Ho Kyung Choung

Incidence and clinical features of ethambutol-induced optic neuropathy in Korea.

Background: The incidence, clinical manifestations, and contributory factors in ethambutol-induced optic neuropathy (EON) have not been widely studied. Methods: A retrospective chart review of 857 patients who took ethambutol for treatment of tuberculosis identified 89 patients who complained of decreased vision after initiation of treatment and were therefore referred to the ophthalmology clinic of Seoul National University Hospital, Korea, between January 2003 and December 2005. Information was extracted in regard to systemic illnesses, duration and dose of ethambutol therapy, visual acuity, color vision, ophthalmoscopic examination, visual fields, and visual evoked potentials (VEPs). Results: EON was diagnosed in 13 (1.5%) patients during a follow-up period of 12.54 ± 9.97 months. The average dose of ethambutol was 17.85 ± 2.21 mg/kg/day, and the duration of therapy was 9.38 ± 10.12 months. Ophthalmic findings included decreased visual acuity (65.4%), abnormal visual fields (65.4%), abnormal color vision (61.5%), optic disc pallor (38.5%), or increased latency on VEP tests (65.4%). Slightly less than one third of patients showed improvement in visual function after discontinuing ethambutol. The latency for recovery was 5.38 ± 1.71 months. No patient with optic disc pallor at the time of diagnosis of EON showed visual function improvement. Renal dysfunction and the daily dose of ethambutol, but not the duration of treatment, contributed to EON. Conclusions: Based on this study, the incidence of EON in Koreans is estimated to be <2%. However, visual function after discontinuation of ethambutol is reversible in only a minority of patients and does not occur if optic disc pallor is present. Renal dysfunction and daily dose of ethambutol, but not duration of ethambutol treatment, seem to be related to development of EON.

Bicanalicular double silicone intubation in external dacryocystorhinostomy and canaliculoplasty for distal canalicular obstruction

Purpose:u2002 We aimed to evaluate the effectiveness of bicanalicular double silicone intubation in dacryocystorhinostomy (DCR) and canaliculoplasty for distal or common canalicular obstruction.

Lens-sparing Vitrectomy for Stage 4 and Stage 5 Retinopathy of Prematurity

Purpose To describe the results of lens-sparing vitrectomy for the correction of retinal detachment associated with retinopathy of prematurity (ROP) and its associated complications. Methods Seventeen patients who underwent a lens-sparing vitrectomy for stage 4 and stage 5 ROP with plus disease at Seoul National University Childrens Hospital between 1999 and 2003 were enrolled in this study. The patients who had bilateral retinal detachment of ROP underwent a lens-sparing vitrectomy in one eye and a scleral buckling surgery or lensectomy-vitrectomy in the other eye. The patients who had a retinal detachment in one eye and a regressed ROP in the other eye underwent unilateral lens-sparing vitrectomies. A review of their preoperative clinical findings (including the status of retinal detachment and plus disease), post-operative results, and any complications encountered was performed. Results In 17 patients, the postoperative success rate of lens-sparing vitrectomy was 58.8%. However, lens-sparing vitrectomy as a treatment for stage 5 ROP (25.0%) produced more negative post-operative results than it did when used to treat either those for stage 4a (75,0%) or 4b (66.7%) ROP. Among the 10 eyes in which the retina was attached, form vision was shown in six eyes, light could be followed by three eyes, and no light perception was present in one eye. Intra- and post-operative complications included retinal break formation, cataracts, vitreous hemorrhages, and glaucoma in patients with stages 4b and stage 5 ROP. Conclusions Lens-sparing vitrectomy resulted in encouraging surgical outcomes in the correction of retinal detachment of ROP, especially in stage 4 patients. Therefore, a lens-sparing vitrectomy for stage 4 ROP patient may be beneficial, although it is still associated with some intra- and post-operative complications.

Free orbital fat graft to prevent porous polyethylene orbital implant exposure in patients with retinoblastoma.

Purpose: To determine if porous polyethylene orbital implant (Medpor®) exposure can be prevented in retinoblastoma patients when the implant is placed in combination with a free orbital fat graft over the anterior surface of the implant. Methods: Free orbital fat grafts were performed after enucleation and Medpor® implantation, and results were compared with patients who underwent conventional enucleation and Medpor® implantation without an orbital fat graft. Results: Although implant exposure occurred in 13 of 39 eyes (33.3%) that had conventional enucleation and Medpor® implantation, exposure did not develop in any of the 38 eyes that had the combined procedure with a free orbital fat graft. Conclusions: These findings suggest that a free orbital fat graft is a simple, effective way to prevent orbital implant exposure in patients requiring enucleation and Medpor® implantation.

Epiblepharon of the lower eyelid: technique of surgical repair and quantification of excision according to the skin fold height.

BACKGROUND AND OBJECTIVEnTo describe our excisional technique for lower eyelid epiblepharon to reduce a medial undercorrection and to provide a guide for the excision amount using a classification system of epiblepharon according to the skin fold height.nnnPATIENTS AND METHODSnAfter classification, an elliptical excision of skin and orbicularis muscle, including that below the lower canaliculus after tarsal suturing of the upper edge of the incised skin, was consecutively performed for 111 eyelids of 58 patients. The widest width of the excisional ellipse was measured.nnnRESULTSnThe results were successful in 108 eyelids. The mean widest width of the excisional ellipse was 1.1, 1.7, 2.5, and 3.0 mm in Class I, II, III, and IV epiblepharons, respectively.nnnCONCLUSIONnThis surgical technique is effective for the correction of epiblepharon, and it is easy to determine the amount of excision. Using this technique, a 1 mm to 3 mm width of excision is sufficient.

