Electroretinographic Assessment in Joubert Syndrome: A Suggested Objective Method to Evaluate the Effectiveness of Future Targeted Treatment.

INTRODUCTION: Joubert syndrome (JS) is an autosomal recessive disorder characterized by a congenital malformation of the mid-hindbrain and a large spectrum of clinical features including congenital retinal dystrophy. The function of different retinal elements (rod, cone, bipolar cells) can be objectively evaluated by electroretinogram (ERG) recordings. Our work aims to evaluate the retinal function (by ERG recordings) in patients with JS with or without congenital retinal dystrophy. In addition, since clinical trials should be performed in the near future in JS, our results could provide information about the possible usefulness of ERG recordings in the assessment of the efficacy of treatments targeted to improve the retinal involvement. METHODS: In this observational and prospective study, 24 children with genetic identification for JS (mean age 10.75 ± 6.59 years) and 25 healthy age-similar normal control subjects (control group, mean age 10.55 ± 3.76 years) were enrolled. On the basis of the presence/absence of retinal dystrophy at fundus examination, patients with JS were divided into two groups: patients with JS with retinal dystrophy (16 children, mean age 11.00 ± 6.74 years, providing 16 eyes; JS-RD group) and patients with JS without retinal dystrophy (8 children, mean age 10.50 ± 6.45 years, providing 8 eyes; JS-NRD group). In patients with JS and controls, visual acuity (VA), dark-adapted, light-adapted, and 30-Hz flicker ERGs were performed according to International Society for Clinical Electrophysiology of Vision (ISCEV) standard protocols. RESULTS: When compared to controls, patients in the JS-RD and JS-NRD groups showed significant abnormalities of the values of dark-adapted, light-adapted, and 30-Hz flicker ERG parameters. The ERG and VA changes were not significantly correlated. CONCLUSIONS: Our results suggest that a dysfunction of photoreceptors and bipolar cells occurs in patients with JS with or without retinal dystrophy. The retinal impairment can be detected by ERG recordings and this method should be proposed to evaluate the effectiveness of adequate treatment targeted to improve the retinal impairment in patients with JS.

Visual field assessment in high myopia with and without tilted optic disc.

BACKGROUND: The aim was to evaluate the effect of the tilted optic disc on the visual field in highly myopic eyes. METHODS: A total of 58 eyes from 58 highly myopic individuals underwent detailed ophthalmic examination and were categorised into two groups according to the presence of a tilted optic disc. The visual field of 20 eyes (mean age of 28.95 ± 7.22 years) with tilted optic discs were compared with 38 eyes (mean age of 27.87 ± 6.08 years) of control subjects without tilted optic discs using the 30-2 SITA standard protocol with a Humphrey Field Analyzer - HFA II-i. Optic disc tilt was assessed from retinal photographs exported to Adobe Photoshop software. Disc ovality was assessed using the ratio of minimum to maximum disc diameter. A ratio of up to 0.80 was considered a tilted optic disc. RESULTS: Foveal threshold sensitivity showed no statistically significant difference between tilted and non-tilted groups (35.16 ± 2.71 dB versus 35.37 ± 2.35 dB, p = 0.76). The mean deviation was -3.29 ± 2.03 dB in the tilted group and -3.49 ± 2.56 dB in the non-tilted group (p = 0.77). Additionally, there were no significant differences in the average deviation between the two groups in four quadrants and four hemifields; however, the lowest average deviation was observed in the superotemporal quadrant in the tilted group (-4.54 ± 3.16 dB). In the non-tilted group, 29 per cent had no visual field defect, 24 per cent had an arcuate scotoma and 20 per cent had generalised depression. In the tilted group, 30 per cent had an arcuate scotoma, 30 per cent had generalised depression and 13 per cent had no visual field defect. Other visual field defects occurred at frequencies less than 15 per cent in both groups. CONCLUSIONS: The investigation of visual field patterns may be more appropriate than quantitative indices (for example, total mean deviation, foveal threshold sensitivity, average deviation) to assess the visual field in highly myopic patients with tilted optic discs.

Preoperative and postoperative assessment by multifocal electroretinography in the management of optic disc pits with serous macular detachment.

PURPOSE: To evaluate the macular function by means of multifocal electroretinogram (MF ERG) in eyes with congenital optic disc pit and serous macular detachment. The evaluation was performed before and after the successful surgical intervention. DESIGN: Nonrandomized, comparative (self-controlled), interventional trial. PARTICIPANTS: Ten patients (10 eyes) with optic disc pit with serous macular detachment were treated with the macular buckling procedure and followed up from March 1999 through May 2001. METHODS: In all patients included in the study, MF ERG was recorded before and after treatment. For recording, the VERIS III system (Visual Evoked Response Imaging System; Tomey, Nagoya, Japan) was used. MAIN OUTCOME MEASURES: The retinal response densities were studied before and after treatment in areas 1 and 2 and were compared with visual acuity. RESULTS: The MF ERG before treatment showed decreased retinal response densities in all 10 cases. Twelve months after the surgical intervention, the electrical response densities in areas 1 (foveal area) and 2 (parafoveal area) improved. Further improvement was noted in 3 of the 10 patients who completed a follow-up of 18 months after treatment. In 8 of the 10 patients, postoperative visual acuity also increased. In the remaining two patients, visual acuity did not change after treatment, despite improvement of the retinal response densities. CONCLUSIONS: In eyes with congenital optic disc pit with serous macular detachment, the decrease in retinal electrophysiologic response before treatment was not limited to the fovea, but also involved the perifoveal area. In all 10 eyes 12 months after treatment, the electrical activities in areas 1 and 2 improved. This improvement was not always followed by an increase in visual acuity. In 2 of the 10 patients, visual acuity remained unchanged. The values of retinal response densities before treatment cannot be used alone as a prognostic factor for the postoperative functional retinal results. It should also be stressed that the results of this study cannot be compared with the results of studies where spontaneous resolution of the macular detachment occurred.