ALPK1 missense pathogenic variant in five families leads to ROSAH syndrome, an ocular multisystem autosomal dominant disorder

Purpose

To identify the molecular cause in five unrelated families with a distinct autosomal dominant ocular systemic disorder we called ROSAH syndrome due to clinical features of retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and migraine headache.

Methods

Independent discovery exome and genome sequencing in families 1, 2, and 3, and confirmation in families 4 and 5. Expression of wild-type messenger RNA and protein in human and mouse tissues and cell lines. Ciliary assays in fibroblasts from affected and unaffected family members.

Results

We found the heterozygous missense variant in the ɑ-kinase gene, ALPK1, (c.710C>T, [p.Thr237Met]), segregated with disease in all five families. All patients shared the ROSAH phenotype with additional low-grade ocular inflammation, pancytopenia, recurrent infections, and mild renal impairment in some. ALPK1 was notably expressed in retina, retinal pigment epithelium, and optic nerve, with immunofluorescence indicating localization to the basal body of the connecting cilium of the photoreceptors, and presence in the sweat glands. Immunocytofluorescence revealed expression at the centrioles and spindle poles during metaphase, and at the base of the primary cilium. Affected family member fibroblasts demonstrated defective ciliogenesis.

Conclusion

Heterozygosity for ALPK1, p.Thr237Met leads to ROSAH syndrome, an autosomal dominant ocular systemic disorder.

Effect of intraocular lens glistening size on visual quality

PURPOSE

To determine whether intraocular glistenings have an impact on light scatter and visual function.

SETTING

John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Retrospective cohort study.

METHODS

Pseudophakic patients with visual acuity no worse than 0.02 logMAR and no ocular pathology were enrolled. All had received a single-piece high-refractive-index acrylic intraocular lens (IOL). All IOLs were photographed, and glistenings were analyzed for size and density. Outcome measures included logMAR corrected distance visual acuity (CDVA), mesopic 10% contrast logMAR CDVA with and without glare, and straylight determination with a straylight meter (C Quant log).

RESULTS

All 79 patients had glistenings within 2 diameter groups: 6 to 25 μm and over 25 μm. Linear regression for the nonstratified group was significant for IOL glistening size versus contrast visual acuity with glare. Linear regression for the 6 to 25 μm group was significant for a measure of severity index (%area) versus the straylight meter measurements, %area/size versus straylight meter measurements, IOL age versus CDVA, IOL age versus contrast visual acuity, and IOL age versus contrast visual acuity with glare. Linear regression for the over 25 μm group was significant for IOL age versus glistening size and %area/size versus contrast visual acuity, and density versus CDVA and contrast visual acuity with glare.

CONCLUSIONS

Glistening %area, at a key size, correlated with random light scatter. The age of the IOL likely affects glistening size and visual parameters.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Blepharospasm in children and adolescents

PURPOSE

Benign essential blepharospasm (BEB) generally is considered a disorder of adults; however, it rarely can present in childhood or adolescence. The main purpose of this study was to determine the prevalence of BEB in children and adolescents. Our research question was whether blepharospasm is seen in children or adolescents as well as in the adult population.

METHODS

We conducted a retrospective chart review at the University of Utah and Johns Hopkins University. We reviewed our databases for diagnoses of blepharospasm and tic disorder over the past 10 years in patients of all ages. Charts then were reviewed to confirm the diagnosis, and a questionnaire was sent to subjects whose blepharospasm had apparently begun before age 20 years.

RESULTS

We identified 26 patients diagnosed with eyelid spasms that had begun while under the age of 20. We confirmed BEB in four of these cases. Of these individuals, all had developed symptoms in adolescence or before and all were still symptomatic but had noted improvement in the severity and frequency of their symptoms.

CONCLUSIONS

Although rare, BEB can develop in the first decade of life, producing symptoms and signs that are similar to adults, with persistence into adulthood.

Adalimumab and Non-Arteritic Anterior Ischaemic Optic Neuropathy: A Case Report

Sequential anterior ischaemic optic neuropathy was observed in a patient treated with a tumour necrosis factor α (TNF) inhibitor, adalimumab, for ankylosing spondylitis. He developed decreased visual acuity in the right eye after 17 months of treatment. Findings showed right optic disc oedema with haemorrhages and visual field defect. Adalimumab was discontinued and vision stabilised. After restarting adalimumab, he developed optic neuropathy in the left eye. Findings showed optic disc oedema, with haemorrhages and visual field changes in the left eye. Adalimumab may be associated with optic neuropathy; providers prescribing TNF inhibitors should be aware of optic neuropathy as a potential complication.

Neuro-ophthalmic disorders in pregnancy

PURPOSE OF REVIEW

This review discusses evaluation and treatment of neuro-ophthalmic disorders in the pregnant patient.

RECENT FINDINGS

Any neuro-ophthalmic abnormality seen in nonpregnant women can be seen in pregnant women. Pregnancy-specific complications (preeclampsia and eclampsia) cause visual symptoms and can affect the entire visual axis.

SUMMARY

Appropriate evaluation and examination is important to preserve the health and vision of the mother and prevent complications in the fetus. Evaluation should proceed in the same way for a pregnant patient as it would for a nonpregnant patient, with few exceptions. Treatment decisions may be influenced by stage of pregnancy.

Correlation of visual quality with satisfaction and function in a normal cohort of pseudophakic patients

PURPOSE

To select a normal post-cataract-surgery cohort, determine visual quality parameters, and compare these parameters with self-reported satisfaction and visual function.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Retrospective cohort study.

