Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features.

AIM: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded. RESULTS: Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score. CONCLUSIONS: Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.

Yellow mercuric oxide: a treatment of choice for phthiriasis palpebrarum.

Thirty-five patients presenting with phthiriasis palpebrarum were all treated with a regimen of 1% yellow oxide of mercury ointment four times daily for 14 days. At the conclusion of treatment there was complete resolution of the signs and symptoms of the disease. No side effects due to the treatment were reported or detected. We have shown that 1% mercuric oxide ointment is both a safe and effective treatment for phthiriasis palpebrarum. We recommend it as the treatment of choice.

Glaucoma in siblings with Morquio syndrome.

Two cases of association between the Morquio Syndrome and glaucoma in one family are described. Possible role of Mucopolysaccharides acting in the anterior chamber angle is discussed.

Accommodation insufficiency induced by glybenclamide.

We present a case of acute accommodation insufficiency after oral ingestion of glybenclamide. The symptom diminished after the drug was discontinued. Such an adverse effect has been described in association with other drugs but previously not with hypoglycemic agents.

Visual thresholds in aphakia and pseudophakia.

Following extracapsular senile cataract extraction, visual thresholds were measured in 15 aphakic eyes corrected with glasses and compared with an appropriately matched group of 23 eyes with poly (methyl methacrylate) posterior chamber lenses. All subjects were six months to three years postoperative and had 20/30 or better visual acuity. The paramacular dark adapted threshold, the foveal luminance threshold, and the glare effect on both thresholds were not significantly different in the two groups despite the optical differences between aphakic and pseudophakic correction.

A table-top fluorescein angiogram viewer.

An electric table lamp covered by a wooden plate with an opening for the fluorescein angiographic film frame can be used in conjunction with a +20-diopter lens for good quality magnification of fluorescein angiograms.

Monocular visual-field testing under binocular conditions.

Spectacles with plastic polarizers in front of each eye, with the polarizing axis at right angles to each other, permit monocular visual-field tangent screen testing under binocular conditions, provided a rotatable polarizer is attached in front of the standard ophthalmic slide projector which generates the test light.

Rayleigh match in congenital stationary night blindness.

Rayleigh matches performed by 13 patients with Schubert-Bornschein type congenital stationary night blindness with normal color vision, revealed that they use consistently slightly more red light primary in order to achieve a brighter yellow match than a control group with normal color vision and visual acuity. The matching differences between the two groups were statistically significant.

The photopic and scotopic visual thresholds in diabetics without diabetic retinopathy.

The foveal photopic threshold for Landolt ring discrimination and the paramacular scotopic threshold has been monocularly measured in 27 diabetic patients, 30 to 50 years old, without funduscopic retinal alterations, and compared with similar thresholds collected from 17 healthy age matched subjects. About 0.3 log threshold elevation for both photopic and scotopic functions were documented in the diabetic group, suggesting a functional impairment before visible retinopathy occurred. The threshold loss was not correlated with the diabetes longevity.

Ocular dimensions following cryotherapy for active stage of retinopathy of prematurity.

In a group of 21 premature children in which 4 to 10 years earlier 26 eyes with stage 4 of active retinopathy of prematurity (ROP) were treated by cryopexy on the avascular retina, and 15 fellow eyes with stage 2 of active ROP were not treated, comparative measurements of the central corneal thickness, anterior chamber depth and eye axial length were performed. Not significant statistical differences of these parameters were found between the cryotreated and untreated eyes. The axial length was correlated with the degree of myopia.

Inherited progressive cone--rod dystrophy and alopecia.

Two young sisters of Yemenite Jewish family with progressive cone-rod dystrophy accompanied with progressive alopecia of the scalp in one patient and with alopecia of the scalp and eyelashes in the other patient are presented. This rare disease seems to be autosomal recessively inherited since the patient's parents are first cousins and the family history is positive for a paternal grandmother and great-aunt having the same condition.

A device for easy slitlamp funduscopy with a +90-diopter lens.

We developed a device which places the +90-dptr double aspheric lens in the slitlamp common axis channel at 11 mm further from the microscope focal plane, enabling easy visualization of the human fundus.

Visual thresholds following posterior chamber lens implants.

