Retinal findings in patients with Alport Syndrome: expanding the clinical spectrum

LEPREL1 -RELATED GIANT RETINAL TEAR DETACHMENTS MIMIC THE PHENOTYPE OF OCULAR STICKLER SYNDROME

PURPOSE

To describe the features of retinal detachments and high myopia in patients with novel pathogenic variants in LEPREL1 and report a possible association with nephropathy.

METHODS

Retrospective study of 10 children with biallelic LEPREL1 pathogenic variants. Data included ophthalmic features, surgical interventions, and genetic and laboratory findings.

RESULTS

10 patients (8 females) from three families with homozygous (2) or compound heterozygous (1) variants in LEPREL1 were included. At presentation, mean age was 9.9 ± 2.6 years. Mean axial length was 28.9 ± 1.9 mm and mean refraction was -13.9 ± 2.8 diopters. Bilateral posterior subcapsular cataracts were present in eight patients (80%), with lens subluxation in five eyes of three patients (30%). Rhegmatogenous retinal detachments (RRD), associated with giant retinal tears (GRT), developed in seven eyes of five patients (50%) at a mean age of 14.14 ± 5.9 years. Six were successfully reattached with mean Snellen best-corrected visual acuity improving from 20/120 preoperatively to 20/60 at last follow-up. Urinalysis in nine patients revealed microhematuria and/or mild proteinuria in six patients (67%).

CONCLUSION

LEPREL1 -related high myopia confers a high risk of early-onset GRT-related RRD. The ocular phenotype may be confused with that of ocular Stickler syndrome if genetic testing is not performed. Further investigations into a potential association with renal dysfunction are warranted.

Vitelliform maculopathy: Diverse etiologies originating from one common pathway

Vitelliform lesions (VLs) are associated with a wide array of macular disorders but are the result of one common pathway: retinal pigment epithelium (RPE) impairment and phagocytic dysfunction. VLs are defined by the accumulation of yellowish subretinal material. In the era of multimodal advanced retinal imaging, VLs can be further characterized by subretinal hyperreflectivity with optical coherence tomography and hyperautofluorescence with fundus autofluorescence. VLs can be the result of genetic or acquired retinal diseases. In younger patients, VLs usually occur in the setting of Best disease. Additional genetic causes of VL include pattern dystrophy or adult-onset vitelliform macular dystrophy. In older patients, acquired VLs can be associated with a broad spectrum of etiologies, including tractional, paraneoplastic, toxic, and degenerative disorders. The main cause of visual morbidity in eyes with VLs is the onset of macular atrophy and macular neovascularization. Histopathological studies have provided new insights into the location, nature, and lifecycle of the vitelliform material comprised of melanosomes, lipofuscin, melanolipofuscin, and outer segment debris located between the RPE and photoreceptor layer. Impaired phagocytosis by the RPE cells is the unifying pathway leading to VL development. We discuss and summarize the nature, pathogenesis, multimodal imaging characteristics, etiologies, and natural course of vitelliform maculopathies.

Sealed Unilateral Full-Thickness Macular Hole with Amniotic Membrane Graft in a Patient with Alport Syndrome: A Case Report

We present a case of unilateral full-thickness macular hole (MH) successfully repaired with an amniotic membrane (AM) graft in a patient with Alport syndrome. A 58-year-old Asian female with past medical history of Alport syndrome diagnosed at early stage, presented with a 5-week history of vision loss in her right eye. Examination of her eyes showed normal retinal vessels and an MH measuring 1,300 μm in basal diameter, 806 μm in minimum linear diameter, and 490 μm in height in the right eye and macular thinning with laser scars inferiorly in the left eye. The patient underwent 23-g pars plana vitrectomy with intraocular lens explantation. After multiple unsuccessful attempts in inducing a posterior vitreous detachment around the optic nerve and in the posterior pole, a 1 mm AM graft placed on the MH and the edges tucked under the edges of the hole using a bimanual technique. Five months after surgery, the MH remained sealed with improved final vision. MHs are rare manifestations of Alport syndrome, and surgical treatment of Alport syndrome-associated MHs is challenging. However, further studies to explore new techniques using AM are needed.

Case report: Unilateral panuveitis as a manifestation of Alport syndrome in a Chinese pediatric patient

Purpose: The study aimed to report a rare case of a patient with Alport syndrome, which was manifested as unilateral non-infectious uveitis after bilateral cataract surgery.

Methods: A case report.

