Normal Fellow Eyes Of Patients Research Articles

Corneal and anterior segment parameters in patients with clinically unilateral pseudoexfoliation syndrome.

Pseudoexfoliation syndrome (PES) is an age-related systemic condition that predominantly affects ocular structures and is characterized by the deposition of material on the lens, ciliary body, zonules, corneal endothelium, iris, and pupillary margin. We compared the corneal endothelial morphology, anterior segment parameters, corneal densitometry, and corneal topographic characteristics between the clinically affected and apparently normal fellow eyes of patients with clinically unilateral PES. This was a comparative, cross-sectional study of 34 patients with clinically unilateral PES. The anterior segment was examined using a Scheimpflug imaging system, and the corneal endothelium was assessed using a noncontact specular microscope. Corneal endothelial cell density, polymegathism, and pleomorphism were assessed using the specular microscope. Furthermore, the Scheimpflug camera was used to measure the corneal power of the flat and steep axis, mean corneal power, maximum keratometry, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, and the corneal thickness at the apex point, center of the pupil, and the thinnest point. Corneal densitometry was evaluated at two concentric zones (0-2 mm and 0-12 mm). In total, 68 eyes from 34 patients were ultimately included in the study. The mean (standard deviation) age of the patients was 73.38 (8.75) years (range: 50-87 years). Among the included patients, 17 (50%) were male and 17 (50%) were female. The anterior segment parameters did not significantly differ between eyes with PES and their clinically unaffected fellow eyes (all P > 0.05). Similarly, no statistically significant difference was observed in corneal endothelial morphology (all P > 0.05). Our measured parameters do not differ between the clinically affected eye and the clinically unaffected fellow eye. This supports the theory that PES is a bilateral disorder. Considering the variety of complications associated with PES, bilateral involvement should be assumed in the clinical and surgical management of patients with clinically unilateral PES. In the future, new research could increase our understanding of this syndrome.

Longitudinal Evaluation of Biomechanical Indices in Fellow Eyes of Patients With Keratoconus Classified as Having Very Asymmetric Ectasia With Normal Topography.

To evaluate the biomechanical longitudinal variability and progression of tomographically normal fellow eyes of patients with keratoconus. Of 513 patients with keratoconus, 30 patients with tomographically normal fellow eyes were included in this study. Tomographic and biomechanical parameters of the Pentacam and Corvis ST (Oculus Optikgeräte GmbH) were analyzed in multiple follow-up examinations, including the ABCD grading, Belin/Ambrósio Enhanced Ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI), Corvis Biomechanical Factor (CBiF), and Tomographic and Biomechanical Index (TBI). A mixed regression model was applied. The results were compared to a healthy control group (n = 17) and a keratoconus group (n = 20). Within a maximum observation period of 3.3 years, no fellow eye (0%) showed a progression to tomographically evident keratoconus. No significant change in tomographic or biomechanical parameters was detected over the study period. The indices BAD-D, CBI, CbiF, and TBI exhibited a certain variability over time, whereas the tomographic ABC parameters and maximum keratometry barely changed. This was also shown in the control group and for all parameters in the keratoconus group, except the TBI. During the observation period none of the normal fellow eyes progressed to tomographically detectable keratoconus. However, biomechanical parameters CBI, CbiF, and TBI showed pathological values in 43.3% of eyes and certain variability. Subsequent studies with a longer observation period are warranted to confirm the biomechanical trends seen in this study and to rate the ability of single measurements to diagnose early keratoconus. [J Refract Surg. 2024;40(1):e48-e56.].

Longitudinal changes in peri-papillary retinal nerve fiber layer thickness in patients with unilateral branch retinal vein occlusion.

