Genotypic and phenotypic characteristics of Korean children with childhood-onset Leber's hereditary optic neuropathy.

PURPOSE: We sought to identify the phenotypic and genotypic characteristics of Korean children with genetically confirmed Leber's hereditary optic neuropathy (LHON). METHODS: The medical records of 64 genetically confirmed LHON patients were reviewed. Seventeen patients aged 13 years or younger with optic atrophy with positive mitochondrial DNA (mtDNA) mutations were considered to demonstrate childhood-onset LHON. The non-childhood-onset group included 47 patients with genetically confirmed LHON who experienced disease onset later than 13 years of age. The type of mtDNA mutation, visual acuity (VA), color vision, fundus photography, retinal nerve fiber layer (RNFL) thickness, and visual field were investigated. RESULTS: Sequence analysis of the mitochondrial genome revealed five different kinds of LHON-associated mtDNA mutations among our childhood-onset patients, including m.11778G>A (58.8%), m.3496G>T (11.8%), m.3497C>T (5.9%), m.11696G>A (5.9%), and m.14502T>C (5.9%). The mean final best-corrected VA in the childhood-onset group was better than that in the non-childhood-onset group with the value of logMAR 0.29 (0.09-0.75) vs. 0.55 (0.27-1.29) (expressed as median (interquartile range); p = 0.05). Spontaneous visual recovery was observed in 35.3% of the childhood-onset group but in only 12.8% of the non-childhood-onset group (p = 0.04). Eight patients (47.1%) showed interocular asymmetry of the disease, with two presenting true unilateral involvement of the optic nerve and the other six patients demonstrating unilateral subclinical manifestations with bilateral optic atrophy. CONCLUSION: Involvement of secondary mitochondrial mutations was confirmed in patients with childhood-onset LHON. Characteristic clinical features of childhood-onset LHON included a higher proportion of subacute or insidious onset of symptoms, better VA, higher spontaneous recovery, and asymmetrical ocular involvement.

Compressive Optic Neuropathy with a Concurrent Mutation of Leber's Hereditary Optic Neuropathy: A Case Report.

Leber's hereditary optic neuropathy (LHON) is a mitochondrial genetic disease that leads to acute or subacute, painless, bilateral loss of vision, caused by degeneration of retinal ganglion cells that most affects men in their second or third decade of life. We describe a woman with compressive optic neuropathy with a concurrent LHON-associated mitochondrial mutation. Temporal hemifield defect connected to central scotoma and concurrent abduction limitation are diagnostic clues in identifying chiasmal compression with craniopharyngioma. This case emphasizes an awareness of the possible coexistence of compressive and hereditary optic neuropathy.

Detailed anatomy of the trochlear nerve in the superior oblique muscle.

PURPOSE: The purpose of this study was to elucidate the detailed anatomy of the trochlear nerve in the superior oblique muscle (SOM) and the intramuscular innervation pattern using Sihler staining. METHODS: SOMs were dissected from their origin to the insertion in 28 eyes of 14 cadavers. The following distances were determined: from the SOM insertion to the trochlear, from the trochlear to the entry site of the anterior branch or posterior branch, and the widths of the main trunk and anterior and posterior branches. Sihler staining was then performed. RESULTS: The trochlear nerve traveled straight ahead medially and divided. Eighteen of 28 (64.3%) orbits showed two anterior and posterior branches, six (21.4%) showed three branches, and four (14.3%) showed no branching. The most distally located intramuscular nerve ending was observed at 62.4 ± 2.4% of the length of each muscle (35.8 mm from insertion when considering that the length of the SOM was 57.4 mm) and at 29.9 ± 3.2% of the length of each muscle (17.2 mm from the trochlear). Additionally, the length of the intramuscular arborization part was 9.4 ± 1.1% of the length of the SOM (5.4 mm when considering that the length of the SOM was 57.4 mm). Nonoverlap between two intramuscular arborizations of the nerve was detected in 20 of 28 cases (71.4%). Eight cases (28.6%) showed a definite overlap of two zones. CONCLUSIONS: This study provided a good understanding of the anatomy of the trochlear nerve in the SOM.

Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model.

The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

Ocular biometric changes following unilateral cataract surgery in children.

