| 1. |
- Abdalla-Elsayed, Maram E.A., et al.
(author)
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Heterozygous mutation in OTX2 associated with early-onset retinal dystrophy with atypical maculopathy
- 2017
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In: Molecular Vision. - 1090-0535. ; 23, s. 778-784
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Journal article (peer-reviewed)abstract
- Purpose: Heterozygous mutations in OTX2 have been associated with a range of ocular and pituitary abnormalities. We report a novel heterozygous deletion in OTX2 underlying early-onset retinal dystrophy with atypical maculopathy. Methods: Clinical examination included electroretinography and multimodal retinal imaging. Molecular genetic testing was composed of next-generation sequencing of a panel of retinal dystrophy genes. Results: A now 17-year-old boy presented 12 years earlier with a history of progressively poor vision since birth, nyctalopia, and early-onset retinal dystrophy with atypical maculopathy. He also had bilateral microphthalmos and a slim prepubertal appearance; growth hormone levels were within normal ranges. Next-generation sequencing of a retinal dystrophy gene panel revealed a heterozygous deletion c.485delC (p.Pro162G.Infs*24) in exon 5 of OTX2. Conclusions: This second report of maculopathy associated with a heterozygous mutation in OTX2 confirms that mutations in OTX2 should be considered in the differential diagnosis of atypical hereditary maculopathy, with or without rod-cone dystrophy.
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| 2. |
- Abdalla Elsayed, Maram E.A., et al.
(author)
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Incidence of Intraocular Lens Exchange after Cataract Surgery
- 2019
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Journal article (peer-reviewed)abstract
- Intraocular lens (IOL) exchange after cataract surgery is unusual but may be associated with suboptimal visual outcome. The incidence of IOL exchange has not been consistently estimated. Such information is invaluable when counseling patients prior to cataract surgery. We examined the incidence of, and indications and risk factors for, IOL exchange after cataract surgery. We also assessed visual outcome of eyes that had an IOL exchange. A cohort design was used to estimate the incidence of IOL exchange and a case-control design to identify factors associated with it. All phacoemulsification surgeries with IOL (n = 17415 eyes) during 2010-2017 and those that had a subsequent IOL removal or replacement during the same time period were identified (n = 34 eyes). The incidence of IOL exchange was 2 per 1000 surgeries (95% confidence interval [CI] 1 to 3) over 8 years. Eyes that underwent subsequent IOL removal or replacement were compared with eyes that had cataract surgery only (n = 47) across demographic and clinical characteristics. In a binary logistic regression analysis, two factors were significantly associated with IOL exchange/removal: an adverse event during cataract surgery (adjusted odds ratio [aOR] 19.45; 95% CI 4.89-77.30, P < 0.001) and a pre-existing ocular comorbidity (aOR 10.70; 95% CI 1.69-67.63, P = 0.021). The effect of gender was marginally significant (P = 0.077). Eyes that underwent IOL exchange or explantation were nearly two and a half times more likely to have a final best-corrected visual acuity of <20/60 compared to those that had cataract surgery alone (adjusted RR 2.60 95% CI, 1.13-6.02; P = 0.025).
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| 3. |
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| 4. |
- Abdalla Elsayed, Maram E.A., et al.
