Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Nizar Saleh Abdelfattah is active.

Publication


Featured researches published by Nizar Saleh Abdelfattah.


Ophthalmology | 2015

Prospective Trial of Treat-and-Extend versus Monthly Dosing for Neovascular Age-Related Macular Degeneration: TREX-AMD 1-Year Results

Charles C. Wykoff; Daniel E. Croft; David M. Brown; Rui Wang; John F. Payne; Lloyd Clark; Nizar Saleh Abdelfattah; Srinivas R Sadda

PURPOSE To assess prospectively a treat-and-extend (TREX) management strategy compared with monthly dosing of intravitreal ranibizumab in treatment-naïve neovascular age-related macular degeneration (AMD) patients. DESIGN Phase IIIb, multicenter, randomized, controlled clinical trial. PARTICIPANTS Sixty patients with treatment-naïve neovascular AMD randomized 1:2 to monthly or TREX management. METHODS Patients with Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) from 20/32 to 20/500 (Snellen equivalent) were randomized to receive intravitreal 0.5 mg ranibizumab monthly or according to a TREX protocol. The TREX patients were treated monthly for at least 3 doses, until resolution of clinical and spectral-domain optical coherence tomography evidence of exudative disease activity; the interval between visits then was individualized according to a strict prospective protocol. MAIN OUTCOME MEASURES Mean ETDRS BCVA change from baseline. RESULTS At baseline, mean age was 77 years (range, 59-96 years), mean BCVA was 20/60 (Snellen equivalent), and mean central retinal thickness (CRT) was 511 μm. Fifty-seven eyes (95%) completed month 12, at which point mean BCVA improved by 9.2 and 10.5 letters in the monthly and TREX cohorts, respectively (P = 0.60). The mean number of injections administered through month 12 was 13.0 and 10.1 (range, 7-13) in the monthly and TREX cohorts, respectively (P < 0.0001). Among TREX patients, 7 (18%) were maximally extended, 4 (10%) demonstrated fluid at every visit, and at month 12, 18 (45%) had achieved an extension interval of 8 weeks or more; the mean maximum extension interval between injections after the first 3 monthly doses was 8.4 weeks (range, 4-12 weeks). Most TREX patients who demonstrated recurrent exudative disease activity (17/24 [71%]) were unable to extend beyond their initial maximum extension interval. CONCLUSIONS The TREX neovascular AMD management strategy used in this prospective, randomized, controlled trial resulted in visual and anatomic gains comparable with those obtained with monthly dosing.


Investigative Ophthalmology & Visual Science | 2016

Drusen Volume as a Predictor of Disease Progression in Patients With Late Age-Related Macular Degeneration in the Fellow Eye.

Nizar Saleh Abdelfattah; Hongyang Zhang; David S. Boyer; Philip J. Rosenfeld; William J. Feuer; Giovanni Gregori; Srinivas R Sadda

PURPOSE Increasing drusen volume was proposed to be a predictor of disease progression in age-related macular degeneration (AMD). In patients with late AMD in one eye, the fellow eyes without neovascularization are known to be at higher risk of developing exudative AMD. We evaluated the relationship between drusen volume in these fellow eyes and their progression to late AMD. METHODS A retrospective analysis included fellow eyes with drusen associated with nonexudative AMD. All eyes with neovascular AMD were treated with intravitreal ranibizumab, aflibercept, and/or bevacizumab and followed for 2 years. All eyes were scanned with the Cirrus HD-OCT using a 512 × 128 scan pattern. Optical coherence tomography (OCT) data at baseline, month 12, and month 24 were collected using the advanced RPE analysis tool to quantify drusen volume within 3- and 5-mm-diameter circles centered on the fovea. Optical coherence tomography scans were also evaluated for the development of geographic atrophy (GA) or macular neovascularization (MNV). RESULTS Eighty-nine patients who had neovascular AMD in only one eye were studied. Optical coherence tomography drusen volume in the absence of MNV could be measured in 61 participants (68.5%). After 12 months, 4 eyes (4.5%) developed MNV and 15 eyes (16.9%) developed GA. By 24 months of follow-up, an additional 5 eyes (7.1%) developed MNV and an additional 10 eyes (14.3%) developed GA. At month 24, the eyes that developed GA or MNV had baseline drusen volumes that were significantly larger than in eyes that did not develop late AMD. Patients with a drusen volume over 0.03 mm3 had a greater than 4-fold increased risk for developing late AMD compared with those with lower drusen volumes. CONCLUSIONS Baseline drusen volume appears to be an important predictor for the development of late AMD within 2 years in eyes that have fellow eyes being actively treated for MNV. This suggests that OCT-derived drusen volume measurements may be a useful biomarker to identify eyes at the highest risk for progression to late AMD.


