Analysis of clinical characteristics, prognosis and antibody pathogenicity of pemphigus patients positive for anti-desmoglein IgG autoantibodies in remission: a retrospective cohort study

BACKGROUND

The detection of serum anti-desmoglein (Dsg) IgG autoantibodies has been reported to be useful for assessment of disease activity in pemphigus. However, previous studies have reported that anti-Dsg autoantibodies remain detectable in some patients without active pemphigus lesions.

OBJECTIVES

To investigate the clinical characteristics and antibody pathogenicity of pemphigus patients positive for anti-Dsg IgG autoantibodies in remission.

METHODS

We retrospectively investigated pemphigus patients with a history of clinical remission who visited the Department of Dermatology of Keio University during 2019 and 2020. The antibody pathogenicity was assessed by bead aggregation assay.

RESULTS

When patients were recognized as having entered remission (PDAI = 0 and PSL ≦ 10 mg/day for 2 months), serum autoantibodies against Dsg were detected in 72 of 132 patients (54.5%, positive group; PG), but were not detected in 60 patients (45.5%, negative group; NG). Anti-Dsg antibody titres in remission declined from the active phase in 33 patients in the PG for whom data were available. There were no differences in the chance of reducing PSL to 5 mg/day (P = 0.885) and rate of relapse (P = 0.279) between PG and NG, but fewer patients in PG discontinued corticosteroids (P = 0.004). The ability of patients' sera to block aggregation of Dsg/desmocollin beads was significantly reduced in remission compared to the active phase. However, our results revealed that whole sera in remission still had pathogenic activity in seven of nine patients, and the approximately equal amounts of anti-Dsg antibodies in active phase and remission showed similar pathogenicity.

CONCLUSIONS

This study will provide guidance in cases where autoantibodies are found to be positive in pemphigus patients during remission or steroid reduction.

Basement membrane zone IgE deposition is associated with bullous pemphigoid disease severity and treatment results

BACKGROUND

A subset of patients with bullous pemphigoid (BP) show deposition of IgE in the basement membrane zone (BMZ), yet the relationship between BMZ IgE and the clinical presentation of BP remains unclear.

OBJECTIVES

To investigate the relationship between IgE deposition, IgE levels in serum, and disease severity in patients with BP.

METHODS

We investigated IgE autoantibodies in 53 patients with BP by direct immunofluorescence (DIF), indirect immunofluorescence and enzyme-linked immunosorbent assay.

RESULTS

Of 53 patients with BP, 23 (43%) had IgE deposition, 10 (19%) of whom were IgE+ and 13 (25%) IgE± according to DIF analyses. Erosion/blister (E/B) Bullous Pemphigoid Disease Area Index (BPDAI) scores were significantly higher in IgE+ patients than in IgE- patients (n = 15), while no significant differences were found for urticaria/erythema BPDAI scores. IgE+ and IgE± patients took longer to reduce their E/B BPDAI score by 75% after systemic corticosteroid treatment. BP180-IgE levels were significantly higher among IgE+ patients than IgE± or IgE- patients (n = 10). Total IgE levels in the serum and blood eosinophil counts did not differ between IgE+, IgE± and IgE- patients. A significant correlation was detected between BP180-IgG and BP180-IgE, but not between BPDAI scores and any of BP180-IgG, BP180-IgE or blood eosinophil count.

CONCLUSIONS

IgE deposition in the BMZ is associated with higher E/B BPDAI scores and longer treatment periods. We conclude that IgE binding in the BMZ may contribute to BP pathogenesis by promoting blister formation. What's already known about this topic? BP180-IgE autoantibodies have an important role in the pathogenesis of bullous pemphigoid (BP). A subset of patients with BP display deposition of IgE within the basement membrane zone (BMZ) of skin tissue. What does this study add? Patients with in vivo IgE deposition in the BMZ displayed higher erosion/blister Bullous Pemphigoid Disease Area Index (BPDAI) scores, while urticaria/erythema BPDAI scores were not significantly different. Patients with in vivo IgE deposition in the BMZ took longer to reduce their erosion/blister BPDAI score by 75% after systemic corticosteroid treatment. BP180-specific IgE levels in serum were higher among patients with linear IgE deposition in the BMZ than in those with granular or no IgE deposition.

Alopecia as a rare but distinct manifestation of pemphigus vulgaris

BACKGROUND

Pemphigus vulgaris (PV) patients may develop scalp erosions, however, the development of alopecia has been reported to be extremely rare.

