Decreased Contrast Sensitivity Research Articles

Visual outcome and contrast sensitivity after photorefractive keratectomy in low to moderate myopia: Wavefront-optimized versus conventional methods

To compare visual outcomes and contrast sensitivity after wavefront-optimized or conventional photorefractive keratectomy (PRK) in myopic patients with or without astigmatism. Vanak Eye Surgery Center, Tehran, Iran. Comparative case series. Patients with low to moderate myopia with or without astigmatism were allocated into 2 groups. The study group was treated with wavefront-optimized PRK (Allegretto Wave Eye-Q software version 2.020 default treatment) and the control group, with conventional PRK (Technolas 217z). In all cases, treatments were bilateral and performed with the same device. Baseline and 3-month postoperative measures were uncorrected and corrected distance visual acuities, manifest refraction, and contrast sensitivity. Each group comprised 66 eyes. The mean preoperative spherical equivalent refraction improved from -2.99 diopters (D) ± 1.02 (SD) preoperatively to -0.08 ± 0.26 D 3 months postoperatively in the study group and from -2.66 ± 0.95 D to 0.01 ± 0.30 D, respectively, in the control group. In both groups, the postoperative mesopic and photopic contrast sensitivity decreased significantly at most spatial frequencies. The postoperative decrease in contrast sensitivity in both groups was comparable except at spatial frequencies of 3 cycles per degree (cpd) under mesopic conditions and 12 cpd under photopic conditions, frequencies at which the control group had a greater reduction. Visual acuity and refractive error outcomes were similar in both treatment groups. After 3 months, mesopic and photopic contrast sensitivity were significantly decreased in both groups; the reduction in the 2 groups was almost comparable. No author has a financial or proprietary interest in any material or method mentioned.

Response to ‘Night-vision tests for evaluating visual performance’

Dear Editor: We thank Jimenez and associates for their interest in our article [1]. Their series of studies [2–5] that evaluated night vision and various ocular diseases are very valuable, and have had a great impact on many other studies. We agree that our night vision testing device is similar to the halometer that Jimenez et al. reported [2] in terms of the design and structure. In our study, Fourier analysis revealed that corneal higher order irregular astigmatism was the main cause of night vision difficulties after orthokeratology treatment. The report by Jimenez et al. showed that after laser in situ keratomileusis and orthokeratology treatment, the eye had increased higher order aberration concomitant with decreased contrast sensitivity [6]. Their report indeed supported our results. If future studies can reveal which Zernike coefficients are mainly responsible for night vision disturbances such as halo and glare, refractive surgery and contact lens technologies would be further improved.

Acute hypoglycemia decreases central retinal function in the human eye

The goal of this pilot study was to assess the effects of acute hypoglycemia on retinal function and contrast sensitivity in individuals with and without diabetes. Hyperinsulinemic hypoglycemic and euglycemic clamp procedures were performed in subjects without diabetes ( n = 7) and with controlled type 1 diabetes ( n = 5). Mean age was 28 years, and none had retinal disease. During euglycemia (glucose 95–110 mg/dl) and acute hypoglycemia (glucose 50–55 mg/dl), contrast sensitivity was measured and spatial retinal responses were recorded with multifocal electroretinograms (mfERG), a rapid technique for mapping sensitivity from the foveal, macular and peripheral areas of the retina. During hypoglycemia, retinal responses (mfERG P1 wave) were decreased in both type 1 diabetes subjects and subjects without diabetes. The dominant effect was in the amplitude of the responses in the central macular retina, not in their temporal properties. Responses from the central region, central 10 0, were on average 1.8-fold lower than those from the periphery for both groups. All diabetes subjects and 3/7 without diabetes reported central scotoma. Decreases in mfERG amplitude were accompanied by decreases in contrast sensitivity. These changes were immediately reversed with the restoration of euglycemia. Overall, this study demonstrates that the acute effects of hypoglycemia in the human eye predominantly involve central vision, and these visual effects originate, at least in part, in the retina. The association between low blood glucose levels and impaired central vision underscores the importance of avoiding when possible and promptly treating hypoglycemia, particularly in individuals with diabetes.

