Tilted disc syndrome and colour vision

PURPOSE: To study colour vision in patients with tilted disc syndrome. METHODS: Colour vision was examined using Bostr?m-Kugelberg (B-K) plates, Farnsworth-Munsell 100-hue test (FM-100) and Farnsworth panel D-15 and Lanthony desaturated panel tests. RESULTS: A total of 35 eyes of 21 patients were examined. Seventeen eyes (49%) of 11 patients were found to have a colour vision defect in at least one eye. The severity of the colour vision defect differed between eyes for six of eight patients with bilateral tilted discs. In two of these patients, colour vision was normal in one eye. Seven patients had a unilateral tilted disc and three of these individuals had a colour vision defect in the affected eye. Of all eyes with a colour vision defect, a red-green defect was found in four eyes (24%), a blue defect in one eye (6%), and a mixed defect in 12 eyes (70%). Colour vision defects were not related to visual acuity or to severity of visual field defects. CONCLUSIONS: This is the first report of colour vision defects in tilted disc syndrome. In the differential diagnosis of tilted disc syndrome, chiasmal lesions and glaucoma, the examination of colour vision may add valuable information. Further, it is recommended that young people with tilted disc syndrome undergo an examination of colour vision so that they can be given appropriate career guidance.     

Clinical and multifocal-electroretinographic findings of congenital tilted disc syndrome associated with choroidal neovascularization: a case report

Purpose To report a case of a tilted disc syndrome associated with choroidal neovascularization. Methods A 55-year-old male patient presented with blurred vision and metamorphopsia of the left eye. He underwent complete ophthalmologic examination, fluorescein angiography, optical coherence tomography (OCT) and multifocal-electroretinogram (mf-ERG). Results All features are consistent with a tilted disc syndrome complicated with a small neovascular membrane. OCT confirmed the presence of a serous retinal detachment. Mf-ERG confirmed a decrease of electrical activity of the photoreceptors in area 1 (fovea). The patient refused to be treated. Conclusion Macular serous retinal detachment due to subretinal leakage is a rare complication of tilted disc syndrome. To the author’s knowledge, this is the first time a tilted disc syndrome with choroidal neovascularization is documented by means of OCT and mf-ERG. These are the only objective tools in order to assess objectively the anatomical and functional damage accordingly.     

Retinal nerve fiber analysis and tomography of the optic disc in eyes with tilted disc syndrome.

BACKGROUND AND OBJECTIVE: To investigate retinal nerve fiber layer thickness and optic disc parameters in eyes with tilted disc syndrome. PATIENTS AND METHODS: Thirty-eight eyes with tilted disc syndrome (20 myopic control eyes, and 20 emmetropic control eyes) were examined. After a routine ophthalmologic examination of all eyes, scanning laser polarimetry (for retinal nerve fiber layer thickness) and scanning laser tomography (for optic disc parameters) were performed. Scanning laser polarimetry and scanning laser tomography parameters were compared in the different groups. RESULTS: On scanning laser polarimetry evaluation, statistically significant differences were found in the superior integral, nasal integral, and superior nasal quadrants of eyes with tilted disc syndrome compared with control groups (P = .01, P = .04, P = .00, P = .00, P = .00, and P = .00, respectively). On scanning laser tomography evaluation, statistically significant differences were found in average diameter, total contour area, effective area, average depth, volume above, neuroretinal rim area, and cup-disc ratio in eyes with tilted disc syndrome compared with control groups (P = .00, P = .00, P = .00, P = .04, P = .02, P = .00, and P = .01, respectively). CONCLUSION: Parameters acquired through imaging with scanning laser polarimetry and scanning laser tomography in eyes with tilted disc syndrome are different from those of normal eyes.     

Central corneal thickness in tilted disc syndrome.

PURPOSE.: Earlier literature reports that abnormal optic disc shape or size seem to be closely associated with the shape or size of the cornea. Here we search for an association between the presence of tilted disc syndrome and the central corneal thickness. METHODS.: Sixty-one eyes of 61 patients with tilted disc syndrome were included in the study. Sixty-one eyes of 61 subjects were chosen as controls. Corneal thickness was evaluated with ultrasound pachymetry from the central region after instillation of topical proparacaine hydrochloride and before the ophthalmologic examination. RESULTS.: The mean central corneal thickness in the tilted disc syndrome group was found to be 547.5 +/- 36.16 mum (median 546, range 467 to 638). The mean central corneal thickness in the control group was measured as 541.09 +/- 29.52 mum (median 540, range 500 to 627). There was no statistically significant difference in corneal thickness between the tilted disc syndrome group and control group (p = 0.218). CONCLUSION.: There seems to be no correlation between the central corneal thickness and the presence of tilted disc syndrome.     

