Dominant Optic Atrophy Caused by the c.1334G>A Mutation of the OPA1 Gene

Purpose@#Dominant optic atrophy is one of the most common hereditary optic neuropathies, causing progressive bilateral vision loss that begins early in life. Optic atrophy 1 (OPA1) gene mutation brings about mitochondrial dysfunction, which results in clinical manifestations of dominant optic atrophy. Here, we report a case of dominant optic atrophy caused by the c.1334G>A mutation of the OPA1 gene, the first known case in Korea to our knowledge.Case summary: A 12-year-old female patient with no specific medical history or systemic symptoms visited our clinic complaining of a progressive decrease in vision in either eye. Slit-lamp microscopy, intraocular pressure, ocular motility, and pupil reflex were normal. However, her best-corrected visual acuity in both eyes was 20/100, and her color vision was reduced to 8/12 in Ishihara’s test. Fundus examination showed temporal pallor of the optic nerve head in both eyes, and a corresponding cecocentral scotoma was observed on Goldmann visual field examination. Optical coherence tomography revealed significant thinning of the peripapillary retinal fiber layer and macular ganglion cell layer in both eyes. Genetic examination confirmed the c.1334G>A mutation of the OPA1 gene. @*Conclusions@#We report a case of dominant optic nerve atrophy caused by c.1334G>A mutation of the OPA1 gene and its clinical manifestations.

Retinal Microvascular Abnormalities in Patients with Type I Neurofibromatosis

Purpose@#To evaluate the findings and frequencies of retinal microvascular abnormalities observed in patients with type 1 neurofibromatosis. @*Methods@#Fundus photographs of 61 patients with type 1 neurofibromatosis and 61 controls without systemic disease or ophthalmic abnormalities were retrospectively compared and analyzed. The presence or absence of retinal microvascular abnormalities in the form of simple vascular tortuosity, corkscrew retinal vessels, and moyamoya-like patterns was confirmed, and the diagnostic sensitivity, diagnostic specificity, positive predictive value, negative predictive value, and diagnostic accuracy for type 1 neurofibromatosis were analyzed. @*Results@#Retinal microvascular abnormalities were found in 19.7% (12 patients) of the patient group, There was no cases in the control group, thus. The difference between the patient group and the control group was significant (p = 0.0003). Of the 12 patients with abnormalities, 10 exhibited simple vascular tortuosity, one had corkscrew retinal vessels, and one exhibited both findings. The diagnostic sensitivity of retinal microvascular abnormalities for type 1 neurofibromatosis was 23.53%, the diagnostic specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 61%. The diagnostic accuracy was 65.18%, which was slightly lower than the 79.5% diagnostic accuracy for the Lisch nodule, but the diagnostic accuracy was comparable to that of neurofibroma (68.03%). @*Conclusion@#Retinal microvascular abnormalities were observed in 19.7% of type 1 neurofibromatosis patients, of which simple vascular tortuosity was the most common. Considering that retinal microvascular abnormalities were not observed at all in the control group, and the diagnostic accuracy was 65.18%, this type of abnormality could be included as a new ophthalmic clinical feature of type 1 neurofibromatosis.

Periosteal Fixation Applied to Patients with Large-angle Paralytic Strabismus

PURPOSE: To evaluate the effect of periosteal fixation in patients with large-angle paralytic strabismus that was not corrected through conventional strabismus surgery. METHODS: Four eyes of three patients with large-angle paralytic strabismus who underwent periosteal fixation from June 2014 to August 2014 were examined. All patients presented with exotropia > 50 prism diopters (PD). Two of them showed exotropia caused by chronic complete oculomotor nerve palsy; the other two showed exotropia caused by medial rectus muscle injury during endoscopic sinus surgery. RESULTS: The mean preoperative exodeviation using the Krimsky test was 58 ± 29 PD. The postoperative values were 6.5 ± 9.4 PD at 1 week, and 11.25 ± 2.5 PD at 6 months. The mean surgical effect of exodeviation was 43.75 ± 21.36 PD. CONCLUSIONS: Periosteal fixation is an effective surgery for the management of paralytic strabismus that was not corrected through conventional strabismus surgery.

