Eila Mustonen

OPTIC DISC HAEMORRHAGES PRECEDE RETINAL NERVE FIBRE LAYER DEFECTS IN OCULAR HYPERTENSION

Both small splinter haemorrhages of the optic disc and retinal nerve fibre layer (RNFL) defects have been reported to be the first signs of glaucomatous development before visual field defects. In this study their time‐ and location‐based relationship to each other was investigated by means of repeated optic disc stereophotography of 25 patients who showed a disc haemorrhage but no disc and field involvement in their ocular hypertensive eyes. During a mean follow‐up time of 6 years, 8 patients developed glaucomatous damage. Their sequential stereo‐photographs showed that disc haemorrhages preceded both development and progression of RNFL defects. Location of a defect was accurately predicted by the haemorrhage. In 4 patients the first visual field defects were detected with routine perimetry only 1 to 2 years after the RNFL defects had been observed. Three patients still show normal fields.

RETINAL NERVE FIBRE LAYER PHOTOGRAPHY WITH A WIDE ANGLE FUNDUS CAMERA

Retinal nerve fibre layer (RNFL) photographs taken with a wide‐angle fundus camera (Canon CF‐60Z) and its built‐in blue interference filter (SE‐40) of 495 nm wavelength were compared with pictures taken with the same camera and a red‐free absorption filter (Wratten No. 58) as well as with photographs taken with a 30° fundus camera and Wratten No. 58 filter. Comparison showed that the best visualisation of the RNFL and its defects was achieved with the 60° picture angle of the Canon camera and SE‐40 filter. With a smaller picture angle (30°) and a filter of longer wavelength quality of reproduction deteriorated.

CONGENITAL PIT OF THE OPTIC NERVE HEAD ASSOCIATED WITH SEROUS DETACHMENT OF THE MACULA

The biomicroscopic, ophthalmoscopic and fluorescein angiographic features of macular detachment secondary to congenital pit of the optic nerve head in three patients are presented. Fluorescein angiography failed to demonstrate evidence of dye leakage from choroidal, retinal or optic nerve blood vessels into the subretinal fluid. Diffuse fluorescence in the area of serous detachment, due to transmission of choroidal fluorescence through defects in the pigment epithelium, was demonstrated in one patient. All of these three patients were treated with photocoagulation along the temporal margin of the optic nerve head.

OPTIC DISC DRUSEN — A PHOTOGRAPHIC STUDY I. AUTOFLUORESCENCE PICTURES AND FLUORESCEIN ANGIOGRAPHY

As part of an examination of 180 patients with optic disc drusen, auto‐fluorescence pictures had been taken in 116 patients and fluorescein angiograms in 67 patients. The superficial optic disc drusen often show a very bright nodular autofluorescence, but more important is the diffuse, not so intensive autofluorescence that the buried drusen may show. Thus, a diagnosis of hidden drusen can also be made if autofluorescence can be demonstrated. Fluorescein angiography may also reveal the buried drusen that do not show autofluorescence, and it may be of help in the differential diagnosis of pseudopapilloedema from true papilloedema. It may also indicate anomalous vascular patterns that may be associated with optic disc drusen.

Ophthalmic changes in hydrocephalus. A follow-up examination of 50 patients treated with shunts.

Abstract. Fifty childen shunted for hydrocephalus aged 5–17 years underwent a later ophthalmological examination. Corrected vision of 0.9 or less was found in 45 out of 93 eyes; in 21 patients this was the vision of both eyes. Corrected vision 0.3 or less was found in 7 eyes; in 3 patients this was the vision of both eyes. Hyperopia ≥ +2.0 D was found in 20%, myopia ≥ –0.5 D in 13% and astigmatism ≥ 1.0 D in 25.5% of 98 eyes. Clear nystagmus was present in 18% of patients. Heterophoria was found in 20% and manifest horizontal strabismus in 33%, but no paretic squint. The optic disc was considered normal in 36 out of 100 eyes on ophthalmoscopy and in 35 out of 78 eyes on colour photography. Retinal nerve fibre layer photographs showed normal nerve fibres in 49 out of 71 eyes. The Friedmann field was in the normal rang e in 33 out of 53 eyes, and the Goldmann field was normal in 37 out of 44 eyes. Right homonymous hemianopia was discovered in 2 patients. The Harrington‐Flocks field was normal in 17 out of 24 eyes, and 1 patient had left homonymous hemianopia. The HRR test showed a red‐green disturbance in 22 out of 71 eyes. The Farnsworth panel D‐15 desaturated test was entirely normal in only 4 out of 65 eyes, but the errors were only slight in 48 cases.

