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.

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.

Long-Term Follow-Up after Surgery for Congenital and Developmental Cataracts.

PURPOSE: To evaluate long-term functional outcomes after surgery for congenital and developmental cataracts. METHODS: In this retrospective interventional study, patients with congenital and developmental cataracts observed from 1996 to 2013 were included. Traumatic cataracts and cataracts secondary to other pathologies were excluded from the study. Minimum follow-up for inclusion was five years. RESULTS: We included 117 patients operated on for congenital cataracts (58 females and 59 males, mean age 0.59 ± 0.2 years, 160 eyes) and 73 patients operated on for developmental cataracts (32 females and 41 males, mean age 6.63 ± 0.7 years, 121 eyes). Mean postsurgical follow-up was 9.26 ± 1.3 years (range, 5-14 years). After surgery for developmental cataracts, both distance and near BCVA were greater (p = 0.001), as was the presence of binocular vision (p = 0.001), while incidence of strabismus and myopic shift was lower (p = 0.001 and p = 0.02, respectively). CONCLUSION: Postsurgical data showed better functional outcomes in developmental cataracts when compared to congenital cataracts.

Long-Term Outcomes of Primary Intraocular Lens Implantation for Unilateral Congenital Cataract.

PURPOSE: In congenital cataracts, the need for early intervention is well established to prevent visual deprivation and amblyopia. We evaluated patients with unilateral amblyogenic congenital who had undergone simultaneous cataract removal and intraocular lens implantation. METHODS: We retrospectively reviewed all patients operated on between 1990 and 2010 at the Pediatric Eye Department of the University Federico II of Naples (Italy). Minimum follow-up for inclusion was 48 months. RESULTS: 52 patients (28 females, 24 males, mean age at surgery 9.0 ± 4.5 months, range 2-21 months) were included in this retrospective review. Mean follow-up was 100.7 ± 57.0 months (range, 48-270 months). At last visit, mean BCVA in the operated eyes was 0.65 ± 0.4 (range, 0.04-1.3) LogMAR and 40 patients (76.9%) had strabismus. In patients undergoing surgery at an age >12 months, BCVA was significantly lower (0.92 ± 0.4 LogMAR versus 0.60 ± 0.4 LogMAR, p = 0.01), although development of myopic shift was less frequent (61.5% versus 43.5%, p = 0.03). BCVA at last visit was higher in patients with a first stable pseudophakic SE between +1D and +3D (p = 0.02). CONCLUSIONS: Worse final BCVA, despite less frequent development of myopic shift, was observed when surgery was performed after 12 months of age. A hyperopic correction in first stable pseudophakic SE seems advisable.

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.