Multimodal Imaging in Autosomal Dominant Cone-Rod Dystrophy Caused by Novel CRX Variant.

AIM: To characterize by multimodal approach the phenotype of patients from a 3 generations pedigree, affected by autosomal dominant cone-rod dystrophy (CRD), found to carry a novel pathogenic variant in the cone-rod homeobox-containing (CRX) gene. METHODS: Examination of the adult patients included the following tests: visual acuity, multicolour imaging, spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) and OCT angiography (OCT-A) recordings. In a 2.5-year-old child, cycloplegic refraction, fundoscopy, ocular motility evaluation and electrophysiological exams were performed. Next Generation Sequencing of patients' DNA has been carried out. RESULTS: A novel CRX pathogenic variant has been identified in our patients. The 2.5-year-old child in the third generation was found to have inherited the variant, with no clinical signs of the condition, but electroretinographic abnormalities in the scotopic component. In the adult patients, diffuse atrophy of the retinal pigment epithelium/photoreceptor complex in the macular region was evident at the OCT and FAF, while OCT-A showed choriocapillaris density reduction. CONCLUSIONS: Multimodal study allowed the characterization of a peculiar form of CRD. The novel pathogenic variant seems to have a different effect on the phenotype if compared with a previously described similar one, giving an insight into the pathogenic mechanism of CRX-related retinal dystrophies and offering valuable information that could lead to the development of possible future therapies.

Developmental visual deprivation: long term effects on human cone driven retinal function.

PURPOSE: To assess whether infantile visual deprivation induced by developmental cataract may influence the cone-driven retinal function in humans. METHODS: A total of 14 patients with history of bilateral developmental cataract (DC), who had undergone uncomplicated cataract extraction surgery and intraocular lens implant, and 14 healthy subjects (HS) were enrolled. All patients underwent complete ophthalmological and orthoptic evaluations and best-corrected visual acuity measurement. Light-adapted full-field electroretinograms (ERG) and photopic negative responses (PhNR) were recorded to obtain a reliable measurement of the outer/inner retinal function and of the retinal ganglion cells' function, respectively. RESULT: Mean values of light-adapted ERG a- and b-wave implicit times were slightly delayed when compared to HS values. Light-adapted ERG a-wave amplitude mean values showed borderline values (p = 0.001), whereas a-wave amplitude analysis at 5 ms, b-wave and PhNR amplitude mean values showed no significant differences when compared to control values. No significant correlations were found when age at surgery, time elapsed from surgery, duration of the visual deprivation, age at examination, age at first detection of the opacity, BCVA and electrophysiological parameters were plotted together. Coherently with morphological studies, the extremely light bioelectrical impairment of the cone pathway in our cohort of patients describes minimal functional abnormalities of a well-structured retina that is not completely mature. CONCLUSIONS: Our present results, combined to those of our previous work on congenital cataracts, allow us to enhance the comprehension of functional developmental mechanisms of children's retinas and highlight the relevance of the timely treatment of lens opacities during infancy.

Short-term effects of vision trainer rehabilitation in patients affected by anisometropic amblyopia: electrofunctional evaluation.

PURPOSE: The aim of the present study was to evaluate the short-term effects of the vision trainer rehabilitation technique on retinal and post-retinal function in young amblyopic patients outside the critical visual developmental period. METHODS: Twenty-one patients (mean age 12.2 ± 2.7 years, ranging from 9.1 to 18 years) affected by unilateral anisometropic amblyopia were studied, providing 21 amblyopic eyes (AE) and 21 sound eyes (SE). Thirty eyes from 15 age-similar normal subjects served as controls. All subjects underwent extensive ophthalmologic characterization to exclude any disease not related to amblyopia. All AE were subjected to rehabilitation sessions performed by the Retimax vision trainer (VT) program. The protocol consisted of 2 sessions per week, each lasting 10 min, for 10 consecutive weeks. Before and after the rehabilitation, electrophysiological [pattern electroretinogram (PERG) and visual evoked potential (VEP)] and psychophysical [best corrected visual acuity (BCVA) and microperimetry] data were collected from AE and SE. RESULTS: When comparing baseline data with those collected at the end of the study, PERG P50-N95 amplitude and BCVA values from AE had improved significantly by the end of the study (p < 0.05). Our electrophysiological findings also showed some abnormalities in SE when the data were compared to control eyes. We found a significant correlation (p < 0.05) between PERG amplitude and VEP implicit time in SE after visual rehabilitation. CONCLUSIONS: Short-term visual rehabilitation performed by the VT program ameliorated the electrofunctional and psychophysical parameters of vision in children outside the critical developmental period, thus indicating that VT might be a potential adjuvant therapy of traditional patching treatment.

Long-term effects of early/late-onset visual deprivation on macular and retinal nerve fibers layer structure: A pilot study.

