Ashkan M. Abbey

Femtosecond laser-assisted astigmatic keratotomy in naturally occurring high astigmatism

The technique and a case report of femtosecond laser-assisted astigmatic keratotomy (FS AK) are reported in a patient with naturally occurring high astigmatism. The operation was performed using flap mode software to create two anterior arcuate side cuts in each eye using a femtosecond laser (IntraLase/AMO, Irvine, California; 30 kHz) in a 30-year-old female with a naturally occurring high astigmatism (with-the-rule) of 5.25 D in both eyes. In the right eye, the manifest refraction improved from −3.5+5.25×89 preoperatively, with an uncorrected visual acuity (UCVA) of counting fingers (CF) and a best spectacle-corrected visual acuity (BSCVA) of 20/25, to −1.75+2.75×90 postoperatively, with a UCVA of 20/50 and a BSCVA of 20/20. In the left eye, the manifest refraction improved from −3.5+5.25×83 preoperatively, with a UCVA of 20/200 and a BSCVA of 20/20, to −1.75+2.25×85 postoperatively, with a UCVA of 20/30 and a BSCVA of 20/20.

Optical coherence tomography measurements of choroidal thickness in healthy eyes: Correlation with age and axial length

BACKGROUND AND OBJECTIVE To evaluate subfoveal choroidal thickness (CT) in healthy eyes using spectral-domain optical coherence tomography (SD-OCT) and provide correlations between age and axial length. PATIENTS AND METHODS Enhanced depth SD-OCT imaging was performed with Cirrus (Carl Zeiss Meditec, Dublin, CA) and Spectralis (Heidelberg Engineering, Heidelberg, Germany) instruments. CT was measured from the outer limit of the retinal pigment epithelium to the inner surface of the sclera. RESULTS The study enrolled 155 patients, with at least 20 in each decade between 22 and 89 years old. Mean axial length was 23.6 mm. Mean Heidelberg subfoveal CT was 286 µm. The correlation between Heidelberg and Zeiss subfoveal CT measurements was strong (r = .978) and significant (P < .001). Mean subfoveal CT was 7.7 µm thinner by Heidelberg versus Cirrus (P < .001). Multiple linear regression analysis revealed that age (P < .001), axial length (P = .001), and sex (P = .025) were significantly related to Heidelberg subfoveal CT. CONCLUSION There is a strong negative correlation between CT and age (P <.001), with a 25 µm decrease in CT for each decade of life. Increasing axial length demonstrated a negative correlation with CT, decreasing 24.9 µm for each mm of axial length. Future studies of CT measurements can be performed on either instrument and must account for axial length, age, and sex to make appropriate conclusions.

Association Between Subfoveal Choroidal Thickness, Reticular Pseudodrusen, and Geographic Atrophy in Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE To compare subfoveal choroidal thickness (CT) measurements in eyes with nonexudative age-related macular degeneration (AMD) in the presence or absence of reticular pseudodrusen (RPD). PATIENTS AND METHODS Subfoveal CT measurements obtained from patients with AMD enrolled in the COMPLETE study (30 drusen-only eyes and 30 eyes with geographic atrophy [GA]) were compared with an age-distributed normal control group. Multimodal images were evaluated to detect the presence of RPD. RESULTS After controlling for age and axial length, the mean CT was significantly thinner in the GA group with RPD (213.7 ± 53.1 µm) than in the GA group without RPD (335.3 ± 123.2 µm; P = .001). The mean CT in the GA group without RPD was not statistically different from the mean CT in the normal control group (P = .076) or the drusen group without RPD (P = .45). In eyes without RPD, there was a correlation between the increasing size of GA and a decrease in CT measurements. CONCLUSION Subfoveal choroidal thinning in eyes with nonexudative AMD was associated with the presence of RPD. In the absence of RPD, CT only decreased as the size of GA increased.

Phototherapeutic keratectomy for the treatment of subepithelial fibrosis and anterior corneal scarring after descemet stripping automated endothelial keratoplasty.