Altered Spatial Frequency Content in Paintings by Artists with Schizophrenia

While it is difficult to imagine the way someone with mental illness perceives the world, paintings produced by mental illness sufferers with artistic talents offer a hint of this experience. Here we analyze these images in terms of statistics related to low-level visual processing. It is known that art in general possesses regular spatial frequency amplitude spectra, probably due to factors including luminance compression, approximation of natural scene spatial statistics, media, and aesthetics. Whatever the contributions of those factors may be, would the same ones apply for artists with schizophrenia? We find that spatial frequency content in paintings by five artists with schizophrenia or schizoaffective disorder is significantly different from that found in a large sample of art by painters without schizophrenia, while other basic spatial and intensity statistics are not different for the two groups. In particular, amplitude spectrum slopes are significantly steeper for paintings by artists with schizophrenia. A separate study of the works of one artist diagnosed with schizoaffective disorder confirmed these findings and showed no effect of medication type on amplitude spectrum slope. We suggest that these results support the notion that people with schizophrenia show decreased contrast sensitivity at low spatial frequencies. If people with schizophrenia cannot perceive low frequencies at the same level of contrast as that at which healthy individuals can, it follows that on average they will portray such components with higher contrast, resulting in steeper spectra.

Contrast Sensitivity and Optical Quality of the Eye after Instillation of Timolol Maleate Gel-Forming Solution and Brinzolamide Ophthalmic Suspension

To investigate the influence of timolol maleate 0.5% gel-forming solution and brinzolamide 1% ophthalmic suspension on contrast sensitivity, ocular higher-order aberration (HOA), and corneal surface light scattering. Prospective, comparative study. Forty normal volunteers were enrolled in this study. We evaluated contrast sensitivity, ocular HOA, and corneal light scattering before and 2, 5, 10, and 15 minutes after instillation of antiglaucoma eyedrops. Contrast sensitivity function was assessed with the CSV-1000RN chart (Vector Vision Co., Greenville, OH). Higher-order aberration was measured for a 4-mm pupil using the Hartmann-Shack aberrometer (KR-9000PW; Topcon, Tokyo, Japan). Corneal surface light scattering was quantitatively evaluated by using the Scheimpflug camera (EAS-1000, Nidek, Aichi, Japan). Time course of changes in contrast sensitivity, ocular HOAs, and corneal light scattering. Both timolol gel-forming solution and brinzolamide significantly decreased contrast sensitivity for at least 5 minutes after instillation (P<0.01). There were no significant differences in contrast sensitivity between the drugs at any time points. Higher-order aberration, such as third- and fourth-order aberrations and total HOAs, significantly increased after instillation of each drug (P<0.001). Timolol gel-forming solution significantly increased HOA up to 5 minutes after instillation (P<0.05), whereas brinzolamide significantly increased HOA for at least 2 minutes after instillation (P<0.001). Corneal surface scattering significantly increased for 5 minutes after instillation of brinzolamide (P<0.01), but not after instillation of timolol gel-forming solution. Both drugs temporarily deteriorate contrast sensitivity function and optical quality of the eye. However, the mechanism underlying contrast sensitivity reduction seems to be different between the drugs. The reduction may be mainly attributed to increased HOA after instillation of timolol gel and increased light scattering after instillation of brinzolamide. The authors have no proprietary or commercial interest in any materials discussed in this article.

Effects of Retinal Morphology on Contrast Sensitivity and Reading Ability in Neovascular Age-Related Macular Degeneration