Associations between retinal venous occlusion (RVO), elevated intraocular pressure, and glaucoma have been reported. Further investigations into structural alterations in the fellow eyes of individuals with unilateral RVO have revealed that the peripapillary retinal nerve fiber layer is thinner than in healthy eyes, suggesting that there may be systemic risk factors common to both RVO and glaucoma. We aimed to evaluate changes in peripapillary retinal nerve fiber layer thickness (pRNFLT) among individuals with unilateral branch retinal vein occlusion (BRVO). This prospective observational study recruited 30 individuals (60 eyes) with newly diagnosed unilateral BRVO and macular edema, and a control group of 30 healthy individuals (30 eyes) with no abnormalities on fundus examination or concurrent systemic comorbidities. After baseline measurements, the participants were reassessed at 6, 12, and 24 months by measuring global and sectoral pRNFLT using spectral-domain optical coherence tomography. The mean age and sex distributions were comparable between the patient and control groups (both P > 0.05). When compared to fellow eyes, global and sectoral pRNFLT in eyes with BRVO were significantly higher at baseline (all P < 0.05). Over time, pRNFLT decreased dramatically, and by the conclusion of the two-year follow-up, there was a significant reduction from baseline in the affected eyes (all P < 0.05). Likewise, affected eyes experienced a significant improvement in best-corrected distance visual acuity and central macular thickness over the two-year follow-up (both P ≤ 0.001). Comparing the global and all-sector pRNFLT of fellow eyes in the patient group with those of normal eyes in the control group, there were no significant differences at any visit, except in the temporal sector, which revealed a significant reduction in pRNFLT at 24 months in the fellow eyes of patients with unilateral BRVO (P = 0.02). Patients with unilateral BRVO experienced a significant reduction in pRNFLT in the affected eyes and, to a lesser extent, in the fellow eyes, compared with that of the control arm, suggesting that they are prone to retinal nerve fiber layer damage. The reduction in pRNFLT in the normal fellow eyes of patients with BRVO may be attributed to age or concurrent systemic comorbidities. Further studies with long follow-up periods are required to shed light on the etiology of functional and structural changes in both the retinal nerve fiber layer and ganglion cell complex in the normal and affected eyes of patients with unilateral BRVO.

Biomechanical Evaluation of Topographically and Tomographically Normal Fellow Eyes of Patients With Keratoconus.

To determine the effectiveness of parameters and indices based on biomechanical measures at discriminating fellow eyes with topographically and tomographically normal corneas in patients with keratoconus from normal control corneas. The study included 47 keratoconus suspect eyes, defined as the topographically and tomographically normal fellow eyes of patients with frank keratoconus in the other eye. Eyes were imaged using the Pentacam HR and Corvis ST (both Oculus Optikgeräte GmbH). Fellow eyes were then categorized as topographically/tomographically normal fellow eyes (TNF) and topographically/tomographically borderline fellow eyes (TBF). The ability of each of the Corvis Biomechanical Index (CBI), Tomographic and Biomechanical Index (TBI), stiffness parameter at applanation 1 (SP-A1), and stress-strain index (SSI) at discriminating between normal controls and keratoconus suspects was assessed. The TBI had the best discriminative ability with the greatest area under the receiver operating characteristic (AUROC) curve value of 0.946 for normal controls versus TBF eyes, and 0.824 for normal controls versus TNF eyes. Compared to the TBI AUROC curves, SP-A1 and CBI had AUROC curve values of 0.833 (P = .09) and 0.822 (P = .01) for normal controls versus TBF eyes, respectively, and AUROC curve values of 0.822 (P = .96) and 0.550 (P = .0002) for normal controls versus TNF eyes, respectively. The TBI had the best positive predictive value for TNF and TBF eyes, followed by CBI and SP-A1. The TBI and the purely biomechanical parameter SP-A1 were of moderate utility in distinguishing between normal and keratoconus suspect eyes. In the absence of topographic/tomographic evidence of keratectasia, an independently abnormal biomechanical parameter may suggest an increased risk of ectasia. [J Refract Surg. 2022;38(5):318-325.].