OBJECTIVE

To delineate the clinicopathological features of alopecia in PV and provide insight into the pathogenesis of this rarely observed manifestation.

METHODS

A retrospective case note review was performed on five PV patients presenting with progressive hair loss and alopecic patches. Data were collected on demographics and clinical findings. Results for hair pull tests, direct immunofluorescence study of plucked hairs, established laboratory tests to detect anti-desmoglein 1 and 3 autoantibodies and scalp swab culture were recorded. A combination of vertical and horizontal sectioning technique enabled detailed histopathological analysis of alopecic patches. Clinical course was monitored.

RESULTS

Anagen hair follicles with the outer root sheath structure were easily pulled from perilesional scalp, with intercellular IgG deposition on the outer root sheath keratinocytes. Acantholysis between outer root sheath keratinocytes extending from the infundibulum to suprabalbar level was evident in anagen hair follicles of affected lesions. Perifollicular cell infiltration was observed in the lesions where scalp swabs detected micro-organisms. The bulge stem cell area was mostly intact. Alopecia was non-scarring and following 4 weeks of therapy hair re-growth was seen in all patients.

CONCLUSION

In PV, the combination of anti-desmoglein autoantibody-mediated acantholysis in conjunction with secondary factors, such as inflammatory changes due to infection, may cause weakening of hair follicle anchorage resulting in hair loss and alopecic patches. This unusual clinical phenotype should alert physicians to PV as a potential diagnosis.

Anti-desmoglein IgG autoantibodies in patients with pemphigus in remission

BACKGROUND

Desmoglein (Dsg) enzyme-linked immunosorbent assay (ELISA) is a highly sensitive and specific method to detect anti-Dsg3 and anti-Dsg1 IgG autoantibodies in pemphigus vulgaris (PV) and pemphigus foliaceus (PF), respectively. Whereas ELISA index values fluctuate in parallel with disease activity, ELISA positivity during clinical remission has been observed.

OBJECTIVE

To determine the prevalence of positive Dsg ELISA index values during clinical remission. To ascertain how positive Dsg ELISA scores during remission compare with those during active disease.

METHODS

Dsg ELISA was performed on serum samples of PV and PF patients taken during remission (lesion-free >or= 3 months on <or= 15 mg or <or= 5 mg/day prednisolone) and active disease. We used a modified ELISA protocol with optimal serum dilutions in sera with very high initial index values, as we previously described.

RESULTS

When remission was defined as no eruption >or= 3 months with <or= 15 mg/day prednisolone, 20 of 43 PV patients (46.5%) and 4 of 12 PF patients (33.3%) showed Dsg3 and Dsg1 ELISA positivity, respectively. With <or= 5 mg/day, 6 of 17 PV (35.3%) and 1 of 6 PF patients (16.7%) showed Dsg3 and Dsg1 ELISA positivity, respectively. The index value of each ELISA-positive remission serum was consistently lower than that of its corresponding active disease serum. We observed consistent correlation between ELISA index values and indirect immunofluorescence titres.

CONCLUSIONS

Circulating anti-Dsg IgG autoantibodies are found in a considerable percentage of pemphigus patients in remission, who have high levels of antibody production during active stages.

The first case of cutaneous mucormycosis caused by Rhizopus azygosporus

A rapidly enlarging leg ulcer appeared in a 54-year-old woman with systemic lupus erythematosus receiving aggressive immunosuppressive therapy. Skin biopsy revealed proliferation of hyphae in the midst of a neutrophilic abscess. Culture yielded Rhizopus azygosporus. As no organ involvement was detected by thorough examination, the patient was diagnosed as having primary cutaneous mucormycosis. Although intravenous amphotericin B therapy seemed to be very effective, it had to be discontinued due to nephrotoxicity. She unfortunately died of subsequent disseminated fungal infection and cerebral infarction in which the primary cause could not be determined. Minimum inhibitory concentrations of several antifungal drugs to the isolate were examined and amphotericin B proved to be the only agent that may potentially reach the effective plasma concentration. This is the first case report of cutaneous mucormycosis caused by R. azygosporus.

[Pulmonary complications following laparoscopic cholecystectomy in patients with abnormal spirometry]

The purpose of this study was to determine the incidence of postoperative pulmonary complications (PPC) and the value of preoperative spirometry to predict PPC after laparoscopic cholecystectomy. Sixty-four of 1372 patients (8%) showed abnormal spirometry data. One out of 1372 patients developed aspiration pneumonia. The patient had high risk factors for serious PPC such as ASA physical status 4.84 y/o, longer anesthesia duration (230 min), multiple brain infarction and low albuminemia. Thirty to 39% of patients with abnormal spirometry showed less severe PPC such as atelectasis, lung collapse and pleural effusion, and incidence was the similar with normal lung function patients. Postoperative blood gas analysis showed a slight increase in arterial carbon dioxide tension during oxygen therapy. However, none of the patients with abnormal spirometry and less severe PPC developed manifest PPC (pneumonia, respiratory failure). Less severe PPC disappeared within second to third postoperative days. We conclude that laparoscopic intervention significantly reduced the incidence of severe PPC and the preoperative spirometry was not recommended in patients with no pulmonary symptoms.

Mathematical and optimal clustering of test points of the central 30-degree visual field of glaucoma

PURPOSE

To determine a mathematically optimal sector pattern of the central 30 degree visual field for the follow-up of glaucomatous visual field change based on a large number of actual visual field test data of patients with glaucoma.

METHODS

Visual field test data obtained from 1,039 eyes of 1,039 patients with open-angle glaucoma (OAG) using the 30-2 program of the Humphrey Field Analyzer were used for sectorization of the central 30 degree visual field. Of the 1,039 visual field data, 698 (modeling data) were used for determining the sector pattern and 341 (testing data) for checking the sector pattern. The modeling data were further divided into three groups according to the mean deviation (MD) (MD > or = -10 dB, -20 < or = MD < -10 dB, and MD < -20 dB), and the sector pattern was constructed from visual field data of each group using a clustering procedure called VARCLUS. The testing data were used for determining the optimal sector pattern. In a separate set of repeated visual field data of 303 patients with OAG, the fluctuation of MD, sector values of each sector determined, and total deviation of each test point were calculated and compared.

RESULTS

The sector pattern constructed from visual field data of MD > or = -10 dB summarized the visual field performance most effectively. The fluctuation of the sector value of each sector was roughly 1.5 times smaller than the total deviation of each test point.

CONCLUSION

The sector pattern determined may be useful in analyses of the visual field data of patients with glaucoma.

Changes in ocular surface caused by antiglaucomatous eyedrops: prospective, randomised study for the comparison of 0.5% timolol v 0. 12% unoprostone

AIM

To study changes induced in ocular surface epithelia and the tear film by antiglaucomatous eyedrops. A beta blocker (0.5% timolol) and a novel prostaglandin F(2alpha) metabolite related drug (0.12% unoprostone) were examined in a prospective, randomised fashion.

METHODS

40 patients were randomly assigned to use either 0. 5% timolol (timolol group) or 0.12% unoprostone eyedrops (unoprostone group) twice a day for 24 weeks. In addition to routine ocular examinations, corneal epithelial integrity (vital staining tests, tear film break up time (BUT), anterior fluorometry, specular microscopy) and tear function (Schirmer's test, cotton thread test, tear clearance test (TCT)) were examined before and after the treatment.

RESULTS

Both eyedrops caused significant reduction in intraocular pressure from the baseline levels. No significant changes were noted in corneal integrity in both groups, except a decrease in BUT at 20 weeks in the timolol group. The timolol group demonstrated significant decreases in Schirmer's test, tear clearance test, and tear function index (Schirmer's test value multiplied by clearance test); however, no such changes were noted in the unoprostone group.

CONCLUSION

While unoprostone eyedrops caused no adverse effects on the corneal epithelial integrity and tear function, timolol caused significant impairments in tear production and turnover.

Trabeculectomy with mitomycin C for post-keratoplasty glaucoma

AIM

To investigate the effect of trabeculectomy with and without mitomycin C in post-keratoplasty glaucoma.

METHODS

A retrospective study was performed on patients who underwent trabeculectomy for glaucoma after penetrating keratoplasty. 34 eyes of 32 patients were included in this study. 26 eyes received trabeculectomy with mitomycin C and eight eyes without mitomycin C. The procedure was deemed successful if the intraocular pressure was maintained below 21 mm Hg with or without use of additional antiglaucoma medication (mean follow up time 22.3 (SD 10.3) months).