Retina-the Journal of Retinal and Vitreous Diseases | 2016

Progression Of Macular Atrophy In Patients With Neovascular Age-related Macular Degeneration Undergoing Antivascular Endothelial Growth Factor Therapy

Nizar Saleh Abdelfattah; Hongyang Zhang; David S. Boyer; Srinivas R. Sadda

Purpose: To define the frequency and quantify the progression of macular atrophy (MA) in patients with neovascular age-related macular degeneration undergoing treatment with antivascular endothelial growth factor therapy for >2 years. Methods: Fifty-four eyes of 46 patients (86.7 ± 6.8 years, 53.7% women) diagnosed with wet age-related macular degeneration were included in this retrospective study. Eyes that received photodynamic therapy or laser treatment were excluded. All eyes were imaged at baseline and after 2 years with the Cirrus spectral domain optical coherence tomography using a 512 × 128 macular cube scan protocol centered on the fovea. Optical coherence tomography en face fundus images were obtained for each 3-dimensional data set using the U.S. Food and Drug Administration–cleared Advanced RPE Analysis software, which automatically identifies atrophic areas by segmenting regions of increased reflectivity in en face choroidal slab images. Segmentation errors were manually corrected by trained Doheny Image Reading Center graders using a standardized grading protocol. The prevalence rates of atrophy at baseline and at 2-years follow-up and enlargement rates were computed. Baseline demographic factors and types and numbers of antivascular endothelial growth factor injections received over time were correlated with the development and enlargement of atrophy. Results: Macular atrophy was noted at baseline in 32 (59.3%) eyes and progressed in all eyes over the next 2 years. Among the 28 eyes without atrophy at baseline, MA developed by 2 years in 6 eyes (21.4% of eyes without MA at baseline). Of note, 22 eyes (40.7% of overall cohort) never developed atrophy during the course of the study. Among eyes with atrophy at baseline, the annual growth rate of MA was found to be 0.89 ± 0.93 mm2. A multiple regression analysis was performed to evaluate the influence of gender, age, smoking status, medication injected, and number of injections on MA. Except for the number of total injections (R2 = 0.3, P < 0.01), the studied variables could not significantly predict development or progression of MA (F [0.73, 13] = 0.378, P = 0.86, R2 = 0.05). However, the study was not powered to detect small effects. Conclusion: Macular atrophy is a frequent finding in eyes with wet age-related macular degeneration both before and after antivascular endothelial growth factor therapy. The frequency of new optical coherence tomography–defined atrophy (21% at 2 years) after starting therapy was close to the rates reported in CATT, IVAN, and HARBOR. The rate of MA enlargement was positively correlated with the number of injections, but did not appear to be greater than that reported for atrophy in the absence of choroidal neovascularization.


International Journal of Ophthalmology | 2015

Clinical correlates of common corneal neovascular diseases: a literature review.

Nizar Saleh Abdelfattah; Mohamed Amgad; Amira A. Zayed; Hamdy Salem; Ahmed E Elkhanany; Heba Hussein; Nawal Abd El-Baky

A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far.


International Journal of Ophthalmology | 2016

Molecular underpinnings of corneal angiogenesis: advances over the past decade

Nizar Saleh Abdelfattah; Mohamed Amgad; Amira A. Zayed; Heba Hussein; Nawal Abd El-Baky

The cornea is maintained in an avascular state by maintaining an environment whereby anti-angiogenic factors take the upper hand over factors promoting angiogenesis. Many of the common pathologies affecting the cornea involve the disruption of such equilibrium and the shift towards new vessel formation, leading to corneal opacity and eventually-vision loss. Therefore it is of paramount importance that the molecular underpinnings of corneal neovascularization (CNV) be clearly understood, in order to develop better targeted treatments. This article is a review of the literature on the recent discoveries regarding pro-angiogenic factors of the cornea (such as vascular endothelial growth factors, fibroblast growth factor and matrix metalloproteinases) and anti-angiogenic factors of the cornea (such as endostatins and neostatins). Further, we review the molecular underpinnings of lymphangiogenesis, a process now known to be almost separate from (yet related to) hemangiogenesis.