(author)
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Sickle cell retinopathy. A focused review
- 2019
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In: Graefe's Archive for Clinical and Experimental Ophthalmology. - : Springer Science and Business Media LLC. - 0721-832X .- 1435-702X. ; 257:7, s. 1353-1364
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Research review (peer-reviewed)abstract
- Purpose: To provide a focused review of sickle cell retinopathy in the light of recent advances in the pathogenesis, multimodal retinal imaging, management of the condition, and migration trends, which may lead to increased prevalence of the condition in the Western world. Methods: Non-systematic focused literature review. Results: Sickle retinopathy results from aggregation of abnormal hemoglobin in the red blood cells in the retinal microcirculation, leading to reduced deformability of the red blood cells, stagnant blood flow in the retinal precapillary arterioles, thrombosis, and ischemia. This may be precipitated by hypoxia, acidosis, and hyperosmolarity. Sickle retinopathy may result in sight threatening complications, such as paracentral middle maculopathy or sequelae of proliferative retinopathy, such as vitreous hemorrhage and retinal detachment. New imaging modalities, such as wide-field imaging and optical coherence tomography angiography, have revealed the microstructural features of sickle retinopathy, enabling earlier diagnosis. The vascular growth factor ANGPTL-4 has recently been identified as a potential mediator of progression to proliferative retinopathy and may represent a possible therapeutic target. Laser therapy should be considered for proliferative retinopathy in order to prevent visual loss; however, the evidence is not very strong. With recent development of wide-field imaging, targeted laser to ischemic retina may prove to be beneficial. Exact control of intraoperative intraocular pressure, including valved trocar vitrectomy systems, may improve the outcomes of vitreoretinal surgery for complications, such as vitreous hemorrhage and retinal detachment. Stem cell transplantation and gene therapy are potentially curative treatments, which may prevent retinopathy. Conclusions: There is lack of evidence regarding the optimal management of sickle retinopathy. Further study is needed to determine if recent progress in the understanding of the pathophysiology and diagnosis of sickle retinopathy may translate into improved management and outcome.
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| 5. |
- Abdelkader, Ehab, et al.
(author)
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Analysis of retinal structure and function in cone dystrophy with supernormal rod response
- 2020
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In: Documenta Ophthalmologica. - : Springer Science and Business Media LLC. - 0012-4486 .- 1573-2622.
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Journal article (peer-reviewed)abstract
- Purpose: To report the clinical and electrophysiological features of cone dystrophy with supernormal rod response (CDSRR). Methods: Retrospective cohort study of 15 unrelated patients (nine males and six females, median age 16, range 5–47 years) diagnosed with CDSRR by clinical examination, full-field electroretinography (ERG) and genetic testing. Observations: History, ophthalmic examination including near vision, color vision and contrast sensitivity assessment, multimodal retinal imaging and ERG. Genetic testing was done for all patients using next-generation sequencing. Results: The rate of consanguinity was 86.7%. Color vision was defective in 56.3%. Near vision was defective in all patients (mean 20/160). Contrast sensitivity was affected in all patients at low contrast of 2.5%. A parafoveal ring of increased autofluorescence imaging was seen in most patients (75%). Supernormal mixed maximal response b-wave was seen bilaterally in 63% of patients (and high normal in 37%). Rod dysfunction with prolonged rod b-wave latency was detected in all. The 30-Hz flicker response was more reduced and delayed compared to the single-flash cone response. A novel homozygous missense variant c.530G>C (p.Cys177Ser) in KCNV2 was detected in one patient, the nonsense homozygous mutation c.427G>T (p.Glu143*) was found in 13 patients, and the nonsense c.159C>G (p.Tyr53*) was found in one patient. Conclusion: This is the largest cohort of CDSRR from a single ethnic background. Rod dysfunction and reduced 30-Hz flicker response were demonstrated in all patients. In contrast to previous descriptions in the literature, a supernormal combined dark-adapted rod-cone ERG was present in the majority of the patients at standard stimulus intensity. Considering the consistent genotype and the demonstration of likely pathogenic genetic variants in all the patients, we argue that the combination of delayed rod b-wave and subnormal flicker response strongly suggests the diagnosis of CDSRR.
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| 6. |
- Abdelkader, Ehab, et al.
