Jaime Tejedor

Early retreatment of infantile esotropia: comparison of reoperation and botulinum toxin

AIM To compare the efficacy of reoperation and botulinum toxin injection in treating infantile esotropes early after unsatisfactory surgical alignment. METHODS 55 strabismic children who had been unsuccessfully operated for infantile esotropia were randomised to reoperation (28 patients) or botulinum toxin injection (27 patients). The motor outcomes (percentage of successful motor outcome and percentage change in deviation) were compared at 6 months, 1 year, and 3 years after retreatment, and the sensory outcomes (percentage with fusion ability and stereo perception) at the 3 year follow up visit. RESULTS The motor and sensory outcomes and the stability of motor results were similar in patients reoperated and treated with botulinum injection. At the 3 year visit 67.8% and 59.2% of children were, respectively, within 8 prism dioptres of orthotropia (p=0.72). The frequency of fusion ability was, respectively, 60.7% and 51.8% (p=0.71), and the frequency of stereo perception (⩽400 seconds of arc, Randot circles), 57.1% and 48.1% (p=0.70). The botulinum injection was more likely to be effective when carried out in the 6 months following initial surgery. CONCLUSIONS Botulinum injection is a rapid and less invasive alternative to reoperation in children who have been unsuccessfully treated with surgery to correct infantile esotropia.

Retreatment of children after surgery for acquired esotropia: reoperation versus botulinum injection.

AIMS Two viable options were compared, reoperation and botulinum toxin injection, in the management of children who need retreatment after surgery for acquired esotropia. METHODS 47 strabismic children previously operated to correct an acquired esotropia were randomised to reoperation or botulinum toxin injection. Reoperation was undertaken in 24 of these patients and botulinum toxin injection in 23 of them. The percentage net change in distance deviation, the percentage of patients with successful motor outcome, detectable fusion, and stereopsis were compared 1 year after retreatment and at last visit (average follow up: 2.9 years in reoperation group, and 2.7 years in botulinum group). The motor success rate relative to time elapsed from initial surgery was evaluated. RESULTS There was no significant difference in the motor and sensory outcomes between patients reoperated and treated with botulinum injection. The frequency of correction to within 8 prism dioptres of orthotropia was, respectively: 75% versus 69.56% at 1 year; 70.83% versus 60.86% at last visit. Botulinum injection could be more effective when performed within 3 months of initial surgery. CONCLUSIONS Botulinum injection is a rapid and safe procedure that may be as effective as reoperation in the management of children who need a secondary procedure after surgery for acquired esotropia.

Astigmatic Change Induced by 2.8-mm Corneal Incisions for Cataract Surgery

PURPOSE To study the induced refractive change caused by different 2.8-mm corneal incision locations in phacoemulsification. METHODS One hundred ten patients were randomly assigned to nasal or temporal incision or to superior incision, depending on preexisting astigmatism. The authors fulfilled visual acuity, refraction, keratometry, and eye scanner analysis before and after phacoemulsification. Outcome measures were induced corneal refractive change (Fourier power vector analysis), index of surface variance (ISV) change, and visual acuity at 6 months. A comparative interventional case series was used for the study design. RESULTS Induced refractive change caused by different incision locations showed differences in parameter J0 (JCC at axis 0 degrees ), which was smaller after temporal than after nasal or superior incision, with marginal clinical significance and influence in uncorrected visual acuity. ISV changes did not differ between incisional groups. CONCLUSIONS Small differential effects of incisions by location may be useful, depending on preexisting astigmatism. Temporal incisions are recommended for negligible astigmatism, whereas nasal and superior incisions are preferable when the steep axis is located at approximately 180 degrees and 90 degrees, respectively. (ClinicalTrials.gov number, NCT00742950).

Comparative Efficacy of Penalization Methods in Moderate to Mild Amblyopia

PURPOSE To compare the efficacy and sensory outcome of pharmacologic and optical penalization in the treatment of moderate to mild amblyopia. DESIGN Randomized clinical trial. METHODS In an institutional setting, two- to 10-year-old children with strabismic or anisometropic amblyopia (visual acuity in the amblyopic eye at least 20/60) who were cooperative to measure visual acuity using the logarithm of the minimum angle of resolution (logMAR) crowded Glasgow acuity cards were randomized into two groups of therapy (n=35 in each group), 1% atropine, and optical penalization with positive lenses, after stratification by cause of amblyopia. Visual acuity was tested by the logMAR crowded Glasgow acuity cards, after retinoscopic refraction, and deviation angle were measured by the simultaneous prism and cover or Krimsky test. Stereoacuity was determined using the Titmus fly test and Randot preschool or Randot circles stereoacuity test. Change in visual acuity of the amblyopic eye and in interocular difference of visual acuity after six months of amblyopia therapy was the main outcome measure; stereoacuity at six months of therapy was a secondary outcome measure. RESULTS Thirty-one and 32 children completed the outcome examination in the atropine and optical penalization group, respectively. Average improvement in visual acuity of the amblyopic eye was larger in the atropine than in the optical penalization group (3.4 and 1.8 logMAR lines, respectively), as well as average improvement in interocular difference of visual acuity (2.8 and 1.3 logMAR lines, respectively). Better stereoacuity, but nonsignificantly different, was detected in the atropine group. CONCLUSIONS Atropine penalization may be considered more effective than optical penalization with positive lenses.

