Variable expressivity of ocular associations of foveal hypoplasia in a family

Investigating Determinants and Evaluating Deep Learning Training Approaches for Visual Acuity in Foveal Hypoplasia

Purpose

To describe the relationships between foveal structure and visual function in a cohort of individuals with foveal hypoplasia (FH) and to estimate FH grade and visual acuity using a deep learning classifier.

Design

Retrospective cohort study and experimental study.

Participants

A total of 201 patients with FH were evaluated at the National Eye Institute from 2004 to 2018.

Methods

Structural components of foveal OCT scans and corresponding clinical data were analyzed to assess their contributions to visual acuity. To automate FH scoring and visual acuity correlations, we evaluated the following 3 inputs for training a neural network predictor: (1) OCT scans, (2) OCT scans and metadata, and (3) real OCT scans and fake OCT scans created from a generative adversarial network.

Main Outcome Measures

The relationships between visual acuity outcomes and determinants, such as foveal morphology, nystagmus, and refractive error.

Results

The mean subject age was 24.4 years (range, 1–73 years; standard deviation = 18.25 years) at the time of OCT imaging. The mean best-corrected visual acuity (n = 398 eyes) was equivalent to a logarithm of the minimal angle of resolution (LogMAR) value of 0.75 (Snellen 20/115). Spherical equivalent refractive error (SER) ranged from −20.25 diopters (D) to +13.63 D with a median of +0.50 D. The presence of nystagmus and a high-LogMAR value showed a statistically significant relationship (P < 0.0001). The participants whose SER values were farther from plano demonstrated higher LogMAR values (n = 382 eyes). The proportion of patients with nystagmus increased with a higher FH grade. Variability in SER with grade 4 (range, −20.25 D to +13.00 D) compared with grade 1 (range, −8.88 D to +8.50 D) was statistically significant (P < 0.0001). Our neural network predictors reliably estimated the FH grading and visual acuity (correlation to true value > 0.85 and > 0.70, respectively) for a test cohort of 37 individuals (98 OCT scans). Training the predictor on real OCT scans with metadata and fake OCT scans improved the accuracy over the model trained on real OCT scans alone.

Conclusions

Nystagmus and foveal anatomy impact visual outcomes in patients with FH, and computational algorithms reliably estimate FH grading and visual acuity.

The Phenotypic and Mutational Spectrum of the FHONDA Syndrome and Oculocutaneous Albinism: Similarities and Differences

Purpose

The purpose of this study was to further expand the mutational spectrum of the Foveal Hypoplasia, Optic Nerve Decussation defect, and Anterior segment abnormalities (FHONDA syndrome), to describe the phenotypic spectrum, and to compare it to albinism.

Subjects and Methods

We retrospectively collected molecular, ophthalmic, and electrophysiological data of 28 patients molecularly confirmed with FHONDA from the Netherlands (9), Israel (13), France (2), and the United States of America (4). We compared the data to that of 133 Dutch patients with the 3 most common types of albinism in the Netherlands: oculocutaneous albinism type 1 (49), type 2 (41), and ocular albinism (43).

Results

Patients with FHONDA had a total of 15 different mutations in SLC38A8, of which 6 were novel. Excluding missing data, all patients had moderate to severe visual impairment (median visual acuity [VA] = 0.7 logMAR, interquartile range [IQR] = 0.6-0.8), nystagmus (28/28), and grade 4 foveal hypoplasia (17/17). Misrouting was present in all nine tested patients. None of the patients had any signs of hypopigmentation of skin and hair. VA in albinism was better (median = 0.5 logMAR, IQR = 0.3-0.7, P 0.006) and the phenotypes were more variable: 14 of 132 without nystagmus, foveal hypoplasia grades 1 to 4, and misrouting absent in 16 of 74.

Conclusions

Compared to albinism, the FHONDA syndrome appears to have a more narrow phenotypic spectrum, consisting of nonprogressive moderately to severely reduced VA, nystagmus, severe foveal hypoplasia, and misrouting. The co-occurrence of nystagmus, foveal hypoplasia, and misrouting in the absence of hypopigmentation implies that these abnormalities are not caused by lack of melanin, which has important implications for understanding the pathogenesis of these features.

Septo-optic dysplasia with fovea plana: A case report

Septo-optic dysplasia (SOD) is characterized by optic nerve hypoplasia, pituitary gland hypoplasia, and midline abnormalities of the brain. The phenotype of SOD is highly heterogeneous, and the existence of at least two features is considered sufficient for diagnosis. Fovea plana is the absence of a foveal pit in the central fovea, and despite being a developmental abnormality of the fovea, good visual acuity may be retained in some individuals. In this case, a 12-year-old female presented to the ophthalmology clinic with the complaint of blurred vision in her right eye. In dilated fundus examination, optic disc hypoplasia and no foveal light reflex were seen. Magnetic resonance imaging and optical coherence tomography revealed optic nerve, brain midline, and foveal abnormalities. The patient was diagnosed as having SOD with optic nerve hypoplasia and septum pellucidum agenesis, and fovea plana. Both SOD and fovea plana are rare conditions, and there are several reports in the literature that separately describe their clinical features. The most important aspect of this case report is to reveal the unusual co-existence of SOD and fovea plana in a young patient.

Posterior Microphthalmia, Peripheral Pigmentary Retinal Changes, Yellow Lesions, and Cleft Lip: A Case Report and Literature Review

Purpose

Posterior microphthalmia is a sporadic or inherited developmental ocular anomaly that may occur isolated or in association with multiple ocular and systemic anomalies. This report documents a case of posterior microphthalmia with atypical presentation including white dots in the posterior pole in addition to systemic anomalies including facial defect that can represent an underlying genetic mutation.

