Optic neuritis after bee sting

The purpose of this report is to document an unusual case of fully recovered vision after optic neuritis caused by bee sting. A 46-year-old man presented with sudden visual loss after being stung by a bee on the left conjunctiva. He developed optic disc swelling and there was a delay in the P100 wave of the pattern visual evoked potential (VEP). The patient received acute treatment, with intravenous methylprednisolone followed by oral prednisolone. Two days later, visual acuity in the left eye was recovered to 20/20 and P100 latency in pattern VEP was also normalized. Furthermore, visual field and color vision tests revealed no remaining abnormalities. This case suggests that early corticosteroid treatment is effective in optic neuritis caused by bee sting.

Long term refractive outcome in eyes of preterm infants with and without retinopathy of prematurity: comparison of keratometric value, axial length, anterior chamber depth, and lens thickness

BACKGROUND/AIMS

A longitudinal study of premature infants was conducted to examine changes in refractive status and their relation with age and factors influencing the occurrence and degree of myopia. Identification of which of the various refractive factors play important parts in relation to myopia in premature infants was attempted.

METHODS

Under observation were 125 eyes in 65 patients who were found to demonstrate no signs of retinopathy of prematurity (ROP) or who had grade I or II ROP without or after cryotherapy. Cycloplegic refractions were conducted at 6 months, 3 years, and 6 years of age; at 6 years of age keratometric values, lens thicknesses, and axial lengths were recorded, and anterior chamber depths also were measured.

RESULTS

Myopia begins to appear at 6 months of age and its severity increases between the ages of 6 months and 3 years. The condition showed no further progress in subjects older than 3 years. Of the 104 eyes with ROP, those eyes with cicatricial retinopathy tended towards myopia and high myopia while there was no difference in the degree of myopia related to whether or not cryotherapy was conducted. At 6 years of age, the premature infants exhibited shallower anterior chambers, thicker lenses, and higher axial lengths when the degree of the myopia was higher. The keratometric values, however, appeared to bear no relation to the degree of the myopia.

CONCLUSION

These results suggest that the occurrence of myopia is related more strongly to whether or not there is cicatricial retinopathy than whether or not there is cryotherapy. Also, the degree of the myopia was found to be related to the depth of the anterior chamber, the thickness of the lens, and the change in axial length but not to keratometric value.

Synchronization in a system of globally coupled oscillators with time delay

We study the synchronization phenomena in a system of globally coupled oscillators with time delay in the coupling. The self-consistency equations for the order parameter are derived, which depend explicitly on the amount of delay. Analysis of these equations reveals that the system in general exhibits discontinuous transitions in addition to the usual continuous transition, between the incoherent state and a multitude of coherent states with different synchronization frequencies. In particular, the phase diagram is obtained on the plane of the coupling strength and the delay time, and ubiquity of multistability as well as suppression of the synchronization frequency is manifested. Numerical simulations are also performed to give consistent results.

Phakomatous choristoma of the eyelid

This article describes the first report of phakomatous choristoma of the eyelid in Korea. A six-month-old boy underwent excision of a congenital inferonasal orbital mass arising from the left lower lid. A dermoid cyst was suspected, however a diagnosis of phakomatous choristoma was made following conventional histology. An immunohistochemical study of this rare benign congenital tumor was conducted. The cuboidal epithelial cells comprising this choristoma showed strongly positive cytoplasmic staining with S-100 protein and vimentin. They also showed focally positive staining with a neuron-specific enolase, while they showed no immunoreactivity to cytokeratin or epithelial membrane antigen. The results of the immunohistochemical study support the conclusion that this tumor is of lenticular anlage origin.

Synchronization and resonance in a driven system of coupled oscillators

We study the noise effects in a driven system of globally coupled oscillators, with particular attention to the interplay between driving and noise. The self-consistency equation for the order parameter, which measures the collective synchronization of the system, is derived; it is found that the total order parameter decreases monotonically with noise, indicating overall suppression of synchronization. Still, for large coupling strengths, there exists an optimal noise level at which the periodic (ac) component of the order parameter reaches its maximum. The response of the phase velocity is also examined and found to display resonance behavior.

Isolation and identification of the cDNA encoding the pheromone biosynthesis activating neuropeptide and additional neuropeptides in the oriental tobacco budworm, Helicoverpa assulta (Lepidoptera: Noctuidae)

The present study is concerned with cloning and characterizing Has-PBAN cDNA which is 756 nucleotides long, isolated from the brain and suboesophageal ganglion complex (Br-Sg) of Helicoverpa assulta adults. The 194-amino acid sequence deduced from this cDNA possessed the proteolytic endocleavage sites to generate multiple peptides. From the processing of the prepro-hormone, it can be predicted that the cDNA has a PBAN domain with 33 amino acids and four additional peptide domains: 24 amino acid-, 7 amino acid-, 18 amino acid- and 8 amino acid-long sequences, with FXPR (or K) L (X = G, T or S) amidated at their C-termini. The amino acid sequence of all five predicted peptides, including the PBAN, are identical to that of Helicoverpa zea (Raina, A.K., Jaffe, H., Kempe, T.G., Keim, P., Blacher, R.W., Fales, H.M., Riley, C.T., Klun, J.A., Ridgway, R.L., Hayes, D.K., 1989. Identification of a neuropeptide hormone that regulates sex pheromone production in female moths. Science 244, 796-798 and Ma, P.W.K., Knipple, D.C., Roelofs, W.L., 1994. Structural organization of the Helicoverpa zea gene encoding the precursor protein for pheromone biosynthesis-activating neuropeptide and other neuropeptides. Proc. Natl. Acad. Sci., U.S.A. 91, 506-510). A single mRNA species corresponding to the size of Has-PBAN cDNA was detected from the Br-Sg of 1-3-day old female and male adults, and their expression was also at a similar level. Pheromone production was induced upon injection of female or male Br-Sg extracts or synthetic PBAN into the haemocoel of decapitated 1-3-day old female adults during the photophase when they are not supposed to produce pheromone. From these results, H. assulta adult females seem to use their own PBAN for regulating sex pheromone biosynthesis. Functions of the four other peptides ending with FXPR (or K) L in the Has-PBAN cDNA and of the male PBAN remain to be elucidated.

Anatomical and visual results of vitreous surgery for advanced retinopathy of prematurity

We studied the visual acuity and anatomical stability of 101 eyes which had undergone vitreous surgery for advanced retinopathy of prematurity. All were followed up for at least six months. The anatomical and visual results of vitrectomy in 87 eyes were reviewed. The patients' average age at surgery was 9.6 months, and the average follow-up period was 37.6 months. To preserve the structure of the eyeball or to prevent further complications due to a shallow anterior chamber, a further 14 eyes underwent lensectomy. Total attachment was achieved in 20 eyes(23.0%), and partial attachment in 24(27.6%). Finally, 42 eyes(48.3%) were able to perceive light, while fixation and following occurred in 15(17.2%). Six eyes(6.9%) were able to identify form. The relatively useful vision achieved in cases of advanced retinopathy of prematurity in this study with long follow-up suggests that the rationale of vitreous surgery is to salvage functional retina and to prevent total blindness and other complications.

Fracture analysis of cast pure Ti and Ti-6Al-4V alloy for dental use

The fracture behavior of cast two types of pure Ti and Ti-6Al-4V alloy was understood by acoustic emission (AE) analysis during a fracture toughness test. Specimens for test were cast by the lost wax method using a specially designed Ti casting machine of pressure-different method for dental use. A fatigue crack was inserted from the machined notch tip into the body of a specimen in the range of 0.45-0.55 a/W. Acoustic emission signals released during the fracture toughness test were detected by two sensors attached to both ends of the specimen. Then the signals were recorded and analysed by the PAC 3000/3104 system. From the early stage of the fracture toughness test, AE signals started to be released in all types of specimens tested. A reaction layer with the investment materials of about 50-100 microns was thought to be the result of the AE release from an early stage of the fracture toughness test. A microfracture behavior of the cast pure Ti and Ti alloys was proposed based on the results obtained from the AE releasing pattern and fracture surface findings.

Management of chronic hypotony following trabeculectomy with mitomycin C

Chronic hypotony is marked by decreased vision and late-onset leaking bleb after filtration surgery using topical mitomycin C; to manage this condition we followed a three-step approach: first, intrableb autologous blood injection; second, surgical exploration and additional suturing of the scleral flap; third, excision of the cystic bleb and advancement of a fornical conjunctival flap. For the avascular flap cystic blebs of five patients. In three of the six eyes, there was no increase of intraocular pressure (IOP); two eyes showed massive hyphema and were mildly resistant to the injection of autologous blood, and in one, a leaking hole was seen in the bleb wall two days after the injection of blood. Two eyes of three in which blood injection had failed, and another, in which the bleb had spread over more than half the eyeball, and which was the patient's only sighted eye, underwent the second step of the procedure. The remaining leaking eye, in which blood injection had been complicated, and another, in which spontaneous leakage from a thin avascular bleb had occurred, were subjected to the third step. After each of the three approaches, IOP increased on average from 1.67 to 5.67 mmHg, from 2.33 to 11.33 mmHg, and from 1.5 to 7 mmHg, respectively; each approach successfully improved vision. Intrableb autologous blood injection is a simple procedure for the management of chronic overfiltration and a way of determining whether excessive filtration is occurring through the scleral flap, in which case additional suturing is required, or in another way. Depending on the status of the bleb, additional suturing or excision of the cystic bleb and advancement of the fornical conjunctival flap are useful modalities for the treatment of late-onset leaking filtration bleb.