Toxic Optic Neuropathy Caused by Chlorfenapyr Poisoning

PURPOSE: To report a case of toxic optic neuropathy caused by chlorfenapyr ingestion accompanied by central nervous system involvement. CASE SUMMARY: A 44-year-old female visited our clinic complaining of reduced visual acuity in both eyes for 7 days. She had ingested a mouthful of chlorfenapyr for a suicide attempt 2 weeks prior to the visit. Gastric lavage was performed immediately after ingestion at the other hospital. Her best-corrected visual acuity was finger count 30 cm in the right eye and hand motion in the left eye. Both pupils were dilated by 5.0 mm and the response to light was sluggish in both eyes. A relative afferent pupillary defect was detected in her left eye. Funduscopy revealed optic disc swelling in both eyes. Magnetic resonance imaging of the brain showed a symmetric hyper-intense signal in the white matter tract including the internal capsule, corpus callosum, middle cerebellar peduncle, and brainstem. The patient was diagnosed with toxic optic neuropathy induced by chlorfenapyr ingestion, and underwent high-dose intravenous corticosteroid pulse therapy. Three days later, the best-corrected visual acuity was no light perception in both eyes. Three months later, optic atrophy was observed in both eyes. Optical coherence tomography revealed a reduction in the thicknesses of the retinal nerve fiber layer and ganglion cell and inner plexiform layer in the macular area. CONCLUSIONS: Ingestion of even a small amount of chlorfenapyr can cause severe optic nerve damage through the latent period, despite prompt lavage and high-dose steroid treatment.

Comparison of the Thickness and Volume of the Macula and Fovea in Patients with Anisometropic Amblyopia Prior to and after Occlusion Therapy

PURPOSE: To compare the thickness of superior, temporal, inferior, and nasal macula and foveal thickness and volume in patients with anisometropic amblyopia prior to and after successful occlusion therapy using optical coherence tomography (OCT) measurement. METHODS: Data were collected prospectively on 30 patients with unilateral anisometropic amblyopia from December 2006 to August 2007. All patients had anisometropia of 2.0 diopters or more. OCT scans were obtained for all patients at diagnosis. Occlusion therapy was then prescribed and OCT scans were obtained again at the time of successful occlusion therapy (defined as interocular difference of 0.05). However, mean foveal volume prior to occlusion therapy (0.15 ± 0.02 mm3) decreased after occlusion (0.14 ± 0.01 mm3) with statistical significance (Wilcoxon signed rank test, p = 0.025). CONCLUSIONS: There was a meaningful decrease in foveal volume in patients with anisometropic amblyopia after successful occlusion therapy. Whether this decrease relates to visual improvement of the amblyopic eye remains to be determined.

Effects of Corneal Toxicity and Conjunctival Injection of Preservative-free 0.1% Fluorometholone after Pediatric Strabismus Surgery

PURPOSE: To compare the degrees of conjunctival injection and corneal toxicity between preservative and preservative-free topical 0.1% fluorometholone after strabismus surgery. METHODS: A randomized, prospective clinical study was performed to compare the degrees of conjunctival injection and corneal toxicity between preservative and preservative-free topical 0.1% fluorometholone after strabismus surgery. Sixty-one patients with intermittent exotropia were included in this study. They were told to apply antibiotic eye drops (ED) and either preservative or preservative-free topical 0.1% fluorometholone (F1) three times a day. Measurements of the degrees of conjunctival injection and corneal toxicity were performed at postoperative 1 week and 3 weeks each. RESULTS: Seventeen patients (34 eyes) were included in group 1 (preservative F1) and twenty patients (40 eyes) were included in group 2 (preservative-free F1). The average pixel value (measured via the Image J software) representing the degree of conjunctival injection was 31,732 ± 9,946 in group 1 and 38,347 ± 12,189 in group 2 at postoperative 1 week, while the average pixel value was 10,150 ± 4,493 in group 1 and 11,836 ± 4,290 in group 2 at postoperative 3 weeks. There was a significant difference between the decrease in pixel value for the two groups (p = 0.040). There was no significant difference in the mean value of the Oxford stain score between the two groups at postoperative 3 weeks, however the mean questionnaire scores in group 2 were significantly lower than in group 1 (p = 0.001). CONCLUSIONS: Preservative-free 0.1% fluorometholone ED demonstrated a larger decrease in the degree of conjunctival injection than for preservative ED after strabismus surgery. Therefore, the use of preservative-free steroid ED may be beneficial for decreasing both conjunctival injection and postoperative discomfort following strabismus surgery.

