Hiroshi Ohtsuki

Accommodative lag under habitual seeing conditions: comparison between myopic and emmetropic children.

PurposeTo determine whether or not myopic children have a larger lag of accommodation than emmetropic children under natural seeing conditions.MethodsIn 61 myopic children (age, 9.5 ± 1.3 years; spherical equivalent refractive error, −6.50 to −1.00u2009D), accommodative response was objectively measured while they were binocularly viewing a target at 50.5, 32.5, 20.9, or 16.0u2009cm (1.98–6.25u2009D) through fully correcting glasses. In the 33 children who habitually wore spectacles, the accommodative responses were also measured while they wore their own spectacles. As controls, 18 emmetropic children were recruited. Accommodative response gradients and lags were compared between the groups after calibration for residual refractive errors and the vertex distance of the glasses.ResultsWith fully correcting glasses, the myopic children showed a larger mean lag of accommodation than the emmetropic children, as well as wide intersubject variation. However, when the children wore their habitual, usually undercorrecting, spectacles, accommodative lags markedly decreased, and a significant correlation was found between residual refractive errors after correcting for the spectacles and accommodative lags. Myopic children with near-point exophoria tended to show smaller lags of accommodation.ConclusionUnder binocular viewing conditions, myopic children when viewing the target through fully correcting glasses tend to show larger lags of accommodation than emmetropic children, but the lags of accommodation are usually reduced by their spectacle undercorrection. Jpn J Ophthalmol 2005;49:189–194

Accommodative Lag Under Habitual Seeing Conditions: Comparison Between Adult Myopes and Emmetropes

PURPOSEnTo clarify whether myopes show poor accommodative response and thus have a larger accommodative lag under natural seeing conditions.nnnMETHODSnForty-three adults without other ocular abnormalities were classified into the early-onset myopia (EOM, n=28) and the emmetropia (EMM, n=15) groups. The subjects wore glasses or contact lenses that they habitually used, and accommodative responses to four accommodative targets (16.0-50.5 cm from their eyes) were measured under a monocular or binocular condition using an open-field infrared autorefractometer.nnnRESULTSnUnder a binocular condition, the accommodative lag for each target was significantly smaller in the EOM group (analysis of variance, P<.01), but the mean slope of the accommodative stimulus-response function did not significantly differ between the EOM and EMM groups (1.05+/-0.11 and 1.02+/-0.10 D/D, respectively). The mean slope under a binocular condition was significantly steeper than that under a monocular condition in both groups (paired t-test, P<.05).nnnCONCLUSIONSnIn adults with EOM, the accommodative stimulus-response function was not impaired, and the habitual accommodative lag was rather small, probably due to the reduced accommodative demand by a vertex distance and/or the intentional undercorrection of spectacles.

Clinical relevance of optineurin sequence alterations in Japanese glaucoma patients.

Purpose:To study the clinical relevance of sequence alterations in the optineurin gene (OPTN) among Japanese patients with open-angle glaucoma, including both primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). Methods:Genomic DNA was isolated from 83 patients with open-angle glaucoma (55 with POAG and 28 with NTG) and 58 control subjects. The 13 exons of OPTN corresponding to the coding region were amplified by polymerase chain reaction and directly sequenced. Clinical factors were compared between glaucoma patients with and without a certain nucleotide change. Results:The reported heterozygous mutations, c.458G > A(Glu50Lys) in exon 4 and c.691_692insAG in exon 6, were not found in any glaucoma patients or control subjects. The reported c.603T > A(Met98Lys) in exon 5 was significantly more prevalent in the POAG (8/55, 14.5%, p = 0.0147) and NTG (4/28, 14.2%, p = 0.0369) patients, and even in both the POAG and NTG patients combined (12/83, 14.4%, p = 0.0149, Fisher exact probability test), than in the control subjects (1/58, 1.7%). The rates of the reported c.1944G > A(Arg545Gln) in exon 16 were not significantly different between open-angle glaucoma patients (3/83, 3.6%) and control subjects (4/58, 6.8%). In addition, a heterozygous change, c.412G > A(Thr34Thr) in exon 4 was found in 18 (21.6%) open-angle glaucoma patients and seven (12.0%) control subjects. Another heterozygous change, c.457C > T(Thr49Thr), in exon 4 was found only in three POAG patients. The 18 open-angle glaucoma patients with c.412G > A showed significantly larger cup-to-disc ratios (p = 0.0178, Mann-Whitney U test), significantly more deteriorated mean deviations of the visual field in the left eye at the final visit (p = 0.0076), and a significantly higher rate of surgery and/or laser history (p = 0.0321, Fisher exact probability test) than the 65 open-angle glaucoma patients without the nucleotide change. Conclusions:Met98Lys is a risk-associated alteration for open-angle glaucoma, including POAG and NTG, in the Japanese population as initially reported. The amino acid-preserving polymorphism, c.412G > A, may be a genetic risk factor for the progression of open-angle glaucoma in this Japanese population.

