the inner and outer segment junction (IS/OS line) integrity and the effect of disturbed IS/OS line integrity on visual acuity. Methods: Patient files and OCT images of OB patients who had been followed-up between January and June of the year 2013 at the Dicle University Eye Clinic were evaluated retrospectively. Sixty-six eyes of 39 patients were included the study. Results: OCT examination of the patients with inactive OB revealed that approximately 25% of the patients had disturbed IS/OS and external limiting membrane (EML) line integrity, lower visual acuity (VA), and lower macular thickness than others. Linear regression analysis revealed that macular thickness was not an independent variable for VA. In contrast, the IS/OS line integrity was an independent variable for VA in inactive OB patients. Conclusion: In this study, we showed that the IS/OS line integrity was an independent variable for VA in inactive OB patients. Further prospective studies are needed to evaluate the integrity of the IS/OS line in OB patients.

Keywords: Behçet disease; Tomography optical coherence; Retinal photoreceptor cell inner segment; Retinal photoreceptor cell outer segment

Purpose: To evaluate the incidence of posterior capsule opacification (PCO) four years after the implantation of a hydrophilic acrylic intraocular lens (IOL). Methods: Fifty-eight randomly selected eyes from 58 patients were analyzed four years after phacoemulsification and Ioflex IOL implantation. The patients underwent an ophthalmic examination to detect PCO and a detailed medical history was obtained. The patients' charts were reviewed for their corrected distance visual acuity prior to the IOL implantation, as well as for one month postoperatively. The Student's t-test was used for statistical analysis. Results: The mean age of patients without PCO was 74.6 ± 9.5 years, compared to 70.3 ± 15 years in patients with PCO. Four years after surgery, 39 of the 58 eyes (67%) had detectable PCO and 24 eyes (41.3%) had decreased visual acuity (VA) due to PCO. These patients were referred for Nd:YAG laser capsulotomy. Three patients (5.1%) had decreased VA due to glaucoma, IOL opacification, or age-related macular degeneration. Twelve eyes (20.7%) presented mild PCO with unchanged VA. Systemic arterial hypertension was reported by 45% of the patients, and in 3.5% of these cases this was associated with diabetes mellitus. Conclusion: This study found the incidence of PCO to be 67% four years after phacoemulsification and Ioflex IOL implantation.

Keywords: Posterior capsule of the lens; Capsule opacification; Postoperative complications; Cataract/epidemiology; Visual acuity

Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP) were allocated to Group 1 (n=138), while those without ROP were allocated to Group 2 (n=236). All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male). The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks), the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g), and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p<0.05). There were no significant differences in horizontal corneal diameter, central corneal thickness, and axial length between the two groups (p>0.05). Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length.

Keywords: Cornea/anatomy and histology; Retinopathy of prematurity; Infant, premature; Birth weight; Gestational age

Purpose: To investigate the effects of topically applied 1% cyclopentolate hydrochloride on anterior segment parameters obtained with a Pentacam rotating Scheimpflug camera in healthy young adults. Methods: Anterior segment analyses of 25 eyes from 25 young adults (Group 1), before and after 45 min of 1% cyclopentolate hydrochloride application, were performed. For a control group (cycloplegia-free, Group 2), 24 eyes of 24 age- and sex-matched healthy cases were evaluated twice at 45 min intervals. The results obtained from the groups were compared statistically. Results: The mean ages of the groups were 23.04 ± 3.42 (range, 18-29) and 22.4 ± 2.05 (range, 18-27) years for Groups 1 and 2, respectively (p=0.259). In Group 1, measurements between the two analyses were significantly different for the values of anterior chamber depth (ACD), anterior chamber angle (ACA), and anterior chamber volume (ACV) (p<0.05), whereas no statistical difference was found for the central corneal thickness (CCT) and keratometry (K1, K2) measurements. In Group 2, none of these parameters were statistically different between the two analyses. Conclusions: Topically applied 1% cyclopentolate hydrochloride caused an increase in the ACD and ACV values, and a decrease in the ACA value. However, it had no significant effect on the CCT and keratometry measurements. It is important to consider these effects when using the Pentacam device on young adults with cycloplegia and when applying it for various reasons.

Keywords: Biometry; Cornea; Corneal pachymetry; Cyclopentolate/administration and dosage; Techniques, measures, measurement equipment

Purpose: To compare the ocular anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, as measured with two different Scheimpflug imaging devices. Methods: This transversal study included 80 right eyes from 80 subjects aged from 20 to 40 years. Their spherical equivalents ranged from -4.25 to +1.00 diopters (D). Each eye's anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, were measured for far vision using both the Galilei G4 (double Scheimpflug camera) and the Pentacam HR (single Scheimpflug camera) systems. Results: Mean anterior chamber depths were calculated as 3.12 ± 0.23 mm and 3.19 ± 0.24 mm when measured with the Galilei G4 and the Pentacam HR, respectively. The mean white-to-white distance measured was 11.84 ± 0.31 mm and 11.90 ± 0.43 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Mean pupil diameters were measured as 3.22 ± 0.58 mm and 3.22 ± 0.52 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Finally, the mean anterior chamber angle was 34.30 ± 2.86 degrees when it was measured with the Galilei G4, and 39.26 ± 2.85 degrees when measured with the Pentacam HR. A comparative analysis revealed that the Galilei G4 yielded a significantly lower (P<0.05) measurement for the anterior chamber depth, anterior chamber angle, and pupil diameter, than the Pentacam HR system. Comparable values (P>0.05) for both devices were obtained for the white-to-white distance measurements. Conclusion: The Galilei G4 and Pentacam HR Scheimpflug systems cannot be used interchangeably because they produce significant measurement differences.