PURPOSE: To analyze ocular biometric changes following unilateral cataract surgery in children. METHODS: A total of 57 children aged under 13 years who underwent unilateral cataract surgery were analyzed. Groups were classified according to their age at surgery: group I (age <3), II (3≤ age <6), III (6≤ age <9), and IV (age ≥9). The myopic shift, axial growth, and corneal curvature changes were compared between the pseudophakic eyes and the fellow phakic eyes. RESULTS: During 7.81 ± 4.39 years, the overall myopic shift (D) and the rate of myopic shift (D/year) were significantly higher at -3.25 ± 3.21 D and -0.45 ± 0.44 D/year in the pseudophakic eyes than -1.78 ± 2.10 D and -0.22 ± 0.29 D/year in the fellow phakic eyes (P = 0.01, 0.004). Group I (-1.14 ± 0.66 vs -0.02 ± 0.45 D/year) and group II (-0.63 ± 0.37 vs -0.31 ± 0.29 D/year) showed significantly higher rate of myopic shift in the pseudophakic eyes than in the phakic eyes. The rate of myopic shift in the pseudophakic eyes decreased in the older age groups (P = 0.001). There was no significant between-eye difference in the changes in axial length and keratometric values postoperatively. CONCLUSION: Following unilateral cataract surgery, a significant postoperative myopic shift was noticed in the pseudophakic eyes compared to the fellow phakic eyes in groups under 6 years old. Postoperative myopic shift and the resultant anisometropia should be considered when selecting the optimal power of IOL in young children requiring unilateral cataract surgery.

Morphological change of the posterior pole following the horizontal strabismus surgery with swept source optical coherence tomography.

Extraocular muscle movement during strabismus surgery causes changes in eyeball shape. Because extraocular muscle insertion is in front of the equator, it is thought that changes due to strabismus surgery mainly occur in the anterior segment. However, changes in the posterior segment of eye may also occur, which may also result in changes in refractive error after strabismus surgery. Using a 3-dimensional reconstruction technique (en face imaging) of the swept source optical coherence tomography, we determined and quantitatively measured the posterior polar change. The deepest interface between Bruch's membrane and the choroid could be identified as the deepest point of the eyeball (DPE), and the location of the DPE relative to the optic disc and the fovea was measured. After lateral rectus muscle recession, the DPE moved away from the fovea, but after medial rectus muscle recession, the DPE moved toward the fovea. The amount of DPE movement differed by age and preoperative refractive error. Our findings suggest that the positional shift of the rectus muscle in horizontal strabismus surgery causes a structural change in the posterior segment of the eye, and the postoperative refractive changes may be related to this shift.

The Effect of Topical Ganciclovir and Corticosteroid on Cytomegalovirus Corneal Endotheliitis in Korean Patients.

PURPOSE: To report long-term outcomes of topical ganciclovir (GCV) and corticosteroids in Korean patients with cytomegalovirus (CMV) corneal endotheliitis. METHODS: This retrospective study included 13 eyes from 13 patients with CMV corneal endotheliitis, with a follow-up period of 24.5 ± 8.2 months. The patients were consistently maintained with topical 2% GCV and 1% prednisolone acetate eyedrop. RESULTS: All patients demonstrated unilateral typical coin-shaped keratic precipitates (KPs) or linear KP, and positive CMV polymerase chain reaction of aqueous humor. After 2 weeks of treatment, all patients showed decrease of clinical signs. During the follow-up, four patients developed mild anterior chamber inflammation with increased intraocular pressure without typical coin-shaped KPs or edema, started to use the initial dose, and resolved the clinical signs. One patient showed recurrence of corneal edema twice, and was administered systemic valgancyclovir for 2 weeks upon second recurrence with resolution of clinical signs. CONCLUSION: Long-term maintenance therapy with topical GCV and corticosteroids are effective and maintain corneal endothelial function in Korean patients with CMV endotheliitis.

Interocular difference associated with myopic progression following unilateral lateral rectus recession in early school-aged children.

PURPOSE: To compare refractive changes in operated eyes and fellow unoperated eyes following unilateral lateral rectus recession in early school-aged children. STUDY DESIGN: A retrospective case control study. METHODS: The medical records of children under ten years of age with intermittent exotropia who underwent unilateral lateral recession surgery were reviewed. The operated eyes were reviewed and the fellow unoperated eyes were used as control. The rate of myopic progression was calculated by spherical equivalent (SE) changes per year, and by the rate of refractive growth (RRG) equation. RESULTS: SE showed a myopic shift one week after surgery and in the following months, from -1.43 ± 1.84 diopters (D) at 1 week post operation to -1.57 ± 2.22 D at one year and, finally -2.95 ± 2.97 D at the average 4.62 years following surgery. However, the SE shift was not significantly different from the unoperated eye. The low myopia group (under -3.0 D) showed a significantly higher myopic change in the operated eye until one year post operation (p = 0.022). The average myopic shift ratio was -0.53 ± 0.46 D yearly in the operated eye. CONCLUSIONS: This study presents data of a large series of refractive changes secondary to lateral rectus recession, and of long-term myopia progression in Korean population.

Detailed Anatomy of the Lateral Rectus Muscle-Superior Rectus Muscle Band.