Accuracy of accommodation in heterophoric patients: testing an interaction model in a large clinical sample

A model of the cross‐link interactions between accommodation and convergence predicted that heterophoria can induce large accommodation errors (Schor, Ophthalmic Physiol. Opt. 1999;19:134–150). In 99 consecutive patients with intermittent tropia or decompensated phoria, we tested these interactions by comparing their accommodative responses to a 2.50‐D target under binocular fused conditions (BFC) and monocular occluded conditions (MOC). The accommodative response in BFC frequently differed from that in MOC. The magnitude of the accommodative errors in BFC, ranging from an accommodative lag of 1.80u2003D (in an esophoric patient) to an accommodative lead of 1.56u2003D (in an exophoric patient), was correlated with distance heterophoria and uncorrected refractive errors. These results indicate that heterophoria affects the accuracy of accommodation to various degrees, as the model predicted, and that an accommodative error larger than the depth of focus of the eye occurs in exchange for binocular single vision in some heterophoric patients.

Downward deviation of progressive addition lenses in a myopia control trial

Purpose:u2002 To clarify how the downward deviation of progressive addition lenses (PALs) reduces their near‐addition effect in schoolchildren participating in a myopia control trial.

ARIX gene polymorphisms in patients with congenital superior oblique muscle palsy

Aim: To identify ARIX gene polymorphisms in patients with congenital superior oblique muscle palsy and to find the relation between the ARIX gene and congenital superior oblique muscle palsy. Methods: The three exons of the ARIX gene were sequenced by genomic DNA amplification with polymerase chain reaction (PCR) and direct sequencing in 15 patients with superior oblique muscle palsy (13 with congenital and two with acquired palsy) and 54 normal individuals. PCR products cloned into plasmids were also sequenced. A family with father and a daughter each having congenital superior oblique muscle palsy was also involved in this study. Results: Four patients with congenital superior oblique muscle palsy carried heterozygous nucleotide changes in the ARIX gene. One patient with the absence of the superior oblique muscle had T7C in the 5′-UTR of the exon 1 and C-44A in the promoter region, both of which were located on the same strand. Another unrelated patient with congenital superior oblique muscle palsy had C76G in the 5′-UTR of the exon 1 and C-9A in the promoter region on the same strand. G153A in the 5′-UTR of exon 1 was found in common in two affected members of a family with congenital superior oblique muscle palsy. This G153A in the 5′-UTR of exon 1 was also present in four unrelated normal individuals. No other heterozygous nucleotide changes were found in normal individuals. Conclusions: The nucleotide change (G153A) in the 5′-UTR of exon 1 co-segregated with congenital superior oblique muscle palsy in one family. Four other nucleotide changes in the exon 1 or the promoter region were found only in patients with congenital superior oblique muscle palsy. These nucleotide polymorphisms may be one of the risk factors for the development of congenital superior oblique muscle palsy.

Myopia Control Trial with Progressive Addition Lenses in Japanese Schoolchildren : Baseline Measures of Refraction, Accommodation, and Heterophoria

PurposeTo describe baseline measures of refraction, accommodation, and heterophoria in Japanese schoolchildren enrolled in a randomized clinical trial that examines whether progressive addition lenses slow myopic progression compared with single-focus lenses.MethodsNinety-five children with myopia between −1.25 and −6.00u2009D spherical equivalent were recruited. Their ages ranged from 6 to 12 years; 46% were girls. The main outcome measure for the trial was progression of myopia determined by cycloplegic (0.5% tropicamide) autorefraction. Accommodative lags and heterophoria were also evaluated.ResultsBecause data were similar in both eyes, they are reported for the right eye only. The mean (±SD) cycloplegic autorefraction (spherical equivalent) was −3.22 ± 1.22u2009D. The cycloplegic subjective refraction was larger (less myopic) than the noncycloplegic subjective refraction by 0.25 ± 0.22u2009D. The mean distance prescription was larger (undercorrection) than the mean cycloplegic autorefraction by 0.74 ± 0.37u2009D. The mean accommodative lag for a 4.74u2009D target was 2.05 ± 0.98u2009D. Near-point esophoria was found in 29 (31%) of the children when their refractive errors were fully corrected with glasses.ConclusionsThe measurements reported herein will serve as a basis for assessing changes that occur over a 3-year follow-up period. Compared with the baseline measurements in the Correction of Myopia Evaluation Trial, clear differences were observed in the mean cycloplegic autorefraction and distance prescriptions. The accommodation and heterophoria data showed characteristics similar to those recently reported in myopic children abroad. Jpn J Ophthalmol 2005;49:23–30

