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Shady T Awwad

Publications and source records attributed to Shady T Awwad.

At least 19 recordsLinked to original sources
PubMed2007

Updates in Acanthamoeba keratitis.

PURPOSE: Acanthamoeba keratitis is a potentially blinding microbial disease that has been increasing in incidence during the past two decades. Prognosis of this serious disease had been dismal, but improvement in diagnosis, a better understanding of the natural course of the disease, and recent introduction of multiple and effective therapeutic agents have resulted in improvement of visual outcomes. METHODS: A review of literature pertaining to Acanthamoeba keratitis. RESULTS: Contact lens wear and exposure to contaminated water sources remain the most important risk factors; however, in vivo confocal microscopy and improved biomicroscopic screening have proven instrumental in accurate early diagnosis. Complications of Acanthamoeba keratitis include dacryoadenitis, corneal melting and scarring, severe secondary glaucoma, cataract, and chronic anterior segment inflammation that can rarely lead to reactive blinding retinal ischemia. Combination chemotherapeutic agents have been shown to be more effective than monotherapy, whereas rehabilitative surgery such as penetrating keratoplasty is best performed on a quiet eye free of ocular inflammation and with no residual amoebae. CONCLUSIONS: Increased suspicion by clinicians for Acanthamoeba and confocal microscopy have allowed more rapid and accurate diagnosis; treatment with multiple antiamoeba drugs is essential to disease resolution. Provided there are no residual amoebae after treatment, penetrating keratoplasty has been successful in visual rehabilitation. Secondary glaucoma occurs frequently and may require drainage procedures for control of intraocular pressure. Posterior complications are rare but may lead to ischemic retinitis.

Acanthamoeba↗
PubMed2006

Severe reactive ischemic posterior segment inflammation in acanthamoeba keratitis: a new potentially blinding syndrome.

OBJECTIVE: To describe a newly recognized clinical syndrome in Acanthamoeba keratitis consisting of severe reactive ischemic posterior segment vascular inflammation. DESIGN: Noncomparative, retrospective, single-institution observational case series. PARTICIPANTS: Five eyes of 5 patients with Acanthamoeba keratitis. METHODS: A retrospective review of the records of patients diagnosed with Acanthamoeba keratitis between January 1, 1995, and December 1, 2005, was conducted to identify those who underwent eventual enucleation. Five enucleated eyes of 118 eyes with Acanthamoeba keratitis were identified. MAIN OUTCOME MEASURES: History, clinical examination results, available laboratory study results, and histopathologic examination results. RESULTS: Histopathologic examination showed Acanthamoeba cysts in the cornea in 4 eyes, whereas it failed to demonstrate amebic cysts or trophozoites in the posterior segment of all eyes studied and unexpectedly revealed chronic chorioretinal inflammation with perivascular lymphocytic infiltration and diffuse neuroretinal ischemia in 4 of 5 eyes. Retinal artery thrombosis was present in 3 of the 4 involved eyes, and central retinal artery and vein thrombosis was found in 1 eye. Hematologic studies in 3 patients showed abnormal anticardiolipin antibody levels in 1 patient and factor V Leiden deficiency in another. CONCLUSIONS: Prolonged Acanthamoeba keratitis can result in a severe sterile ischemic posterior segment inflammation that is potentially blinding, especially in patients with underlying hypercoagulation disorders.

Acanthamoeba Keratitis↗
PubMed2006

Ocular surface restoration using non-surgical transplantation of tissue-cultured human amniotic epithelial cells.

PURPOSE: To assess the effect of tissue-cultured human amniotic epithelial cells (AECs) in restoring the ocular surface, transplanted using a collagen shield seeded with AECs supported by a soft contact lens. DESIGN: Prospective interventional single-institutional case series with crossover controls. METHODS: Three eyes in three patients were identified with persistent corneal epithelial defects (PEDs) refractory to medical therapy. Two cases were secondary to neurotrophic keratopathy, while one case was attributable to longstanding alkali injury. AECs were isolated from serologically screened donor human placenta, seeded onto collagen corneal shields, and incubated in tissue culture medium for 7 days. These collagen shields were placed over the PED and supported by an overlying soft contact lens. The collagen shields dissolved by 72 hours, and the contact lenses were removed after this time. This cycle was repeated every week until healing was achieved. As a crossover control, collagen shields without AECs were placed in the same eye 1 week before placing collagen shields containing AECs. The PED was assessed by vital staining and slit-lamp color photography. RESULTS: The PEDs had a mean duration of 4 months and involved 20% to 37% of the corneal surface area, one case secondary to longstanding alkali injury and two cases attributable to neurotrophic keratopathy. No change in PED size was observed in those control eyes receiving collagen shields without AECs. Complete resolution of the PED was seen after two cycles of AEC-seeded collagen shield in one case, and four cycles in two cases, from 7 to 12 weeks following treatment in all patients. No loss of visual acuity was seen and clinical improvement was maintained in all cases, with a mean follow-up of 6.3 months. CONCLUSIONS: Nonsurgical transplantation of tissue-cultured AECs on a collagen shield provides a promising approach to restoring the ocular surface in cases of PED.

