Magdi Mansour

Predicting sulcus size using ocular measurements

Purpose: To predict sulcus size using ocular measurements. Setting: Michel Pop Clinics, Montreal, Quebec, Canada. Methods: Forty‐three eyes were evaluated using several techniques. Ultrasound biomicroscopy (UBM) echograms were taken to measure the anterior chamber depth (ACD), sulcus size, and central corneal thickness. The limbus size was measured with a caliper. Axial length, ACD, and pachymetry were measured by contact ultrasonography. Refraction and corneal power were also evaluated. Results: The coefficient of linear regression was 0.05 between the limbus and the sulcus size (P = .78), 0.76 between ultrasonography and UBM ACD measurements (P < .001), and 0.69 between ultrasonography and UBM pachymetry (P < .001). Paired t tests showed that ultrasound and UBM ACD measurements were not statistically different (P = .70) but that ultrasound and UBM pachymetry measurements were (P < .001). The sulcus versus limbus difference was 0.6 mm for myopia and 0.3 mm for hyperopia. A backward elimination multiple regression performed with all measures to predict sulcus size resulted in the following formula: Sulcus size = 18.9 − 0.023 × sphere + 0.15 × mean keratometry (R = 0.49; P = .005; statistical power = 0.89; standard error of estimate = 0.5 mm). Conclusion: Traditional estimation of sulcus size through limbal measurement is inadequate because limbus size alone cannot predict sulcus size. A general formula using the sphere and the mean corneal power can help predict sulcus size. Corneal power was significantly and negatively correlated with sulcus and limbus size as well as sphere. The standard error of sulcus measurement by UBM was 0.4 mm.

Ultrasound biomicroscopy of sclerotomy sites: the effect of vitreous shaving around sclerotomy sites during pars plana vitrectomy.

Purpose To study the difference in the amount of vitreous incarceration between conventional pars plana vitrectomy (PPV) and PPV with vitreous shaving around sclerotomy sites. Methods A dynamic in vivo examination using ultrasound biomicroscopy (UBM) was performed on the sclerotomy sites of 22 eyes after PPV. Patients were divided into two groups. In the study group (n = 11), the vitreous was completely shaved from the internal initial sclerotomy by cotton-tip depressed vitrectomy under coaxial illumination. In the control group (n = 11), no vitreous shaving was performed. Results Vitreous incarceration into sclerotomy sites was significantly less in the study group compared with the control group (P <0.001). No difference was seen among the three sclerotomy sites regarding vitreous incarceration within individual eyes. No difference was seen between eyes operated by right- and left-handed surgeons. Conclusions Vitreous shaving of sclerotomy sites using depressed vitrectomy significantly reduces vitreous incarceration. This may reduce the rate of sclerotomy-related complications following PPV in selected cases.

Ultrasound biomicroscopy of the Artisan phakic intraocular lens in hyperopic eyes

Purpose: To study in situ the intraocular position of the Artisan iris‐claw intraocular lens (IOL) (model 203) (Ophtec) in phakic hyperopic eyes using ultrasound biomicroscopy (UBM). Methods: Echograms of the anterior chamber were taken preoperatively and 24 to 317 days postoperatively in 4 eyes implanted with the Artisan IOL (power +4.0 to +6.0 diopters). The preoperative anterior chamber depth (ACD) and the postoperative distance between the IOL and the corneal endothelium (endothelium−optic distance) and between the IOL and the lens were measured. The echograms were assessed for the effect of the IOL on iris tissue. Results: The preoperative ACD ranged from 3.10 to 3.56 mm and the postoperative endothelium−optic distance, from 2.03 to 2.54 mm. The distance between the lens and the posterior surface of the IOL ranged from 0.35 to 0.79 mm. Several UBM echograms showed indentation of iris tissue by the IOL haptics and optic edge, although no pigmentary dispersion was noted. Conclusions: Adequate space was maintained between the Artisan hyperopic IOL and the corneal endothelium, angle, and crystalline lens. Haptic indentation of the iris, which could lead to pigment erosion, was observed. Preoperative gonioscopy and maintenance of normal intraocular pressure postoperatively suggest the indentation was secondary to inadequate lens vaulting relative to the high natural arch of the iris in hyperopic eyes. Shortening the haptics or increasing the lens vault might resolve this problem.

