Optical coherence tomography findings in alport syndrome

Frail inner limiting membrane maculopathy suggested to describe a new retinal Alport-like condition with two variants in three generations of females

BACKGROUND

We report a three-generation family with isolated Alport-like retinal abnormalities in the absence of lenticonus, hearing loss, kidney disease, and detectable molecular genetic defects in known Alport-related genes.

METHODS

Clinical examination includes ocular biomicroscopy, fundus photography, optical coherence tomography, dipstick urinalysis, serum creatinine assessment, and molecular genetic analysis.

RESULTS

The proband, her mother, and her maternal grandmother had normal best-corrected visual acuity and normal visual fields in both eyes. The macula presented a petaloid stair-case profile with scarce vessels in both eyes of the proband and a flat temporal macula lacking a foveal avascular zone in her mother and her grandmother. No family member had renal symptoms, unexplained subnormal hearing, or lenticonus. Sequencing and MLPA found no defect in COL4A3, COL4A4, and COL4A5. Common SNPs around the genes ± 1Mb showed no segregation. Furthermore, none of the variants shared between the affected individuals in genes from a gene panel of genes relevant for ophthalmopathy nor whole exome- and genome sequencing explained the phenotype.

CONCLUSION

A new condition with two retinal Alport-like phenotypes was found. No abnormalities of the kidneys and lens were found, neither abnormalities of the type IV collagen genes related to Alport syndrome. Homology with retinal abnormalities seen in patients after surgical removal of the inner limiting membrane of the retina suggests that this is where the defect is located. We therefore suggest that the new retinal phenotypes and similar phenotypes can be described with the new definition "frail inner limiting membrane maculopathy."

AUTOLOGOUS RETINA TRANSPLANTATION FOR TREATMENT OF REFRACTORY DOUBLE FULL-THICKNESS MACULAR HOLE IN ALPORT SYNDROME

PURPOSE

To report the structural and functional outcomes of autologous neurosensory retinal transplantation for closure of refractory double full-thickness macular hole in a patient diagnosed with Alport syndrome.

METHODS

Patient with previous pars plana vitrectomy and a failed macular hole surgery (internal limiting membrane removal) underwent pars plana vitrectomy and autologous neurosensory retinal flap transplantation with silicone oil tamponade. Follow-up was performed after one year. The anatomic outcomes were evaluated mainly by fundus examination, optical coherence tomography (OCT), and microperimetry (MAIA). The functional changes were evaluated comparing best-corrected visual acuities preoperative and 1 year after surgery.

RESULTS

A 35-year-old man with progressive visual loss of two years of evolution presented a double full-thickness macular hole in the left eye. After retinal flap transplantation, the macular hole appeared successfully closed during the entire follow-up. Integration of both retinal flaps into the surrounding retina and regeneration of the external retinal layers were observed in optical coherence tomography. Best-corrected visual acuities improved from 20/200 preoperatively to 20/80 one-year postoperatively.

CONCLUSION

Pars plana vitrectomy combined with autologous neurosensory retinal flap transplantation is an effective option to achieve the anatomic closure of recurrent double full-thickness macular hole and significant visual recovery in Alport syndrome.

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.

Missing Internal Limiting Membrane during Macular Hole Repair in Alport Syndrome

The aim of this manuscript is to describe a novel retinal finding of Alport syndrome during surgical management of an associated macular hole. A retrospective chart review of a 65-year-old man with a diagnosis of Alport syndrome confirmed by renal biopsy was found to have an associated full-thickness macular hole. Pars-plana vitrectomy surgery with internal limiting membrane (ILM) peeling was attempted, but intraoperatively the ILM was found to be absent at the macula. Alport syndrome may be associated with the absence of the ILM. This can complicate attempts at macular hole repair.

[Macular hole and Alport's syndrome]

CASE REPORT

We present the clinical cases of two male patients of 38 and 39 years, diagnosed with Alport's syndrome, who suffered a bilateral macular hole and a giant unilateral macular hole with retinal thinning in the other eye, respectively.

DISCUSSION

Alport's syndrome is a genetic disorder characterised by mutation of genes encoding type IV collagen, the main component of the internal limiting membrane, a structure identified in basal membrane of the retinal pigment epithelium-Brüch's membrane complex. This alteration can influence the predisposition to macular holes.