Foveal Morphology of Normal Fellow Eyes of Patients with Unilateral Macular Hole

To determine the morphology of the fovea in the ophthalmoscopically and tomographically normal fellow eyes of patients with a unilateral idiopathic macular hole (MH) and determine the association between foveal morphological parameters and foveal outer nuclear layer (ONL) thickness. Retrospective observational study. Two hundred three normal fellow eyes of patients with a unilateral MH and 216 normal eyes of 216 healthy subjects. All the eyes were examined using swept-source OCT. A built-in software was used to measure the average retinal and choroidal thickness in the center and in the inner 4 subfields defined in ETDRS. The total retinal thickness, thickness of 3 retinal layers at the fovea and parafovea (0.25 and 0.5 mm nasal and temporal from the fovea), and foveal floor width (FFW) were measured on a scan image of a horizontal line passing through the center of the fovea. We defined the thickness between the internal limiting membrane and outer plexiform layer as inner retinal thickness and the thickness between the external limiting membrane and retinal pigment epithelium as outer retinal thickness. Multiple regression analyses were performed with age, sex, axial length, and the presence of a posterior vitreous detachment as the dependent variables. OCT measurements and correlations between foveal parameters and foveal ONL thickness. The fellow eyes had a thinner central retinal subfield, thinner fovea, thinner ONL at all points except at 0.5 mm nasal, significantly thicker outer retina at all points, and a wider FFW (P= 0.040 to P < 0.0001). The foveal ONL thickness was significantly and positively correlated with the central subfield retinal thickness and foveal thickness and negatively correlated with the FFW (all P < 0.0001). The thinner and deeper fovea and the thinner ONL of the fellow eyes of patients with a unilateral MH make these eyes more susceptible to the formation of an MH.

Influence of extended depth of focus intraocular lenses on visual field sensitivity.

PurposeTo investigate the influence of EDOF IOLs, TECNIS Symfony® (Johnson & Johnson Surgical Vision, Inc.), on visual field sensitivity and to compare the IOLs with other kinds of IOLs.MethodsThe subjects included the normal fellow eyes of patients who underwent the Humphrey Field Analyzer (HFA) 30–2 with Swedish Interactive Threshold Algorithm Fast within 6 months after cataract due to glaucoma or suspected glaucoma. Each parameter of HFA was compared among eyes implanted with TENIS Symfony® (EDOF group), diffractive bifocal IOLs (bifocal group), and monofocal IOLs (monofocal group).ResultsThe total of 76 eyes, including 24 eyes in the EDOF group, 26 eyes in the bifocal group, and 26 eyes in the monofocal group, were included in this study. Mean deviation (MD) of HFA was -0.24±0.58 dB in the EDOF group, -1.38±0.58 dB in the bifocal group, and 0.02±0.44 dB in the monofocal group. Foveal threshold (FT) of HFA was 35.8±1.6 dB in the EDOF group, 33.6±1.7 dB in the bifocal group, and 36.6±1.4 dB in the monofocal group. In both MD and FT, there was significant difference between the bifocal group and the others (p<0.001). There was no difference between the EDOF group and the monofocal group. Moreover, there was no significant difference between the three groups about pattern standard deviation (PSD) of HFA.ConclusionTECNIS Symfony® may have little influence on visual field sensitivity, whereas diffractive bifocal IOLs decrease visual field sensitivity.

Fixation behavior in macular dystrophy assessed by microperimetry

PurposeTo investigate the fixation behavior in macular dystrophy using microperimetry.MethodsThis retrospective study included patients with macular dystrophy and unilateral macular pucker. Macular dystrophic eyes were compared based on fixation within or outside of the atrophic region. The normal fellow eyes in patients with unilateral macular pucker formed the control group. Clinical and demographic characteristics of age, sex, best-corrected visual acuity, spherical equivalent, and fixation behavior (which included foveal mean sensitivity (MS), fixation MS, MS improvement, stability, centrality, and eccentric distance of fixation) were analyzed. A total of 58 patients were recruited, comprising 29 eyes of 29 patients in the macular dystrophy group and 29 eyes of 29 patients in the control group.ResultsCompared to the control group, patients with macular dystrophy had significantly poorer visual acuity, foveal MS, fixation MS, stability, and centrality, and more eccentric preferred retinal locations (PRLs). In macular dystrophy, the PRLs were most common on the superior side (48.3%). Compared to fixation in the atrophic region, PRLs out of the atrophic lesion gained more MS (7.41 vs. 0.89 dB, p = 0.001), although with less stable fixation (10.0 vs. 47.4%, p = 0.044). By multivariate linear regression, eccentric distance was found to be significantly associated with MS improvement (p = 0.023).ConclusionsThe commonest location of PRLs in macular dystrophy is anatomically superior to the lesion. The dystrophic eye can gain better sensitivity by using PRLs outside the atrophic area.