RESULTS

At the last examination trabeculectomy was successful in 19 of 26 eyes (73.0%) with mitomycin C (+) and two of eight (25.0%) without (p=0.0219). When the prognosis was analysed by Kaplan-Meier curve, the mitomycin C (+) group showed a better prognosis (p=0.0182). Mean intraocular pressure and average number of glaucoma medications improved in the group with mitomycin C without severe side effects on the graft. Graft rejection after trabeculectomy was seen in two eyes in the mitomycin C group. Final graft clarity rate was 69.2% (18/26) in the mitomycin C (+) group and 37.5% (3/8) in the mitomycin C (-) group. Complications such as persistent epithelial defect, cystoid macular oedema, choroidal detachment, leakage from bleb were seen in four eyes in the mitomycin C (+) group and in one eye in the mitomycin C (-) group.

CONCLUSIONS

Trabeculectomy with mitomycin C showed better results for glaucoma following keratoplasty.

Effects of oral brovincamine on visual field damage in patients with normal-tension glaucoma with low-normal intraocular pressure

PURPOSE

To prospectively study the effect of oral brovincamine, a relatively selective cerebral vasodilator, on further deterioration of visual field in patients with normal-tension glaucoma (NTG) with low-normal intraocular pressure (IOP).

METHODS

Fifty-two patients with NTG (average age 57.7 years) with an IOP that was consistently less than 15 mmHg were randomly assigned to receive oral brovincamine (20 mg three times daily) or to an untreated control group. The groups were prospectively followed for 2 years with visual field examinations every 4 months, using the 30-2 Humphrey perimeter program. Changes in mean deviation (MD), corrected pattern standard deviation (CPSD), and total deviation (TD) at 74 test points were analyzed using regression analysis with linear mixed model. Data from one eye without media opacity of each subject were analyzed.

RESULTS

There were no differences between groups in age; sex distribution; refraction; blood pressure; baseline IOP; MD, CPSD, or TD at each point. Changes in MD (standard error [SE]) during the study period were -0.778 (0.178) and -0.071 (0.195) dB/year in the control and brovincamine groups, respectively; change in the control group was significantly more negative than in the brovincamine group. Change in CPSD (SE) was 0.032 (0.015) and 0.004 (0.016) dB/year in the control and brovincamine groups, respectively. Change in the control group was significantly positive, but the intergroup difference was not significant. Change in TD was significantly negative at six test points in the control group, whereas no points showed a significant trend in the brovincamine group; the intergroup difference was significant. The average IOP was 13.2 mmHg and 13.1 mmHg in the control and brovincamine groups, respectively, and there was no significant intergroup difference.

CONCLUSION

Oral brovincamine may retard further visual field deterioration in patients with NTG who have low-normal IOP.

[Effect of non-surgical ocular hypotensive therapy in normal-tension glaucoma]

We investigated the effects of the topical ocular hypotensives with or without half circumference argon laser trabeculoplasty (ALT) on intraocular pressure (IOP) of normal-tension glaucoma (NTG) eyes. Seventy-two NTG patients whose pretreatment mean IOP was > or = 15 mmHg at least in one eye were included and one randomly chosen eye from one patient were used for analysis. They were followed for at least 15 months after commencement of the therapy. The mean pretreatment IOP averaged 17.2 +/- 1.6 mmHg (mean +/- standard deviation, n = 72). All eyes were first treated with topical 2% carteolol. In eyes where IOP reduction was considered unsatisfactory, topical 1% pilocarpine or 0.04% dipivefrine was added. In eyes where IOP reduction was still unsatisfactory even with the two medications, half circumference ALT was performed. Mean IOP reduction was 1.5 mmHg in the eyes treated with topical medications alone and 2.5 mmHg in those treated by topical medications plus ALT. The mean outflow pressure reduction was 16 and 26%, respectively. In 40% of the all eyes, satisfactory IOP reduction was obtained by topical medications with or without additional ALT.

Visual field defects in normal-tension and high-tension glaucoma

BACKGROUND

Differences in visual field characteristics between normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) have not been established. This study re-examined the problem by pointwise between-group comparison of data obtained with the Humphrey 30-2 program.

METHODS

Sixty-eight NTG cases with maximum intraocular pressure (IOP) of 21 mmHg or lower and 62 HTG cases with maximum IOP of 25 mmHg or greater with a mean deviation (STATPAC) greater than -10 decibels (dB) were included. Age, refraction, mean deviation, or sex ratio were matched between the two groups. Total deviation (STATPAC), the difference between the measured threshold and the age-corrected normal reference at each test point of the 30-2 program, was used for pointwise between-group comparisons. Another parameter, total deviation - mean total deviation, was introduced to normalize the total deviation by the overall visual field damage as an index of disease stage. Mean total deviation is the average of total deviations across the test field. Further, logistic discriminant analysis was applied to confirm that the difference at a questioned test point was due to the difference of disease type, but not disease stage, between the two groups.