Comparison of Astigmatism Induced by Combined Inferior Oblique Anterior Transposition Procedure and Lateral Rectus Recession Alone

PURPOSE: The purpose of this study is to compare the magnitude and axis of astigmatism induced by a combined inferior oblique (IO) anterior transposition procedure with lateral rectus (LR) recession versus LR recession alone. METHODS: Forty-six patients were retrospectively analyzed. The subjects were divided into two groups: those having concurrent inferior oblique muscle overaction (IOOA) and intermittent exotropia (group 1, 20 patients) and those having only intermittent exotropia as a control (group 2, 26 patients). Group 1 underwent combined anterior transposition of IO with LR recession and group 2 underwent LR recession alone. Induced astigmatism was defined as the difference between preoperative and postoperative astigmatism using double-angle vector analysis. Cylinder power, axis of induced astigmatism, and spherical equivalent were analyzed at 1 week, 1 month, and 3 months after surgery. RESULTS: Larger changes in the axis of induced astigmatism were observed in group 1, with 4.5° incyclotorsion, than in group 2 at 1 week after surgery (axis, 84.5° vs. 91°; p < 0.001). However, there was no statistically significant inter-group difference thereafter. Relaxation and rapid regression in the incyclotorsion of induced astigmatism were observed over-time. Spherical equivalent significantly decreased postoperatively at 1 month in both groups, indicating a myopic shift (p = 0.011 for group 1 and p = 0.019 for group 2) but did not show significant differences at 3 months after surgery (p = 0.107 for group 1 and p = 0.760 for group 2). CONCLUSIONS: Combined IO anterior transposition procedures caused an increased change in the axis of induced astigmatism, including temporary incyclotorsion, during the first week after surgery. However, this significant difference was not maintained thereafter. Thus, combined IO surgery with LR recession does not seem to produce a sustained astigmatic change, which can be a potential risk factor of postoperative amblyopia or diplopia compared with LR recession alone.

The Stereoscopic Acuity in Patients with Unilateral or Bilateral Visual Field Defects

PURPOSE: To evaluate the stereoscopic acuity in patients with unilateral or bilateral visual field defects. METHODS: Stereoscopic acuity was measured using the Titmus stereo test for 36 subjects with visual field defects (VFD). VFD was assessed by sum of MD (mean deviation, MDsum) and PSD (pattern standard deviation, PSDsum) of both eyes in Humphrey visual field test and presence of central VFD (within 30degrees isopter) in Goldman visual field test. 25 glaucoma subjects and 11 optic neuritis subjects were included. Patients with strabismus or ocular motility disorders which could affect stereoscopic acuity were excluded. RESULTS: The mean of MDsum was -20.10 +/- 12.31 dB (-45.13~-10.64 dB) and PSDsum was 13.10 +/- 8.76 dB (9.62-25.47 dB). The mean stereoscopic acuity was 710 +/- 922 arc sec (40-3000 arc sec) with Titmus stereo test. The associations between stereoscopic acuity and PSDsum (r = 0.400, p = 0.016), presence of central VFD within 30 degrees (r = 0.428, p = 0.03) were statistically significant. There was positive trend between stereoscopic acuity and duration of VFD, but with no statistical significance. CONCLUSIONS: Decreased stereoscopic acuity was associated with PSDsum and VFD in the central 30 degrees. We should consider this decrease of stereoscopic acuity as well when evaluating visual function of the patients with VFD.

The Stereoscopic Acuity in Patients with Unilateral or Bilateral Visual Field Defects