Adult↗
PubMed2006

Comparative higher-order aberration measurement of the LADARWave and Visx WaveScan aberrometers at varying pupil sizes and after pharmacologic dilation and cycloplegia.

PURPOSE: To compare higher-order aberration (HOA) measurements of LADARWave and Visx WaveScan aberrometers, to test the validity of the peripheral wavefront data, and to evaluate the effect of pharmacologic dilation and mild cycloplegia. METHODS: Thirty-three myopic eyes of 17 volunteers were enrolled and had the ocular HOAs measured and analyzed with varying pupil diameters (PD) controlled by a tunable light intensity source and after instillation of tropicamide 1% and phenylephrine 2.5%. RESULTS: Higher-order aberrations increased with PD and optical zone (OZ), especially an OZ between 6.0 mm and 6.5 mm. Spherical aberration increased the most, followed by coma, then trefoil and secondary astigmatism. Measurement differences were observed between LADARWave and WaveScan at an OZ of 6.0 mm, although measurement correlations between the 2 machines were high. In the case of the WaveScan, when PD = OZ (6.0 mm), the spherical aberration and, to a less extent, the coma data differed from those obtained with larger PDs and the same OZ. In the case of the LADARWave, at an OZ of 6.0 mm, the HOAs measured in eyes with physiologic pupils were similar to those in pharmacologically dilated pupils when the physiologic pupil center was taken as the reference. CONCLUSIONS: There were detectable measurement differences between LADARWave and Visx WaveScan. Ensuring that the PD is at least 0.5 mm larger than the desired OZ is very important. Dilation and mild cycloplegia did not clinically affect the wave measurement magnitude or pattern.

Adult↗
PubMed2006

Tandem scanning confocal corneal microscopy in the diagnosis of suspected acanthamoeba keratitis.

OBJECTIVE: To evaluate the role of in vivo corneal tandem scanning confocal microscopy (TSCM) in the definitive diagnosis of suspected Acanthamoeba keratitis (AK). DESIGN: Noncomparative interventional single-institution case series. METHOD: A retrospective case review of patients consecutively referred with suspected AK and undergoing corneal TSCM was performed. RESULTS: A total of 63 cases that met the inclusion criteria for the study were referred for diagnostic evaluation. Tandem scanning confocal microscopy demonstrated Acanthamoeba cysts/trophozoites in 54 cases and fungal hyphae in 2, whereas 1 case was positive for both Acanthamoeba and fungus. Culture of the cornea or contact lenses was carried out in 35 cases, 9 of which were positive for Acanthamoeba. Six of the TSCM-positive cases also underwent corneal biopsy, being positive for Acanthamoeba in only 2. Six patients were negative for Acanthamoeba on TSCM, the etiology being fungal in 1 case, as shown by subsequent culture. One patient was positive on culture for Acanthamoeba but falsely negative by TSCM, which was limited by poor cooperation during the examination. Two cases initially masqueraded as Acanthamoeba keratitis but showed fungus on TSCM. Mean follow-up was 14 months. CONCLUSION: In vivo corneal TSCM can establish the diagnosis of Acanthamoeba keratitis rapidly and noninvasively, particularly when conventional microbiology is inconclusive.

Acanthamoeba Keratitis↗
PubMed2006

Assessment of the corneal endothelium in acute ultraviolet keratitis.

BACKGROUND: The purpose of this prospective case-control study was to investigate whether exposure to ultraviolet (UV) light produces detectable damage to the corneal endothelium in patients presenting with acute UV keratitis. MATERIAL/METHODS: Non-contact specular microscopy was performed on 20 consecutive patients who presented to our clinic from July 2000 to July 2002 with acute UV keratitis and similarly on 20 age-matched healthy controls. Both the coefficient of variation in mean cell size (CV) and the mean cell density (CD) were compared in these two groups using the Student t-test. RESULTS: Mean age was 28.6 years in the study group and 28.4 years in the control group. The mean CD in the patient group was 2609.6 (SD = 103.47) and in the control group 2632.87 (SD = 117.05). No statistically significant difference was found between the mean CDs in these two groups (p = 0.93). The mean CV in the patient group was 46.7 (SD = 4.40) and in the control group 45.4 (SD = 5.60). Similarly, there was no statistically significant difference between the mean CVs in these two groups (p = 0.85). CONCLUSIONS: UV light exposure does not seem to have a direct immediate effect on the corneal endothelium in humans with acute UV keratitis. Whether UV light produces cumulative and/or longer-term damage requires further studies with a larger number of patients and a longer follow-up time.