Results: A 2-year-old boy was diagnosed with unilateral panuveitis based on the clinical and multimodal imaging findings. Intraocular fluid samples for metagenomic next-generation sequencing (mNGS) and microbial culture were negative. However, urine tests found proteinuria and microscopic hematuria. Pathologic findings of the kidney revealed a thickened membrane, and a diagnosis of Alport syndrome was considered. Gene analysis found deletions in exon 1 of COL4A5 and exons 1 and 2 of COL4A6. The uveitis resolved gradually, following the administration of oral steroids.

Conclusion: Uveitis may be an ocular manifestation of Alport syndrome.

Ocular Manifestations and Potential Treatments of Alport Syndrome: A Systematic Review

Objectives. Alport syndrome (AS) is a severe, rare hereditary disorder that can lead to end-stage renal disease, auditory degeneration, and ocular abnormalities. Despite extensive research on AS in relation to auditory and renal disorders, more research is needed on the ocular presentations of AS. This systematic review aims to summarize the common ocular abnormalities in patients with AS and to explore the potential treatment options for these irregularities. Methods. The PubMed, MEDLINE, and EMBASE databases were systematically searched from January 1977 to April 2022. Only papers that were published in the English language and explored the ocular abnormalities in AS patients were selected. We manually searched reference lists of included papers for additional studies. Results. A total of 23 articles involving 195 patients were included in this review. The common ocular manifestations in AS patients are lenticonus, macular holes, fleck retinopathy, and thinning of the macula. Although published literature has described the use of cataract surgeries and vitrectomies as standard surgical techniques to alleviate ocular abnormalities in non-AS patients, it must be noted that surgical techniques have not been evaluated in a large research study as a solution for AS abnormalities. Another prospective treatment for AS is gene therapy through the reversion of causative COL4 variants to wild type or exon-skipping therapy for X-linked AS with COL4A5 truncating mutations. Gene therapy, however, remains unable to treat alterations that occur in the fetal and early development phase of the disease. Conclusions. The review found no definitive conclusions regarding the efficacy and safety of surgical techniques and gene therapy in AS patients. Recognition of ocular abnormalities through an ophthalmic examination with an optical coherence tomography (OCT) and slit-lamp examination is critical to the medical field, as ophthalmologists can aid nephrologists and other physicians in diagnosing AS. Early diagnosis and care can minimize the risk of detrimental ocular outcomes, such as blindness and retinal detachment.

Temporal retinal thinning might be an early diagnostic indicator in male pediatric X-linked Alport syndrome

AIM

To evaluate temporal retinal thinning changes in retinal layers using spectral-domain optical coherence tomography (SD-OCT) in pediatric X-linked Alport syndrome (XLAS) patients.

METHODS

A retrospective case-control study. SD-OCT scans of pediatric patients diagnosed with XLAS and age- and sex-matched healthy control participants were reviewed. Automated segmentation of SD-OCT scans was induced to analyze the retinal thickness (RT) of different layers. The temporal thinning index (TTI) was calculated for each layer and compared between the patients and the control group.

RESULTS

Forty-three pediatric XLAS patients and 60 healthy controls were included. Temporal retinal thinning was present in 33 patients (76.74%), while 28 patients (65.11%) had severe pathological temporal retinal thinning and 5 patients (11.63%) had moderate thinning. The temporal inner sector RT (P<0.0001), the temporal outer sector RT (P<0.0001), and the nasal outer sector RT (P=0.0211) were significantly thinner in the XLAS male patients. The TTI of the total retina was significantly higher in the XLAS group than in the control group (P<0.0001). The TTI of the inner retina layers (P<0.0001), ganglion cell layer (P<0.0001), inner plexiform layer (P<0.0001), inner nuclear layer (P<0.0001), and outer nuclear layer (P<0.0001) were significantly higher in the XLAS group. The central RT of the XLAS group was significantly thinner than that of the control group (P<0.0001).

CONCLUSION

Temporal retinal thinning appears early in XLAS patients, especially in male patients. The thinning is mainly caused by structural abnormalities of the inner retina. This suggests that temporal retinal thinning could be helpful for the early diagnosis and follow-up of XLAS with noninvasive SD-OCT examination.

Quantitative Optical Coherence Tomography Angiography Biomarkers for Alport Syndrome

PURPOSE

The aim of this study was to evaluate microvascular abnormalities of patients with Alport syndrome (AS) using optical coherence tomography angiography (OCT-A) quantitative biomarkers.

METHODS

This was cross sectional, prospective evaluation of consecutive patients with AS and healthy subjects. AS diagnosis was performed by the genetic test. All participants underwent a retinal vasculature evaluation by spectral-domain optical coherence tomography (SD-OCT) and OCT-A of the macula. Quantitative analysis included whole vascular density, foveal avascular zone area, fractal dimension (FD), and lacunarity (LAC).