PURPOSE: To evaluate the stereoscopic acuity in patients with unilateral or bilateral visual field defects. METHODS: Stereoscopic acuity was measured using the Titmus stereo test for 36 subjects with visual field defects (VFD). VFD was assessed by sum of MD (mean deviation, MDsum) and PSD (pattern standard deviation, PSDsum) of both eyes in Humphrey visual field test and presence of central VFD (within 30degrees isopter) in Goldman visual field test. 25 glaucoma subjects and 11 optic neuritis subjects were included. Patients with strabismus or ocular motility disorders which could affect stereoscopic acuity were excluded. RESULTS: The mean of MDsum was -20.10 +/- 12.31 dB (-45.13~-10.64 dB) and PSDsum was 13.10 +/- 8.76 dB (9.62-25.47 dB). The mean stereoscopic acuity was 710 +/- 922 arc sec (40-3000 arc sec) with Titmus stereo test. The associations between stereoscopic acuity and PSDsum (r = 0.400, p = 0.016), presence of central VFD within 30 degrees (r = 0.428, p = 0.03) were statistically significant. There was positive trend between stereoscopic acuity and duration of VFD, but with no statistical significance. CONCLUSIONS: Decreased stereoscopic acuity was associated with PSDsum and VFD in the central 30 degrees. We should consider this decrease of stereoscopic acuity as well when evaluating visual function of the patients with VFD.

An Adult Case of Fisher Syndrome Subsequent to Mycoplasma pneumoniae Infection

Reported herein is an adult case of Fisher syndrome (FS) that occurred as a complication during the course of community-acquired pneumonia caused by Mycoplasma pneumoniae. A 38-yr-old man who had been treated with antibiotics for serologically proven M. pneumoniae pneumonia presented with a sudden onset of diplopia, ataxic gait, and areflexia. A thorough evaluation including brain imaging, cerebrospinal fluid examination, a nerve conduction study, and detection of serum anti-ganglioside GQ1b antibody titers led to the diagnosis of FS. Antibiotic treatment of the underlying M. pneumoniae pneumonia was maintained without additional immunomodulatory agents. A complete and spontaneous resolution of neurologic abnormalities was observed within 1 month, accompanied by resolution of lung lesions.

Additional Retrobulbar Triamcinolone Acetonide Injection for Retrobulbar Optic Neuritis Patients

PURPOSE: To evaluate the effect of additional retrobulbar triamcinolone acetonide (TA) injection on early recovery of visual acuity in retrobulbar optic neuritis patients. METHODS: A prospective, randomized clinical study including 30 patients with retrobulbar optic neuritis was conducted between March 2003 and June 2007. Patients were divided into 2 groups: Group 1 (n = 9) with retrobulbar triamcinolone (TA, 40 mg/1 ml) injection on the first day of ONTT protocol, and group 2 (n = 21) with conventional ONTT protocol. The following parameters were measured and analyzed: patient's sex, age, pupillary reactions, color vision, visual field, and best-corrected visual acuity before treatment, and after 1 day, 1 week, 2 weeks, 1 month, and 3 months of follow-up. RESULTS: Mean visual acuity before treatment was 1.00 +/- 0.89 log MAR units in group 1 and 0.98 +/- 0.75 log MAR units in group 2. One day after injection, visual acuity was better in group 1 (0.50 +/- 0.42 log MAR units) than in group 2 (0.73 +/- 0.61 log MAR units), however, there was no statistically significant difference between the 2 groups (p = 0.07). There was no significant difference in visual acuity, recovery of RAPD, color vision, or visual field at 3 months of follow-up. No serious side effect related to retrobulbar TA injection was observed. CONCLUSIONS: Additional retrobulbar TA injection may help optic neuritis patients who have a need for prompt visual recovery. However, further studies are required to ascertain whether this procedure can help early recovery of visual acuity in retrobulbar optic neuritis patients.

Trypan Blue-Assisted Measurements of Anatomical Positions of the Superior Rectus Muscle and Superior Oblique Muscle in Enucleated Eyes

PURPOSE: To recognize the anatomical positions of the superior oblique muscle in enucleated eyes using trypan blue. METHODS: Twenty-two surgically-enucleated eyes of 11 bodies were studied. The shortest distance from the nasal insertion of superior rectus to the anterior end of the superior oblique tendon, the distance from the temporal insertion of superior rectus to the anterior end of the superior oblique insertion, and the greatest width of superior oblique tendon insertion were measured by caliper 3 consecutive times. The average values in each of the above 3 points were calculated, and values prior to and after trypan blue staining were compared. RESULTS: Prior to staining with trypan blue, the average distance from the nasal insertion of superior rectus to the anterior end of the superior oblique tendon was 4.97 mm and the average distance from the temporal insertion of superior rectus to the anterior end of the superior oblique insertion was 7.57 mm; after staining with trypan blue, the average values were 5.09 mm and 7.65 mm, respectively. There was no statistically meaningful difference in values prior to and after staining (p > 0.05). Prior to staining, the average value of the greatest width of the superior oblique tendon was 10.32 mm, and after staining with trypan blue, the average value increased to 10.76 mm. There was a statistically meaningful difference between the values (p = 0.02). CONCLUSIONS: Trypan blue staining helped to recognize the location and the width of the superior oblique tendon more precisely.

