Pulfrich Stereo-Illusion Phenomenon in Serous Sensory Retinal Detachment of the Macula

The Pulfrich effect in the clinic

“…As most ophthalmic surgeons are only willing to operate on one eye at a time in patients with bilateral cataracts, due to the potential risk of simultaneous complications to both eyes, the presence of the spontaneous Pulfrich effect in patients with unilateral cataracts after the first cataract surgery may be useful in assessing the need for second-eye cataract surgery with acceptable visual acuity and stereoacuity [25]. In patients with central serous elevation of the macula, the spontaneous Pulfrich effect resolved upon resolution of the maculopathy [26].…”

“…On top of a reduction in retinal illumination, it has been suggested that a unilateral cataract can also cause a spontaneous Pulfrich effect through retinal defocusing, i.e., blurring, which also slows retinocortical transmission and increases visual latency [23]. However, Cetinkaya et al [23,24] Corneal opacity [21] Iatrogenic, e.g., uniocular mydriasis, X-chrom lens [19] Traumatic anisocoria [21] Affecting neural conduction Post retinal detachment repair [21] Macular disease [26,27] Asymmetric pigmentary glaucoma [22] Central pathway conditions Optic neuritis/multiple sclerosis [21,[33][34][35][36][48][49][50] Mid-facial injuries [31,32] Other optic nerve pathologies [28][29][30]51] Pituitary tumours and temporoparietal astrocytomas [38] Anisometropic amblyopia [16] reported that the magnitude of the spontaneous Pulfrich effect in patients with unilateral cataracts did not correlate with visual acuity, but correlated with the presence of binocular symptoms [25]. Indeed, it has been suggested that the presence of the Pulfrich effect may account for visual symptoms in patients with unilateral cataracts that are independent of visual acuity, stereoacuity and contrast sensitivity [23].…”

“…Disorders that affect neural conduction directly in the central visual pathways, when unilateral or asymmetric, can also give rise to an inter-ocular signal latency difference that manifests as a spontaneous Pulfrich effect. Disorders affecting the retina, including central serous elevation of the macula [26], unilateral epiretinal membrane of the macula [27] and repaired retinal detachment [21], can delay conduction and have been reported to manifest a spontaneous Pulfrich effect associated with increased visual latency. Neural conduction can also be slowed in asymmetric optic nerve pathologies such as optic nerve hypoplasia [28], optic nerve head drusen [29], acute ischaemic optic neuropathy due to a presumed vascular accident [30], traumatic optic neuropathy due to mid-facial injury [31,32], and optic neuritis commonly associated with multiple sclerosis [21,[33][34][35][36].In patients with optic neuritis, the Pulfrich effect may account for difficulties with motion perception even in apparent recovery from optic neuritis, as it can be present due to residual optic nerve defects, and appears not to be related to the extent of acute visual loss and time elapsed since an attack of acute optic neuritis [34].…”

Influence of the Pulfrich phenomenon on driving performance

“…In our experience, most patients with subacute or chronic optic nerve disorders have only small spontaneous Pulfrich phenomenons, with delays of 5 ms or less [20]. Some patients with retained gross stereovision may have delays up to 30 ms [11,26]. Since a viewing angle of 90°is usually only adopted at slower car speeds, most probably only patients with large relative delays of more than 5 ms will experience distance misjudgements at slower speeds.…”

“…A bedside test allows estimation of the size of the illusion with just a black pen [20]. A spontaneous Pulfrich phenomenon was reported in the following diseases: drusen of the optic nerve [2], glaucoma [13], pituitary tumours and temporoparietal astrocytoma [5], anisometropic amblyopia [31], strabismus [13,25,31], serous sensory retinal detachment of the macula [11], diabetic retinopathy [13], cataract [13,18], corneal opacity, vitreous opacity, aphakia, anisometropia [18,19,31], anisocoria [30] and after midfacial injuries [14]. All these heterogeneous conditions must introduce a relative conduction delay between the images of the right and left eye.…”