International Journal of Ophthalmology | 2014

Development of an Arabic version of the National Eye Institute Visual Function Questionnaire as a tool to study eye diseases patients in Egypt.

Nizar Saleh Abdelfattah; Mohamed Amgad; Ahmed Salama; Marina Israel; Ghada Elhawary; Ahmed E Radwan; Mohamed Mostafa Elgayar; Tamer M El Nakhal; Islam T. Elkhateb; Heba A Hashem; Doha K Embaby; Amira Abdelrazak Elabd; Reem K Elwy; Magdi S Yacoub; Hamdy Salem; Mohamed Abdel-Baqy; Ahmad Kassem

AIM To develop and test an Arabic version of the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). METHODS NEI-VFQ-25 was translated into Arabic according to WHO translation guidelines. We enrolled adult consenting patients with bilateral chronic eye diseases who presented to 14 hospitals across Egypt from October to December 2012, and documented their clinical findings. Psychometric properties were then tested using STATA. RESULTS We recruited 379 patients, whose mean age was (54.5±15)y. Of 46.2% were males, 227 had cataract, 31 had glaucoma, 23 had retinal detachment, 37 had diabetic retinopathy, and 61 had miscellaneous visual defects. Non-response rate and the floor and ceiling numbers of the Arabic version (ARB-VFQ-25) were calculated. Internal consistency was high in all subscales (except general health), with Cronbach-α ranging from 0.702-0.911. Test-retest reliability was high (intraclass correlation coefficient 0.79). CONCLUSION ARB-VFQ-25 is a reliable and valid tool for assessing visual functions of Arabic speaking patients. However, some questions had high non-response rates and should be substituted by available alternatives. Our results support the importance of including self-reported visual functions as part of routine ophthalmologic examination.


International Journal of Ophthalmology | 2016

Host immune cellular reactions in corneal neovascularization

Nizar Saleh Abdelfattah; Mohamed Amgad; Amira A. Zayed

Corneal neovascularization (CNV) is a global important cause of visual impairment. The immune mechanisms leading to corneal heme- and lymphangiogenesis have been extensively studied over the past years as more attempts were made to develop better prophylactic and therapeutic measures. This article aims to discuss immune cells of particular relevance to CNV, with a focus on macrophages, Th17 cells, dendritic cells and the underlying immunology of common pathologies involving neovascularization of the cornea. Hopefully, a thorough understanding of these topics would propel the efforts to halt the detrimental effects of CNV.


Translational Vision Science & Technology | 2017

Variability of Retinal Thickness Measurements in Tilted or Stretched Optical Coherence Tomography Images

Akihito Uji; Nizar Saleh Abdelfattah; David S. Boyer; Siva Balasubramanian; Jianqin Lei; Srinivas R Sadda

Purpose To investigate the level of inaccuracy of retinal thickness measurements in tilted and axially stretched optical coherence tomography (OCT) images. Methods A consecutive series of 50 eyes of 50 patients with age-related macular degeneration were included in this study, and Cirrus HD-OCT images through the foveal center were used for the analysis. The foveal thickness was measured in three ways: (1) parallel to the orientation of the A-scan (Tx), (2) perpendicular to the retinal pigment epithelium (RPE) surface in the instrument-displayed aspect ratio image (Ty), and (3) thickness measured perpendicular to the RPE surface in a native aspect ratio image (Tz). Mathematical modeling was performed to estimate the measurement error. Results The measurement error was larger in tilted images with a greater angle of tilt. In the simulation, with axial stretching by a factor of 2, Ty/Tz ratio was > 1.05 at a tilt angle between 13° to 18° and 72° to 77°, > 1.10 at a tilt angle between 19° to 31° and 59° to 71°, and > 1.20 at an angle ranging from 32° to 58°. Of note with even more axial stretching, the Ty/Tz ratio is even larger. Tx/Tz ratio was smaller than the Ty/Tz ratio at angles ranging from 0° to 54°. The actual patient data showed good agreement with the simulation. The Ty/Tz ratio was greater than 1.05 (5% error) at angles ranging from 13° to 18° and 72° to 77°, greater than 1.10 (10% error) angles ranging from 19° to 31° and 59° to 71°, and greater than 1.20 (20% error) angles ranging from 32° to 58° in the images axially stretched by a factor of 2 (b/a = 2), which is typical of most OCT instrument displays. Conclusions Retinal thickness measurements obtained perpendicular to the RPE surface were overestimated when using tilted and axially stretched OCT images. Translational Relevance If accurate measurements are to be obtained, images with a native aspect ratio similar to microscopy must be used.