Effects of postoperative mitomycin C eyedrop on trabeculectomy in refractory glaucoma patients

To investigate the effects of postoperative mitomycin C (MMC) eyedrop as an adjunct to intraoperative MMC in refractory glaucomas, 15 eyes of 14 glaucoma patients (age; 47.0 +/- 15.5 years) in need of trabeculectomy were studied. Preoperative diagnoses were secondary glaucoma to uveitis in seven patients, neovascular glaucoma in four, pseudophakic glaucoma in three, and aphakic glaucoma in one. Six patients who had neovascular glaucoma or history of a failed trabeculectomy with intraoperative 0.2 mg/ml MMC received intraoperative 0.4 mg/ml MMC. The others received 0.2 mg/ml MMC for 3 minutes. During the follow-up period, postoperative MMC eyedrop was applied, depending on the condition of the filtration bleb. The eyedrop was 0.2 or 0.4 mg/ml, applied four times a day for one week. The follow-up period was 18.1 /+- 7.4 months. The success rates were 93.3%, 86.7%, and 78.0% at postoperative 1, 4, and 18 months, respectively. There was neither early hypotony nor wound leak. Corneal epithelial defects (26.7%), corneal ulcers (6.7%), and cataracts (6.7%) were, however, observed. Postoperative MMC eyedrop application was a convenient and effective adjunct to intraoperative MMC in refractory glaucomas.

Induction of vitreolysis and vitreous detachment with hyaluronidase and perfluoropropane gas

To simulate the posterior vitreous detachment (PVD) in the rabbit, 1 IU hyaluronidase and/or 0.2 ml of perfluoropropane gas was intravitreally injected. Ophthalmoscopic, light microscopic examination prepared by cryotechnique, electron microscopic examination, and electroretinogram were done on the 3rd and 28th postoperative days. As a result, the eyes undergone simultaneous intravitreal injection of 1 IU hyaluronidase and 0.2 ml perfluoropropane gas showed membranous structure split from the internal limiting membrane of the superior retina in 3 days after injection. The eyes also demonstrated membranous structure separated from the superior retina after 28 days, simulating vitreous detachment. On the contrary, neither agent alone induced vitreous detachment. No toxic retinal changes associated with simultaneous intravitreal injection of 1 IU hyaluronidase and 0.2 ml perfluoropropane gas were observed. Therefore, with a future support by histologic examination other than cryotechnique and by immunohistochemical analysis, the simultaneous intravitreal injection of perfluoropropane gas and hyaluronidase would be a promising method to induce vitreous detachment in non-vitrectomized eye.

Dacryocystitis associated with nasolacrimal duct cyst

An infant presented with persistent epiphora after successful probing of the lacrimal system. Examination of the nose showed a cystic structure occluding lower portion of the lacrimal drainage system. In cases of recurrent obstruction, nasal examination and endoscopic marsupialization may help guide the clinician towards the most appropriate treatment.

Distinction between benign and malignant causes of cervical, axillary, and inguinal lymphadenopathy: value of Doppler spectral waveform analysis

OBJECTIVE

Vessels in inflamed lymph nodes are dilated compared with vessels in lymph nodes involved with metastases, which may be compressed by tumor cells. Accordingly, we hypothesized that the Doppler spectral waveform might be different in lymph nodes involved by benign disease and those involved by metastases. We compared spectral waveforms of benign and malignant superficial lymphadenopathy to determine the value of color Doppler sonography in distinguishing between the two.

SUBJECTS AND METHODS

Palpable superficial lymph nodes (41 cervical, one axillary, one inguinal) of 43 untreated patients were prospectively evaluated with color Doppler sonography. We measured resistive index, pulsatility index, peak systolic velocity, and end diastolic velocity from the fastest or next fastest arterial signal in the lymph node that showed the most vigorous flow. Final diagnosis was established by pathologic examination (n = 24) and clinical follow-up (n = 19).

RESULTS

Color Doppler sonography showed blood flow in all cases. The mean resistive index was 0.92 +/- 0.23 in lymph nodes involved with metastases and 0.59 +/- 0.11 in lymph nodes affected by benign processes. The mean pulsatility index was 2.66 +/- 1.59 in lymph nodes involved with metastases and 0.90 +/- 0.23 in lymph nodes affected by benign processes. Lymph nodes involved with metastases showed a characteristic high resistive index (> 1.0) and a high pulsatility index (> 1.5) in 10 of 13 cases. Lymph nodes affected by benign processes showed a low resistive index (< 0.8) and a low pulsatility index (< 1.5) in all cases. The resistive indexes and pulsatility indexes were significantly different (p < .005) between lymph nodes affected by benign versus malignant disease. The mean peak systolic velocity was 25 +/- 11.7 cm/sec in lymph nodes involved with metastases and 24 +/- 16 cm/sec in lymph nodes affected by benign processes. The mean end diastolic velocity was 2 +/- 6.7 cm/sec in lymph nodes involved with metastases and 10 +/- 9.5 cm/sec in lymph nodes affected by benign processes. Although the peak systolic velocities were not significantly different, the end diastolic velocities were significantly different (p < .005) between the two types of lymph nodes.

CONCLUSION

Our results suggest that superficial lymphadenopathy due to benign and malignant diseases can be distinguished with a high degree of accuracy (p < .005) by means of spectral waveform analysis. Color Doppler sonography is a useful adjunct to routine sonography. Lymph nodes with a high resistive index are almost always involved by metastases.