RESULTS

Ninety-four eyes were included in this study, 45 eyes from patients with AS and 49 eyes from healthy subjects. The pathogenic mutation in the COL4A5 gene on the chromosome X was found in 14 patients; the pathogenic autosomal recessive mutations in the COL4A3 gene were found in 9 patients. Quantitative evaluation demonstrated a significant difference between AS and healthy subjects on LAC of the superficial capillary plexus and deep capillary plexus (DCP) (p < 0.001 and p < 0.001, respectively) and on FD in the DCP (p < 0.001).

CONCLUSION

The DCP Alport patients have a higher vessel nonuniformity than DCP of healthy subjects. We hypothesize that endothelial cell lesion in the setting of low resistance at the DCP circuit could lead to long-term structural disorganization.

Development of Posterior Lenticonus Following the Diagnosis of Isolated Anterior Lenticonus in Alport Syndrome

Alport syndrome is a genetic disorder that manifests as renal disease, hearing loss and ocular dysfunction. Lenticonus is one such ocular condition, in which the lens takes on an abnormal cone shape, with a protrusion either at the front or back of the lens. Both sides of the lens are rarely affected at the same time in the general patient population. Although anterior lenticonus is the type that is often reported in Alport syndrome, it is rare for such patients to have both anterior and posterior lenticonus. Here, the case of a 32-year-old male with Alport syndrome is described. The patient was diagnosed with a progressive posterior lenticonus, having been diagnosed eight years earlier with isolated anterior lenticonus. Examination of the eye revealed the typical indications of lenticonus with flecked retinopathy. The patient had co-presenting astigmatism and a refractive error, which could not be corrected by wearing contact lenses or spectacles. It is critical that such cases are anticipated and identified prior to performing surgery, so that an appropriate approach can be taken, thereby minimizing surgical complications.

INNER MACULAR CHANGES AFTER VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING FOR RHEGMATOGENOUS RETINAL DETACHMENT: Similarity With Alport Syndrome

PURPOSE

The internal limiting membrane (ILM), the innermost basement membrane of the retina, is peeled occasionally during vitreous surgery. This study aimed to investigate the effect of ILM loss on the retina.

METHODS

We used optical coherence tomography to retrospectively evaluate retinal changes in 26 eyes (11 ILM-peeled and 15 ILM-unpeeled eyes) of 26 patients after vitrectomy for retinal detachment. In addition, we studied six eyes of three patients with Alport syndrome, in which ILM is genetically impaired.

RESULTS

We observed significant inner retinal displacement of the foveal pit toward the optic disk with inner retinal thickening in the nasal area (fellow, 191.9 ± 24.3 μm vs. affected, 210.3 ± 31.4 μm; P = 0.048), inner retinal thinning in the temporal area (fellow, 174.3 ± 18.3 μm vs. affected, 142.2 ± 23.6 μm; P < 0.001), foveal thickening (ILM-unpeeled, 217.0 ± 39.4 μm vs. ILM-peeled, 302.0 ± 86.2 μm; P = 0.006), inner retinal dimples predominantly in the temporal area, and deviation between the foveal pit and foveal bulge. Eyes with Alport syndrome exhibited similar findings.

CONCLUSION

Internal limiting membrane loss seems to cause characteristic inner retinal changes of the macula in both congenital and acquired conditions.

Pediatric glomerular hematuria: a clinicopathological study

BACKGROUND

Hematuria is a common problem in pediatric practice and necessitates exhausting studies to detect etiology and establish proper management and counselling.

SUBJECTS AND METHODS

We reviewed the clinical and pathological findings in 95 children presented between 2013 and 2019 with gross or microscopic hematuria with or without proteinuria in whom non-glomerular causes were excluded. In addition, a reference range for normal glomerular basement membrane thickness (GBMT) is introduced based on the assessment of biopsies of 20 steroid-resistant nephrotic syndrome cases aged 3-15 years, and with minimal change pathology.

RESULTS

Fifty-seven males and 38 females with a mean age of 7.72 ± 3.27 years were included. Recurrent gross hematuria was the most frequent presentation (42%) while accidentally discovered hematuria was reported in 34.7% of patients. Alport syndrome (AS) was the most frequent diagnosis (66.3%) followed by thin basement membrane disease (TBMD) (29.5%) and Immunoglobulin A nephropathy (IgAN) (4%). A reference for normal GBMT was 360.3 ± 87.5 nm which is comparable to published references. Males with AS had a higher incidence of progression to renal failure and requirement for dialysis (p = 0.006 and 0.03, respectively) compared to females. Persistent proteinuria and lower glomerular filtration rate at diagnosis were associated with poor outcomes (p < 0.001 each).