METHODS

A cohort of pseudophakic patients was selected based on uneventful surgery, good corrected visual acuity (no worse than logMAR 0.02), and lack of ocular complaints or pathology including dry-eye syndrome or posterior capsule opacification. A single-piece high-refractive-index acrylic intraocular lens, age 50 or older, and at least 1 year out from surgery were other inclusion criteria. Testing included logMAR corrected distance visual acuity (CDVA), mesopic 10% contrast logMAR CDVA with and without glare, straylight determination, Rasch-modified National Eye Institute Visual Function questionnaire 11R (NEI VF-11R), custom pseudophakic dysphotopsia survey, and overall satisfaction question. Correlations were determined between these parameters.

RESULTS

Of the 2953 patients considered, 70 patients met all criteria, provided consent, and enrolled. Only pseudophakic dysphotopsia (r = -0.60; P<.0001) and the NEI VF-11R (r = -0.44; P<.0001) correlated with overall satisfaction. In addition, pseudophakic dysphotopsia correlated with the NEI VF-11R (r = 0.58; P<.0001).

CONCLUSIONS

When evaluating a highly controlled population with expected high satisfaction after cataract surgery, pseudophakic dysphotopsia was clearly the only significant dissatisfier. Furthermore, dysphotopsia highly correlated with the NEI VF-11R questionnaire; thus, symptoms of dysphotopsia are also seen to have functional significance. A shortened NEI VFQ survey and satisfaction correlated strongly with the full survey.

Comparison of stromal hydration techniques for clear corneal cataract incisions: conventional hydration versus anterior stromal pocket hydration

Anterior stromal pocket hydration was compared with conventional hydration for preventing wound leak after 2.8 mm uniplanar clear corneal incisions (CCIs) in patients having routine cataract surgery. Conventional hydration involves hydration of the lateral walls of the main incision with visible whitening of the stroma. The anterior stromal pocket hydration technique involves creation of an additional supraincisional stromal pocket overlying the main incision, which is then hydrated instead of the main incision. Sixty-six eyes of 48 patients were included in the data analysis with 33 assigned to each study group. The anterior stromal pocket hydration technique was significantly better than conventional hydration in preventing wound leak due to direct pressure on the posterior lip of the incision.

Femtosecond-assisted preparation of donor tissue for Boston type 1 keratoprosthesis

We describe a technique for femtosecond laser-assisted preparation of donor tissue for Boston type 1 keratoprosthesis to provide accurate double punching of the donor tissue for optimized alignment in the visual axis. The technique was reproducibly performed in four donor corneas mounted in an artificial anterior chamber. This technique can provide optically centered donor tissue with smooth trephinated edges.

Neural reprogramming in retinal degeneration

PURPOSE

Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. The authors sought to explore the functional expression of ionotropic (iGluR) and group 3, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degeneration.

METHODS

Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degeneration and a sample of human RP.

RESULTS

After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, whereas amacrine and ganglion cells retain iGluR-mediated responsivity. Paradoxically, amacrine and ganglion cells show spontaneous iGluR signals in vivo even though bipolar cells lack glutamate-coupled depolarization mechanisms. Cone survival can rescue iGluR expression by OFF bipolar cells. In a case of human RP with cone sparing, iGluR signaling appeared intact, but the number of bipolar cells expressing functional iGluRs was double that of normal retina.

CONCLUSIONS

RP triggers permanent loss of bipolar cell glutamate receptor expression, though spontaneous iGluR-mediated signaling by amacrine and ganglion cells implies that such truncated bipolar cells still release glutamate in response to some nonglutamatergic depolarization. Focal cone-sparing can preserve iGluR display by nearby bipolar cells, which may facilitate late RP photoreceptor transplantation attempts. An instance of human RP provides evidence that rod bipolar cell dendrite switching likely triggers new gene expression patterns and may impair cone pathway function.

Molecular mapping of the binding site for a blocker of hyperpolarization-activated, cyclic nucleotide-modulated pacemaker channels

Hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channels mediate rhythmic electrical activity of neural and cardiac pacemaker cells. Drugs that block these channels slow the beating rate of the heart and are used to treat angina. Here, we characterized the effect of the HCN channel blocker, ZD7288 [4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyrimidinium chloride] on HCN2 channels that were heterologously expressed in Xenopus oocytes. A site-directed mutagenesis approach was used to identify specific residues of the mouse HCN2 channel pore that interact with ZD7288. Two residues (Ala425 and Ile432) located in the S6 transmembrane domain were found to be the primary determinants for block of HCN2 channels by ZD7288. I432A mutant HCN2 channels were approximately 100-fold less sensitive to block by ZD7288. Substitution of Ile432 with more hydrophobic residues (Phe, Leu, or Val) caused only modest shifts in the IC(50) for the drug. HCN1 channels have a Val (Val390) in the equivalent position of Ile432 and are less sensitive to block by ZD7288. Accordingly, mutation of this Val390 to Ile in HCN1 increased the sensitivity of these channels to drug block. Mutation of Ala425 and Ile432 also attenuated the block of HCN2 by the more potent blocker cilobradine. An HCN2 homology model based on the bacterial KcsA K(+) channel predicts that the phenyl ring of ZD7288 occupies a hydrophobic cavity formed by Ala425 and Ile432 and that the charged ring aligns with the axis of the inner pore closely corresponding to the localization of K(+) ions observed in the KcsA crystal structure.