Effectiveness of Home-Based Pencil Push-ups (HBPP) for Patients with Symptomatic Convergence Insufficiency

PURPOSE: To report the effectiveness of home-based pencil push-ups (HBPP) therapy for patients with symptomatic convergence insufficiency. METHODS: Data was collected prospectively on 16 patients who were diagnosed with convergence insufficiency beginning in January 2009. The study group was composed of ten male and six female patients. The duration of symptoms, refractive error, distant and near deviation angles, and near point of convergence (NPC) prior to and after 12 weeks of HBPP therapy were measured in all patients. RESULTS: The mean age of the patients was 19.3 years. The mean deviation angle of exophoria was 3 prism diopters (PD) at distant and 11.2 PD at near. The mean value of NPC prior to HBPP therapy was 36.3 cm; however, the near point of accommodation was within the normal range. After 12 weeks of HBPP therapy, the mean deviation angle of exophoria decreased to orthophoric at distant and 4 PD at near. The mean value of NPC decreased to 14.4 cm. CONCLUSIONS: Twelve weeks of HBPP therapy appears to be an easy, cost-free and effective therapy for patients with symptomatic convergence insufficiency.

Early Resolution of Convergence Spasms Following the Addition of Antipsychotic Medications

We report a case of early resolution of convergence spasms following the addition of antipsychotic medications and present it as a possible alternative to the conventional treatment for convergence spasms. The cessation of atropinization of the eyes and the use of reading glasses was achieved after only 2 months following the initiation of antipsychotic medications for childhood emotional disorder.

Comparison of the Effects of Prophylactic Nonsteroidal Anti-inflammatory Drugs on Macular Edema After Cataract Surgery

PURPOSE: To evaluate and compare the efficacy of prophylactic administration of topical nonsteroidal anti-inflammatory (NSAID) drugs on macular edema (ME) following cataract surgery. METHODS: The present open-label non-masked randomized (random number assignment) study was comprised of 90 eyes. Thirty eyes were administered Diclofenac sodium 0.1%, and 30 eyes were administered Pranoprofen 0.1% starting three days before surgery and continued for one month after surgery. The remaining 30 eyes made up the control group. The results consisted of the measurements of foveal thickness (FT), macular thickness (MT), and total macular volume (TMV), which were quantified by optical coherence tomography (OCT, Carl Zeiss Meditec) before and one month after phacoemulsification surgery. RESULTS: At one month, there were statistically significant differences in FT in the Diclofenac group (0.48+/-10.9 micrometer) and the Pranoprofen group (1.87+/-14.7 micrometer) (p<0.05) compared with the control group (11.65+/-18.6 micrometer). In addition, there was a statistically significant difference in MT between the control group (71.06+/-90.8 micrometer) and the Diclofenac group (15.19+/-36.1 micrometer) (p<0.05). However, no statistical difference in MT was noted between the control group and the Pranoprofen group (27.57+/-70.93 micrometer). Between the control group and the NSAID groups, only the Diclofenac group showed statistical differences in TMV throughout the observational period. CONCLUSIONS: Used prophylactically after cataract surgery, the NSAIDS eye drops were effective in reducing postoperative ME.

Reunion of the Rabbit Superior Oblique Tendon After Weakening Procedures

PURPOSE: To investigate the degree of reunion in rabbit eyes of the superior oblique tendon after several surgical weakening procedures. METHODS: A total of 32 rabbits (64 eyes) were used in this study. The rabbits were randomly assigned to four groups, eight rabbits (16 eyes) in the tenotomy group, eight rabbits (16 eyes) in the tenectomy group, eight rabbits (16 eyes) in the disinsertion group and eight rabbits (16 eyes) in the recession group. The degree of reunion or reattachment of the superior oblique tendon on the globe were examined on four eyes in each group at postoperative weeks two, four, six and eight. RESULTS: At eight weeks, the newly created insertion site remained at the same site in all eyes in the recession group, and the distal end of the superior oblique tendon was reattached at the medial border of the superior rectus muscle in all four eyes in the tenotomy and disinsertion groups, and in three of four eyes in the tenectomy group. CONCLUSIONS: From this experimental study, it was speculated that superior oblique recession is more effective than other superior oblique weakening procedures. This result could be helpful in the prediction of time of recurrence for superior oblique overaction after superior oblique weakening procedures.