British Journal of Ophthalmology | 2017

Neovascular age-related macular degeneration management in the third year: Final results from the TREX-AMD randomised trial

Charles C. Wykoff; William C. Ou; Daniel E. Croft; John F. Payne; David M. Brown; W. Lloyd Clark; Nizar Saleh Abdelfattah; Srini Vas R Sadda

Background/Aims Prospectively evaluate outcomes in the third year of neovascular age-related macular degeneration (AMD) management using ranibizumab with continued treat and extend (TREX) dosing compared with monthly visits with retreatment upon evidence of exudative disease activity (PRN, pro re nata). Methods Subjects with treatment-naïve neovascular AMD were randomised 1:2 to Monthly or TREX and managed through 2 years. In the third year, subjects randomised to Monthly were managed PRN while subjects randomised to TREX were continued on TREX dosing or transitioned to PRN after achieving an interval of 12 weeks between visits. Results Sixty subjects enrolled and 46 (77%) completed month 36 (M36). Transition from Monthly to PRN was associated with a decline in best corrected visual acuity (BCVA) (+10.5 letters (month 24) to +5.4 (M36, p=0.09)); three (15%) subjects required no dosing during year 3, and 47% (114/243) of possible PRN injections were delivered, yielding a mean of 6.1 injections during year 3. Among the 9 (23%) TREX subjects transitioned to PRN, the need for ongoing anti-vascular endothelial growth factor retreatments was small, with 4 (4%) intravitreal injections being delivered among 106 PRN visits; this subgroup displayed an inferior BCVA trajectory compared with the remainder of subjects. Outcomes among subjects continued on TREX were more favourable, with a mean gain of +5.0 letters at M36. Conclusions Upon transition to PRN, subjects randomised to monthly dosing experienced a decline in BCVA. Among subjects initially randomised to TREX who transitioned to PRN after achieving a 12-week interval between visits, the overall need for additional treatment was low. Trial registration number NCT01748292, Results.


Journal of Cataract and Refractive Surgery | 2016

Keratoconus correction using a new model of intrastromal corneal ring segments

Marina Israel; Mohamed Omar Yousif; Nermin A. Osman; Marina Nashed; Nizar Saleh Abdelfattah

Purpose To evaluate the optical value of a new model of intrastromal corneal ring segments (ICRS) (Keratacx Plus) in patients with keratoconus and to quantify subsequent changes in corneal topography and asphericity. Setting Private practice. Design Prospective case series. Methods This study comprised patients who had primary keratoconus or keratectasia after laser in situ keratomileusis (LASIK); none wore contact lenses. Rings were implanted through tunnels created manually or with a femtosecond laser. All eyes had clear visual axes and corneal thickness over 450 &mgr;m at the incision site. Preoperative and postoperative pachymetry images were acquired. Results were analyzed using a matched‐pair t test and the Kolmogorov‐Smirnov test. Results Twenty‐nine eyes (24 patients; mean age 30.1 years ± 10.6 [SD]) were evaluated. The ICRS significantly increased uncorrected and corrected visual acuities from 0.05 to 0.16 and from 0.17 to 0.5, respectively (z = 4.7, P < .001). They reduced the median spherical error from −4.0 to −0.5 diopters (D) (P < .001) and median cylindrical error from −4.4 to −2.5 D (P < .001). All topographic parameters were reduced, including maximum keratometry (K) (49.4 D versus 45.1 D), minimum K (49.4 D versus 45.1 D), mean K (51.4 D versus 48.4 D), astigmatism (−2.0 D versus −0.5 D), and asphericity (eccentricity 0.49 versus 0.23) (all P < .001). Conclusions The ICRS provided topographic and visual improvement in keratoconus and post‐LASIK keratectasia. Variance in surgical outcomes with manual versus femtosecond tunneling and the effect of different ring sizes are yet to be studied. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

Collaboration


Dive into the Nizar Saleh Abdelfattah's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Charles C. Wykoff

Houston Methodist Hospital

View shared research outputs
Top Co-Authors

Avatar

Daniel E. Croft

Houston Methodist Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

David S. Boyer

University of Southern California

View shared research outputs
Top Co-Authors

Avatar

Akihito Uji

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jianqin Lei

University of California

View shared research outputs
Top Co-Authors

Avatar

John F. Payne

Medical University of South Carolina

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge