Comparison of the Effect of Different Types of Experimental Anisometropia on Stereopsis Measured with Titmus, Randot and TNO Stereotests.

PURPOSE: To assess the effect of experimental anisometropia and monovision on stereopsis using the Titmus, Randot, and TNO stereoacuity tests. METHODS: Sixty adult volunteers were enrolled in the present study. Four different types of anisometropia-myopia, hyperopia, and astigmatism (both 90° and 45°)-were induced by placing trial lenses over the dominant eye (from 3 to 1 D). Stereoacuity was measured using the Titmus, Randot, and TNO tests. RESULTS: In all the anisometropia types, stereopsis deteriorated with increase in anisometropia in the three stereoacuity tests performed (P < 0.001). The largest decrease in stereopsis was attributed to 3 D myopic anisometropia-6.51 ± 2.10, 6.59 ± 2.35, and 7.36 ± 1.89 arc seconds in Titmus circles, Randot circles, and TNO, respectively. Minimal change in stereopsis was observed in 1 D astigmatism of 45°. CONCLUSION: Any type of anisometropia may reduce stereoacuity; this reduction is most noticeable with myopic anisometropia, especially in the TNO test, probably due to the lack of monocular cues.

Effect of artificial anisometropia in dominant and nondominant eyes on stereoacuity.

OBJECTIVE: To evaluate the effect of artificial anisometropia in dominant and nondominant eyes on stereoacuity. METHODS: In this descriptive analytic study, 60 healthy adult volunteers 18-37 years of age (mean age: 25.58 years) without any ocular disease were enrolled at Tabriz Nikookari eye hospital over a 1-year period. Anisometropia (unilateral myopia) was induced by placing trial lenses over the dominant and nondominant eyes in 1-diopter (D) increments ranging from 1 to 3 D. Stereoacuity was measured using the TNO, Randot, and Titmus stereotests and values were converted into Napierian logarithm (ln) and compared between the 2 eyes. RESULTS: Of the 60 adults (25 male and 35 female subjects), the right eye was dominant in 49 (81.7%) of the cases. Stereoacuity levels were reduced proportionately to the degree of anisometropia in all participants. Mean stereoacuity was 4.3, 5.5, and 7.4 ln for dominant eyes and 4.1, 5.4, and 7.3 ln for nondominant eyes using the TNO test by applying 1, 2, and 3 D lenses, respectively (p > 0.05). Corresponding values were 3.5, 4.6, and 6.6 ln for dominant eyes and 3.4, 4.6, and 6.5 ln for nondominant eyes by the circles subcategory of Randot test, respectively (p > 0.05). The scores were 3.8, 4.7, and 6.5 ln for dominant eyes and 3.8, 4.7, and 6.4 ln for nondominant eyes by the circles subcategory of Titmus test, respectively (p > 0.05). CONCLUSION: Artificial anisometropia could reduce stereoacuity. However, ocular dominance has no effect on the amount of stereoacuity reduction.

Factors Affecting Improvement of Stereopsis Following Successful Surgical Correction of Childhood Strabismus in Adults.

PURPOSE: To evaluate the factors affecting improvement of stereopsis following successful surgical correction of childhood strabismus in adults. METHODS: In a prospective study, consecutive patients with childhood-onset, comitant, horizontal, constant strabismus; stereoacuity of more than 480 seconds of arc in TNO stereo test (absent stereopsis in TNO); and who had successful postoperative alignment (within 10 prism diopters [PD] of orthotropia) were enrolled. Postoperative stereopsis testing was performed using the TNO stereo test at 3 months after surgery. RESULTS: A total of 34 patients (20 exotropes and 14 esotropes) were included. The mean age at the time of surgery was 26.08±10.53 years (range, 14-53 years). Stereopsis was improved in 8 of 34 patients (23.5%). Postoperative alignment had influence on improvement of stereopsis; 38.1% of patients who had orthotropia gained stereopsis, whereas none of patients who had horizontal heterotropia (esotropia or exotropia) of 10 PD or less gained stereopsis (p=0.01). Misalignment of 10 years' duration or longer did not preclude the development of postoperative stereoacuity (p=0.31). There was a statistically insignificant increase in improvement of stereopsis in nonamblyopic group (30.4%) compared with amblyopic group (9.1%) (p=0.22). Also, there was a statistically insignificant increase in improvement of stereopsis in exotropes (35%) compared with esotropes (7.1%) (p=0.1). The angle of preoperative deviation had no influence on improvement of stereopsis (p=0.44). CONCLUSION: A postoperative correction of orthotropia was the only predictive factor for improvement of stereopsis in adults with childhood strabismus.

A comparison between monocanalicular and pushed monocanalicular silicone intubation in the treatment of congenital nasolacrimal duct obstruction.

AIM: To compare the success rate of monocanalicular versus pushed monocanalicular silicone intubation (PMCI) of the nasolacrimal duct for congenital nasolacrimal duct obstruction (CNLDO). METHODS: In a prospective randomized clinical trial 53 eyes of 49 patients with CNLDO underwent either monocanalicular silicone intubation (MCI) (n=28 eyes) or PMCI (n=25 eyes). All procedures were performed by 1 oculoplastic surgeon. Treatment success was defined as the complete resolution of epiphora at 3mo after tube removal. RESULTS: The surgical outcome was assessed in 20 eyes with MCI and 20 eyes with PMCI. The mean age of treatment was 26.25±10.08mo (range, 13-49mo) for MCI and 26.85±12.25mo (range, 16-68mo) for PMCI. Treatment success was achieved in 18 of 20 eyes (90.0%) in the MCI group compared with 10 of 20 eyes (50%) in the PMCI group (P=0.01). In the PMCI group, the tube loss (30%) was greater than the MCI group (5%), however the differences between the 2 groups proved to be not significant (P=0.91). CONCLUSION: Our results indicate that MCI has higher success rate in CNLDO treatment compared with PMCI in this small series of patients.

Silicone intubation for nasolacrimal duct stenosis in adults: monocanalicular or bicanalicular intubation.

PURPOSE: The purpose of this study was to compare the success rate of monocanalicular versus that of bicanalicular silicone intubations of the nasolacrimal duct for nasolacrimal duct stenosis (NLDS) in adults (patent nasolacrimal duct with resistance to positive-pressure irrigation). MATERIALS AND METHODS: In a prospective randomized clinical trial, 52 eyes of 38 patients with NLDS underwent either monocanalicular silicone intubation (MCI) (n = 26 eyes) or bicanalicular silicon intubation (BCI) (n = 26 eyes). All procedures were performed by 1 oculoplastic surgeon. Tube removal was planned for 3 months postoperatively. Treatment success was defined as the complete resolution of epiphora or intermittent epiphora with normal dye disappearance test at 6 months after tube removal. RESULTS: The surgical outcome was assessed in 25 eyes with MCI and 21 eyes with BCI. The mean (SD) age of treatment was 52.7 (18.6) years for MCI and 49 (18.8) years for BCI. Treatment success was achieved in 19 of 25 eyes (76%) in the MCI group compared with 16 of 21 eyes (76.2%) in the BCI group. Differences between the 2 groups proved to be not significant (P = 0.9). The only complication was peripunctal pyogenic granuloma in 2 eyes with BCI. CONCLUSIONS: Both MCI and BCI were successful in a similar percentage of patients with NLDS. The main advantages of the former technique were simple insertion and easy removal of the tube.

Macular and retinal nerve fiber layer thickness in unilateral anisometropic or strabismic amblyopia.