BACKGROUND: To elucidate the detailed anatomy of the lateral rectus muscle-superior rectus muscle (LR-SR) band by cadaver eye investigation. METHODS: In total, 48 eyes of 24 cadavers were observed macroscopically. The lateral rectus muscle (LRM) and superior rectus muscle (SRM) were dissected from their origins to their insertions under the dissecting microscope, and the location, width, length, and tensile strength of the LR-SR bands were measured. RESULTS: The LR-SR band is the thick ligament interconnecting LRM pulleys with SRM pulleys. The LR-SR band was covered by the orbital part of the lacrimal gland superiorly, and the intermuscular septum between the LRM and SRM was shown anterior to the LR-SR band. The length of the attachment site between the LR-SR band and the SRM was less at 8.64 ± 1.52 mm (p=0.040), its thickness was thinner at 0.74 ± 0.16 mm (p=0.002), and its tensile strength was weaker at 7.64 ± 1.82 N (p=0.028) compared to the attachment site between the LR-SR band and the LRM. CONCLUSIONS: This study revealed the detailed anatomy of the LR-SR band and provided helpful information to understand heavy eye syndrome and sagging eye syndrome.

Factors Affecting Long-term Myopic Regression after Laser In Situ Keratomileusis and Laser-assisted Subepithelial Keratectomy for Moderate Myopia.

PURPOSE: High myopia is known to be a risk factor for long-term regression after laser refractive surgery. There have been few studies about the correction of moderate myopias that did not need retreatment after long-term follow-up. We evaluated 10 years of change in visual acuity and refractive power in eyes with moderate myopia after laser refractive surgery. METHODS: We included patients that had undergone laser in situ keratomileusis (LASIK) or laser-assisted subepithelial keratectomy (LASEK) to correct their myopia and that had at least 10 years of follow-up. We evaluated the stability of visual acuity in terms of safety, efficacy, and refractive changes at examinations 6 months and 1, 2, 5, 7, and 10 years after surgery. RESULTS: The study evaluated 62 eyes (36 eyes in LASIK patients and 26 eyes in LASEK patients). In both groups, the efficacy index tended to decrease, and it was consistently higher in the LASEK group compared to the LASIK group over the 10 years of follow-up. The safety index improved over 10 years and was always higher than 0.9 in both groups. The difference between the spherical equivalent at 6 months postoperatively and later periods was statistically significant after 5, 7, and 10 years in both groups (LASIK, p = 0.036, p = 0.003, and p < 0.001, respectively; LASEK, p = 0.006, p = 0.002, and p = 0.001, respectively). Ten years after surgery,26 eyes (66.7%) in the LASIK group and 19 eyes (73.1%) in the LASEK group had myopia greater than 1 diopter. In comparison with the thickness at 6 months postoperatively, central corneal thickness was significantly increased after 5, 7, and 10 years in both LASIK and LASEK groups (LASIK, p < 0.001, p < 0.001, and p < 0.001, respectively; LASEK, p = 0.01, p < 0.001, and p < 0.001, respectively). CONCLUSIONS: Moderately myopic eyes showed progressive myopic shifting and corneal thickening after LASIK and LASEK during 10 years of follow-up. We also found that early refractive regression may indicate the long-term refractive outcome.

Otitis media with effusion in an allergic animal model: A functional and morphological study.

OBJECTIVES: Allergy is considered as one of important etiologic factor of otitis media with effusion (OME). In present study, we evaluated the causal effect of allergy on OME in an animal model, and investigated the secondary effect of bacterial infection. METHODS: Allergy and control animals were subdivided into groups with and without intratympanic injection of lipopolysaccharide (IT-LPS). Allergic otitis media was induced via intraperitoneal ovo-albumin injection with intranasal challenge. We assessed the occurrence of OME in allergic animals and the effect of IT-LPS on allergic otitis media. We also investigated the Th1 and Th2 responses in the middle-ear mucosa. Hearing of the animals was measured by ABR and DPOAE. RESULTS: OME was observed in 75% of the allergic animals. After IT-LPS, 100% of the control and allergy groups showed otitis media. Light microscopy revealed that the middle-ear mucosa of animals of both groups also was significantly increased after IT-LPS, and the Th1 response (IL-2 and IFN-γ) and Th2 response (IL-5 and IL-13) cytokines were expressed at higher levels in the allergy group with IT-LPS than in control group with IT-LPS. Hearing tests between the allergy and control group with IT-LPS did not reveal any differences. CONCLUSION: Our findings may be direct evidence of an allergic causal effect on OME. Th2 response cytokines were strongly expressed in allergic OME, and the inflammatory reaction to LPS was more intense in the allergic group, which indicates that otitis media related to allergy can be severely aggravated by an inflammatory reaction to bacterial infection.