Testing Visual Fields in Children

Visual fields in the pediatric population are an essential part of the eye exam that remain challenging to even the most experienced clinicians. Becoming educated in the multiple ways a child's visual field can be tested regardless of age and cognitive and physical abilities will allow the clinician to gain better insight into the child's function and in some cases, allow the clinician to identify pathological or neurological anomalies in the visual pathway. Gross visual field or functional visual field extent can be estimated by tests such as confrontation visual field testing, finger counting field testing, and white sphere kinetic perimetry. For threshold measurements of a child's visual fields, the Goldmann perimeter, or the more advanced computerized tests such as the Humphrey perimeter, Octopus perimeter, or frequency doubling technology perimeter can be used. Modifications can be made to certain tests to better suit the child's cognitive and physical abilities. The chapter covers different methods of visual field testing specific for the pediatric population.

Dissociation between red and white stimulus perception: A perimetric quantification of protanopic color vision deficiencies

Significance Horizontal visual field extension was assessed for red and white stimuli in subjects with protanopia using semi-automated kinetic perimetry. In contrast to a conventional anomaloscope, the “red/white dissociation ratio” (RWR) allows to describe protanopia numerically. For the majority of subjects with protanopia a restriction for faint red stimuli was found. Purpose Comparing the horizontal visual field extensions for red and white stimuli in subjects with protanopia and those with normal trichromacy and assessing the related intra-subject intra-session repeatability. Methods The subjects were divided into groups with protanopia and with normal trichromacy, based on color vision testing (HMC anomaloscope, Oculus, Wetzlar/FRG). Two stimulus characteristics, III4e and III1e, according to the Goldmann-classification, were presented with semi-automated kinetic perimetry (Octopus 900 perimeter, Haag-Streit, Köniz/CH). They moved along the horizontal meridian, with an angular velocity of 3°/s towards the visual field center, starting from either the temporal or nasal periphery. If necessary, a 20° nasal fixation point offset was chosen to capture the temporal periphery of the visual field. For each condition the red/white dissociation ratio (RWR); Pat Appl. DPMA DRN 43200082D) between the extent of the isopter for red (RG610, Schott, Mainz/ FRG) and white stimuli along the horizontal meridian was determined. Results All data are listed as median/interquartile range: Five males with protanopia (age 22.1/4.5 years) and six males with normal trichromacy (control group, age 30.5/15.2 years) were enrolled. The RWR is listed for the right eye, as no clinically relevant difference between right and left eye occurred. Protanopes’ RWR for mark III4e (in brackets: control group) was 0.941/0.013 (0.977/0.019) and for mark III1e 0.496/0.062 (0.805/0.051), respectively. Conclusions In this exploratory “proof-of-concept study” red/white dissociation ratio perimetry is introduced as a novel technique aiming at assessing and quantifying the severity of protanopia. Further effort is needed to understand the magnitude of the observed red-/white dissociation and to extend this methodology to a wider age range of the sample and to anomalous trichromacies (protanomalia) with varying magnitude.

Periphery kinetic perimetry: clinically feasible to complement central static perimetry

Background Existing evidence suggests that visual field defect in eyes with glaucoma significantly varies between individuals. The following study compared the central visual field defects with the peripheral visual field defects in patients with suspect glaucoma and primary open-angle glaucoma (POAG) and investigated whether using the central visual field test alone could result in loss of clinically valuable information. Methods In this prospective observational study, 167 eyes from 89 patients with suspect glaucoma or POAG were first examined with static automated perimetry (SAP), followed by a peripheral visual field test on Octopus 900 perimeter (Haag-Streit, Koeniz, Switzerland). The peripheral visual field test was performed by “Auto Kinetic Perimetry” program, in which Goldmann III4e stimuli randomly moved along 16 vectors at a constant angular velocity of 5 deg/s. Results Glaucomatous peripheral visual field defects were seen in 18% of the eyes with a normal central visual field. In addition, 86% of glaucoma patients with moderate-to-severe central visual field defects had corresponding peripheral visual field defects in the form of localized or diffuse depression of the isopters. Furthermore, a moderate correlation was found between the central and peripheral visual fields. The median test duration was 71 s for the peripheral test and 803 s for the central test (p < 0.001). Conclusions Our study demonstrated the diversity of glaucomatous visual field defects, as well as the possibility of losing the clinically valuable information due to focusing on the central visual field test alone. The peripheral kinetic perimetry is clinically feasible to complement the central static perimetry for a comprehensive assessment of visual function in glaucoma patients.