Convergence Accommodation to Convergence (CA/C) Ratio in Patients with Intermittent Exotropia and Decompensated Exophoria

PurposeTo evaluate the convergence accommodation to convergence (CA/C) ratio in strabismic patients and to clarify its clinical implications.MethodsSeventy-eight consecutive patients (mean age: 12.9 ± 6.0 years) with intermittent exotropia and decompensated exophoria who showed binocular fusion at least at near viewing were recruited. The CA/C ratio was estimated by measuring accommodative responses induced by horizontal prisms with different magnitudes under accommodation feedback open-loop conditions. The CA/C ratios were compared with accommodative convergence to accommodation (AC/A) ratios and other clinical parameters.ResultsA linear regression analysis indicated that the mean (±SD) CA/C ratio was 0.080 ± 0.043 D/prism diopter or 0.48 ± 0.26 D/meter angle. There was no inverse or reciprocal relationship between CA/C and AC/A ratios. The patients with lower CA/C ratios tended to have smaller tonic accommodation under binocular viewing conditions and larger exodeviation at near viewing.ConclusionsThe CA/C ratio, like the AC/A ratio, is an independent parameter that characterizes clinical features. A lower CA/C may be beneficial for the vergence control system to compensate for ocular misalignment with minimum degradation of accommodation accuracy.

Transposition of the anterior superior oblique insertion as a treatment for excyclotorsion induced from limited macular translocation.

PURPOSEnTo evaluate the transposition of the anterior superior oblique insertion as a treatment for cyclovertical diplopia accompanied by an awareness of tilted image perceived with the affected eye induced from limited macular translocation (LMT).nnnDESIGNnObservational case series.nnnMETHODSnTransposition of the anterior part of the superior oblique tendon combined with or without vertical muscle surgery on the affected eye was retrospectively studied in seven patients. Clinical outcome was assessed for binocular and monocular vision. A successful result was defined as restoration of single binocular vision (SBV) at distance and near examined with the Bagolini test with disappearance of a tilted image perceived in the affected eye.nnnRESULTSnSix of seven patients (86%) became unaware of tilted image, and three patients (43%) obtained successful results after the strabismus surgery. Of these three patients with successful results, one (33%) patient recognized metamorphopsia, whereas two (67%) of the three patients with unfavorable results reported metamorphopsia. Patients with successful results showed a visual acuity of 20/25 or better in the affected eye and a significantly smaller difference in visual acuity between the two eyes than those patients with unfavorable surgical results (0.133 logarithm of the minimal angle of resolution for SBV(+) vs 0.675 logarithm of the minimal angle of resolution for SBV(-); P =.0255).nnnCONCLUSIONSnThe relatively low success for restoration of SBV indicates that strabismus surgery is recommended for patients whose difference in visual acuity between the two eyes is small and who have a high level visual acuity of the affected eye.

Time-Frequency Analysis of Electronystagmogram Signals in Patients with Congenital Nystagmus

PurposeTo evaluate the usefulness of the short-time Fourier transform (STFT) in the analysis of temporal congenital nystagmus characteristics.MethodsWe carried out an observational case series in patients with congenital nystagmus. An electronystagmogram (ENG) recording was performed for 300s in 13 consecutive subjects with congenital nystagmus (age: 7–68 years). Digitized ENG signals (12 bits, 100Hz) were divided into 2-s segments with a Hanning window, and a Fourier transform was carried out for each segment. The power spectrum obtained for each segment was graphically reconstructed as a function of time. The results were compared among the patients.ResultsClear periodicity in the time-frequency distribution was observed in 3 of the 13 patients (23%). One of the three patients was diagnosed with periodic alternating nystagmus, but the other two patients showed periodicity without alternation of beat direction. No significant difference was observed in clinical characteristics, except for sex, between patients who showed periodicity and those who did not.ConclusionsSome patients with congenital nystagmus showed clear periodicity in the nystagmus waveform without alternation of beat direction. The STFT is a useful tool to evaluate the temporal characteristics of congenital nystagmus in clinics.