(author)
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Novel causative variants in patients with achromatopsia
- 2018
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In: Ophthalmic Genetics. - : Informa UK Limited. - 1381-6810 .- 1744-5094. ; 39:6, s. 678-683
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Journal article (peer-reviewed)abstract
- Purpose: To report five novel genetic variants in seven unrelated consanguineous families with achromatopsia (ACHM). Methods: Patients were examined with multimodal retinal imaging and full-field electroretinography (ffERG). Genetic testing was conducted using next-generation sequencing (NGS). Results: Three novel homozygous variants were detected in CNGA3: a missense c.967G > C (p.Ala323Pro) variant was detected in exon 8 (one patient), a splice site variant c.101 + 1G > A in intron 2 (three patients), and a splice site variant c.395 + 1G > T in intron 4(one patient). Another two novel variants were found in PDE6C: a homozygous missense variant c.1899C > A (p.His633Gln) in exon 15 (one patient) and a homozygous splice site variant c.1072-1G > C in intron 7 (one patient). Mutation segregation assessment was possible in 3 of the 7 families. All patients had nonrecordable ffERG 30-Hz flicker responses, reduced single-flash cone responses but preserved rod responses. Patients presented with variable degrees of foveal outer retinal layer loss and variable patterns of foveal hyperautofluorescence. Conclusions: These novel variants expand the genotypes associated with ACHM and may help in future therapy development for ACHM.
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| 7. |
- Abdelkader, Ehab, et al.
(author)
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Severe retinal degeneration at an early age in Usher syndrome type 1B associated with homozygous splice site mutations in MYO7A gene
- 2018
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In: Saudi Journal of Ophthalmology. - : Medknow. - 1319-4534. ; 32:2, s. 119-125
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Journal article (peer-reviewed)abstract
- Purpose: Usher syndrome is the most common cause of deafness associated with visual loss of a genetic origin. The purpose of this paper is to report very severe phenotypic features of type 1B Usher syndrome in a Saudi family affected by positive homozygous splice site mutation in MYO7A gene. Methods: Affected siblings went through detailed history. Complete ophthalmic examination was done. Imaging with colour fundus photography, fundus autofluorescence (AF), and optical coherence tomography (OCT) scans was performed. Full field electroretinogram (ffERG) was recorded. Molecular genetic testing was done using next-generation sequencing. Results: Visual acuity was more reduced (range 20/300–20/40) in older siblings (age>30 years), than in younger (age <30 years) siblings (range 20/70–20/25). OCT scans showed macular atrophy in all but one case that has cystoid macular edema (CME). AF demonstrated atrophy outside a small foveal area showing high signal. FfERG was flat in all cases. The homozygous splice site mutation c.470+1G>A in intron 5 of the MYO7A gene was detected in all affected siblings. Conclusions: This mutation manifested with advanced retinal degeneration at a young age. This may have implications regarding future gene therapy in Usher syndrome cases with this genotype.
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| 8. |
- Al Akeely, Adel, et al.
(author)
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Electrophysiological evaluation of fleck retina and temporal macular thinning in X-Linked alport's syndrome
- 2021
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In: Middle East African Journal of Ophthalmology. - : Medknow. - 0974-9233. ; 28:4, s. 257-259
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Journal article (peer-reviewed)abstract
- We report a 39-year-old with Alport's syndrome. The patient presented with anterior lenticonus, cataract, and a corrected distance visual acuity of 20/25 and 20/60 in the right and left eyes, respectively. Fundus examination revealed generalized retinal flecks sparing the fovea in both eyes. Optical coherence topography showed temporal macular thinning. Normal fundus autofluorescence was observed in both eyes. Full-field electroretinography (ERG) demonstrated normal photopic and scotopic responses, while multifocal ERG showed no reduction of amplitudes generated from the temporal thinned macula, compared to the nasal macula, indicating preserved functional integrity of the retina.
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| 9. |
- Al-Barki, Abdulrahman, et al.