Comparison of Visual Outcomes and Patient Satisfaction Following Cataract Surgery with Two Monofocal Intraocular Lenses: Clareon® vs AcrySof® IQ Monofocal

Aim: This study aimed to compare the performance of two monofocal Intraocular Lenses (IOL) platforms. Background: The Clareon® Intraocular Lens (IOL) is a relatively new monofocal lens platform designed to improve postoperative results compared to other monofocal platforms. Objective: This study aimed to assess and compare the visual and refractive outcomes, and incidence of YAG capsulotomy of the Clareon® IOL and a standard non-preloaded AcrySof® monofocal IOL following contralateral implantation in patients undergoing cataract surgery. Methods: A total of 20 patients (40 eyes; 12 female, average age 72.8±6.4 years) who had undergone contralateral implantation of an AcrySof® IQ monofocal lens (SN60WF or SN6AT; Alcon; Texas, USA) and a Clareon®monofocal lens (CNAOT0; Alcon; Texas, USA) were selected. Uncorrected Distance Visual Acuity (UDVA), Contrast Sensitivity (CS), kinetic perimetry, and refraction were measured 1 month following the second surgery and subjective vision was measured 6 months following the second surgery using a quality-of-life questionnaire. Results: There was no difference in postoperative UDVA (P=0.94), CS (P>0.05), or refraction (P=0.64) between eyes that received the Clareon® and AcrySof® IQ lenses. Clareon® eyes had a higher incidence of glare/haloes and positive dysphotopsia while AcrySof® IQ eyes had a higher incidence of negative dysphotopsia. Patient satisfaction was similar between the groups (P=0.86), although 25% of patients reported more clarity in the eye that received the Clareon® lens. The incidence of posterior capsular opacification was low for both groups. Conclusion: Clareon® and AcrySof® IQ lenses perform similarly, providing good refractive, visual, and subjective outcomes. Clareon® is available as a preloaded lens option and may reduce PCO and the need for Nd: YAG capsulotomy.

Functional Evaluation of Splicing for Variants of Uncertain Significance in Patients with Inherited Retinal Diseases

Inherited retinal diseases (IRD) comprise a heterogeneous set of clinical and genetic disorders that lead to blindness. Given the emerging opportunities in precision medicine and gene therapy, it has become increasingly important to determine whether DNA variants with uncertain significance (VUS) are responsible for patients’ IRD. This research was performed to assess the functional consequence of six VUS identified in patients with IRD. Clinical assessments included an ophthalmic examination, best-corrected visual acuity, and kinetic perimetry. Imaging was acquired with the Optos ultra-widefield camera and spectral domain optical coherence tomography (SD-OCT). Genetic testing was performed by Molecular Vision Laboratories. VUS that were predicted to alter splicing were analyzed with a minigene assay, which revealed that VUS in the genes OPA1, CNGB1, and CLUAP1 altered spicing mechanisms. Due to emerging gene and cell therapies, these results expand the genotype-phenotype correlations for patients diagnosed with an IRD.

Functional Evaluation of Splicing for Variants of Uncertain Significance in Patients with Inherited Retinal Diseases

Inherited retinal diseases (IRD) comprise a heterogeneous set of clinical and genetic disorders that lead to blindness. Given the emerging opportunities in precision medicine and gene thera-py, it has become increasingly important to determine whether DNA variants with uncertain significance (VUS) are responsible for the patients&rsquo; IRD. This research was performed to assess the functional consequence of six VUS identified in patients with IRD. Clinical assessments in-cluded an ophthalmic examination, best corrected visual acuity, and kinetic perimetry. Imaging was acquired with the Optos ultra-widefield camera and spectral-domain optical coherence to-mography (SD-OCT). Genetic testing was performed by Molecular Vision Laboratories. VUS that were predicted to alter splicing were analyzed with a minigene assay which revealed that VUS in the genes OPA1, CNGB1, and CLUAP1 altered spicing mechanisms. Due to the emerging gene and cell therapies, these results expand the genotype-phenotype correlations for patients diag-nosed with an IRD.

Kinetic and static perimetry after 16 years and additional OCT-A analysis in eyes with long-lasting optic disc drusen

The aim of the study is to evaluate the progression of visual field (VF) defects over 16 years of observation and to assess abnormalities in vessels and retinal nerve fibre layer (RNFL) thickness in patients with optic disc drusen (ODD). Both static automated perimetry (SAP) and semi-automated kinetic perimetry (SKP) were performed in 16 eyes of 8 patients (mean age 54 years) with ODD among 26 eyes of 13 patients examined 16 years before. The area of I2e, I4e, III4e, and V4e isopters was measured in deg2. The MD and PSD parameters were estimated using SAP. Optical coherence tomography angiography (OCT-A) was additionally performed in 16 ODD eyes and 16 eyes of 8 healthy subjects to estimate the RNFL thickness and vessel density of the optic nerve disc and the macula. The differences in all isopter areas of SKP and SAP parameters after 16 years were not significant. The analysis of OCT-A showed a significant reduction of the vessel density and RNFL of the peripapillary area in each segment in patients with ODD, compared with the control group. The highest reduction of RNFL was observed in the superior segment of the optic disc area (92.56μm vs 126.63μm) also the macular thickness was decreased in ODD patients, compared with the control group. In the macula, there was a significant vascular defect in the whole superficial layer and in the parafoveal deep layer. A strong significant correlation of the parafoveal deep plexus with MD and PSD parameters was detected. In conclusion, VF loss due to ODD after 16 years of the follow-up was not significant both in SKP and SAP. ODD caused a reduced vessel density and RNFL, as well as macular thickness in OCT-A. SAP parameters were influenced by parafoveal deep plexus.