BACKGROUND/AIMS: Tomographic analysis of macular and peripapillary retinal nerve fibers layer (RNFL) thickness in patients with history of congenital (CC) and developmental cataract (DC). METHODS: Analysis of macular and RNFL thickness using a spectral-domain optical coherence tomography was performed. Retinal layers thickness was measured using the internal segmentation software. Measurements of affected (unilateral and bilateral), contralateral eyes and control eyes were compared. RESULTS: Patients with history of CC or DC (n = 13 and 11 respectively) and 35 healthy control subjects were enrolled. Thicker inner and outer nuclear layers (INL, ONL) and thicker ONL were found when CC and DC group when compared to controls respectively. Bilateral CC showed the most relevant differences. Slight thickening of CC inner retinal layers were found when compared to DC. Increased superonasal RNFL thickness was found in CC group when compared to DC and controls. Thickening of RNFL of contralateral unaffected eyes of unilateral CC were found when compared to controls. CONCLUSION: Significant macular and RNFL thickness changes between CC, DC patients and controls that partially involve also contralateral unaffected eyes of unilateral congenital cataract were found. CC and DC groups show significant differences only in inner retinal layers thickness. Our data suggest that early visual deprivation may influence retinal arrangements occurring during development involving predominantly the outer nuclear layer and para/perifoveal inner retinal layers, and confirm that early treatment of CC allow to achieve better long-term visual outcome. Moreover functional and structural data support the hypothesis that unilateral amblyopia is not exclusively an unilateral issue.

Reoperation in esotropic Duane retraction syndrome: Long-term motor outcome of superior rectus transposition.

AIM: The aim was to evaluate the long-term motor outcome of superior rectus transposition procedure in patients affected by unilateral esotropic Duane retraction syndrome with residual esotropia and anomalous head position. METHODS: A retrospective analysis of medical records of patients affected by esotropic Duane retraction syndrome who underwent superior rectus transposition procedure as reoperation for residual esotropia and/or residual anomalous head position. Amount of deviation, anomalous head position, duction limitation, globe retraction, presence of upshoot/downshoot, and vertical deviation were analyzed before and after superior rectus transposition procedure. RESULTS: Twenty patients were selected. All patients underwent unilateral medial rectus recession or bilateral medial rectus recession, for unilateral esotropic Duane retraction syndrome at least 2 years before superior rectus transposition reoperation. Mean age at surgery (superior rectus transposition) was 12 ± 6.8 years, and the follow-up period was 2.7 ± 0.6. Mean deviations at distance and near before surgery were 19.5 ± 5.7 and 15.2 ± 6.8, respectively. Two patients showed upshoot. Head turn was 11.4 ± 5.1°; abduction limitation was -2.6 ± 0.9. After superior rectus transposition, all patients showed an improvement of esotropia at distance and near (8.1 ± 5.7 and 5.1 ± 5.6, respectively; p < 0.05), anomalous head position (5.6 ± 3.9°; p < 0.05), and abduction limitation (-2.3 ± 0.8; p < 0.05). No statistically significant changes occurred in globe retraction. No adduction limitation, vertical deviation, and upshoot/downshoot were present after superior rectus transposition procedure. Results were stable during follow-up. CONCLUSION: Superior rectus transposition procedure is an effective procedure in esotropic Duane retraction syndrome patients who previously undergone unilateral/bilateral medial rectus recession, with residual esotropia and anomalous head position. It allows improvement of esotropia, head turn, and partial recovery of abduction in a significant percentage of patients (30%) with no vertical complications.

Long-Term Effects of Botulinum Toxin in Large-Angle Infantile Esotropia.

PURPOSE: The purpose of this study is the motor outcome analysis of early Botulinum toxin (BT) treatment in patients affected by large-angle infantile esotropia (IE). PATIENTS AND METHODS: Retrospective analysis of 130 medical charts of IE patients who underwent BT injections between 2004 and 2019 was performed. All patients underwent BT injections within 13 months of age. RESULTS: Thirty patients, matching the inclusion criteria, were included in the study. Twenty-eight patients showing residual ET ≥25 PD (34.3±6.6 PD ranged from 25 to 50) underwent surgery. CONCLUSION: Our result after 1 Botulinum toxin injection showed a very low success rate (6.7%) at last follow-up (28.3±7.2 months). Our data would suggest one Botulinum toxin injection in children affected by large-angle infantile esotropia allows a significant reduction of deviation but does not avoid the need for surgical treatment.

Long-term development of refractive error in refractive, nonrefractive and partially accommodative esotropia.