CONCLUSION

Alport Syndrome is the most common cause of glomerular hematuria in Egyptian children. Persistence of proteinuria and lower GFR at initial presentation were the main predictors of poor outcomes. The establishment of GBMT reference range for each locality is mandatory for the proper diagnosis of such cases.

Multiple Vitelliform Lesions as a Retinal Manifestation of Alport Syndrome

Alport syndrome is associated with various ocular phenotypic features, including several retinal manifestations. The purpose of this case report was to describe a case of multiple vitelliform lesions in Alport syndrome. This particular finding has, to our knowledge, not been reported previously. A 63-year-old man with known Alport syndrome presented with symptomatic, bilateral anterior lenticonus. Fundoscopic examination revealed multiple vitelliform lesions, which were symmetrically distributed at the posterior poles. Additional retinal findings included an irregular foveal contour and central macular thinning in both eyes, as well as a multilayered retinoschisis in the left eye. The underlying pathophysiology of the vitelliform lesions may be a dysfunctional Bruch's membrane.

A triad of retinal signs in Alport syndrome: The 'stair-case' fovea, choroidal thinning and peripheral schisis

BACKGROUND

Alport syndrome is an inherited Type IV collagenopathy characterised by renal failure, hearing loss and ophthalmic manifestations such as lenticonus and dot-and-fleck retinopathy. New signs have been described which can be useful both for diagnosis and for prognosticating the risk of complications. This study examines and describes a triad comprising the unusual 'stair-case' foveal sign, together with choroidal thinning and late-stage peripheral schisis in a patient with Alport syndrome.

CASE PRESENTATION

This is a case report of a 49-year-old Caucasian male with a background of X-linked Alport syndrome presenting with gradual and progressive diminution of vision in the left eye with a central blur. He had already undergone three renal allografts, was deaf and suffered from hypertension by the time of his first presentation to ophthalmology. On examination, corrected visual acuity was 6/9.5 in the right eye and 6/30 in the left eye. Optical coherence tomography imaging showed an unusual 'stair-case' sign of the fovea in both eyes, together with choroidal thinning. We postulate that an abnormal vitreomacular interface followed by vitreomacular traction and eventually separation, removing layers of the inner retina with the vitreous, led to this unusual appearance. Subsequently, this patient also developed schitic changes more peripherally in the retina which progressed over the following 5 years.

CONCLUSION

The stair-case foveal sign, choroidal thinning and mid-peripheral schisis are three signs that clinicians might expect to encounter on optical coherence tomography imaging of patients with Alport syndrome. These findings can be attributed to unique mutations of collagen IV which lead to a variety of clinical phenotypes affecting basement membrane structures. Identification of these features may not only be useful diagnostically and in forecasting complications such as macular holes, but also predict mode of inheritance and likelihood of early-onset renal failure.

Increased Subfoveal Choroidal Thickness and Retinal Structure Changes on Optical Coherence Tomography in Pediatric Alport Syndrome Patients

Objective

To evaluate optical coherence tomography (OCT) findings of pediatric Alport syndrome (AS) patients with no retinal pathology on fundus examination.

Materials and Methods

Twenty-one patients being followed up with the diagnosis of AS (Group 1) and 24 age- and sex-matched healthy volunteers (Group 2) were prospectively evaluated. All participants underwent standard ophthalmologic examination, retinal nerve fibre layer (RNFL) analysis, and horizontal and vertical scan macula enhanced depth imaging OCT (EDI-OCT). Statistical analysis of the data obtained in this study was performed with SPSS 15.0.

Results

Macula thickness was significantly decreased in the temporal quadrant in Group 1 compared to those of the control group (p=0.013). RNFL measurements revealed statistically significant thinning in the temporal, superior, inferotemporal, and inferonasal quadrants and in average thicknesses in cases with AS compared to the controls (p < 0.001, p < 0.001, p=0.022, p=0.016, p < 0.001, respectively). The mean subfoveal coronial thickness (SCT) was 362.2 ± 77.8 μm in Group 1 and 256,18 ± 71.7 μm in Group 2. There was a statistically significant difference between the two groups in terms of mean CT (p < 0.001).

Conclusion

OCT provides valuable information in identifying the structural changes and evaluation of ocular findings in patients with AS. Even if no pathological retinal findings were found in the clinical examination, structural changes in the OCT examination begin in early period of AS.