Method

Case report.

Results

A 29-year-old male with high hyperopia and history of bilateral clear lens presented with pigmentary changes and white-yellow dots in the posterior pole in both eyes. Patient had a history of cleft lip repair. A complete ocular evaluation including A/B scan and optical coherence tomography confirmed the diagnosis of posterior microphthalmia with a retinitis pigmentosa like fundus and drusen deposits in the subretinal pigment epithelium.

Conclusion

The white-yellow drusenoid deposits in the posterior pole in association with posterior microphthalmia are poorly documented in the literature. Cases of craniofacial developmental defects in association with posterior microphthalmia may represent a genetic defect.

Color Vision in Aniridia

Purpose

To assess color vision and its association with retinal structure in persons with congenital aniridia.

Methods

We included 36 persons with congenital aniridia (10–66 years), and 52 healthy, normal trichromatic controls (10–74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0–4).

Results

Five participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology.

Conclusions

Arrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.

Absent Foveal Pit, Also Known as Fovea Plana, in a Child without Associated Ocular or Systemic Findings

The purpose of this report is to describe a case of bilateral foveal hypoplasia in the absence of other ophthalmological or systemic manifestations. We characterize the case of a 9-year-old Caucasian male who underwent full ophthalmologic examination, including functional measures of vision and structural measurements of the eye. Best corrected visual acuity was 0.50 logMAR in the right eye and 0.40 logMAR in the left eye. Ophthalmoscopy revealed a lack of foveal reflex that was further investigated. Optical coherence tomography (OCT) confirmed the absence of foveal depression (pit). OCT images demonstrated the abnormal structure of retina in a region in which we expected a fovea; these findings were decisive to determine the cause of reduced acuity in the child.

Optical Coherence Tomography Angiography in Foveal Hypoplasia

BACKGROUND AND OBJECTIVE

A retrospective case series reporting optical coherence tomography angiography (OCTA) findings in foveal hypoplasia.

PATIENTS AND METHODS

Patients with foveal hypoplasia who presented to the authors' tertiary eye center. Cases of foveal hypoplasia that underwent OCTA were reviewed, and the clinical histories as well as imaging findings were summarized.

RESULTS

Three patients presented to the authors' eye center for evaluation of foveal hypoplasia and underwent OCTA: a 5-year-old girl, a 40-year-old woman, and a 22-year-old man. OCTA images were taken for both eyes of all patients. Four of five eyes with foveal hypoplasia had a small but present foveal avascular zone in the deep capillary plexus, whereas all eyes had an absent or severely reduced superficial capillary plexus.

CONCLUSION

OCTA can be helpful in the diagnosis of foveal hypoplasia and can aid in the anatomical characterization of disease. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1127-1131.].

Isolated foveal hypoplasia: clinical presentation and imaging findings

PURPOSE

To describe the clinical presentation and imaging findings of a patient with isolated foveal hypoplasia.

CASE REPORT

A 16-year-old teenager presented to our clinic with mild to moderate visual impairment since early childhood. Lack of foveal depression was noted on both clinical examination and optical coherence tomography, and absence of the foveal avascular zone was demonstrated on fluorescein angiography. His ocular examination was otherwise unremarkable.

CONCLUSIONS

Isolated foveal hypoplasia should be considered in the differential diagnosis of early-onset bilateral visual impairment, especially when the foveal reflexes seem absent.

Isolated foveal hypoplasia without nystagmus

We report the case of a 23-year-old healthy Caucasian male with isolated foveal hypoplasia without nystagmus. Clinical examination and spectral-domain optical coherence tomography demonstrated the bilateral absence of a foveal depression and the patient was diagnosed with isolated foveal hypoplasia. This is a rare condition which is probably under-diagnosed since it can exist without nystagmus and low vision.

Recessive mutations in SLC38A8 cause foveal hypoplasia and optic nerve misrouting without albinism

Foveal hypoplasia and optic nerve misrouting are developmental defects of the visual pathway and only co-occur in connection with albinism; to date, they have only been associated with defects in the melanin-biosynthesis pathway. Here, we report that these defects can occur independently of albinism in people with recessive mutations in the putative glutamine transporter gene SLC38A8. Nine different mutations were identified in seven Asian and European families. Using morpholino-mediated ablation of Slc38a8 in medaka fish, we confirmed that pigmentation is unaffected by loss of SLC38A8. Furthermore, by undertaking an association study with SNPs at the SLC38A8 locus, we showed that common variants within this gene modestly affect foveal thickness in the general population. This study reveals a melanin-independent component underpinning the development of the visual pathway that requires a functional role for SLC38A8.

Isolated foveal hypoplasia: tomographic, angiographic and autofluorescence patterns

Purpose. To report clinical aspects, tomographic, angiographic, and autofluorescence patterns of two cases of isolated foveal hypoplasia. Methods. Foveal hypoplasia was found in a 23-year-old male patient and in a 64-year-old woman with impaired visual acuity of unknown etiology that remained unchanged for years. Results. In the first case, spectral-domain optical coherence tomography (SD-OCT) showed reduced foveal pit and continuity of inner retinal layers in the fovea. Photoreceptor layer had a normal thickness centrally. The foveal avascular zone (FAZ) was absent in the flourescein angiogram (FA). Fundus autofluorescence showed reduced foveal attenuation of autofluorescence. In the second patient, there was the same pattern in SD-OCT, with normal aspect in FA and only a slightly reduced foveal attenuation of autofluorescence. Conclusion. OCT, as a noninvasive and quick method, is helpful in the diagnosis of foveal hypoplasia. FA and fundus autofluorescence were less sensitive.