RESULTS

Comparison using total deviation and total deviation - mean total deviation gave similar results, which were collaborated by logistic discriminant analysis. For a given amount of visual field damage, an area just above the horizontal meridian was significantly more depressed in NTG, while HTG had significantly more diffuse visual field damage.

CONCLUSION

Visual field defect of NTG differs from that of HTG, which may suggest that different regions of the optic disc are more susceptible to damage in NTG.

[The central visual field defects in low-tension glaucoma. A comparison of the central visual field defects in low-tension glaucoma with those in primary open angle glaucoma]

To discover if there is difference in central visual field damage between low-tension glaucoma (LTG) and primary open angle glaucoma (POAG) eyes, the data obtained with the 10-2 threshold program of the Humphrey visual field analyzer were analysed using logistic discriminant analysis. One hundred and four LTG eyes from 65 case (maximum IOP < or = 21 mmHg) and 48 POAG eyes from 34 cases (maximum IOP > or = 25 mmHg) with early to moderately advanced visual field damage were included. There was no significant difference in mean deviation (MD, STATPAC), refraction, or age between the 2 groups. The analysis demonstrated that an arcuate area in the upper central 5-10 degrees of the visual field was significantly more depressed in LTG than in POAG eyes.

Diurnal variation in intraocular pressure of normal-tension glaucoma eyes

BACKGROUND

The nature of intraocular pressure (IOP) in normal-tension glaucoma (NTG) has not been studied in detail, although the information on the IOP is indispensable for diagnosis and treatment of NTG.

METHODS

After at least six IOP measurements at daytime clinic, diurnal IOP was measured at 10:00 AM, 12:00 noon, 2:00, 4:00, 6:00, 8:00, 10:00 PM, 12:00 midnight, and at 3:00, 6:00, 8:00, and 10:00 AM by 1-day hospitalization in 118 NTG suspects. Four subjects with peak IOPs exceeding 21 mmHg were diagnosed as primary open-angle glaucoma (POAG) whose eyes all had mean clinic IOPs above 16 mmHg. The remaining 114 patients were diagnosed as having NTG, and their right eye data were used for analysis.

RESULTS

The rhythmic nature of the diurnal IOP of NTG was analyzed by fitting the data to a cosine curve. In 54.4% of the eyes, the correlation between the measured IOP and the values predicted from the cosine curve was significant (r > 0.60, P < 0.05), and the equation, diurnal IOP = 13.9 + 1.7 cos 2 pi (t/24-0.40) mmHg, which was similar to that reported in normals, was obtained. Multiple regression analysis showed that the mean diurnal IOP was best predicted with the mean of the six clinic IOPs and systolic blood pressure (R2 = 0.67), and the peak diurnal IOP with the mean of six clinic IOPs (R2 = 0.50). The estimate fell within +/- 1 and +/- 2 mmHg of the actual value in 83% and 96% of the left eyes for the former and in 69% and 93% for the latter, respectively. No eyes with peak diurnal IOP exceeding 21 mmHg were overlooked with the cutoff IOP of 16 mmHg.

CONCLUSION

The mean and peak diurnal IOP could be predicted with the mean of clinic IOPs.

[A study of para-foveal color vision in normal-tension and primary open angle glaucoma eyes]

A perimetric color vision test developed by Iijima et al. for evaluating parafoveal color vision provides information regarding local retinal function which can not be evaluated by other color vision tests. Using this method, we investigated para-foveal color sensitivity in normal-tension glaucoma (NTG) and primary open angle glaucoma (POAG) eyes whose glaucomatous visual field change determined with the central 30-2 program of the Humphrey visual field analyzer was confined to either the upper or the lower hemifield. The examined eyes had no abnormalities in ocular media with best corrected visual acuity of 1.0 or higher, and age, refraction, mean deviation, and extent of visual field loss were matched between NTG and POAG eyes. In the para-foveal area of the spared hemifield, acquired blue-yellow dyschromatopsia was detected in 52.3% of the POAG eyes and in 11.3% of the NTG eyes (p < 0.02, chi 2-test), and in damaged hemifield, it was found in 76.1% of the POAG eyes and 80.7% of the NTG eyes. We suggest that visual function is more diffusely damaged in POAG than in NTG and that the perimetric color vision test is useful for detecting glaucomatous damage which cannot be detected with conventional light threshold measurements.