The Effect of an Intravitreal Triamcinolone Acetonide Injection for Acute Nonarteritic Anterior Ischemic Optic Neuropathy

The purpose of this case report is to evaluate the visual outcome of an intravitreal triamcinolone acetonide injection (IVTA) as a treatment for a patient with acute nonarteritic anterior ischemic optic neuropathy (NAION). A 65-year-old male patient with severe visual loss due to acute NAION was treated with 4 mg/0.1mL IVTA. Fundus examination and measurements of the patient's best-corrected visual acuity and visual field were performed before and after the injection at 2 weeks, 1 month, 3 months, and 6 months. The best-corrected visual acuity changed from 0.05 before the injection to 0.16 at 2 weeks, 0.3 at 1 month, and 0.4 at 3 months and at the final visit. Optic disc swelling had markedly decreased at 1 week postoperatively and disappeared at 2 weeks after the injection. The clinical course of this patient suggests that an IVTA may be effective in increasing visual acuity following an acute NAION. A large randomized controlled trial is needed to assess the efficacy of IVTA as a treatment for NAION.

Comparison of the Stability of Postoperative Alignment in Sensory Exotropia: Adjustable Versus Non-Adjustable Surgery

PURPOSE: To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia. METHODS: A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery. RESULTS: There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups. CONCLUSIONS: Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.

A Case of DiGeorge Syndrome With Ocular Manifestation

PURPOSE: DiGeorge syndrome (chromosome 22q11.2 deletion syndrome) is a syndrome of multiple congenital anomalies characterized by hypoplasia or aplasia of the thymus and parathyroid, cardiovascular malformation, immune deficiency, cleft palate, characteristic facial features, and hypocalcemia. Ocular findings of DiGeorge syndrome are posterior embryotoxon, retinal vascular tortuosity, strabismus, ptosis, amblyopia and tilted optic disc. The authors present a case of DiGeorge syndrome with ocular manifestation not reported previously in Korea. Case summary: A six-year old female diagnosed with DiGeorge syndrome was referred to the authors' department within the hospital. The chief complaint was blurring vision in both eyes. Best corrected visual acuity of the right eye was 0.5 and of the left eye was 0.63. Cycloplegic refraction revealed high hyperopia and astigmatism in both eyes (OD: +7.25 Dsph; -2.5 Dcyl axis 180degrees, OS: +6.25 Dsph; -3.75 Dcyl axis 180degrees). In addition, hypertelorism, ptosis and tortuous retinal vessels during fundus examination were noted. CONCLUSIONS: Upon the initial diagnosis of DiGeorge syndrome in children, a comprehensive ocular examination is necessary because other ocular conditions may exist which can affect the visual development of the patient.

The Effect of Unilateral Medial Rectus Muscle Resection in Patients with Recurrent Exotropia

PURPOSE: To investigate the effect of unilateral medial rectus muscle resection for recurrent exotropia after bilateral lateral rectus muscle recession for intermittent exotropia METHODS: A retrospective analysis was made of thirtypatients who underwent unilateral medial rectus resection for recurrent exotropia. All had prior bilateral lateral rectus recession for intermittent exotropia. Data were collected for age, the preoperative deviation, the postoperative deviation at 2 weeks, 3 months, 6 months and the last visit, and the amount of medial rectus resection performed. RESULTS: The average preoperative deviation was 27.0+/-3.6 PD. After unilateral medial rectus resection, average deviation at distance was 2.8 PD at postoperative 2 weeks, 4.5 PD at 3 months, 5.1 PD at 6 months and 5.8 PD at last visit. The average deviation corrected per millimeter of medial rectus resection was 3.53+/-0.17 PD/mm. CONCLUSIONS: Considering that deviation angles of recurrent exotropia is smaller than those of primary surgery and the possibility of saving the other medial rectus muscle, unilateral rectus muscle resection could be effective surgical method for recurrent exotropia.