Renal, auricular, and ocular outcomes of Alport syndrome and their current management

Alport syndrome is a hereditary glomerular basement membrane disease caused by mutations in the COL4A3/4/5 genes encoding the type IV collagen alpha 3-5 chains. Most cases of Alport syndrome are inherited as X-linked dominant, and some as autosomal recessive or autosomal dominant. The primary manifestations are hematuria, proteinuria, and progressive renal failure, whereas some patients present with sensorineural hearing loss and ocular abnormalities. Renin-angiotensin-aldosterone system blockade is proven to delay the onset of renal failure by reducing proteinuria. Renal transplantation is a curative treatment for patients who have progressed to end-stage renal disease. However, only supportive measures can be used to improve hearing loss and visual loss. Although both stem cell therapy and gene therapy aim to repair the basement membrane defects, technical difficulties require more research in Alport mice before clinical studies. Here, we review the renal, auricular, and ocular manifestations and outcomes of Alport syndrome and their current management.

Temporal retinal thinning and the diagnosis of Alport syndrome and Thin basement membrane nephropathy

BACKGROUND AND OBJECTIVES

Alport syndrome is an inherited disease characterized by renal failure, hearing loss, and ocular abnormalities, including temporal retinal thinning. This study compared retinal thinning in Alport syndrome and other renal diseases.

METHODS

Alport syndrome was diagnosed on renal biopsy and genetic testing. Subjects underwent optical coherence tomography (OCT) (Spectralis OCT, Heidelberg Instruments). Retinal thinning was determined from horizontal macular OCT scans through the foveal center using the formula: Temporal thickness index (TTI) = (nasal - temporal thickness) ÷ nasal thickness × 100%, and compared with the normal range for each age group. Statistical analysis was performed using Student's t test, Mann-Whitney U test, and ROC analysis (SPPS, IBM).

RESULTS

The mean temporal retinal thickness index was 12.4 ± 5.2% in men (n = 19) and 7.4 ± 1.4% in women (n = 28) with X-linked Alport syndrome; 13.1 ± 4.5% (n = 4) in recessive disease; 6.4 ± 2.2% (n = 5) in Thin basement membrane nephropathy; and 6.3 ± 3.3% (n = 14) in other renal diseases. Thinning was worse in men than women with X-linked disease (p < 0.01), and worse in men who developed early onset renal failure (R² = 0.75). Temporal retinal thinning was 84% sensitive for men with X-linked Alport syndrome and 67% specific (AUC = 0.83) compared with other renal diseases.

CONCLUSIONS

Retinal temporal thinning is diagnostic for X-linked Alport syndrome in men and distinguishes them this condition from Thin basement membrane nephropathy, but only in men (p = 0.002). Temporal retinal thinning may also identify men and women with the rarer autosomal recessive disease.

Electrophysiological features and multimodal imaging in ritonavir-related maculopathy

PURPOSE

The purpose of this study is to report a case of ritonavir-related retinal toxicity followed over a year. Electrophysiological features and multimodal imaging, including adaptive optics, are provided and discussed.

METHODS

Electrophysiological recordings and multimodal imaging were performed and repeated over 1 year.

RESULTS

Fundus examination revealed crystalline maculopathy in conjunction with pigment disruption. Spectral domain optical coherence tomography displayed thinning of the macula without cysts. Autofluorescence imaging revealed a mixed pattern of complete loss of the autofluorescence in the area of retinal pigment deposit and an increased transmission of the autofluorescence in the area of retinal thinning. Fluorescein angiography ruled out parafoveal telangiectasia. Indocyanine green angiography was not contributive. Increased spacing of the macular cone mosaic, crystal deposits and pigment migrations were seen with adaptive optics. Full-field electroretinogram was slightly reduced for both eyes, especially in the light-adapted responses, and mfERG confirmed bilateral maculopathy. Functional and structural abnormalities did not change with follow-up besides constant pigmentary changes monitored with adaptive optics.

CONCLUSION

Ritonavir-related retinal toxicity is a maculopathy with peculiar features including crystalline and pigment migration associated with central or temporofoveolar thinning and inconstant macular telangiectasia. Despite drug cessation, retinal remodelling continues to progress.

MACULAR HOLES, VITELLIFORM LESIONS, AND MIDPERIPHERAL RETINOSCHISIS IN ALPORT SYNDROME

PURPOSE

To describe the retinal findings in two cases of Alport syndrome.

METHODS

Observational case series. The clinical findings of the two patients were documented with color fundus photography and high resolution spectral domain optical coherence tomography.

RESULTS

Patient 1 was found to have fleck retinopathy in both eyes, inner retinal thinning in the right eye and a full-thickness macular hole in the left eye. Patient 2 was found to have a full-thickness macular hole in the right eye as well as retinoschisis in the temporal macula in the right eye. The left eye revealed inner retinal thinning involving the fovea, a vitelliform lesion of the temporal macula and midperipheral retinoschisis involving multiple retinal layers.