[A comparative study of visual field damage in low-tension and primary open-angle glaucoma]

We compared the results of visual field examination obtained with a Humphrey 30-2 program between 57 eyes of 57 low-tension glaucoma (LTG) and 57 eyes of 57 primary open-angle glaucoma (POAG; max IOP > or = 25 mmHg) cases, whose mean deviation (MD) given by STATPAC was > -10 dB. MD, age, and refraction showed no differences between the two groups. Corrected pattern standard deviation (CPSD) was significantly higher in the LTG group (p < 0.01). The total deviation (TD), deviation from the age-corrected normal reference, was found to be significantly lower by about 5 dB in the LTG group at two test points nasal-superior to the fixation point (Wilcoxon rank sum test, p < 0.01). Logistic discriminant analysis carried out to exclude a subtle difference in the distribution of the stage of disease between the two groups confirmed a significant between-group difference at the above-mentioned points. Furthermore, to compare the unevenness of visual field in the two groups, [TD-mean TD] was calculated, where mean TD was the average of 70 points of TD excluding the uppermost four points, and the same two points obtained above were found to decrease significantly in LTG, while all points were diffusely damaged in POAG. These results may imply a difference in the mechanism of visual field damage between LTG and POAG.

[Combined posterior chamber intraocular lens implantation and trabeculectomy--a life-table analysis of postoperative clinical course]

Postoperative courses of 68 eyes of 58 glaucoma patients who underwent posterior chamber intraocular lens implantation combined with trabeculectomy were studied retrospectively. The visual acuity was 0.5 or better in 66% of the eyes at 3 months postoperatively. The average intraocular pressure (IOP) was below 15 mmHg till 16 months postoperatively. An analysis of the postoperative course using the life-table method of Kaplan-Meier revealed that the probability of successful IOP control with medication was 83% at 18 months and 47% without medication. The subjects aged 75 years or older showed significantly higher success probability than those younger than 75 years, while types of glaucoma, the preoperative IOP control, location of conjunctival or sclerocorneal incision, postoperative 5-fluorouracil (5-FU) injections or surgical intervention on the iris had no significant effects on the probability of successful IOP control. The probability of subsistence of functional filtering bleb was 24% at 18-month follow-up, on which postoperative administration of 5-FU of 35 mg or more had a favorable effect.

[Relationship of the office intraocular pressure (IOP) to diurnal fluctuation of IOP in low-tension glaucoma: a multivariate analysis]

In 288 eyes of 114 low-tension glaucoma (LTG) patients, the mean, peak, trough and magnitude of the diurnal fluctuation of the intraocular pressure (IOP) determined over a period of 24 hours (diurnal IOP) were correlated with the IOPs recorded at the daytime office (office IOP), refraction, extent of visual field loss, age, sex, blood pressure and obesity index by the method of multivariate analysis. Only the mean office IOP was found to have a statistically significant contribution for estimating the mean, peak and trough of the diurnal IOP with the proportion (R) of 0.71 0.67 and 0.68 respectively. Furthermore, an analysis of the IOP data obtained from 118 LTG suspects using the receiver operating characteristics (ROC) curve showed that a patient whose peak diurnal IOP exceeds 21 mmHg could be detected with a sensitivity of 100% and a specificity of 46% if around-the-clock IOP measurements were carried out in patients whose mean office IOP are above 16 mmHg at least in one eye. In view of high prevalence of LTG in Japanese, estimation of mean diurnal IOP from mean office IOP and exclusion of primary open angle glaucoma using the mean office IOP of 16 mmHg as a cutoff IOP level are thought to be clinically useful.