(author)
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Comparison of short-pulse subthreshold (532 nm) and infrared micropulse (810 nm) macular laser for diabetic macular edema
- 2021
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Journal article (peer-reviewed)abstract
- The purpose of the study was to assess both anatomic and functional outcomes between short-pulse continuous wavelength and infrared micropulse lasers in the treatment of DME. This was a prospective interventional study from tertiary care eye hospital—King Khaled Eye Specialist Hospital (Riyadh, Saudi Arabia). Patients with center-involving diabetic macular edema were treated with subthreshold laser therapy. Patients in the micropulse group were treated with the 810-nm diode micropulse scanning laser TxCell (IRIDEX Corporation, Mountain View, CA, USA) (subthreshold micropulse—STMP group). Laser was applied according to recommendations for MicroPulse (125 microns spot size, 300 ms pulse duration and power adjustment following barely visible testing burn) in a confluent mode (low intensity/high density) to the entire area of the macular edema. Patients in the short-pulse group were treated with grid pattern laser with 20 ms pulse PASCAL laser 532 nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn (EndPoint 30% and EndPoint 50% groups, respectively). Main outcome measures included best-corrected visual acuity (BCVA in logMAR) and foveal thickness at baseline and the last follow-up visit at 6 months. There were 44 eyes in the micropulse group, 54 eyes in the EndPoint 50% group and 18 eyes in the EndPoint 30% group. BCVA for the whole cohort (logMAR) was 0.451 (Snellen equivalent 20/56) at baseline, 0.495 (Snellen equivalent 20/62) (p = 0.053) at 3 months, and 0.494 (Snellen equivalent 20/62) at the last follow-up (p = 0.052). Foveal thickness for the whole cohort was 378.2 ± 51.7 microns at baseline, 347.2 ± 61.3 microns (p = 0.002) at 3 months, and 346.0 ± 24.6 microns at the final follow-up (p = 0.027). As such the short-pulse system yields more temporary reduction in edema. Comparison of BCVA between baseline and 6 months for EndPoint 30%, EndPoint 50% and STMP groups was p = 0.88, p = 0.76 and p = 0.003, respectively. Comparison of foveal thickness between baseline and 6 months for EndPoint 30%, EndPoint 50% and STMP groups was p = 0.38, p = 0.22 and p = 0.14, respectively. We conclude that the infrared micropulse system seems to improve functional outcomes. When applied according to previously published reports, short-pulse system may yield more temporary reduction in edema while infrared micropulse system may yield slightly better functional outcomes.
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| 10. |
- Al-Hujaili, Haneen, et al.
(author)
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Long-term follow-up of retinal function and structure in trpm1-associated complete congenital stationary night blindness
- 2019
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In: Molecular Vision. - 1090-0535. ; 25, s. 851-858
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Journal article (peer-reviewed)abstract
- Purpose: TRPM1-associated congenital stationary night blindness (CSNB) is characterized by nystagmus and high myopia. We assessed retinal function and structure over long-term follow-up up to 10 years in two siblings from a family with the homozygous deletion c.2394delC in exon 18 that we previously identified. In addition, we describe retinal function and structure in two other siblings with the novel homozygous c.1394T>A (p.Met465Lys) missense mutation. Methods: Clinical examination included full-field electroretinography, axial length measurements, and multimodal retinal imaging. Molecular genetic tests included next-generation sequencing and Sanger sequencing. Results: All patients had non-recordable rod responses and electronegative configuration of the rod-cone responses at presentation. There was a median of 26% reduction in the dark-and light-adapted electroretinographic (ERG) amplitudes over 4 years. Myopia progressed rapidly in childhood but showed only a mild progression after the teenage years. Visual acuities were stable over time, and there was no sign of progressive retinal thinning. All patients had axial myopia. A novel homozygous c.1394T>A (p.Met465Lys) missense mutation in TRPM1 was identified in two siblings. Conclusions: Further prospective study in larger samples is needed to establish whether there is progressive retinal degeneration in TRPM1-associated CSNB. The associated myopia was found to be mainly axial, which has not been described previously. The mechanism of myopia development in this condition remains incompletely understood; however, it may be related to altered retinal dopamine signaling and amacrine cell dysfunction.
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