Purpose: To describe the use of phototherapeutic keratectomy (PTK) and transepithelial photorefractive keratectomy (PRK) for the treatment of subepithelial fibrosis and anterior corneal scarring after Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: The settings included the Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, FL, and Carolina Cataract and Laser Center, Ladson, SC. Two patients with Fuchs endothelial dystrophy were noted to have anterior corneal opacities and corneal decompensation before DSAEK. Although both patients demonstrated improvement in corneal edema after DSAEK, they were left with residual anterior corneal opacities that were visually significant. The opacities were treated with excimer laser photoablation. Results: Both patients demonstrated an improvement in best-corrected visual acuity after elimination of the anterior corneal opacity using PTK or transepithelial PRK. Conclusions: Excimer laser ablation is an effective option for the treatment of residual subepithelial fibrosis and anterior corneal scarring after DSAEK. When appropriate, use of PTK or PRK can also eliminate residual refractive error.

Hybrid 25- and 27-Gauge Vitrectomy for Complex Vitreoretinal Surgery.

BACKGROUND AND OBJECTIVE The authors report the technique of using the 27-gauge (G) vitreous cutter through 25-G valved cannulas to allow hybrid instrumentation of both gauges. PATIENTS AND METHODS Vitrectomy is initiated with standard placement of 25-G valved cannulas, followed by insertion of a 27-G vitreous cutter through the 25-G cannulas. RESULTS The hybrid procedure emphasizes the advantages of both platforms: The 25-G cutter is more efficient for core vitrectomy and is more rigid to facilitate peripheral vitrectomy; the 25-G platform enjoys a wider armamentarium of instrumentation options; and the smaller profile of the 27-G cutter can be maneuvered more easily into tight surgical planes to act analogous to vertical scissors, with the added benefits of aspiration and spatula-like features. The authors illustrate this technique in three cases: diabetic tractional retinal detachment with dense plaques, posterior stage 4B retinopathy of prematurity, and sutureless scleral fixation of an intraocular lens. CONCLUSIONS Hybrid use of the 25-G and 27-G platforms offers greater versatility for the management of complex vitreoretinal conditions.

Spectral-Domain Optical Coherence Tomography Measurements of Choroidal Thickness and Outer Retinal Disruption in Macular Telangiectasia Type 2

BACKGROUND AND OBJECTIVE To evaluate subfoveal choroidal thickness (CT) and the extent of outer retinal disruption in patients with macular telangiectasia type 2 (MacTel2) compared with healthy eyes. PATIENTS AND METHODS In this prospective, observational, cohort study, 62 patients (62 eyes) with Mac-Tel2 and 130 healthy controls (130 eyes) underwent a complete ophthalmological examination, spectral-domain optical coherence tomography (SD-OCT) imaging, and axial length measurements. Patients in the study group also underwent color fundus photography, fundus autofluorescence, and fluorescein angiography. En face SD-OCT imaging was used to assess abnormalities involving the photoreceptor inner segment/outer segment/ellipsoid zone (IS/OS/EZ). RESULTS After adjusting for age and axial length, the authors found that eyes with MacTel2 had a mean CT measurement that was greater than control eyes (P = .007). There was a negative correlation between the visual acuity and the area of IS/OS/EZ damage (P = .009), but no statistically significant correlation was seen between CT and the area of IS/OS/EZ damage. CONCLUSION Eyes with MacTel2 were found to have thicker CT measurements than control eyes. While the extent of IS/OS/EZ disruption correlated with the loss of visual acuity, this damage did not correlate with CT measurements.

Short-term Efficacy of Intravitreal Dexamethasone Implant in Vitrectomized Eyes with Recalcitrant Diabetic Macular Edema and Prior Anti-VEGF Therapy

Purpose: To determine the efficacy of an intravitreal dexamethasone implant (IDI) for diabetic macular edema (DME) in vitrectomized eyes. Methods: This interventional retrospective consecutive case series included vitrectomized eyes undergoing IDI placement for treatment of recalcitrant DME between June 2011 and June 2014. All patients had previously received anti-VEGF therapy (ranibizumab or bevacizumab). Primary endpoints were changes in visual acuity (VA) and central retinal thickness (CRT) from baseline values one month after device implantation. Secondary endpoints were VA and CRT changes at 3 months. Results: A total of 8 eyes of 8 patients met the inclusion criteria. One month after IDI placement, there was a significant (p = 0.01) improvement in VA from 0.79 ± 0.52 logMAR (20/123 Snellen equivalent) to 0.64 ± 0.55 logMAR (20/88), meanwhile CRT improved from 455.75 ± 123.19 to 295.00 ± 90.39 μm (p = 0.02). These findings persisted at 3 months. Conclusion: In vitrectomized eyes previously treated with anti-VEGF agents for recalcitrant DME, implantation of the IDI appears to be efficacious in improving VA and CRT at 1-month with the observed benefits persisting for at least for 3 months.