Corneal tomography and biomechanics in primary pterygium.

To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. Of the total 55 patients, mean age was 43.0+11.4years (range: 20-72years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21+0.20 and 0.12+0.15, respectively (p=0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09+3.38/44.33+2.29 in pterygium eyes, 43.13+1.79/43.98+2.17 in control eyes (p<0.0005) and mean posterior corneal curvature (Kp1/Kp2 D) values were 6.14+0.39/6.53+0.43 in pterygium eyes and 6.13+0.28/6.46+0.47 in control eyes (p>0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ=0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ=0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

CHANGES OF OUTER RETINAL THICKNESS WITH INCREASING AGE IN NORMAL EYES AND IN NORMAL FELLOW EYES OF PATIENTS WITH UNILATERAL AGE-RELATED MACULAR DEGENERATION.

To test the hypothesis that the thickness of outer retinal layers will change with increasing age in normal eyes and in the normal fellow eyes of patients with unilateral age-related macular degeneration. Spectral domain optical coherence tomography images of 127 normal eyes of 127 subjects and 58 normal fellow eyes of 58 patients with unilateral age-related macular degeneration were studied. The thickness between the retinal pigment epithelium line and the cone outer segment tips line, between the cone outer segment tips line and the photoreceptor inner segment/outer segment line, and between the inner segment/outer segment line and the external limiting membrane line were measured at the fovea in both groups. The thickness between retinal pigment epithelium line and the cone outer segment tips line, and between inner segment/outer segment line and the external limiting membrane line were significantly and negatively associated with age in the normal group. Cone outer segment tips line and the photoreceptor inner segment/outer segment thickness was not significantly associated with age. Retinal pigment epithelium line and the cone outer segment tips line was thinner in the fellow eyes of patients with unilateral age-related macular degeneration than in the age-matched normal eyes. Cone outer segment tips line and the photoreceptor inner segment/outer segment and inner segment/outer segment line and the external limiting membrane line thicknesses in the fellow eyes were not significantly different from that of normal eyes. The tissue between the retinal pigment epithelium line and the cone outer segment tips line may become atrophic in older eyes and in the normal fellow eyes of patients with unilateral age-related macular degeneration.

Spectral domain optical coherence tomography measurements in amblyopic Egyptian patients

Purpose The aim of this study was to compare the macular thickness and each retinal layer thickness of the amblyopic eyes with their normal fellow eyes in patients with unilateral amblyopia using the Spectralis spectral domain optical coherence tomography new segmentation software. Patients and methods A total of 20 patients with unilateral amblyopia were enrolled in this study. Seventeen patients (85%) had anisometropic amblyopia, and three (15%) had combined amblyopia (strabismic and anisometropic). Best-corrected visual acuity was measured and converted to the logarithm of the minimum angle of resolution (logMAR). Patients underwent a comprehensive ophthalmic examination, including Spectralis spectral domain optical coherence tomography scanning. The mean of each of the three macular thickness map circles and the mean thickness of each of the retinal layers at the fovea and at 1000 μm circle and the 2500 μm circle were automatically extracted using Spectralis new segmentation software. Results There was a statistically significant increase in the macular thickness at the central subfield region of the early treatment diabetic retinopathy study (ETDRS) map in the amblyopic eyes (288.65±22.61 μm) compared with the fellow normal eyes (281.1±22.6 μm). In addition, there was a statistically significant increase in the outer nuclear layer thickness at the fovea of the amblyopic eyes (114.7±13.93 μm) compared with the fellow normal eyes (104.4±15.63 μm). There was also a statistically significant increase in the thickness of the retinal nerve fiber layer at the outer circle of the amblyopic eyes (33.03±3.816 μm) compared with the fellow normal eyes (30.76±3.75 μm). However, there was a statistically significant decrease in the thickness of the ganglion cell layer at the outer circle in the amblyopic eyes (36.38±5.27 μm) compared with the fellow normal eyes (39.09±6.19 μm). Conclusion The increase in the thickness of the central subfield region in the macular thickness map and the outer nuclear layer at the fovea implies that the photoreceptors may be affected by amblyopia.