PURPOSE: To compare the macular and nerve fiber layer thicknesses as measured by optical coherence tomography (OCT) in amblyopic and fellow eyes. METHODS: Fifty patients with monocular strabismic (n = 25) or anisometropic (n = 25) amblyopia (best corrected visual acuity (BCVA) ranging from 20/40 to 20/400) were included in a prospective cross-sectional descriptive study. A refractive error more than 5 diopters in either eye or an axial length difference between the eyes of more than 1 mm was excluded in the anisometropic group. In all cases, the thickness of the macular area and the peripapillary nerve fiber layer were measured by OCT in both amblyopic and fellow eyes and compared with each other. RESULTS: The mean age of patients was 10 ± 3.1 years (range: 6 to 18 years) in the anisometropic group and 8.9 ± 3.7 years (range: 6 to 18 years) in the strabismic group. In the anisometropic group, the mean macular thickness was significantly increased in the amblyopic eyes (222.6 ± 47.8 µm) versus the fellow eyes (205.6 ± 33.3 µm) (P = .002), although there was no significant difference observed when comparing with the prepapillary nerve fiber layer (P = .55). There was no significant correlation of above-mentioned matters in the strabismic group (P = .07 and .52). CONCLUSION: A thicker macula was found in anisometropic amblyopic eyes, but the increase of macular thickness in strabismic amblyopic eyes was not significant. Retinal involvement was not observed in the peripapillary nerve fiber layer of amblyopic eyes.

Calcium dobesilate reduces endothelin-1 and high-sensitivity C-reactive protein serum levels in patients with diabetic retinopathy.

PURPOSE: To determine the benefits of calcium dobesilate (CaD) administration on endothelial function and inflammatory status in patients with diabetic retinopathy through measurement of serum levels of endothelin-1 and high-sensitivity C-reactive protein (hsCRP). METHODS: In a double-blind, randomized clinical trial, 90 patients with either severe nonproliferative or proliferative diabetic retinopathy and with blood glucose level of 120-200 mg/dl were randomly allocated to treatment with either CaD tablets (500 mg daily) or placebo for 3 months. Visual acuity, intraocular pressure, and macular status were performed before the study. The serum levels of endothelin-1 and hsCRP were evaluated in both groups before and at the third month of the trial. RESULTS: The median serum level of hsCRP significantly differed between the groups 3 months following the CaD or placebo administration (2.2 mg/l in the CaD group versus 3.7 mg/l in the placebo group, p=0.01). The mean endothelin-1 serum level was 0.69±0.32 pg/ml in the CaD group and 0.86±0.30 pg/ml in the placebo group (p=0.01). Furthermore, in the CaD group, the serum levels of both endothelin-1 and hsCRP were significantly decreased 3 months after administration of CaD (p<0.001). CONCLUSIONS: Administration of the CaD in the patients with diabetic retinopathy may reduce the serum levels of endothelin-1 and hsCRP. This might imply amelioration of the endothelial function and inflammatory status following CaD therapy in these patients.

Intraoperative prognostic factors for probing outcome in children with congenital nasolacrimal duct obstruction.

PURPOSE: To evaluate the intraoperative prognostic factors for probing outcome in children with congenital nasolacrimal duct obstruction (CNLDO). METHODS: In a prospective interventional study, 69 eyes of 60 children aged 12 to 24 months with CNLDO underwent probing and irrigation. All procedures were performed by a single oculoplastic surgeon. The nature of the obstruction was classified by the surgeon as simple or complex. The fluency of irrigation after probing was defined as easy or difficult. Treatment success was defined as no epiphora or mucus discharge at 3 months after probing. RESULTS: The mean age at the time of probing was 15.3±3.1 months (range, 12-23 months). Treatment success was achieved in 56 of 69 eyes (81.2%). There was a significant difference in success rate of probing in eyes with simple obstruction (87.8%) compared with complex obstruction (65%) (p=0.02). Also, there was a significant difference in success rate of probing in eyes with easy irrigation (100%) compared with difficult irrigation (53.6%) (p<0.001). CONCLUSIONS: Probing was more successful in eyes with simple obstruction or easy irrigation in children aged 12 to 24 months. The fluency of irrigation as an objective finding was a reliable intraoperative prognostic factor for probing success.