A comparative study of optic nerve head in low- and high-tension glaucomas

The disc and rim areas in 15 eyes from 15 selected low-tension glaucoma (LTG) patients were compared with those in 15 eyes from 15 selected high-tension glaucoma (HTG) patients. In all patients, visual field defects (VFD) were at an early stage (mean deviation greater than -5 dB, program 30-2 of Humphrey Visual Field Analyzer, STATPAC) and were confined to either the upper or lower hemifield. There were no significant differences in the degree of VFD between LTG and HTG, and the peak intraocular pressure averaged 18.9 and 29.2 mmHg for LTG and HTG eyes, respectively. The disc and rim areas were determined from stereoscopic disc photographs using the method of Littman. The half rim area corresponding to the upper or lower hemifield without VFD was significantly smaller for LTG than HTG (LTG 0.26 +/- 0.08 mm2, HTG 0.31 +/- 0.08 mm2, mean +/- SD, n = 15, P less than 0.005). The rim area corresponding to the upper or lower hemifield with VFD was also significantly smaller for LTG than HTG (LTG 0.19 +/- 0.08 mm2, HTG 0.24 +/- 0.08 mm2, P less than 0.01). On the other hand, there was no significant difference in the disc area between LTG and HTG (LTG 1.96 +/- 0.57 mm2, HTG 2.03 +/- 0.45 mm2, P greater than 0.4). It was suggested that the differences in rim area were already present prior to the manifestation of the VFD.

[Diurnal variation of intraocular pressure in low tension glaucoma]

Around-the clock intraocular pressure (IOP) measurement were performed in 104 eyes of 52 low tension glaucoma (LTG) cases. Subjects were all hospitalized and IOP measurements were done every 2 hours from 6:00 AM to 12:00 PM and every 3 hours from 12:00 PM to 6:00 AM. All LTG patients met the following criteria, (1) glaucomatous optic nerve head change and corresponding visual field defect, (2) normal open angle, (3) IOP less than or equal to 21mmHg at any time of IOP measurement, (4) no obvious neurological or rhinological disorders that could affect the optic nerve, (5) no history of hemodynamic crisis or cardiovascular disorders except mild hypertension. Peak IOPs were most frequently observed at 10:00 AM, but about 55% of all observed peaks were in the time period from 6:00 PM to 8:00 AM. Most troughs were observed from 2:00 PM to 10:00 PM. The mean IOP, the diurnal variation and the difference between both eyes in the same person averaged 14.1, 4.9, and 0.6mmHg, respectively. Assuming that the period of rhythm is 24 hours, the results of IOP measurements fitted a cosine curve using the least square method. In 44% of all eyes, significant correlation coefficient (r greater than or equal to 0.6, p less than 0.05) between the measured and the predicted IOPs was noted, and an equation, IOP = 14.3 + 1.7cos 2 pi (t/24-0.4 radian), was obtained. Comparing the present results with former ones, we concluded that the IOP changes in LTG patients were similar to those in normal individuals.

[The influence of the intraocular pressure on the visual field of low tension glaucoma]

To study the effect of the intraocular pressure (IOP) on the visual field (VF) damage in low tension glaucoma (LTG), we compared the IOP and the VF damage in both eyes of 46 LTG patients. As an index of the VF damage, we used the mean deviation (MD) value calculated by the Humphry (30-2) STATPAC program, and for the IOP data, the mean of 24 hour IOP measurements (diurnal IOP) and the mean of the IOPs measured at each visit to our outpatient clinics (follow-up IOP). In 13 cases, the diurnal and the follow-up IOPs were 0.3 mmHg higher or more in the more damaged eye than those in the less damaged eye, and in 7 cases they were 0.3 mmHg higher or more in the less damaged eye than those in the more damaged eye. Between these two groups, no significant difference was seen in the value of MD, but the diurnal IOP and the follow-up IOP was significantly higher in the former than in the latter group. By discrimination analysis, the two groups were distinguished at the diurnal IOP of 14.1 mmHg (hit rate 77.6%) and the follow-up IOP of 15.0 mmHg (74.2%). An analysis using the whole 46 LTG cases yielded the following results: when the diurnal or follow-up IOP of the more damaged eye was higher than the above determined level, the IOP in the more damaged eye was significantly higher than that in the contralateral less damaged eye.(ABSTRACT TRUNCATED AT 250 WORDS)

An optimal method for calculation of the frontal-plane vector from the data of the standard and unipolar limb leads

An optimal estimation of the frontal-plane cardiac vector (R, theta) was derived from the scalar ECG data of the standard and unipolar limb leads by the least square method which minimized the sum of squares of measurement errors of each lead data. The optimal vector was given by R = (Formula: see text) with V1, V2, V3, Vr, Vl and Vf being the measured values of the lead data. This estimation is optimal in that it coincides with the center of gravity of the vector obtained by using the two-lead data. A statistical evaluation of the reduction in measurement errors was performed.