Accuracy of machine learning classifiers using bilateral data from a Scheimpflug camera for identifying eyes with preclinical signs of keratoconus

To describe the topographic and tomographic characteristics of normal fellow eyes of unilateral keratoconus cases and to evaluate the accuracy of machine learning classifiers in discriminating healthy corneas from the normal fellow corneas. Department of Ophthalmology, Semmelweis University, Budapest, Hungary. Retrospective case-control study. Patients with bilateral keratoconus (keratoconus group), clinically and according to the keratoconus indices of the Pentacam HR Scheimpflug camera; normal fellow eyes of patients with unilateral keratoconus (fellow-eye group); and eyes of refractive surgery candidates (control group) were compared. Tomographic data, topographic data, and keratoconus indices were measured in both eyes using the Scheimpflug camera. Receiver operating characteristic (ROC) analysis was used to assess the performance of automated classifiers trained on bilateral data as well as individual parameters to discriminate fellow eyes of patients with keratoconus from control eyes. Keratometry, elevation, and keratoconus indices values were significantly higher and pachymetry values were significantly lower in keratoconus eyes than in fellow eyes of unilateral keratoconus cases (P < .001). These fellow eyes had significantly higher keratometry, elevation, and keratoconus index values and significantly lower pachymetry values than control eyes (P < .001). Automated classifiers trained on bilateral data of index of height decentration had higher accuracy than the unilateral single parameter in discriminating fellow eyes of patients with keratoconus from control eyes (area under ROC 0.96 versus 0.88). Automatic classifiers trained on bilateral data were better than single parameters in discriminating fellow eyes of patients with unilateral keratoconus with preclinical signs of keratoconus from normal eyes. No author has a financial or proprietary interest in any material or method mentioned.

Assessment of Corneal Epithelial Thickness in Asymmetric Keratoconic Eyes and Normal Eyes Using Fourier Domain Optical Coherence Tomography.

Purpose. To compare the characteristics of asymmetric keratoconic eyes and normal eyes by Fourier domain optical coherence tomography (OCT) corneal mapping. Methods. Retrospective corneal and epithelial thickness OCT data for 74 patients were compared in three groups of eyes: keratoconic (n = 22) and normal fellow eyes (n = 22) in patients with asymmetric keratoconus and normal eyes (n = 104) in healthy subjects. Areas under the curve (AUC) of receiver operator characteristic (ROC) curves for each variable were compared across groups to indicate their discrimination capacity. Results. Three variables were found to differ significantly between fellow eyes and normal eyes (all p < 0.05): minimum corneal thickness, thinnest corneal point, and central corneal thickness. These variables combined showed a high discrimination power to differentiate fellow eyes from normal eyes indicated by an AUC of 0.840 (95% CI: 0.762–0.918). Conclusions. Our findings indicate that topographically normal fellow eyes in patients with very asymmetric keratoconus differ from the eyes of healthy individuals in terms of their corneal epithelial and pachymetry maps. This type of information could be useful for an early diagnosis of keratoconus in topographically normal eyes.