Frontalis sling operation using silicone rod for the correction of ptosis in chronic progressive external ophthalmoplegia.

Aims: The aim of the study was to evaluate the results of the frontalis sling operation using silicone rod for the correction of ptosis in chronic progressive external ophthalmoplegia patients. Methods: Chronic progressive external ophthalmoplegia patients who received the frontalis sling operation using silicone rods from 1999 to 2006 were included in this study. The medical records were retrospectively reviewed and the clinical characteristics and postoperative surgical results of these patients were analysed. This study was a retrospective, non-randomised, interventional case series and the main outcome measures were margin reflex distance, eyelid contour and corneal status. Results: Seven patients were recruited (one male and six female). The mean age at the time of operation was 29.6 (range 15–62) years. Two patients had unilateral ptosis and five patients had bilateral ptosis. The mean follow-up period was 22.7 (range 1–61) months. Satisfactory lid height was achieved in all patients. Although corneal erosions were detected in five patients 1 month after surgery, these findings eventually resolved in three patients 2 months later, after the use of artificial tear eyedrops and ointments. Conclusion: The frontalis sling operation using silicone rod can safely and effectively correct ptosis in chronic progressive external ophthalmoplegia patients without serious corneal complications.

Eye-Preserving Therapy in Retinoblastoma: Prolonged Primary Chemotherapy Alone or Combined with Local Therapy

Purpose To evaluate the efficacy of primary chemotherapy combined with local therapy in the treatment of retinoblastomas not treatable with a single therapeutic method. Methods We performed a retrospective chart review of 227 patients diagnosed with retinoblastoma. Sixty-five eyes in 52 patients had tumors not treatable with a single therapeutic method and received primary chemotherapy combined with local therapy as needed. Results Tumor control and eye salvage was achieved in 34 of the 65 eyes; the probability of ocular survival was 46.56% using the Kaplan-Meier method. Forty-three of the 65 eyes were group D or E tumors, in which tumor control and eye salvage was achieved in 16 eyes. Twenty eyes were treated with chemotherapy only, while 28 eyes received one additional modality of local therapy, and 17 eyes received two modalities of local therapy. Of the eyes treated with chemotherapy only, tumor control was achieved in 5 eyes. Conclusions Primary chemotherapy combined with local therapy can be effective and safe in the treatment of retinoblastomas otherwise untreatable with other therapeutic methods, such as group D and E retinoblastomas. More vigorous treatment with more local therapeutic methods combined may yield even better results.

Visual Function after Primary Posterior Chamber Intraocular Lens Implantation in Pediatric Unilateral Cataract: Stereopsis and Visual Acuity

Purpose To investigate the association between binocular function and vision after cataract removal and primary posterior chamber intraocular lens (PC-IOL) implantation in children with unilateral cataract and to identify visual function differences according cataract type. Methods Clinical records of 2- to 6-year-old patients with unilateral cataract removal and primary PC-IOL implantation were reviewed retrospectively. Visual acuity and ocular alignment were measured. Sensory fusion was assessed with the Worth 4-dot test, and stereoacuity with the Titmus stereo test. Cataracts were classified according to cause, lens opacity location, age at onset, and presence of strabismus. Clinical characteristics of patients who obtained good visual function were identified. Results Forty-seven patients were included. Among 22 (46.8%) with good vision (20/40 or better), only 6 (27.3%) achieved good binocular function (the presence of fusion and 100 seconds of arc or better of stereoacuity). Visual acuity was better in eyes with good binocular function (p=0.002). No other variables were significant for achieving good binocular function. Conclusions The removal of unilateral cataract in a visually immature child can result in a combination of good visual acuity and binocular function. Good binocular function is closely related to good visual acuity.

Retroscleral implantation technique for porous polyethylene orbital implant after evisceration.

The authors developed a technique for the retroscleral implantation of a porous polyethylene orbital implant after evisceration for the placement of an adequately large orbital implant without wound tension. The surgical results of the technique in 27 patients are reported. The technique involves the severance of the optic nerve after standard evisceration and the insertion of the orbital implant into the retroscleral and intraconal space through the side of the scleral shell. All patients received a 20-mm orbital implant. No complications such as infection, implant exposure, or worsened implant motility were observed during the average follow-up period of 22.4 months. Retroscleral implantation of the orbital implant after evisceration may be an appropriate procedure that allows placement of a large orbital implant without exposure or decreased implant motility.

Management of Porous Polyethylene Implant Exposure in Patients With Retinoblastoma Following Enucleation

BACKGROUND AND OBJECTIVEnTo report the features and the management of porous polyethylene implant exposure in patients with retinoblastoma following enucleation.nnnPATIENTS AND METHODSnThe medical records of 33 patients (33 sockets) following enucleation and porous polyethylene implantation for retinoblastoma were reviewed.nnnRESULTSnThe mean age at enucleation was 24 months (range, 2 to 85 months). The exposure rate was 33% (11 cases), and the mean time from enucleation to exposure was 15 months (range, 7 to 29 months). One case was resolved only by supportive management, and the remaining 10 were successfully treated with a scleral patch graft and maintained well during a mean follow-up of 15 months after surgical repair. There was no statistical evidence that age, gender, implant size, or chemotherapy had an effect on implant exposure.nnnCONCLUSIONSnPorous polyethylene implant exposure does not seem to be resolved by conservative management. We recommend early surgical management, such as scleral patch graft, as opposed to supportive management.