CONCLUSION

Retinal abnormalities including fleck retinopathy, retinal thinning, macular holes, retinoschisis, and vitelliform lesions are variably present in Alport syndrome. This is only the second report of a vitelliform lesion in a patient with Alport syndrome and the first report of midperipheral retinoschisis. The array of retinal findings is believed to reflect a dysfunctional Type IV collagen present in the internal limiting membrane and Bruch membrane.

Alport Syndrome in Women and Girls

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Inheritance is X-linked (85%) or autosomal recessive (15%). Many renal physicians think of Alport syndrome as primarily affecting men. However, twice as many women are affected by the X-linked diseases. Affected women are commonly undiagnosed, but 15%-30% develop renal failure by 60 years and often hearing loss by middle age. Half of their sons and daughters are also affected. Autosomal recessive Alport syndrome is less common, but is often mistaken for X-linked disease. Recessive inheritance is suspected where women develop early-onset renal failure or lenticonus. Their family may be consanguineous. The prognosis for other family members is very different from X-linked disease. Other generations, including parents and offspring, are not affected, and on average only one in four of their siblings inherit the disease. All women with Alport syndrome should have their diagnosis confirmed with genetic testing, even if their renal function is normal, because of their own risk of renal failure and the risk to their offspring. Their mutations indicate the mode of inheritance and the likelihood of disease transmission to their children, and the mutation type suggests the renal prognosis for both X-linked and recessive disease. Women with X-linked Alport syndrome should be tested at least annually for albuminuria and hypertension. The "Expert guidelines for the diagnosis and management of Alport syndrome" recommend treating those with albuminuria with renin-angiotensin-aldosterone system (RAAS) blockade (and adequate birth control because of the teratogenic risks of angiotensin converting enzyme inhibitors), believing that this will delay renal failure. Current recommendations are that women with autosomal recessive Alport syndrome should be treated with RAAS blockade from the time of diagnosis. In addition, women should be offered genetic counseling, informed of their reproductive options, and monitored closely during pregnancy for the development of hypertension.

Bull's eye and pigment maculopathy are further retinal manifestations of an abnormal Bruch's membrane in Alport syndrome

BACKGROUND AND OBJECTIVES

The retinal features of Alport syndrome include a central and peripheral fleck retinopathy, temporal retinal thinning, and a macular hole. Here we describe further retinal abnormalities.

METHODS

We identified a case of bull's eye maculopathy 20 years previously in a 68-year-old female, and reviewed archived retinal images from our cohort of X-linked (28 males, 28 females) or autosomal recessive (n = 13) Alport syndrome. All individuals had Alport syndrome confirmed on genetic testing or renal biopsy, were examined by an ophthalmologist, and underwent retinal imaging (KOWA non-mydriatic camera, Japan).

RESULTS

The index case had the p.Q379X variant in COL4A5 and currently had renal impairment, (eGFR = 45 ml/min/1.73 m²), bilateral hearing loss, and central and peripheral retinopathies. Her maculopathy had deteriorated, and she had a bilateral central visual field loss. Optical coherence tomography (Heidelberg Spectralis) demonstrated a disrupted retinal pigment epithelium and retinal atrophy. We identified a further early bull's eye maculopathy (1/69, 1.4%) from a female with autosomal recessive disease and normal renal function. We also noted a subtle pigment maculopathy associated with an abnormal retinal pigment epithelium in 27 (27/69, 39%) subjects with Alport syndrome, in both males (8/28, 29%) and females (13/28, 46%) with X-linked disease, and in autosomal recessive disease (6/13, 38%).

CONCLUSIONS

The bull's eye and pigment maculopathies in Alport syndrome result mainly from the damaged Bruch's membrane and overlying retinal pigment epithelium. Bull's eye maculopathy affects vision and patients should undergo regular monitoring for retinal complications.

Choroidal thinning and "stair-case" foveal sign in a patient with Alport syndrome

PURPOSE

To quantitatively describe choroidal thickness in a patient with Alport syndrome and to qualitatively describe an unusual "stair-case" foveal sign.

METHODS

Retrospective case report.

RESULTS

This is the first case, to our knowledge, of the stair-case foveal sign. This is also the first case where choroidal thickness in a patient with Alport rsyndrome has been quantitatively described using enhanced depth imaging optical coherence tomography.

CONCLUSION

Stair-case foveal sign and choroidal thinning are two new signs that clinicians can expect to encounter on optical coherence tomography imaging of patients with Alport syndrome.