Long-Term Observation of the Vitreomacular Relationship in Normal Fellow Eyes of Patients with Unilateral Idiopathic Macular Holes

Purpose: To describe long-term changes in the vitreomacular relationship in normal fellow eyes of patients with unilateral idiopathic macular holes (MHs). Methods: This is a retrospective, observational case series. The medical records of patients who underwent surgery for idiopathic MHs between May 2000 and December 2010 were reviewed. Patients who had clinically normal fellow eyes and underwent 12 months or more of follow-up were included. The vitreomacular relationship in the fellow eyes was evaluated using optical coherence tomography (OCT) and slit-lamp biomicroscopy. Results: The study included 153 patients with a mean age of 65.5 years and a mean follow-up of 33.5 months (range, 12-121). The incidence of vitreomacular attachments evaluated by OCT was 52% (80 eyes) at initial examination, which decreased to 41, 37 and 23% at 1, 2 and 3 years after the initial examination, respectively. Of the 80 eyes with vitreomacular attachments at initial examination, 40 (50%) still had vitreomacular attachments at the final visit. Of the remaining 40 eyes in which vitreomacular separation occurred during follow-up, 11 (28%) developed an MH, with a mean interval of 45 months. None of the eyes with vitreomacular separation at presentation developed an MH. Conclusion: This largest series of fellow eyes of MHs followed by OCT shows that, at presentation, about half of the patients already have premacular vitreous detachment and therefore no risk of MH, and that second MH develops in about 30% in the process of vitreomacular separation, which evolves over a prolonged period.

VITREOMACULAR INTERFACE AND OUTER FOVEAL MICROSTRUCTURE IN FELLOW EYES OF PATIENTS WITH UNILATERAL MACULAR HOLES

To investigate the relationship between the vitreomacular interface and the integrity of the photoreceptor microstructures in the normal fellow eyes of patients with unilateral macular holes. Retrospective observational case series. Fifty-five normal fellow eyes of 55 patients with unilateral macular holes were enrolled in the study. All patients underwent complete ophthalmologic examination including best-corrected visual acuity, slit-lamp biomicroscopy, fundus photography, and spectral domain optical coherence tomography at initial and follow-up visits. The features of the vitreomacular interface were graded based on spectral domain optical coherence tomography findings. At the initial visit, 28 of 55 eyes (51%) had vitreomacular attachments with or without perifoveal posterior vitreous detachment. On their initial visit, a triangular elevation of the cone outer segment tips line was identified in 11 of 18 eyes (61%) with perifoveal posterior vitreous detachment across all quadrants with persistent attachment to the fovea. Conversely, none of the remaining 37 eyes with the other stages of posterior vitreous detachment showed any abnormalities. Over a mean follow-up period of 18 months (range, 12-24 months), the elevation of the cone outer segment tips line resolved after spontaneous vitreomacular separation without macular holes in 3 eyes, remained unchanged in 6 eyes, and showed progression to a full-thickness macular hole in 2 eyes. These findings suggest that an elevation of the cone outer segment tips line in the normal fellow eyes of patients with macular holes is caused by the focal traction of the vitreous at the foveal center. This is considered to be an important primary change observed in the macular tissue in full-thickness macular hole formation.

Differentiating Mild Papilledema and Buried Optic Nerve Head Drusen Using Spectral Domain Optical Coherence Tomography

To evaluate the clinical utility of spectral domain optical coherence tomography (SD-OCT) in differentiating mild papilledema from buried optic nerve head drusen (ONHD). Comparative case series. Sixteen eyes of 9 patients with ultrasound-proven buried ONHD, 12 eyes of 6 patients with less than or equal to Frisén grade 2 papilledema owing to idiopathic intracranial hypertension. Two normal fellow eyes of patients with buried ONHD were included. A raster scan of the optic nerve and analysis of the retinal nerve fiber layer (RNFL) thickness was performed on each eye using SD-OCT. Eight eyes underwent enhanced depth imaging SD-OCT. Images were assessed qualitatively and quantitatively to identify differentiating features between buried ONHD and papilledema. Five clinicians trained with a tutorial and masked to the underlying diagnosis independently reviewed the SD-OCT images of each eye to determine the diagnosis. Differences in RNFL thickness in each quadrant between the 2 groups and diagnostic accuracy of 5 independent clinicians based on the SD-OCT images alone. We found no difference in RNFL thickness between buried ONHD and papilledema in any of the 4 quadrants. Diagnostic accuracy among the readers was low and ranged from 50% to 64%. The kappa coefficient of agreement among the readers was 0.35 (95% confidence interval, 0.19-0.54). We found that SD-OCT is not clinically reliable in differentiating buried ONHD and mild papilledema.