To investigate the effect of changes in retinal morphology on contrast sensitivity and reading ability in patients with neovascular age-related macular degeneration (AMD) in the Avastin (bevacizumab; Genentech, South San Francisco, CA) for choroidal neovascularization (ABC) Trial. Contrast sensitivity obtained with Pelli-Robson charts, reading ability assessed with Minnesota Reading charts, and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) obtained by protocol refraction, were recorded. Raw Stratus optical coherence tomography (OCT; Carl Zeiss Meditec, Inc., Dublin, CA) images were analyzed with the publicly available software OCTOR, which allows precise delineation of any retinal compartment of interest. Thickness and volume were calculated for neurosensory retina, subretinal fluid (SRF), subretinal tissue, and pigment epithelium detachment, and the resulting measurements were correlated with each visual function parameter. One hundred twenty-two patients with newly diagnosed neovascular AMD and enrolled in the ABC Trial, were evaluated. Increased subretinal tissue volume correlated with decreased contrast sensitivity (Pearson's correlation coefficient, r = -0.4944, P = 0.001). A modest correlation was detected between SRF volume and contrast sensitivity (r = -0.2562, P = 0.004). Increased retinal thickness at the foveal center also correlated with decreased visual function (ETDRS VA: r = -0.4530, P < 0.001). The strongest correlation detected between the functional parameters assessed and any of the OCT-derived morphologic parameters was that between decreased contrast sensitivity and increased subretinal tissue. In the future, assessment of contrast sensitivity and reading ability, in combination with quantitative subanalysis of retinal compartments, may lead to the identification of parameters relevant to functional improvement and ultimate prognosis in patients with newly diagnosed neovascular AMD (www.controlled-trials.com number, ISRCTN83325075).

Visual Outcomes of LASIK-Induced Monovision in Myopic Patients With Presbyopia

To evaluate binocular visual acuity (VA), contrast sensitivity, and stereopsis in myopic patients after laser in situ keratomileusis (LASIK)-induced monovision. Prospective, observational study. We performed a prospective study of 37 consecutive patients older than 45 years who underwent bilateral myopic LASIK with planned monovision. At the 6-month postoperative visit, we evaluated distance and near binocular visual acuity, contrast sensitivity, and stereopsis. Binocular tests were done without spectacles (in monovision condition) and compared with the results obtained by repeating the same binocular tests with the same patients (serving as a control group) after spectacle correction of the residual myopic defect in the nondominant eye for distance tests (reverting monovision) and after spectacle correction of the presbyopia bilaterally for near tests (near best spectacle-corrected VA). By inducing a mean residual spherical equivalent defect of -0.97 diopter in the nondominant eye, the patients achieved a mean near binocular uncorrected visual acuity (UCVA) of 0.74, a mean reading test binocular UCVA of 0.88 using an acceptable spontaneous reading distance (48 cm), and a mean distance binocular UCVA of 1.08. A slight decrease in contrast sensitivity and stereopsis was observed in monovision compared to full distance correction. Monovision is a valid option for myopic patients with presbyopia who are considering LASIK. Good distance and near UCVAs can be obtained with this procedure.

Diffractive multifocal intraocular lens interferes with intraoperative view

We report an unusual finding during vitreous surgery in an eye implanted with a diffractive multifocal intraocular lens (IOL). A 70-year-old woman reported gradual visual deterioration to 20/40 in the left eye two and a half years after uneventful cataract surgery with implantation of a diffractive multifocal IOL. Funduscopic examination showed an epiretinal membrane (ERM) in the left eye. Increased macular traction was believed to cause the visual deterioration. Vitreous surgery with removal of the ERM was performed and triamcinolone acetonide (TA) was injected intravitreally to visualize the residual vitreous cortex. Although the ERM was peeled successfully, the ability to focus on the vitreoretinal interface through the IOL required great effort with decreased contrast sensitivity and ghost images of the intravitreal TA crystals. The vision improved to 20/25 4 months postoperatively. Macular surgery can be performed in an eye with a diffractive multifocal IOL; however, decreased contrast sensitivity and ghost images may interfere with the intraoperative view through the diffractive IOL in complicated cases.