Agreement between refractive and corneal astigmatism in pseudophakic eyes.

Purpose: To examine the agreement and relationship between refractive and corneal astigmatism in a population of pseudophakic eyes. Methods: Patients of age at least 40 years, visual acuity 20/40 or better, and no ocular disease were included (n = 111). Refractive astigmatism was obtained by subjective refraction. Corneal astigmatism was measured by automated keratometry and Scheimpflug scanning analysis. All refractive values were converted to power vector components J0 and J45 for comparison and regression analysis of refractive versus corneal astigmatism. Main outcome measures were refractive and corneal astigmatism components. Results: Median single Jackson cylinder (J) was similar in refractive [0.37 diopter (D)], keratometric (0.46 D), and Pentacam astigmatism (0.49 D) (P = 0.157). Median J0 astigmatic component was slightly negative, indicating against-the-rule (ATR) astigmatism, in refractive and Scheimpflug, but not in keratometric astigmatism (refractive J0: −0.10 D; keratometric J0: 0.05 D; Pentacam J0: −0.08 D) (P = 0.049). J45 astigmatic component was nearly zero and similar with the 3 methods (P = 0.416). Refractive and keratometric J0 were significantly correlated (r = 0.7, P < 0.01), as well as the corresponding J45 values (r = 0.65, P < 0.01). Refractive and Pentacam astigmatic components were worse correlated (J0: r = 0.36, P = 0.01; J45: r = 0.45, P < 0.01). Keratometric and Pentacam astigmatic components were also significantly correlated (J0: r = 0.58, P < 0.01; J45: r = 0.51, P < 0.01). Conclusions: Mean internal ATR astigmatism, which comes mainly from the posterior corneal surface, adds to anterior corneal astigmatism, resulting in ATR refractive astigmatism. Correlation between refractive and corneal astigmatism components is better when keratometric data are used.

RETRACTED: Surgery for Esotropia Under Topical Anesthesia

PURPOSE To compare a surgically adjusted dose of strabismus surgery using topical anesthesia in cooperative patients with dosage guidelines adapted to the surgeons personal technique using sub-Tenons anesthesia. DESIGN Randomized, controlled, single-site clinical trial. PARTICIPANTS Sixty patients with nonparalytic, nonrestrictive esotropia who were cooperative for surgery under topical anesthesia. METHODS Twenty-eight patients were assigned to topical anesthesia, and 32 patients were assigned to sub-Tenons anesthesia. Visual acuity, refraction, and deviation angle were determined in all patients preoperatively and postoperatively, and stereoacuity was measured postoperatively. Deviation angle was measured by simultaneous and alternate prism and cover test, and stereoacuity was measured using Randot circles (Stereo Optical Co., Chicago, IL). The amount of surgery under topical anesthesia was adjusted intraoperatively. MAIN OUTCOME MEASURES The amount of surgery used in the 2 treatment groups (measured in millimeters and millimeter/degree of deviation angle) and 6-month motor and stereoacuity outcomes. RESULTS Patients in the topical group required 3.2 mm less surgery on average than those in the sub-Tenons group (5.9 and 9.1 mm, respectively; 0.4 and 0.6 mm of recession/degree, respectively) (P<0.01). Motor success (84% and 75%, respectively, P=0.38) and stereoacuity (339.6 and 323.9 arc seconds, respectively, P=0.87) at 6 months were similar in the 2 groups. CONCLUSIONS Topical anesthesia requires a smaller amount of surgery and number of operated muscles to correct esotropia compared with classic surgery guidelines adapted to the surgeons personal technique.

Diagnosis and Imaging of Corneal Astigmatism

Accurate diagnosis and measurement of corneal astigmatism is of vital importance for treatment. Refractive and corneal astigmatic power and axis values are correlated but not coincidental. Corneal power and astigmatism amount measurements have a considerable degree of variability, which may be due to systematic error of the devices employed. Test to test variations may be falsely estimated as surgically induced refractive or astigmatic changes. Manual and automated keratometry instruments sometimes yield non-coincidental corneal power and axis readings, with differing reproducibility or repeatability. Even among modern automated keratometry, Placido-disk based videokeratoscopy and advanced slit-scanning or Scheimpflug technology scanning, diverging corneal measurements have been reported, which are attributable to different underlying methodology, reliability and repeatability. In this chapter, we will summarize the basic functioning principles of the main devices used for the evaluation of corneal power and astigmatism. We will also review published studies about variations in corneal power measurements using different equipment, in astigmatic power and axis calculated values, and correlation obtained among measurements taken with different instruments. Results reported by different authors will be compared with our own data where available.