The dark-adapted threshold for a 2 degree white test imaged 10 degrees parafoveal and the foveal threshold luminance for Landolt ring gap discrimination were measured on 23 pseudophakic eyes with 6/9 or better visual acuity, 6 months to 3 years following posterior chamber lens implantation, and on 15 phakic eyes from an appropriately matched control group. Both scotopic and photopic thresholds were higher for the pseudophakic than for the control group by 0.3 and 0.6 log, respectively. These parafoveal and foveal thresholds, when measured under the influence of glare, were likewise significantly higher for the pseudophakic group.

Isolated foveal hypoplasia.

Fifteen patients presented with foveal hypoplasia as an isolated ocular finding. The characteristic findings associated with this entity are a visual acuity of 6/21 or worse, nystagmus, and a typical ophthalmoscopic appearance of the macular area, including absent or abnormal maculofoveal reflexes, unclear definition of the maculofoveal area, and capillaries running abnormally close to the presumed macular area, some of them even crossing the horizontal meridian. Fluorescein angiography revealed a variable and incomplete filtering effect of the choroidal fluorescence in the macular area, suggesting abnormalities in the amount and distribution of macular pigments. The fundal findings of isolated foveal hypoplasia, although typical, are very subtle and often difficult to detect, especially because of the accompanying nystagmus. For this reason we suspect that foveal hypoplasia may be more common than is generally believed.

Optic nerve trauma with prolonged blindness followed by visual-evoked potential.

An accidental deep intraorbital penetration of a radio antenna tip damaged the optic nerve and caused immediate amaurosis in a 19-year-old female with normal funduscopic, electroretinographic and computerized tomographic orbital findings. A small visual-evoked potential (VEP) recorded within 2 h of injury and in the following days revealed persistent electrical nerve conduction despite loss of vision and afferent pupillary reaction. The VEP constituted the only anticipating sign for the visual recovery which occurred after 3 days. Further increase of the VEP amplitudes preceded the visual improvement, resulting, finally, in 6/24 visual acuity with only lower nasal quadrant scotoma and slight optic disk pallor.

Electroretinograms evoked by sinusoidal excitation of human cones.

The amplitude and phase of the fundamental Fourier component of the human electroretinogram (e.r.g.) were recorded with a synchronous detection method under conditions in which each of the three species of cones can be assumed most sensitive in turn. Weber-Fechner behaviour is well established at, or more distal in the retina than, the source of these voltages. Results over the frequency range 7-50 Hz exclude a diffusion model of human flicker perception. The e.r.g. phase vs. frequency plot found with a 'red' test differs from that obtained with a 'green'. The shapes of the e.r.g. field sensitivity action spectra agree with those of the subject's IIj(mu) (j = 3, 4 and 5) mechanisms of Stiles and with in situ measurements of the absorbance spectra of human cone pigments. Threshold phase with each test was independent of background wave-length but, consistent with the results in 3, the phase of the response to the 'red' test (25 Hz) differed significantly from that to the 'green'. If these differences resulted from the absorption of test photons of different colours at different points along the outer segment (independent of cone spectral sensitivity), they would be as clear on dichromats as on trichromats. Results on a protanope are inconsistent with this prediction. We infer that differences in phase are due to the different kinetics of different cone mechanisms and that the e.r.g.s studied here are evoked by exciting only the most sensitive cone mechanism, even though dark-adaptation studies prove that at e.r.g. threshold the test is well above psychophysical threshold for all three cone species. If the inference in 5 is correct, studies of sensitivity across the retina suggest that the spatial distribution of long-, middle- and short-wave-sensitive cones in the human retina differ remarkably.

Retinal function in mucolipidosis IV.

In an 18-month-old girl affected by mucolipidosis IV (ML IV) with mild corneal clouding, normal retinal activity was documented by electroretinogram (ERG) and slightly delayed optic pathway conduction was revealed by visual evoked potential (VEP). Re-examination 9 years later disclosed severe retinal alterations resulting in atrophy with reduced photopic and missing scotopic ERG components and flat VEP. These fundoscopic and electrophysiologic deteriorations in ML IV suggest progressive rod-cone impairment similar to tapetoretinal dystrophy.