Ocular features in Alport syndrome: pathogenesis and clinical significance

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Mutations in the COL4A5 (X-linked), or COL4A3 and COL4A4 (autosomal recessive) genes result in absence of the collagen IV α3α4α5 network from the basement membranes of the cornea, lens capsule, and retina and are associated with corneal opacities, anterior lenticonus, fleck retinopathy, and temporal retinal thinning. Typically, these features do not affect vision or, in the case of lenticonus, are correctable. In contrast, the rarer ophthalmic complications of posterior polymorphous corneal dystrophy, giant macular hole, and maculopathy all produce visual loss. Many of the ocular features of Alport syndrome are common, easily recognizable, and thus, helpful diagnostically, and in identifying the likelihood of early-onset renal failure. Lenticonus and central fleck retinopathy strongly suggest the diagnosis of Alport syndrome and are associated with renal failure before the age of 30 years, in males with X-linked disease. Sometimes, ophthalmic features suggest the mode of inheritance. A peripheral retinopathy in the mother of a male with hematuria suggests X-linked inheritance, and central retinopathy or lenticonus in a female means that recessive disease is likely. Ocular examination, retinal photography, and optical coherence tomography are widely available, safe, fast, inexpensive, and acceptable to patients. Ocular examination is particularly helpful in the diagnosis of Alport syndrome when genetic testing is not readily available or the results are inconclusive. It also detects complications, such as macular hole, for which new treatments are emerging.

Ocular features in Alport syndrome: pathogenesis and clinical significance

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Mutations in the COL4A5 (X-linked), or COL4A3 and COL4A4 (autosomal recessive) genes result in absence of the collagen IV α3α4α5 network from the basement membranes of the cornea, lens capsule, and retina and are associated with corneal opacities, anterior lenticonus, fleck retinopathy, and temporal retinal thinning. Typically, these features do not affect vision or, in the case of lenticonus, are correctable. In contrast, the rarer ophthalmic complications of posterior polymorphous corneal dystrophy, giant macular hole, and maculopathy all produce visual loss. Many of the ocular features of Alport syndrome are common, easily recognizable, and thus, helpful diagnostically, and in identifying the likelihood of early-onset renal failure. Lenticonus and central fleck retinopathy strongly suggest the diagnosis of Alport syndrome and are associated with renal failure before the age of 30 years, in males with X-linked disease. Sometimes, ophthalmic features suggest the mode of inheritance. A peripheral retinopathy in the mother of a male with hematuria suggests X-linked inheritance, and central retinopathy or lenticonus in a female means that recessive disease is likely. Ocular examination, retinal photography, and optical coherence tomography are widely available, safe, fast, inexpensive, and acceptable to patients. Ocular examination is particularly helpful in the diagnosis of Alport syndrome when genetic testing is not readily available or the results are inconclusive. It also detects complications, such as macular hole, for which new treatments are emerging.

Comparison of drusen and modifying genes in autosomal dominant radial drusen and age-related macular degeneration

BACKGROUND

Autosomal dominant radial drusen (ADRD), also termed Malattia Leventinese and Doyne honeycomb retinal dystrophy, causes early-onset vision loss because of mutation in EFEMP1. Drusen in an exceedingly rare ADRD human donor eye was compared with eyes affected with age-related macular degeneration (AMD). This study also elucidated whether variations in high-risk AMD genotypes modify phenotypic severity of ADRD.

METHODS

Morphologic and histochemical analyses of drusen in one ADRD donor and seven AMD donors. Evaluation of complement factor H (CFH) and ARMS2/HTRA1 alleles in a cohort of 25 subjects with ADRD.

RESULTS

Autosomal dominant radial drusen had unique onion skin-like lamination but otherwise shared many compositional features with hard, nodular drusen and/or diffuse soft drusen with basal deposits. Autosomal dominant radial drusen also possessed collagen type IV, an extracellular matrix protein that is absent in age-related drusen. Antibodies directed against the membrane attack complex showed robust labeling of ADRD. Vitronectin and amyloid P were present in drusen of both types. High-risk alleles in the CFH and ARMS2/HTRA1 genes were not associated with increasing ADRD severity.

CONCLUSION

Drusen from ADRD and AMD exhibit overlap of some major constituents, but ADRD exhibit distinct alterations in the extracellular matrix that are absent in AMD.

Posterior Polymorphous Corneal Dystrophy Concomitant to Large Colloid Drusen

Purpose

To describe the previously unreported concomitance of 2 uncommon ocular conditions: posterior polymorphous corneal dystrophy (PPCD) and large colloid drusen (LCD).

Methods

A 45-year-old woman underwent a complete ophthalmologic examination with slit-lamp biomicroscopy and blue fundus autofluorescence with spectral-domain optical coherence tomography, as well as complete systemic examination and renal function investigation.