Anesthesia for Small-Incision Cataract Surgery

Consideration of patient characteristics is vital for indication of anesthesia in manual small-incision cataract surgery. Local techniques, including topical, intracameral, and regional blocks (retrobulbar, peribulbar, and sub-Tenon’s block), are commonly used with advantages, disadvantages, and associated complications, which will be described. Topical anesthesia has gained popularity, and the benefit of additional intracameral anesthesia, although used by many surgeons, is controversial. Among regional block procedures, peribulbar anesthesia is frequently preferred, but retrobulbar block is more effective and the rate of complications is very low. Sedation in local anesthesia can be useful but should be used with caution. General anesthesia is rarely employed.

Prism under cover test in alternate fixation horizontal strabismus

ABSTRACT Purpose: To evaluate the applicability of the prism under cover test (PUCT) to quantify manifest deviation in horizontal strabismus with alternate fixation when simultaneous prism and cover test (SPCT) is not feasible. Methods: Children aged 4–11 years, with alternate fixation horizontal strabismus and alternate prism and cover test (APCT) distance deviation (DD) up to 25 PD were eligible. In group 1 of the study, SPCT was not feasible (n = 18), whereas in group 2, it was feasible (n = 24). Refraction, PUCT, APCT, central/peripheral fusion, and stereoacuity were measured. Repeatability of PUCT, agreement between PUCT and SPCT, and Pearson correlations between variables were studied. Results: In group 1, mean DD was 15.6 and 9.5 PD using APCT and PUCT, respectively (intraclass correlation, ICC: 0.90). Mean stereoacuity was 201.1 arc seconds. PUCT was better correlated with stereoacuity than APCT, but not significantly (p = 0.12). Coefficient of repeatability for PUCT was 3.4 PD. In group 2, mean DD was 17.6, 14.1, and 12.5 PD using APCT, PUCT, and SPCT, respectively. Mean stereoacuity was 285.9 arc seconds. Correlations APCT-PUCT (0.87), APCT-SPCT (0.82), and SPCT-PUCT (0.95) were significant. APCT did not show as good correlation with stereoacuity (0.58) as SPCT and PUCT (0.74 and 0.78, respectively). Concordance correlation coefficient between SPCT and PUCT was 0.91, and Bland Altman agreement between the two variables was also good. Conclusions: PUCT is a procedure with good repeatability, of interest in children to estimate manifest deviation when SPCT is not feasible, and in support of the diagnosis of monofixation syndrome.

Polynomial Curve Fitting of the Corneal Profile in 2.2-mm Corneal Incision Phacoemulsification

PURPOSE To model incisional axis and perpendicular corneal profile pattern changes in 2.2-mm corneal incision phacoemulsification. METHODS Sixty-seven eyes of 67 patients were included in this prospective, interventional, before-after paired design study. Power vector components were obtained from keratometry (IOLMaster; Carl Zeiss Meditec, Göttingen, Germany) and topography corneal height data with the Pentacam HR (Oculus Optikgeräte, Wetzlar, Germany) preoperatively and at 6 months postoperatively. Second- to sixth-order curve fitting polynomial functions of the corneal profile in the incisional and perpendicular axes were created using Matlab (The Mathworks, Inc., Natick, MA). Multivariate regression analysis was run to study the influence of potential predictors. Correlation of changes in corneal elevation and corneal radius with astigmatic parameters was also obtained. RESULTS Significant changes occurred only in the J(0) (P = .004) and M (P = .001) parameters. R(2) was high with all of the fitted polynomials (0.98 to 0.99) and although the smallest root mean square error was obtained with sixth-degree polynomials (0.63 to 1.13), they were more badly conditioned and redundant than quadratic polynomials. Corneal flattening changes were obtained on axis, which was the most frequent pattern (n = 52, 77%), but were significantly larger in the incisional side than the non-incisional side (P = .001) and only coupled with perpendicular axis steepening in 23 patients. In the non-incisional side on axis, corneal steepening was a relatively frequent pattern (n = 22 patients, 33%). Predictors studied for profile pattern of change were only near significance. Corneal radius of curvature changes were significantly correlated with astigmatic parameters. CONCLUSIONS Polynomial curve fitting is adequate for corneal biomechanical modeling of curvature and profile changes in the incisional and perpendicular axes of a 2.2-mm incision for phacoemulsification.