Keywords: Anterior chamber/pathology; Pupil/physiology; Corneal topography; Diagnostic techniques, ophthalmological; Photography/methods; Interferometry

Purpose: The goal of this cross-sectional observational study was to quantify the pattern-shift visual evoked potentials (VEP) and the thickness as well as the volume of retinal layers using optical coherence tomography (OCT) across a cohort of Parkinson's disease (PD) patients and age-matched controls. Methods: Forty-three PD patients and 38 controls were enrolled. All participants underwent a detailed neurological and ophthalmologic evaluation. Idiopathic PD cases were included. Cases with glaucoma or increased intra-ocular pressure were excluded. Patients were assessed by VEP and high-resolution Fourier-domain OCT, which quantified the inner and outer thicknesses of the retinal layers. VEP latencies and the thicknesses of the retinal layers were the main outcome measures. Results: The mean age, with standard deviation (SD), of the PD patients and controls were 63.1 (7.5) and 62.4 (7.2) years, respectively. The patients were predominantly in the initial Hoehn-Yahr (HY) disease stages (34.8% in stage 1 or 1.5, and 55.8 % in stage 2). The VEP latencies and the thicknesses as well as the volumes of the retinal inner and outer layers of the groups were similar. A negative correlation between the retinal thickness and the age was noted in both groups. The thickness of the retinal nerve fibre layer (RNFL) was 102.7 μm in PD patients vs. 104.2 μm in controls. Conclusions: The thicknesses of retinal layers, VEP, and RNFL of PD patients were similar to those of the controls. Despite the use of a representative cohort of PD patients and high-resolution OCT in this study, further studies are required to establish the validity of using OCT and VEP measurements as the anatomic and functional biomarkers for the evaluation of retinal and visual pathways in PD patients.

Keywords: Evoked potentials, visual; Tomography, optical coherence/methods; Parkinson disease

Purpose: To study the changes in anterior chamber depth (ACD), anterior chamber angle (ACA), and pupil diameter (PD) during accommodation. Methods: Eighty eyes of 80 subjects, aged 22 to 40 years, were included. The rotating Dual Scheimpflug and a Placido disc system (Galilei G4, Ziemer Ophthalmic Systems AG, Switzerland) was used to measure the changes in ACD, ACA, and PD during accommodation. ACD measurement was taken for the central zone and for 4 more positions, each in different orientation (nasal, superior, temporal and inferior), 4 mm away from the centre. ACA was measured for the whole eye as well for the nasal, superior, temporal, and inferior quadrants. These metrics were obtained for various accommodation stimuli, ranging from +1 D to -4 D in 1-D steps. Results: For a given position, the ACD did not vary significantly with accommodation. For the central ACD, the percentage of relative change between far and near vision was -4.11%. The ACA was significantly lower at the inferior, temporal, and superior positions. There was no change in the ACA of the whole eye and that of the nasal orientation. These two eye metrics were significantly lower in the superior-nasal than in the inferior-temporal region. At each vergence studied, the PD decreased significantly with accommodation. The relative change after the -4 D stimulus was -8.13%. Conclusion: ACA and PD varied significantly with accommodation, whereas no such variation of ACD was observed. Further, the anterior chamber was found to be asymmetrical, with the nasal-superior area becoming significantly shallower than the inferior temporal region.

Keywords: Anterior chamber; Pupil; Accommodation, ocular; Techniques, measures, measurement equipment

Purpose: One of the challenges in strabismus is to guarantee stability of the surgical corrections. Re-surgeries are often required even after careful diagnosis, planning, and execution. Several factors contribute to this undesired outcome and the existing management strategies are ineffective. The present alternative is to compensate for their consequences. Ocular rotations are evoked by muscular contractions and relaxations (active forces). During eye movement, periocular tissues are stretched, storing part of the kinetic energy, which may be posteriorly recovered (passive forces), whereas the remaining part of the energy is lost via friction and inelastic deformations (dissipative forces). A method for measuring the forces that cause post-surgery eye drift has not been reported. However, this may be indirectly determined as a function of the respective mechanical variables. The estimated ratio between the kinetic energies of a post-surgery eye drift and a normal pursuit eye movement is ~10-15. Theoretically, it can be expected that the addition of continuously acting forces of such magnitudes to the oculomotor system might prevent the undesired post-surgery eye movement. Methods: Several methods for increasing the restraining, dissipative forces to ocular rotations may be conceived. One method is to increase the friction to ocular movements, as for instance, by periocular injection of viscous substances. Another possibility is to use the forces of a magnetic field, which may stabilize the eye in a desired position without avoiding the rotations caused by greater muscular forces acting on it. It has been demonstrated that these forces neutralize the nystagmic movements, whose intensities of mechanical variables are much higher than those of a post-surgery eye drift. Some models of application of this technique are then discussed. Small magnets fixed to the orbit and metallic ferromagnetic elements fixed to the sclera to cover a suitable extension appears to be the best method for providing starting and sliding friction to the oculomotor system. Results: Weak magnetic fields do not cause ocular ill effects. Additionally, the magnetic field may be confined to the elements of the circuit and may not leak. However, the magnetic materials may interfere with magnetic resonance image (MRI) examinations.