Decreased Contrast Sensitivity in Children and Adolescents with Type 1 Diabetes Mellitus

To evaluate contrast sensitivity in children and adolescents with diabetes mellitus without evidence of diabetic retinopathy. Sixty patients with insulin-dependent diabetes mellitus (age range: 8 to 18 years) were studied. Their contrast sensitivity scores were obtained using the CSV-1000 device (Vector Vision, Dayton, OH) for four spatial frequencies and were compared with v scores of 45 age-matched and gender-matched "healthy" patients. Contrast sensitivity values were also correlated to patient's age, duration of disease, and metabolic control of diabetes mellitus. The patients with insulin-dependent diabetes mellitus had a significant contrast sensitivity score reduction at all spatial frequencies tested. Glycosylated hemoglobin levels were inversely related to the contrast sensitivity thresholds. No significant correlation was found between the contrast sensitivity scores and the patient's age or duration of disease. Contrast sensitivity defects are detected in patients with insulin-dependent diabetes mellitus. These defects may represent an early dysfunction of the retina, visual pathway, or both in patients with insulin-dependent diabetes mellitus who do not show any signs of diabetic retinopathy.

Mitochondrial Haplogroups Are Associated With Risk of Neuroretinal Disorder in HIV-Positive Patients

Although highly active antiretroviral therapy has improved survivorship dramatically and decreased the incidence of cytomegalovirus retinitis among patients with AIDS, other ophthalmic complications continue to occur. One complication observed in approximately 12% of HIV-infected patients is a presumed neuroretinal disorder (NRD), manifested as decreased contrast sensitivity and associated with vague subjective complaints of hazy vision. Pathologically, patients with AIDS even without ocular opportunistic infections have loss of optic nerve axons, suggestive of mitochondrial dysfunction. We explored whether variation in mitochondrial DNA was associated with time to NRD in HIV-infected patients in the Longitudinal Study of Ocular Complications of AIDS cohort. Within the Western European, or "N", mitochondrial DNA macrohaplogroup, haplogroup J, was associated with 80% decrease in the risk of progression to NRD during the study (hazard ratio = 0.20, P = 0.039) and suggested an independent association with protection against NRD in a cross-section of all patients taken at enrollment (1.5% vs. 8.9% in patients with vs. without haplogroup J, respectively, P = 0.05). These data suggest that mitochondrial genotype may influence propensity to develop HIV-associated NRD in patients with AIDS.

Intraocular lens choices for patients with glaucoma

To discuss the unique functional and structural changes in glaucoma and the impact on intraocular lens (IOL) selection. Glaucoma is a common ocular disease. Functional and structural changes associated with glaucoma require special consideration in the patient who is undergoing cataract/IOL surgery. Decreased contrast sensitivity found in glaucoma may be enhanced by the use of aspheric IOLs. Small pupils and weakened zonules necessitate meticulous surgical technique and increase the risk of IOL dislocation, as does anterior capsular contraction. Posterior capsular opacification is a common postoperative complication and may be related to IOL material and design. Both anterior chamber depth and axial length may change in patients who have had trabeculectomy and should be considered in the preoperative plan. Multifocal IOLs may afford spectacle independence for patients; however, there is a paucity of data for their use in concurrent ocular disease. Although there are challenges in performing cataract surgery in patients with glaucoma, excellent outcomes may be obtained with proper preoperative planning, meticulous intraoperative technique, and appropriate selection of IOL design.

Refractive error and visual functions in children with special needs compared with the first grade school students in Oman

Background:We evaluated the refractive status and visual function of children with special needs (other handicap) in 2010 and compared them with healthy 1st grade school students in Oman.Materials and Methods:This was a cohort study. Optometrists recorded vision using a logarithm of minimum angle of resolution (LogMAR) chart. Preferential looking method was used for testing 31 children. Cycloplegic refraction was performed on all children. Contrast sensitivity was tested using 2.5%, 10%, and 100% contrast charts. Ocular movement, alignment, and anterior segment were also assessed. A pediatrician reviewed the health records of all the children at the time of their enrollment in this study to determine if the child had been diagnosed with a systemic condition or syndromes. The visual functions were assessed by study investigators. We estimated the rates and the risk of different visual function defects in children with special needs.Result:The prevalence of refractive error in 70 children (4.7 ± 0.8 years) with special needs (group 1) and 175 normal healthy first grade students (group 2) were 58.5% and 2.9%, respectively. The risk of refractive error was significantly higher in children with special needs [relative risk, 48.1 (95% confidence interval, 17.54–131.8)]. Hyperopia (>1.00 D), myopia (≥ 1.00D) and astigmatism (≥ ±1.00 D) were found in 18.6%, 24.3%, and 27.1%, respectively, in group 1. Six children in this group had defective near vision. Sixteen (80%) children with Down syndrome had refractive error. Seven (50%) children with developmental disorder showed decreased contrast sensitivity.Conclusion:Prevalence of uncorrected refractive error was much higher in children with special needs. Prevalence of strabismus, nystagmus, and reduced contrast sensitivity was also higher in children with special needs. Early vision screening, visual function assessment, correction of refractive error, and frequent follow-up are recommended.