Accommodative esotropia (AE) is a convergent deviation due to an excess of the convergence linked to the innervational stimulus for accommodation and it is usually associated to the presence of hyperopia. The development of hyperopia over time has been widely described but the lack of comparative analysis among accommodative esotropia subtypes, does not allow to verify the existence of different developmental patterns. In this study we aimed to describe the long term changes of refractive error in patients affected by accommodative esotropia as a function of the strabismus type: refractive (RAE), non-refractive (NRAE) and partially accommodative esotropia (PAE). The medical records of 66 patients (24 RAE, 22 PAE, 20 NRAE), who wore the full correction of their cycloplegic refraction error during the entire follow up period, were retrospectively reviewed. Mean outcome was the analysis of the variations, among groups, of refractive error over time; differences between mild (≤3.00D) and high (≥5.00D) hyperopia, effects of amblyopia and relationship with AC/A ratio were also investigated. All patients were followed up from approximately 4 years of age to 20, with mean follow up of 16.06±0.29 years. Our results described similar non-linear trend of refractive error development among groups. The initial increase of hyperopia (up to 7-8 years) was followed by a decreasing trend persisting up to adulthood (approximately 20 years of age). During this period, spherical equivalent decreased at a lower mean annual rate in patients affected by RAE (-0.07D) compared to other groups (NRAE -0.11D, p = 0.003 and PAE 0.13D, p = 0.002). In all groups, however, significant amount of hyperopia was found at last examination; indeed the observed difference in SE values from baseline to the end of follow up, was not significant (RAE: +0.27D, 95% C.I. -0.49 to +1.04D, p = 0.472; PAE: -0.69D, 95% C.I. -1.67 to +0.28D, p = 0.154; NRAE: -0.39D, 95% C.I. -1.11 to +0.34D, p = 0.278). AC/A ratio, amblyopia and amount of initial hyperopia appeared to have no significant role in longitudinal change of the refractive error. In conclusion, this study provides a complete overview, from childhood to adulthood, of refractive error development in different form of accommodative esotropia.

Early light deprivation effects on human cone-driven retinal function.

PURPOSE: To assess whether the early light deprivation induced by congenital cataract may influence the cone-driven retinal function in humans. METHODS: Forty-one patients affected by congenital cataract (CC) who had undergone uncomplicated cataract extraction surgery and intraocular lens implant, and 14 healthy subjects (HS) were enrolled. All patients underwent complete ophthalmological and orthoptic evaluations and best-corrected visual acuity (BCVA) measurement; light-adapted full-field electroretinograms (ERG) and photopic negative responses (PhNR) were recorded to obtain a reliable measurement of the outer/inner retinal function and of the retinal ganglion cells' function respectively. RESULTS: Mean values of light-adapted ERG a- and b-wave and PhNR amplitude of CC eyes were significantly reduced and photopic ERG b-wave implicit time mean values were significantly delayed when compared to HS ones. When studying photopic ERG mean amplitudes at 5 ms, significant differences were found when comparing CC and control eyes. In CC eyes, statistically significant correlations were found between a- and b- wave amplitudes and PhNR amplitudes. No significant correlations were found between ERG parameters and BCVA, as well as between the age of CC patients at surgery and the time elapsed from lens extraction. No significant differences were found when functional parameters of bilateral and unilateral congenital cataract (uCC) eyes were compared, however uCC eyes showed significant differences when compared with contralateral healthy eyes. CONCLUSION: We found a significant impairment of cone-driven retinal responses in patients with a history of congenital cataract. These changes might result from the long-lasting effects of early light deprivation on the cone retinal pathways. Our findings support the relevance of retinal involvement in deficits induced by early light deprivation.

Essential infantile esotropia with inferior oblique hyperfunction: long term follow-up of 6 muscles approach.

AIM: To evaluate long term follow-up (10y) of 6 muscle surgical approach in essential infantile esotropia (EIE). METHODS: A 6 muscle approach to EIE was retrospectively evaluated in patients with inferior oblique (IO) hyperfunction and lateral rectus (LR) pseudoparalysis, who underwent surgery at different ages. Different clinical characters were analyzed pre- and postoperatively, in patients who underwent a 6 muscles approach ≤4 years of age. All patients underwent a multiple muscles approach: bilateral medial recti (MR) recession (4-5 mm), bilateral LR resection (lower than 7 mm) and bilateral IO recession and anteroposition. Of 108 children with preoperative angle ≥+30 prism diopters (PD) and IO hyperfunction were selected from larger cohort of patients (n=213, 103 females and 110 males) after excluding patients with: angle variability, who underwent reoperation and with incomplete follow up. Preoperative assessment and complete orthoptic examination were performed. Follow-up was performed 3mo, 2, 5 and 10y after surgery. Statistical analysis was performes using SAS statistical software package (version 9.1, SAS Institute Inc., Cary, NC, USA). RESULTS: Ten years follow up data analysis showed the following percentage of orthotropic patients: (0 PD): 3mo, 22.2%; 2y, 16.7%; 5y, 25.0% and 10y, 27.8%. A slight, significant (P<0.01), increase of 2y follow up residual deviation was found when compared to 3mo one. Stationary surgical results is reported during time, with a trend of mean residual deviation reduction (P=0.04). CONCLUSION: Our results confirm the reliability of multiple muscles surgical approach in the treatment of patients affected by EIE with OI hyperfunction.