Keywords: Strabismus/surgery; Oculomotor muscles/physiopathology; Adaptation, ocular; Muscle tonus; Optical rotation; Viscoelastic substances

A 4 year-old girl with bilateral, non-familial retinoblastoma (RB) was referred to our care after primary enucleation OS and active tumor OD refractory to multiple therapies (intravenous chemotherapy, laser/cryotherapy, and I-125 plaque radiotherapy). Vitreous seeding OD, initially controlled by several sessions of Ophthalmic Artery Infusion Chemotherapy (OAIC) and periocular chemotherapy, recurred shortly thereafter. The patient underwent intravitreal (IVit) Melphalan injections achieving tumor control despite the concurrent development of keratopathy, pupillary synechiae, cataract, and necrosis of the inferior fornix and the adjacent orbital fat, all secondary to the treatments administered. Repeated amniotic membrane implants and tarsorrhaphy were performed to alleviate the symptoms. Despite being tumor free for 6 months, a poor fundus view and treatment-related complications prompted us to consider enucleation, but parents declined. Following recent negative magnetic resonance imaging (MRI), her cataract was removed. She was then found to have tumor recurrence. Her eye was enucleated 12 months ago and she recovered well from the surgery. As ocular oncology embarks in eye-preserving treatments for retinoblastoma, it is important to address the cumulative effects and associated impact of such treatments and the possibility of failure.

Keywords: Retinoblastoma/drug therapy; Retinoblastoma/surgery; Melphalan/administration & dosage; Vitreous body/pathology; Intravitreal injections; Retinal neoplasms/surgery; Eye enucleation; Humans; Female; Child; Case reports

A 49-year-old woman with acute loss of vision in her left eye was examined in our clinic. Two months before arriving at out clinic, she was diagnosed with pancreatic endothelial carcinoma. Her visual acuities were 20/20 for the right and 20/200 for the left eye. Fundus examination and fundus fluorescein angiography showed bilateral subretinal solitary mass. Multiple metastases to lung, pleura, liver, spleen, and abdominal lymph nodes were detected during the initial diagnosis. The patient underwent chemotherapy during the period when the visual symptoms were observed. No additional treatment was offered because of the extent of the disease and poor general health. Although pancreatic endothelial carcinoma usually spreads to the abdominal visceral organs and lungs, choroidal metastases are rarely observed.

Keywords: Choroidal neoplasms/secondary; Neoplasms metastasis; Pancreatic neoplasms

Congenital dacryocystocele is an unusual type of nasolacrimal obstruction. Treatment with antibiotics or surgical removal is practiced to reduce the risks of infection (acute dacryocystitis) and potentially lethal septicemia. Here, we report a case of congenital dacryocystocele, antenatal ultrasonographic diagnosis (intrauterine), and postnatal reassessment.

Keywords: Dacryocystitis/congenital; Dacryocystitis/ultrasonography; Dacryocystorhinostomy/methods; Pregnancy; Prenatal diagnosis; Humans; Female; Infant, newborn; Case reports

A 46-year-old woman complained of blurred and distorted vision in both eyes. Ophthalmic examination showed that visual acuity was 20/200 for the right eye and counting fingers left eye. Fundoscopy revealed perimacular hemorrhages, aneurismal dilatation of the vessels in the posterior pole, and a white and elevated lesion adjacent to vascular changes. We report a case of idiopathic macular telangiectasia and epiretinal membrane that occurs concomitantly. To our knowledge, this is the first report that describes an association between idiopathic macular telangiectasia and epiretinal membrane formation.

Keywords: Telangiectasia; Epiretinal membrane; Retina/cytology; Diagnostic techniques, ophthalmological; Fluorescein angiography; Humans; Female; Adult; Case reports

Some intriguing concepts of visual optics cannot be explained by ray tracing. However, they can be clarified using wavefront formalism. Its main advantage is in the use of the concept of vergence, which is very helpful in interpreting the optical phenomena involved in the neutralization of the ametropias. In this line of thinking, the major role of a lens is in the creation of a new light source (the image point) that orientates the refracted waves. Once the nature and position of this source is known, one can easily predict the behavior of the wavefronts. The formalism also allows for an easier understanding on how wavefronts relate to light rays and on how algebraic signs are assigned to optical distances.

Keywords: Refractive errors/diagnosis; Refraction ocular/physiology; Optics and photonics; Corneal wavefront aberration; Mathematics; Light