Pigmentary retinopathy in patients with the MELAS mutation 3243A-->G in mitochondrial DNA.

Abstract Background. Our objective was to determine the penetrance of retinal pigment epithelium (RPE) abnormalities and other ophthalmologic manifestations in patients with the 3243A→G mutation in mitochondrial DNA. Methods. Adult members in two generations were examined from a population-based cohort of 13 pedigrees with 3243A→G. Twenty-six patients underwent a thorough ophthalmological examination. A chart review was carried out on an additional 44 patients. Results. Paramacular RPE atrophy and areas of hyperpigmentation were found in 10 patients (38%; 95% confidence interval 20–59%). Electroretinography was normal in only one of the eight patients tested, whereas dark adaptation was abnormal in two. RPE abnormalities were associated with more severe clinical phenotypes and higher degrees of 3243A→G mutation heteroplasmy in muscle. Ten patients had diabetes mellitus, nine of whom had also RPE abnormalities. This finding, however, reflected the severity of the phenotype, and diabetic retinopathy was confidently diagnosed in only two patients. External ophthalmoplegia was detected in occasional patients. Conclusion. RPE abnormalities were found in this population-based cohort at a frequency that was lower than that reported earlier. RPE abnormalities were associated with more severe phenotypes, suggesting that they are expressed in patients with syndromic features. RPE abnormalities and diabetes mellitus co-occurred frequently, but diabetic retinopathy was not common.

Arachnoid cyst of the intraorbital portion of the optic nerve with unilateral disc oedema and transient shallowing of the anterior chamber. A case report.

An unusual occurrence of chronic monocular disc oedema, visual loss and shallowing of the anterior chamber in a patient with an arachnoid cyst involving a portion of the intraorbital optic nerve was reported. Decompression of the optic nerve sheath through a Krönlein approach was followed by prompt deepening of the anterior chamber and a gradual, delayed relief of the disc oedema. It is concluded that orbitotomy and decompression of the optic nerve sheath should be done before atrophic changes of the optic nerve and visual loss begin to develop.

ELECTRORETINOGRAPHY BY SKIN ELECTRODES AND SIGNAL AVERAGING METHOD

In the investigation of suspected visual disorders, ERG is of considerable value. A simplified method for clinical electroretinography by non‐corneal electrodes is presented. The latency and amplitude values were measured in 22 normal subjects. Using skin electrodes and signal averaging, we can record, without discomfort to the patient, an electroretinogram with a waveform and time relations similar to those obtained by corneal electrodes. Non‐corneal ERG is useful for infants, children as well as sensitive adult patients, and is also applicable after recent eye surgery and in cases of infection or injury of the anterior segment. Since non‐corneal electrodes do not obstruct the stimulus light or cause refractive change, they are advantageous when ERG is recorded simultaneously with visually evoked cortical response (VER). When it is important to stimulate only one eye at a time in flash VER, the adequacy of the cover is verified by the absence of an ERG from the covered eye.

ELECTRORETINOGRAM (ERG) AND VISUAL EVOKED RESPONSE (VER) STUDIES IN PATIENTS WITH OPTIC DISC DRUSEN

Non‐corneal ERGs, recorded from infraorbital skin electrodes to flash stimulation and mid‐occipital and parasagittal VERs to both flash stimulation and pattern reversal were performed in 26 patients with optic disc drusen. ERGs were normal in all patients. The mean VER amplitude was lower in the eyes with optic disc drusen than the mean amplitude of VERs in the normals but the interindividual variation was also so great in normals that the difference was not significant. The waveform of the major positive peak was quite often broad or split. VER latencies were usually in normal range although the visual field defects could be rather severe. Some other cause was present when the major positive peak was delayed.

CHANGES IN OPTIC DISC DRUSEN demonstration by stereophotographs and electronic subtraction

As a part of more comprehensive examination of 180 patients with optic disc drusen, fundus photographs of 159 cases were evaluated. There were 70 patients whose optic discs were photographed two or more times during the years from 1967 to 1981. Four patients were selected to present the changes which can take place in optic discs with drusen and the alterations are demonstrated by autofluorescence pictures, stereophotographs, and electronic subtraction method.