Acute Disease↗
PubMed2005

Results of penetrating keratoplasty for visual rehabilitation after Acanthamoeba keratitis.

PURPOSE: To assess the results of penetrating keratoplasty in quiet eyes after resolution of Acanthamoeba keratitis. DESIGN: A retrospective interventional case series. METHODS: Penetrating keratoplasty was undertaken in 13 eyes of 13 patients with an average age of 29 +/- 13 years and a history of Acanthamoeba keratitis that was diagnosed by culture and/or confocal microscopy between January 1995 and September 2004. All eyes were observed for at least 3 months (average, 5 months) after the discontinuation of antiamebic therapy that had been administered for at least 4.5 months. In vivo confocal microscopy was used to ensure that no residual amoeba were present before the operation. Two keratoplasties were combined with a valve insertion; five keratoplasties were combined with cataract extraction, and one keratoplasty was preceded by a ciliary laser ablation. RESULTS: Postoperative best-corrected visual acuity ranged from 20/40 to 20/15, with the exception of one eye with advanced glaucoma that did not improve from a preoperative vision of light perception. No eye experienced rejection or amoebic recurrences, and 12 grafts remained clear throughout the follow-up period (8 months to 9 years; median, 23 months). One graft failed at 4 months because of uncontrolled glaucoma. The eye was regrafted, and the graft remained clear during the 28 months of follow-up evaluation. Two eyes with preoperatively diagnosed glaucoma needed subsequent surgery to control their intraocular pressure. CONCLUSION: Penetrating keratoplasty for visual restoration after Acanthamoeba keratitis appears to have an excellent long-term prognosis, provided amoebic infection has resolved and concurrent glaucoma is controlled.

Acanthamoeba↗
PubMed2005

Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy.

PURPOSE: To assess the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in eyes with previous radial keratotomy (RK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Thirty-eight eyes of 25 patients were treated with LASIK for secondary hyperopia after RK using a Visx Star S2, S3, S4, or LADARVision excimer laser. Retreatment was done in 7 eyes. The main outcome measures were manifest refraction spherical equivalent (MRSE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), predictability of treatment, and complications. RESULTS: Preoperative mean MRSE was +2.39 diopters (D) +/- 1.28 (SD) (range +0.87 to +6.00 D). At the last visit (25 eyes with minimum follow-up of 12 months, including retreatments), the mean follow-up was 23.3 +/- 7.3 months (range 12 to 34 months), the mean MRSE was +0.11 +/- 0.71 D, and the UCVA was 20/40 or better in 24 eyes (96%). Although no significant change in the mean MRSE was observed, the postoperative mean refractive cylinder showed a gradual increase over the follow-up period. No eye lost more than 2 lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis was a safe and effective treatment with good predictability for the correction of consecutive hyperopia after RK. Cylindrical errors were difficult to correct, and astigmatic correction tended to regress over time. Retreatments are safe when old flaps were relifted.

Adult↗
PubMed2005

Mucous membrane graft versus Gunderson conjunctival flap for fitting a scleral shell over a sensitive cornea.

PURPOSE: To assess the efficacy of full-thickness mucous membrane grafts in forming a total and permanent corneal cover. METHODS: The records of all patients with a phthisical globe or microphthalmos who underwent a corneal covering procedure to allow comfortable wearing of a cosmetic scleral shell between March 1999 and July 2004 were reviewed. RESULTS: Ten eyes underwent a Gunderson conjunctival flap (group A), and 9 eyes underwent a full-thickness mucous membrane graft (group B). In group A, 3 eyes had total flap retraction and one eye had partial flap retraction. In group B, only one eye had partial graft retraction. The flap retraction in group A occurred in those eyes with a corneal diameter of 9 mm or more. CONCLUSIONS: The results from this small series of patients indicate that a full-thickness mucous membrane graft might be a better alternative for corneal coverage than a Gunderson conjunctival flap, especially in eyes with conjunctival scarring or relatively large corneal diameter.