PERIPHERAL RETINAL NONPERFUSION IN FELLOW EYES IN COATS DISEASE

To measure peripheral nonperfusion and describe bilateral vascular abnormalities in patients with Coats disease, emphasizing subtle findings in the contralateral eyes of patients diagnosed with unilateral disease. Clinical records, including retina drawings and fluorescein angiography images obtained under anesthesia, were retrospectively reviewed from consecutive pediatric patients with Coats disease. The main outcome measure was disk diameters of peripheral nonperfusion and proportion of Coats disease patients with bilateral findings. Twenty-two of 32 patients with Coats disease had bilateral abnormal peripheral vasculature. In Group 1 (classic Coats disease: presumed unilateral, ocular only disease), 15 of 24 patients had peripheral nonperfusion >2 disk diameters in their contralateral eyes, 5 with telangiectasis and/or microaneurysms. Seven of 8 patients in Group 2 (Coats-like disease: systemic and/or clinically bilateral disease) had bilateral vascular anomalies. Bilateral vascular abnormalities are more common in Coats disease than previously reported. This observation supports a systemic and/or genetic association with Coats disease. Patients with Coats disease should have careful evaluation of the periphery of the less affected eye, preferably with fluorescein angiography, to identify vascular changes not visible clinically. Both eyes warrant surveillance over the lifetime of the patient for potential progression to exudative disease that would warrant treatment.

Heterochromia Iridis and Pertinent Clinical Findings in Patients with Glaucoma Associated with Sturge–Weber Syndrome

To examine the clinical and gonioscopic findings in patients with glaucoma associated with Sturge-Weber syndrome. Retrospective review of clinical findings of all patients with Sturge-Weber syndrome who presented between January 1978 and December 2003. Koeppe gonioscopy was performed under general anesthesia and findings were photographed when feasible. Iris color was documented by color sketch or photograph at initial presentation. Fisher exact test was used to determine whether the presence of heterochromia was statistically higher in the glaucomatous group. Fifty-five patients who met inclusion criteria were identified, of whom 44 (80%) had glaucoma. Unilateral glaucoma was diagnosed in 30 eyes and bilateral glaucoma in 14 eyes, yielding 58 eyes with glaucoma and 52 eyes without. Gonioscopic examination revealed distinct anatomic abnormalities in the anterior chamber angle in 32 (55%) of the glaucomatous eyes in contrast to the normal fellow eyes in patients with unilateral glaucoma and to the patients without glaucoma. Heterochromia iridis with darker iris on the glaucomatous side was present in 11 of the 30 patients with unilateral glaucoma (37%, P < .001) but in none of the patients without glaucoma. The characteristics observed in the anterior chamber angle in this large, uniquely examined series are the first reported to the authors' knowledge and may support a role for neural crest derived anomalies in the pathogenesis of glaucoma in these infant eyes. Careful examination for heterochromia iridis may be judicious in these patients.

Shift of temporal responsivity curve of pattern reversal visually evoked potentials to lower frequencies in patients after recovery from optic neuritis