Chorioretinal degenerative changes in the tilted disc syndrome

Ninety patients (163 eyes) with tilted disc syndrome were examined in order to show possible chorioretinal degenerative lesions associated with the typical ectasia of the infero-nasal fundus observed in this anomaly. Eighteen out of the 163 eyes had pigmentary accumulations, either branched, linear or dotted and five had roundish areas of chorioretinal atrophy. Furthermore, in 7 eyes areas of pigmentary atrophy at the posterior pole were observed. The most serious lesions were represented by macular choroidal neovascular membranes, seen in 3 eyes, which were responsible for the loss of vision in these eyes. A relationship was found between the depth of the ectasia, the degree of tilt of the optic disc and the development of chorioretinal degeneration. Because of possible complication by macular choroidal neovascularization, the tilted disc syndrome can not be regarded in every case as a benign and not evolutive ocular anomaly.     

Retinal nerve fiber layer analysis and interpretation of GDx parameters in patients with tilted disc syndrome

This study was conducted to determine abnormalities of the GDx Glaucoma Scanning System parameters in patients with tilted discs, in order to set guidelines for the evaluation of glaucomatous damage in this situation. The objective was to determine which GDx parameters displayed the highest level of variation, and which remained unchanged in tilted disc syndrome. RNFA was polarimetrically conducted on 45 eyes from 26 subjects with tilted discs, and 43 normal eyes withNerve Fiber Analyzer II (Laser Diagnostic Technologies). All parameters except inferior maximum, average thickness, ellipse average, and inferior average displayed a significant difference between the two groups (p < 0.05). Although NFA is useful in glaucoma diagnosis, the majority of the GDx parameters, as shown in our study, are unreliable in tilted disc syndrome in this respect.     

Macular function in tilted disc syndrome

Tilted disc syndrome can cause visual field defects due to an optic disc anomaly. Recent electrophysiological findings demonstrate reduced central outer retinal function with ophthalmoscopically normal maculae. We measured macular sensitivity with the microperimeter and performed psychophysical assessment of mesopic rod and cone luminance temporal sensitivity (critical fusion frequency) in a 52-year-old male patient with tilted disc syndrome and ophthalmoscopically normal maculae. We found a marked reduction of sensitivity in the central 20° and reduced rod- and cone-mediated mesopic visual function. Our findings extend previous electrophysiological data that suggest an outer retinal involvement of cone pathways and present a case with rod and cone impairment mediated via the magnocellular pathway in uncomplicated tilted disc syndrome.     

Tilted disc syndrome: an OCT and mfERG study

Purpose To evaluate retinal thickness and function in eyes with tilted disc syndrome with optical coherence tomography (OCT) and multifocal electroretinogram (mfERG). Methods Twenty-one eyes of 12 patients (4 males and 8 females) with tilted disc were studied with OCT3 and mfERG and compared with 40 eyes of 20 age and sex-matched control subjects. The thickness of the fovea and the thickness of retinal nerve fibre layer (RNFL) along a 3.4-mm-diameter circle centred on the optic nerve head were evaluated using OCT3. The macular cone function was tested by mfERG. Results The OCT-derived RNFL thickness was significantly decreased in the superior area of eyes with tilted disc with a mean value equal to 106.47 μm (SD 24.1). The mean response amplitude density of the fovea (11.75 nV/deg2) and parafovea (8.22 nV/deg2) was significantly lower in eyes with tilted disc than in normal eyes. Conclusion OCT and mfERG can be objective tools for assessing anatomical and functional damage of the macula. Our results suggest that in tilted disc syndrome even without visual impairment the optic nerve and the macula show dysfunction not visible by other means.     

Rare oculo-rhino-auditive variants of the branchial arch syndrome Report of three cases with two necropsy records

Different kinds of optic disc deformities are considered in this paper. These optic disc deformities include the tilted disc, the morning glory syndrome, the optic pit and the typical coloboma. All of these optic nerve deforrnities are probably typical and atypical optic disc colobomas. A clinical approach of these typical and atypical colomobas included different tests: angiography, electrophysiology and psychophysics. The genetic characteristics of these colobomas are considered.     