Ultrasound biomicroscopy of pseudophakic eyes with chronic postoperative inflammation

Purpose: To evaluate the ultrasound biomicroscopy (UBM) findings in pseudophakic eyes with chronic noninfectious postoperative inflammation and discuss the use of the technique in these cases. Setting: Uveitis Service, Department of Ophthalmology, McGill University, Montréal, Québec, Canada. Methods: Fifty‐four eyes of 51 patients with chronic noninfectious postoperative inflammation were prospectively evaluated between January 1998 and September 2001. Patients with aphakia, a dislocated intraocular lens (IOL) in the posterior segment, and endophthalmitis were excluded. All patients had a UBM examination that comprised locating the IOL position, investigating the presence of lens remnants, and evaluating the anterior segment of the eye. Results: Ultrasound biomicroscopic examination revealed IOL misplacement in 37 eyes (68.5%). Of these, 23 (62.2%) had a sulcus‐implanted posterior chamber IOL (PC IOL), 9 (24.3%) an in‐the‐bag PC IOL, and 5 (13.5%) an anterior chamber IOL. Haptic misplacement was significantly higher with sulcus‐implanted PC IOLs than with in‐the‐bag PC IOLs (P<.01). Other UBM findings included edematous ciliary body processes and hypoechogenic and/or thickened ciliary bodies in 11 eyes (20.4%), peripheral anterior synechias in 8 eyes (14.8%), a significant number of lens remnants (graded as severe) in 6 eyes (11.1%), a thick cyclitic membrane in 3 eyes (5.6%), and an early cyclitic membrane in 2 eyes (3.7%). Conclusions: Irritation of ocular tissues by an IOL was the main cause of chronic postoperative noninfectious inflammation in pseudophakic eyes. Therefore, detecting the IOL position and its relationships to ocular tissues is very important in planning the treatment. Ultrasound biomicroscopy is a practical method that accurately provides this information.

Visualization of posterior lens capsule integrity by 20-MHz ultrasound probe in ocular trauma.

PURPOSE To evaluate the use of the 20-MHz ultrasound probe in facilitating visualization of the posterior lens capsule in ocular trauma. DESIGN Interventional case report. METHODS Serial examinations using 10-MHz, 20-MHz, and 50-MHz ultrasound technologies were performed on the anterior segment of the right eye of an 18-year-old man referred with a diagnosis of globe penetration and secondary traumatic cataract. RESULTS Cross-sectional echograms of the anterior segment using the 20-MHz ultrasound showed posterior lens capsule integrity. CONCLUSION When verifying the status of the posterior lens capsule in cases of ocular trauma, the 20-MHz ultrasound probe is a useful and novel approach.

Uveal effusion after cataract surgery : An Echographic study

PURPOSE To determine the incidence of uveal effusion after cataract surgery and to relate its presence to selected preoperative, intraoperative, and postoperative variables. DESIGN Prospective consecutive observational case series. PARTICIPANTS Two hundred seven eyes of 205 subjects undergoing cataract surgery. METHODS Several preoperative, intraoperative, and postoperative variables of potential significance in uveal effusion after cataract surgery were studied. On the first postoperative day and within 2 weeks after the surgery, subjects were examined clinically and echographically with B-scan for evidence of suprachoroidal (uveal) effusion. When effusion was present, follow-up examinations were performed until complete resolution was documented. MAIN OUTCOME MEASURES Echographic presence of uveal effusion in the postoperative period. RESULTS Uveal effusion was documented echographically in 12 patients (5.8%). Only one of these cases was clinically evident. All effusions were small and resolved with no intervention. The presence of postoperative hypotony related to wound leak (intraocular pressure <10 mmHg) was significantly correlated with uveal effusion after cataract surgery (P<0.0001). The combination of oral acetazolamide and topical pilocarpine gel given after the surgery also correlated with effusion (P<0.02). Intraoperative complications and prolonged phacoemulsification time were not shown to be risk factors for effusion. CONCLUSIONS Uveal effusion is rarely seen after modern, small-incision, closed-system cataract surgery. It is correlated with postoperative hypotony related to wound leak and with the administration of both oral acetazolamide and topical pilocarpine after surgery.

Intraoperative Sonographically Assisted Radioactive Iodine 125 Plaque Brachytherapy for Choroidal Melanoma Visual Acuity Outcome

The purpose of this study was to present a retrospective series of cases from a single Canadian academic center assessing visual acuity outcomes after intraoperative sonographically assisted iodine 125 (125I) plaque brachytherapy treatment.