Adult↗
PubMed2004

Corneal intrastromal gatifloxacin crystal deposits after penetrating keratoplasty.

BACKGROUND: An 85-year-old man developed faint crystallike white precipitates in the mid peripheral stroma of his left cornea 3 weeks after undergoing penetrating keratoplasty. The patient had been initially treated with 1% prednisolone acetate ophthalmic suspension and 0.3% gatifloxacin eyedrops to his left eye from the first day postoperatively. Three weeks later, the precipitates were more numerous, larger, and diffuse in distribution. Gatifloxacin was discontinued and substituted with a neomycin-polymixin B-dexamethasone ophthalmic ointment. METHODS: A detailed history, physical examination, laboratory workup, and tandem scanning confocal microscopy were performed. RESULTS: Tandem scanning corneal confocal microscopy confirmed the presence of crystals in the cornea. CONCLUSIONS: Gatifloxacin, a fourth-generation fluoroquinolone, can cause intrastromal macroscopic crystalline deposits through a compromised corneal epithelium, similar to what has been described for ciprofloxacin, a second-generation fluoroquinolone.

Aged↗
PubMed2004

Upper eyelid retraction after glaucoma filtering surgery and topical application of mitomycin C.

PURPOSE: To describe 3 cases of upper eyelid retraction after glaucoma filtering surgery and topical application of mitomycin C and to highlight possible causes. METHODS: A report of 3 patients, identified over an 8-year interval period, who had development of upper eyelid retraction a few months after undergoing trabeculectomy with mitomycin C in the ipsilateral eye. RESULTS: Testing for Graves disease, including second-generation thyrotropin receptor antibodies (TRAb), was negative in all cases. A complete physical examination was performed by an internist: Orbital and intracranial neuroimaging studies were ordered when necessary, and all were negative. One patient underwent surgical repair of the eyelid retraction and had a satisfactory result. CONCLUSIONS: Upper eyelid retraction after filtering surgery is a rarely reported entity. Müller muscle overaction, independent of Graves disease, is a likely cause and has been pointed out as a possible factor in one previous report. Müller muscle fibrosis, euthyroid Graves disease, and mechanical hindrance to an elevated bleb are other possible factors.

Administration, Topical↗
PubMed2002

Vector summation of anterior and posterior corneal topographical astigmatism.

PURPOSE: To determine whether vector addition of posterior corneal astigmatism improves the correlation between topographical and refractive astigmatism. SETTING: Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, Massachusetts, USA. METHODS: Orbscan topographical maps of 40 eyes (31 patients) showing 1.0 to 6.0 diopters (D) of astigmatism were analyzed. Topographical anterior and posterior corneal surface astigmatism was determined. Refractive astigmatism was compared to topographical astigmatism using 3 methods: anterior topographical astigmatism, overall topographical astigmatism obtained by vector summation of anterior and posterior topographical astigmatism, and simulated keratometry (SimK). RESULTS: Refractive astigmatism ranged from 0.25 to 5.00 D. The mean error in magnitude between topographical and refractive astigmatism was significantly smaller with the overall topographical method (1.06 D +/- 0.92 [SD]) than the anterior topographical method (1.37 +/- 1.04 D) (P <.0001). The mean error in axis between topographical and refractive astigmatism was smaller with the overall topographical method (10.4 +/- 13 degrees) than with the anterior topographical method (15.5 +/- 30.6 degrees) and with SimK (13.3 +/- 15.1 degrees), but these differences were not statistically significant. CONCLUSION: Consideration of the Orbscan measurement of posterior corneal surface toricity may improve the prediction of the magnitude of refractive astigmatism.

Astigmatism↗
PubMed2002

Mitomycin C as adjunct therapy in correcting punctal stenosis.

PURPOSE: To assess the efficacy of intraoperative mitomycin C in improving the success rate of the posterior punctectomy procedure. METHODS: The charts of all patients who underwent posterior punctectomy between the years 1997 and 2000 were reviewed. The procedure was done without mitomycin C (n = 26 eyes, group A) until the end of 1998 and with mitomycin C (n = 25 eyes, group B) starting in 1999. The Kaplan-Meier curve was used for statistical evaluation. RESULTS: In group A, 5 of 26 (19.2%) eyes had complete anatomic obstruction and scarring of their puncta after surgery, compared with 0 of 25 (0.0%) eyes in group B. The difference was statistically significant (P<0.02). No significant complications were observed. CONCLUSIONS: Mitomycin C appears to be a safe and effective adjunct therapy in correcting punctal stenosis.

Adult↗