Clinical and electrophysiological features of tilted disc syndrome

Nine patients with tilted disc syndrome were examined psychophysically and electrophysiologically. Visual field defects did not correspond to fundus abnormalities in half of the eyes. Visual evoked responses were more reduced than electroretinogram responses. These results indicate that associated visual field defects and impairment of visual acuity were related not only to a localized staphylomatous ectasia of the posterior globe but also to a lesion of the inner retinal layer, optic nerve, or more proximal visual pathway. This suggests that a developmental abnormality in the embryonic retina may result in hypoplasia of the retinal pigment epithelium and neural elements as well as an anomaly of the optic disc. Investigation of visual function in patients with tilted disc syndrome may help to identify possible concomitant retinal and optic nerve dysfunction.     

Electrofunctional features of the tilted disc syndrome

The ERG, EOG and VEPs of 15 patients with tilted disc syndrome were studied. The ERG showed abnormal amplitudes in about 1/4 of the eyes and the EOG values were pathological in 3 patients. It is probable that the abnormality of the inferiornasal portion of the retina and retinal pigment epithelium seen in the tilted disc syndrome causes the changes in the ERG and EOG. Pattern VEPs latency was delayed in most patients. This finding is probably due to the poor focusing of the light in the retina.     

Hypothesis on the pathogenesis of the papillary dysversion syndrome

The tilted disc syndrome is an ocular anomaly characterized by dysversion of the optic nerve head, congenital crescent, vessel anomalies, ectasia and depigmentation of the infero-nasal fundus. Its pathogenesis is not known, but there are many theories as to its origin. The most convincing one links the tilted disc syndrome to an anomalous closing of the embryonic fissure. However this hypothesis does not adequately explains the origin of all the anomalies found in the syndrome. In this paper a new theory is suggested. The ganglion cell fibres of the infero-nasal retina could be misdirected toward the orbit through an anomalous embryonic fissure. In this way the fibres could not reach their central connections and degenerate. The hypoplasia of the infero-nasal quadrant of the eye could originate from the anomalous closing of the embryonic fissure and from the atrophy of the ganglion fibres; the crescent from the lack of fibres in the inferior optic disc; the anomalous appearance of the optic nerve head and the retinal vessels from a shifting of the disc upward due to the imbalance between the ganglion cell fibres coming from the superior and inferior retina.     

Optic disc drusen in tilted disc

PURPOSE: To investigate if a congenital anomaly of the head of the optic nerve like such as tilted disc can be a risk factor for the development of optic disc drusen. METHODS: The study was performed retrospectively on the files of 47 patients with optic disc drusen. The diagnosis was confirmed by fluorescein angiography and B-scan ultrasonography. The authors examined the fundus photographs and the fluorescein angiographies of these patients looking for the presence of tilted discs. RESULTS: Two of the 47 patients with optic nerve drusen had tilted discs as well, about twice the expected rate. Both cases presented a parapapillary hemorrhage. CONCLUSIONS: The concomitant presence of tilted disc and optic disc drusen can have a cause-effect relationship. The axonal crowding in a scleral canal of reduced size, as seen in tilted disc, can compress the nerve fibers against the stiff lamina cribrosa, producing a chronic optic neuropathy leading to drusen.     

Tilted disc syndrome may mimic false visual field deterioration

Purpose: Tilted disc syndrome is a congenital anomaly of the eye characterized by mostly upper temporal visual field defects. The aim of the present study was to evaluate the effect of gradual myopic correction in the improvement of visual field defects associated with tilted disc syndrome. Methods: The visual field was examined in 38 eyes of 24 patients using standard Goldmann perimetry. The isoptres IV‐4e, I‐4e, I‐3e and I‐2e were plotted. The defective isoptres were tested again with gradually increasing myopic correction until no further change was noted. Results: The most common type of defect was a relative upper temporal defect (19 eyes). Temporal relative defects were found in five eyes, upper altitudinal field defects in six eyes, an enlarged blind spot in four eyes, and an inferior field defect in one eye. The visual field defect partly or totally disappeared with increased myopic correction in 18 (50%) eyes. The mean improvement was 17.0 ± 6.2 degrees and the mean additional myopic correction was 3.1 ± 1.5 D. Conclusions: Even a small change in near correction during visual field examination may imply worsened or improved visual field defects in tilted disc syndrome. To prevent a false interpretation of field deterioration in a patient with tilted disc syndrome and glaucoma, visual field assessment should include examination with the myopic correction that provides the maximal improvement of the defective visual field.     