Successful treatment of juvenile xanthogranuloma using bevacizumab

Juvenile xanthogranuloma (JXG) is an uncommon non-Langerhans cell histiocytic disorder that occurs predominantly in infants. Traditional treatment of ocular JXG involves the administration of topical or local corticosteroids. We treated 2 children with JXG refractory to local corticosteroid therapy with off-label intraocular bevacizumab. To our knowledge, this is the first report of successful use of bevacizumab for ocular JXG.

Association Between Oral Fluoroquinolones and Retinal Detachment

I N A RECENT ISSUE OF THE JOURNAL OF THE AMERICAN Medical Association (JAMA), Etminan and associates report in a case-control study that the use of oral fluoroquinolones is associated with a significantly higher risk of rhegmatogenous retinal detachment (RRD), with an adjusted rate ratio (ARR) of 4.5. Oral fluoroquinolones are one of the most commonly prescribed classes of antibiotics in the United States. The study has important potential ramifications, including: 1) increased patient referrals to retina specialists for evaluation of retinal complications of fluoroquinolone use; 2) decreased use of fluoroquinolones in patients otherwise at risk for retinal detachment; and 3) medicolegal risks for physicians and pharmaceutical companies. Given these dramatic potential implications, a critical appraisal of the clinical findings of this article is warranted. Fluoroquinolones provide broad-spectrum coverage for a number of infectious diseases, including sinus/respiratory tract infections and genitourinary tract infections. The mechanism of action of fluoroquinolones involves inhibition of deoxyribonucleic acid (DNA) gyrase and topoisomerase IV, which are essential enzymes in bacterial DNA replication. The fluoroquinolones are bactericidal agents since drug binding to the enzyme-DNA complex blocks progression of DNA polymerase, ultimately leading to bacterial DNA damage and cell death. Common nonocular adverse effects associated with fluoroquinolone use include gastrointestinal toxicity, typically manifesting as mild anorexia, nausea, vomiting, abdominal discomfort, or diarrhea; and central nervous system toxicity, presenting predominantly as mild headache, dizziness, insomnia, or mood alterations. Other adverse effects include tendinitis and tendon rupture, prolongation of the QT interval, hypoglycemia and hyperglycemia, elevated transaminases and liver

WIDEFIELD FLUORESCEIN ANGIOGRAPHY IN PATIENTS WITHOUT PERIPHERAL DISEASE: A Study of Normal Peripheral Findings.

Purpose: Widefield photography and angiography provide access up to 200-degrees of the retinal periphery. The range of normal peripheral findings has not been characterized, yet is relevant to studies addressing putative peripheral retinal vascular pathology. Methods: This study was an observational retrospective cohort study. Adult patients with epiretinal membrane or choroidal nevi who underwent imaging with Optos 200 MA/200Tx were included. Dye transit times, peripheral arteriovenous shunting, presence of vessels crossing the horizontal raphe, right angle vessels, terminal networks, absence of capillary detail, ground glass hyperfluorescence, peripheral drusen, and microaneurysms were evaluated. Results: Fifty-eight eyes of 31 patients met inclusion criteria. Mean peripheral arterial filling time was 8.65 ± 2.54 seconds (range 3–15 seconds). One or more peripheral anomalies were noted in all patients (P < 0.01). The prevalences of findings were: arteriovenous shunting (0.00%), vessels crossing the horizontal raphe (44.83%), right angle vessels (70.69%), terminal networks (77.59%), absence of capillary detail (98.28%), ground glass hyperfluorescence (87.93%), drusen (34.48%), and microaneurysms (41.38%). Conclusion: There was a high prevalence of peripheral vascular anatomic variations in eyes expected to have normal peripheral retinal vasculature. These findings may provide a reference for future studies addressing putative pathologic peripheral angiographic findings.