Binocular Interaction in Post-LASIK Subjects with Unsatisfactory Outcome

Purpose: A shift from binocular summation to binocular inhibition has been observed when there is a significant decrease in contrast sensitivity or reduced retinal illuminance in one eye compared to the other as in cases of unilateral cataract and amblyopia. This study aims to determine how binocular function in post-LASIK subjects with unsatisfactory outcomes is influenced by differences between the two eyes in visual acuity and contrast sensitivity.Materials and Methods: A retrospective analysis of monocular and binocular visual acuity (VA) and contrast sensitivity (CS) results was performed for 23 LASIK subjects who previously underwent a Functional Vision Test battery at Vision Sciences Research Corp. (San Ramon, CA). Photopic VA was measured with ETDRS chart and sine-wave grating CS was measured with FACT chart.Results: The difference between binocular and better monocular VA and CS was calculated for each subject and referred to as binocular difference. The interocular difference was calculated as better eye-worse eye for VA and CS. Significant negative correlations (P < 0.01) were observed between binocular difference and interocular difference for VA (r = -0.84) and CS at each spatial frequency of 1.5 (r = -0.90), 3 (r = -0.85), 6 (r = -0.79), 12 (r = -0.68), and 18c/d (r = -0.72). The greater the difference between the eyes, the lesser the binocular summation. Linear regression predicted a 1-line decrease in binocular summation for a 4-line increase in interocular acuity difference and a 35% decrease in binocular summation for a 50% increase in interocular difference of contrast sensitivity at 3c/d (ANOVA, P < 0.01).Conclusions: Binocular inhibition in post-LASIK subjects increases as the visual sensitivity difference between the two eyes increases. Since the peak of human contrast sensitivity function is at the middle spatial frequencies, the decrease in binocular CS at 3c/d due to reduced CS in one eye is functionally significant.

Influence of induced decentered orthokeratology lens on ocular higher-order wavefront aberrations and contrast sensitivity function

To quantitatively evaluate the effect of overnight orthokeratology lenses intentionally left decentered after 3 months of wear and assess the influence on clinical outcomes such as ocular higher-order wavefront aberrations and contrast sensitivity function. Department of Ophthalmology, Tsukuba University Hospital, Ibaraki, Japan. This prospective study assessed refraction, visual acuity, corneal topography, wavefront aberration, and contrast sensitivity function before and 3 months after overnight orthokeratology treatment. Decentration of the treatment zone from the center of the entrance pupil was determined using computerized videokeratography (TMS-4) and data-analysis software (MatLab). The relationship between decentration and the clinical parameters was analyzed. The mean age of the 23 patients (46 eyes) was 24.2 years+/-3.3 (SD) and the mean spherical equivalent refraction before treatment, -2.38+/-0.98 diopters. The mean magnitude of decentration (0.85+/-0.51 mm) was statistically significantly correlated with the amount of myopic correction (P<.05), increases in coma-like aberration (P<.01), increases in spherical-like aberration (P<.01), and reductions in contrast sensitivity function (P<.0001). Changes in contrast sensitivity function were also statistically significantly correlated with the amount of myopic correction (P<.05), changes in coma-like aberration (P<.01), and changes in spherical-like aberration (P<.01). Stepwise multiple regression analysis showed that the magnitude of decentration was the only explanatory variable related to contrast sensitivity function (P<.0001). Decentered treatment of orthokeratology resulted in decreased contrast sensitivity after treatment, showing that centration of the procedure is crucial to good outcomes.

Seeing the World Dimly: The Impact of Early Visual Deficits on Visual Experience in Schizophrenia

Deficits in early visual processing are well documented in schizophrenia, using methods such as contrast sensitivity. Higher, integrative stages of functioning, such as susceptibility to visual illusions, have been evaluated less extensively. For example, patients show increased susceptibility to (ie, are more easily affected by) the Muller-Lyer illusion but decreased susceptibility (ie, are less easily affected by) to stereopsis based upon binocular disparity. The basis for pattern of illusion response and interaction between sensory and integrative stages of processing, however, is unclear. We tested a group of 38 patients and 28 control subjects in contrast sensitivity, the Muller-Lyer and Poggendorff illusions, as well as a subgroup in stereopsis and the Ponzo illusion, Sander parallelogram, and Hermann grid illusions. We predicted that patients would be more susceptible to tests that become more apparent with increased contrast (Muller-Lyer illusion), less susceptible to tests that become less apparent with increased contrast (stereopsis, Ponzo illusion, Hermann grid), and equally susceptible to contrast-insensitive tests (Poggendorff illusion). Additionally, the Hermann grid was tested at varying levels of contrast. Patients demonstrated significant deficits in contrast sensitivity, especially to brief, low spatial frequency stimuli, and the predicted differential response to the tested illusions. Additionally, poor performance on stereopsis and the Hermann grid significantly correlated with decreased contrast sensitivity (all P's <.01). Muller-Lyer illusion and stereopsis performance were also inversely related (P < .01). This study replicates and expands upon previous findings with visual illusions. Our results offer a unifying explanation for disparate studies and suggest that deficits in early sensory gain affect subsequent integrative processes.

Contrast Sensitivity and Tear Layer Aberrometry in Dry Eye Patients

Dry eye disease is a common condition that affects millions of people world wide. The common findings of dry eye disease are blurred vision and tear film instability. The purpose of this study was to determine if long-term use of artificial tears altered visual disturbances and tear film instability of dry eye patients. Contrast sensitivity and optical aberrations were measured in 22 dry eye and 10 normal patients before and after daily use of artificial tears. The contrast sensitivity and optical aberrations were measured in response to the administration of a single drop of artificial tear placed in the eye. The short-term effect (i.e., a few minutes) of a single drop of artificial tear placed in the eye was a decrease in contrast sensitivity and an increase in optical aberrations. Long-term daily use of the artificial tears (i.e., up to 2 weeks) resulted in less of a short-term effect in dry eye patients. No long-term effect was observed for normal subjects. Both contrast sensitivity loss and optical aberrations decreased by 35% per week of artificial tear use for the dry eye patients suggesting that the changes in contrast sensitivity were the result of optical aberrations. The results suggest that the changes in contrast sensitivity with artificial tear administration were the result of optical aberrations. It appears that long-term use of artificial tears may normalize the tear layer of dry eye disease patients.

Clinical outcomes and functional visual performance: comparison of the ReSTOR apodised diffractive intraocular lens to a monofocal control

Aims:To compare clinical outcomes of patients bilaterally implanted with SN60D3 intraocular lenses (IOLs) with outcomes of bilateral monofocal controls, and to determine the validity of implanting an apodised diffractive lens...

Epithelial, Stromal, and Corneal Pachymetry Changes during Orthokeratology

To describe epithelial, stromal, and corneal thickness profile changes induced by orthokeratology treatment. This is a case report of a mild myopic patient (OD -3.25/-0.50 x 172 and OS -3.25/-0.50 x 45) treated with orthokeratology lenses. The patient was assessed before treatment (following 2 weeks of no orthokeratology contact lens wear) and during treatment (after 30 consecutive nights of wearing orthokeratology lenses). Epithelial, stromal, and corneal thickness profile in vivo was measured by Artemis very high-frequency digital ultrasound scanning across the central 10 mm diameter of the cornea before and during orthokeratology treatment. Manifest refraction, contrast sensitivity, corneal topography, and corneal front surface aberrations were also measured before and during orthokeratology treatment. Thickness changes were correlated with corneal topography changes and corneal front surface aberrations changes. The effects of these changes on the patient's quality of vision were measured with manifest refraction and contrast sensitivity. Orthokeratology lenses effectively corrected the patient's myopic refraction. Corneal topography demonstrated typical central flattening and an annulus of mid-peripheral steepening in both the eyes. The epithelial thickness profile was altered, with up to 18 microm of central epithelial thinning and up to 16 microm of annular mid-peripheral epithelial thickening. There also appeared to be a degree of stromal changes, with central stromal thickening and mid-peripheral stromal thinning, in particular in the left eye. There was a large increase in higher order aberrations, in particular in the left eye. This was associated with a decrease in contrast sensitivity in both the eyes. Refractive changes during orthokeratology treatment are mainly induced by changes in epithelial thickness profile, while stromal changes may also contribute to a small extent.

Corneal Verticillata After Dual Anti-Epidermal Growth Factor Receptor and Anti-Vascular Endothelial Growth Factor Receptor 2 Therapy (Vandetanib) for Anaplastic Astrocytoma

To describe a patient with a history of epithelial basement membrane dystrophy who developed symptomatic corneal verticillata after vandetanib therapy for anaplastic astrocytoma. Retrospective interventional case report. A 48-year-old female patient with a history of anaplastic astrocytoma status post resection, external beam radiation, and chemotherapy presented with glare symptoms, decreased contrast sensitivity, and increased lacrimation after approximately 12 months of therapy with the anti-epidermal growth factor receptor (EGFR) and anti-vascular endothelial growth factor receptor 2 protein tyrosine kinase inhibitor, vandetanib. Ophthalmic examination revealed diffuse corneal verticillata and fine subepithelial opacities. Schirmer 1 testing was normal bilaterally. Therapy with carboxymethylcellulose, 5% sodium chloride ointment, and a decrease in the dose of vandetanib led to an improvement in the patient's ophthalmic symptoms despite persistence of the corneal findings. The patient remained under surveillance for tumor recurrence. Vandetanib (ZD6474), a protein tyrosine kinase inhibitor with dual anti-EGFR and anti-vascular endothelial growth factor receptor 2 action, may have contributed to the formation of corneal verticillata in our patient. Inhibition of EGFR, which is involved with corneal epithelial cell migration and wound healing, may play a role in the pathogenesis underlying corneal vortex keratopathy and ocular surface conditions with significant epithelial turnover.

Contrast Sensitivity Among Patients with Birdshot Chorioretinopathy

To assess contrast sensitivity in patients with birdshot chorioretinopathy; to identify relationships between contrast sensitivity, other measures of visual function, clinical findings, and quality of life. Single-center, cross-sectional study. We measured contrast sensitivity in 63 patients (126 eyes) at four spatial frequencies (3, 6, 12, 18 cycles/degree [cpd]) using the CSV-1000E instrument (VectorVision, Greenville, Ohio, USA). Abnormal contrast sensitivity was defined as two standard deviations below the mean for population norms. Results at spatial frequency 12 cpd were compared to the following parameters in per-eye analyses: best-corrected visual acuity (BCVA); presence of eight specified symptoms; color vision; visual field parameters (foveal threshold, mean deviation); and optical coherence tomography parameters (central macular thickness, loss of the third highly reflective band). Results were compared to the National Eye Institute Visual Function Questionnaire (VFQ)-25 in per-patient analyses. Results were adjusted for age, disease duration, treatment, BCVA, and lens status. Contrast sensitivity (spatial frequency 12 cpd) was abnormal in 99 eyes (92%), and was related to poor BCVA (P = .0004) and the symptom of poor contrast sensitivity (P = .025). Among 38 eyes with normal BCVA (> or =1.0), 31 eyes (82%) had abnormal contrast sensitivity. There was a positive correlation between contrast sensitivity in better eyes and the VFQ-25 composite scores (r = 0.51; P < .001). Decreased contrast sensitivity is common in patients with birdshot chorioretinopathy and may occur in the absence of other visual changes. Contrast sensitivity may be a useful measure for clinical studies of birdshot chorioretinopathy and for monitoring patients with the disease.