To investigate the responsivity of the visual system to pattern reversal stimuli of different reversal rates in optic neuritis patients after a full recovery of visual acuity. Thirty eyes with optic neuritis and 30 eyes of age-matched normal controls were studied. Steady-state pattern reversal visually evoked potentials (P-VEPs) were recorded using reversal rates of 2, 10, 20 and 30 Hz. The relationship between the amplitudes of the P-VEPs and reversal rate was analysed. The temporal responsivity curves of the two groups were compared. The means ± standard deviations (SDs) of the P-VEP amplitudes in the normal controls were 7.08 ± 2.97, 8.60 ± 2.37, 4.69 ± 1.99 and 2.11 ± 1.24 μV at reversal rates of 2, 10, 20 and 30 Hz, respectively. The comparable amplitudes from the recovered optic neuritis patients were 8.01 ± 2.45, 6.57 ± 2.54, 2.73 ± 1.76 and 0.94 ± 1.27 μV. The mean amplitude of the P-VEPs elicited at a reversal rate of 2 Hz was not significantly different from that of normal controls. However, the amplitudes of the P-VEPs at reversal rates of 10, 20 and 30 Hz were significantly smaller in the recovered optic neuritis patients than in the controls. In addition, the average maximum amplitude of the P-VEPs was obtained at 10 Hz in normal subjects and at 2 Hz in the recovered optic neuritis patients. These results indicate that the peak of the temporal tuning curve of the P-VEP shifts to lower frequencies in recovered optic neuritis eyes, and that the reduced amplitudes at higher frequencies seem to be characteristic of the visual system of patients with recovered optic neuritis.

Parafoveal letter recognition at reduced contrast in normal aging and in patients with risk factors for AMD

Patients with early age-related maculopathy (ARM) do not necessarily show obvious morphological signs or functional impairment. Many have good visual acuity, yet complain of decreased visual performance. The aim of this study was to investigate the aging effects on performance of parafoveal letter recognition at reduced contrast, and defects caused by early ARM and normal fellow eyes of patients with unilateral age-related macular degeneration (nfAMD). Testing of the central visual field (8 degrees radius) was performed by the Macular Mapping Test (MMT) using recognition of letters in 40 parafoveal target locations at four contrast levels (5, 10, 25 and 100%). Effects of aging were investigated in 64 healthy subjects aged 23 to 76 years (CTRL). In addition, 39 eyes (minimum visual acuity of 0.63;20/30) from 39 patients with either no visible signs of ARM, while the fellow eye had advanced age-related macular degeneration (nfAMD; n = 12), or early signs of ARM (eARM; n = 27) were examined. Performance was expressed summarily as a "field score" (FS). Performance in the MMT begins to decline linearly with age in normal subjects from the age of 50 and 54 years on, at 5% and 10% contrast respectively. The differentiation between patients and CTRLs was enhanced if FS at 5% was analyzed along with FS at 10% contrast. In 8/12 patients from group nfAMD and in 18/27 from group eARM, the FS was statistically significantly lower than in the CTRL group in at least one of the lower contrast levels. Using parafoveal test locations, a recognition task and diminished contrast increases the chance of early detection of functional defects due to eARM or nfAMD and can differentiate them from those due to aging alone.

Correspondence

Purpose: To determine the optical coherence tomography (OCT) findings in eyes with group 2a idiopathic juxtafoveal retinal telangiectasis (IJRT). Methods: Forty-one eyes of 22 patients with nonproliferative group 2a IJRT were examined. OCT testing including retinal topographic mapping and analysis, and horizontal and vertical line scans, was obtained on each eye. Results: None of the 41 eyes had a thickened foveal center. The average center foveal thickness was 166 μm (31–264 μm). Stage 1 eyes (n = 2) were normal fellow eyes in patients with contralateral group 2a IJRT. Stage 2 eyes (n = 11) all had parafoveolar temporal graying and intraretinal temporal fluorescein leakage, but rarely had photoreceptor disruption (18%) on OCT testing. Stage 3 eyes (n = 14) all had clinical and fluorescein findings similar to or more pronounced than stage 2 eyes. All stage 3 eyes also had one or more foveal cysts at various retinal depths on OCT. Most of these eyes (86%) had photoreceptor disruption and outer retinal atrophy on OCT. Stage 4 eyes (n = 14) all had a black foveal or parafoveolar pigment plaque and intraretinal temporal fluorescein leakage. All stage 4 eyes had a hyper-reflective plaque with shadowing on OCT corresponding to the pigment plaque. Most of these eyes had one or more foveal cysts (64%) and all of these eyes had photoreceptor disruption and outer retinal atrophy. Conclusion: OCT helps in the staging of group 2a IJRT and reveals multiple retinal structural abnormalities.