Anchored versus conventional hang-back bilateral lateral rectus muscle recession for exotropia.

PURPOSE: To compare the results of conventional hang-back and anchored hang-back technique for bilateral lateral rectus muscle recessions in patients with exotropia. METHODS: In a prospective, randomized clinical study, 60 patients underwent lateral rectus muscle recession by either conventional hang-back or anchored hang-back technique. Patients were then followed for 6 months; postoperative deviation and complications were compared. Surgery was considered successful if the postoperative deviation was within 10(Δ) of orthophoria. RESULTS: The mean age of patients was 14.2 ± 10.3 years (median, 12 years) in the conventional hang-back group and 11.5 ± 9.3 years (median, 8 years) in anchored group (P = 0.85). The mean preoperative deviation at distance and near between the 2 groups was not statistically significant. The mean postoperative deviation was 8(Δ) ± 9(Δ) at distance and 7(Δ) ± 9(Δ) at near in the conventional group and 9(Δ) ± 8(Δ) at distance and 8(Δ) ± 8(Δ) at near in the anchored group. (P = 0.48 for distance, P = 0.98 for near). After 6 months, 63% of the conventional group and 60% of the anchored group were within 10(Δ) of orthophoria. Complications such as globe perforation, A and V patterns, and vertical deviations did not occur in either group. There were no statistically significant differences in the success rates (P = 0.79) or complications between the 2 groups. CONCLUSIONS: The placement of additional posterior scleral sutures to "anchor" the insertion did not improve outcomes in lateral rectus muscle recession surgery.

Monocanalicular versus bicanalicular silicone intubation for congenital nasolacrimal duct obstruction.

PURPOSE: To compare the success rate of monocanalicular versus bicanalicular silicone intubation of the nasolacrimal duct for congenital nasolacrimal duct obstruction (CNLDO). METHODS: In a prospective randomized clinical trial, 70 eyes of 57 children with CNLDO underwent either monocanalicular silicone intubation (MCI) (n = 35 eyes) or bicanalicular silicone intubation (BCI) (n = 35 eyes). All procedures were performed by 1 oculoplastic surgeon. Tube removal was planned for 3 months postoperatively. The results were assessed using a Munk score. Treatment success was defined as Munk score 0-1 at 3 months after tube removal. RESULTS: The surgical outcome was assessed in 29 eyes with MCI and 27 eyes with BCI. The mean age of treatment was 34.9 ± 12.7 months for MCI and 38.7 ± 18.6 months for BCI. Treatment success was achieved in 25 of 29 eyes (86.2%; 95% CI, 79%-96%) in the MCI group compared with 24 of 27 eyes (89%; 95% CI, 84%-94%) in the BCI group (RR = 0.96; 95% CI, 0.79-1.18). There were no corneal or canalicular complications in either group. CONCLUSIONS: MCI and BCI were successful in a similar percentage of children with CNLDO. The mainadvantage of the former technique was easy tube removal without sedation in the office.

Lateral rectus muscle disinsertion and reattachment to the lateral orbital wall in exotropic Duane syndrome: a case report.

INTRODUCTION: The surgical correction of anomalous movement such as upshoot in Duane syndrome is challenging. Lateral rectus muscle disinsertion and reattachment to the lateral orbital wall is a new approach used to minimize or eliminate the effects of co-contraction including globe retraction, palpebral fissure narrowing and anomalous vertical movement. CASE PRESENTATION: We report a case of a 7-year-old boy who underwent this procedure for severe upshoot, globe retraction and exotropia in the left eye due to Duane syndrome. The patient achieved satisfactory ocular alignment following surgery. Upshoot and globe retraction were substantially improved. CONCLUSION: Lateral rectus muscle disinsertion and reattachment to the lateral orbital wall is a safe and effective procedure for weakening of the anomalous lateral rectus muscle in Exotropic Duane Syndrome.