Choroidal neovascularization in tilted disc syndrome

In the paper the authors describe two cases of tilted disc syndrome associated with choroidal neovascularization. The presumed causes of development of this neovascularization and factors that can influence the location of neovascular membrane are discussed.     

Heterotopic fundus. An easily missed abnormality]

This study demonstrates 12 patients with "tilted disc syndrome" which includes an inferior conus and inversion of the optic disc, sectorial ectasia of the fundus, and refractive scotoma. Knowledge of the anomaly can help to prevent the patient from repeated neurologic and neuroradiologic examinations to exclude a cerebral tumor.     

Clinical studies of the tilted disc syndrome

Frequency of occurrence of all clinical signs in the tilted disc syndrome was studied in the paper because of variability of clinical picture in this syndrome. The most frequently occurring signs were: tilting of the disc (89%), oblique direction of the vessels (89%) and myopic astigmatism (96%). Other signs were observed less frequently: hypoplastic changes of retina and choroid in 82%, congenital conus in 45% and defects in the visual field in 55%. All sign of the syndrome were seen in 45% od the examined eyes. The most important signs of the syndrome are: tilting of the disc, oblique direction of the vessels and congenital conus.     

Electrodiagnostics of the tilted disc syndrome

In five patients with a tilted disc syndrome the visually evoked potentials were examined by means of pattern stimulation. It was hoped that by such an examination this syndrome could be distinguished from a chiasma syndrome, since it is known that compression of the anterior visual pathways causes delayed responses, whereas defects or atrophies generally do not. In 4 patients, however, delayed responses were found and they were not found in only one patient.     

Topographical analysis of corneal astigmatism in patients with tilted-disc syndrome

PURPOSE: To evaluate the corneal topography in patients with tilted-disc syndrome to determine the relationship between optic disc dysversion and corneal astigmatism and the pattern of astigmatism in these patients. METHODS: The study included 23 eyes of the 13 tilted-disc syndrome patients with spheric refractive errors ranging between +1.00 D and -9.00 D (mean -4.00 +/- 3.4 D) and astigmatic errors ranging between -0.50 and -4.50 D (mean -1.95 +/- 0.93 D). Corneal topography was performed by computer-assisted videokeratoscope topographic modelling system 2 (TMS-2) and incidence of corneal astigmatism, corneal topographic patterns, and mean values of the topographic indices were determined. RESULTS: Corneal topographic analysis showed corneal astigmatism in 22 out of 23 patients with tilted discs. Corneal astigmatism was symmetric bow tie pattern in 10 eyes (45.45%), asymmetric bow tie pattern in 11 eyes (50%) and irregular in 1 eye (4.5%). Among the patients with bow tie pattern group (21 eyes), 14 eyes had with-the-rule astigmatism, 1 eye had against-the-rule astigmatism, and 6 eyes had oblique astigmatism. In 18 eyes, astigmatism was corneal, whereas combined corneal and lenticular in 4 eyes and lenticular in 1 eye. CONCLUSION: In the majority of tilted-disc cases, ocular astigmatism is mainly corneal. Morphogenetic factors in the development of the tilted disc might possibly influence the corneal development in such a way to result in corneal astigmatism.     

The Effect of Tilted Disc Syndrome on Ocular Hemodynamic Measurements

Background: The purpose of this study was to assess ocular hemodynamics in patients with unilateral tilted disc syndrome (TDS) using color Doppler ultrasonography (CDUS). Methods: Fifteen consecutive patients with unilateral TDS and normal-appearing contralateral optic nerves were enrolled. Both eyes of all participants underwent detailed ophthalmological examination including automated visual field testing. CDUS was performed in the eyes with tilted discs and fellow unaffected eyes. Peak systolic velocities, end diastolic velocities, and vessel resistance were measured in the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA), and temporal posterior ciliary artery (TPCA). The minimum and maximum blood flow velocities were also measured in the central retinal vein (CRV). Results: No statistically significant differences were found between eyes with tilted discs and fellow normal eyes in terms of OA, CRA, NPCA, or TPCA mean peak systolic or end diastolic velocities, resistivity indices, and the mean maximal and minimal CRV blood flow velocities. Conclusion: Ocular hemodynamic measurements determined by CDUS do not appear to be altered in tilted disc syndrome.