Results

On slit-lamp biomicroscopy, a corneal lesion located at Descemet membrane was observed in the right eye. The clinical features of deep posterior stromal-endothelial linear bands with vesicles and irregular opacities of posterior corneal surface were consistent with the diagnosis of PPCD. Fundus biomicroscopy and blue fundus autofluorescence showed LCD.

Discussions

We report the unusual coexistence of PPCD and LCD in a young, healthy subject. Posterior polymorphous corneal dystrophy and LCD share morphologic similarities and dysfunctions of collagen architecture in the basement membrane layer, which suggests a possible common pathogenic pathway.

The blind kidney: disorders affecting kidneys and eyes

There are many disorders that can affect both the kidneys and the eyes. Awareness of the ocular manifestations of kidney disorders is important as it can guide the diagnosis and facilitate the choice of a specific treatment. Conversely, ophthalmologists need to be aware of potential renal manifestations in disorders presenting initially with visual failure. We review disorders affecting both of these organ systems, based upon cases from our clinical practice to highlight the importance of interdisciplinary collaboration.

Challenge in pathologic diagnosis of Alport syndrome: evidence from correction of previous misdiagnosis

Background

Pathologic studies play an important role in evaluating patients with Alport syndrome besides genotyping. Difficulties still exist in diagnosing Alport syndrome (AS), and misdiagnosis is a not-so-rare event, even in adult patient evaluated with renal biopsy.

Methods

We used nested case–control study to investigate 52 patients previously misdiagnosed and 52 patients initially diagnosed in the China Alport Syndrome Treatments and Outcomes Registry e-system.

Results

We found mesangial proliferative glomerulonephritis (MsPGN, 26.9%) and focal and segmental glomerulosclerosis (FSGS, 19.2%) were the most common misdiagnosis. FSGS was the most frequent misdiagnosis in female X-linked AS (fXLAS) patients (34.8%), and MsPGN in male X-linked AS (mXLAS) patients (41.2%). Previous misdiagnosed mXLAS patients (13/17, 76.5%) and autosomal recessive AS (ARAS) patients (8/12, 66.7%) were corrected after a second renal biopsy. While misdiagnosed fXLAS patients (18/23, 78.3%) were corrected after a family member diagnosed (34.8%) or after rechecking electronic microscopy and/or collagen-IV alpha-chains immunofluresence study (COL-IF) (43.5%) during follow-up. With COL-IF as an additional criterion for AS diagnosis, we found that patients with less than 3 criteria reached have increased risk of misdiagnosis (3.29-fold for all misdiagnosed AS patients and 3.90-fold for fXLAS patients).

Conclusion

We emphasize timely and careful study of electronic microscopy and COL-IF in pathologic evaluation of AS patients. With renal and/or skin COL-IF as additional criterion, 3 diagnosis criteria reached are the cutoff for diagnosing AS pathologically.

Alport syndrome--insights from basic and clinical research

In 1927, Arthur C. Alport first published his description of a triad of symptoms in a family with hereditary congenital haemorrhagic nephritis, deafness and ocular changes. A few years after his death, this group of symptoms was renamed Alport syndrome. To this day, Alport syndrome still inevitably leads to end-stage renal disease and the need for renal replacement therapy, starting in young adulthood. During the past two decades, research into this rare disease has focused on the effects of mutations in collagen type IV and the role of changes in podocytes and the glomerular basement membrane that lead to early kidney fibrosis. Animal models of Alport syndrome also demonstrate the pathogenetic importance of interactions between podocytes and the extracellular matrix. Such models might also help researchers to answer basic questions about podocyte function and the development of fibrosis, and to develop new therapeutic approaches that might be of use in other kidney diseases. In this Review, we discuss the latest basic and clinical research on Alport syndrome, focusing on the roles of podocyte pathology and the extracellular matrix. We also highlight early diagnosis and treatment options for young patients with this disorder.

Bilateral macular retinoschisis in a patient with x-linked alport syndrome

PURPOSE

To report a case of bilateral macular retinoschisis in a patient with X-linked Alport syndrome.

METHODS

Observational case report. A 57-year-old woman with X-linked Alport syndrome who presented with bilateral macular retinoschisis, which was demonstrated by high-resolution optical coherence tomography.

RESULTS

The patient's visual acuity was only mildly decreased, and she was observed for a period of 30 months.

CONCLUSION

This is the first and only report of bilateral macular retinoschisis in a patient with Alport syndrome. We suggest that the basement membrane of Bruch's membrane and the retinal pigment epithelium may be impaired and permit passage of fluid into the retina resulting in retinoschisis.