Central 10-degree visual field change following trabeculectomy in advanced open-angle glaucoma.

PURPOSE: To prospectively examine changes in the central visual field (VF) in patients with advanced open-angle glaucoma (OAG) with advanced late stage after trabeculectomy for 12 months. DESIGN: Prospective interventional case series. METHODS: In all, 27 eyes of 27 OAG patients at a single center with a best-corrected visual acuity (BCVA) of ≥40/200 and a mean total deviation of test locations of the 10-2 program of the Humphrey VF analyzer of ≤-20 dB preoperatively were enrolled. Intraocular pressure (IOP), VF parameters of the 10-2 program, and BCVA were examined for 12 months after trabeculectomy with mitomycin C. Slopes of VF parameters and their correlation with presumed risk factors were studied. RESULTS: IOP decreased from 19.7±5.8 to 9.7±2.6 mm Hg (P<0.001) over postoperative 1 year. The slopes of all VF parameters did not significantly differ from zero (P>0.33), and none of the presumed factors significantly correlated with the slopes of those parameters (P>0.14). There were two eyes (7%) and one eye (4%) with ≥2 lines of deterioration in BCVA (decimal fraction) at 1 and 12 months, respectively, after surgery with no apparent causes. CONCLUSIONS: Trabeculectomy resulted in little change in the central 10-degree VF, but significant decrease in BCVA without apparent causes might occur approximately 5% of the cases.

Initial trabeculectomy with mitomycin C in eyes with uveitic glaucoma with inactive uveitis.

PURPOSE: To analyse clinical outcomes of trabeculectomy with mitomycin C (MMC) in eyes with uveitic glaucoma (UG) with inactive uveitis and compare them to those in eyes with primary open-angle glaucoma (POAG). DESIGN: Retrospective non-randomized comparative interventional case series. METHODS: A total of 53 eyes with UG and 80 eyes with POAG that received MMC trabeculectomy as an initial ocular surgery with average follow-up of 5.4 years were reviewed retrospectively. The intraocular pressure (IOP) control and persistence of filtering bleb were analysed using the Kaplan-Meier life-table method based on two definitions of successful IOP control, ie complete success (IOP

Topical phenylephrine decreases blood velocity in the optic nerve head and increases resistive index in the retinal arteries.

PURPOSE: To investigate the effects of topical phenylephrine on circulation in the optic nerve head (ONH), posterior choroids, or retina in rabbits and healthy humans. METHODS: Tissue blood velocity in the ONH and posterior choroid was measured using the laser speckle method as normalized blur (NB(ONH) and NB(CH)) in 28 anaesthetized albino rabbits. NB and intraocular pressure (IOP) in both eyes were measured for 180 min after unilateral single instillation of 5% phenylephrine and contralateral physiological saline as a control. In 11 normal volunteers aged 26.0+/-2.7 years, NB(ONH) was measured for 180 min after unilateral three drops of 5% phenylephrine and contralateral physiological saline in a double-masked manner. In the other 17 normal volunteers aged 25.5+/-2.4 years, blood velocity and blood flow in a major branch of the central retinal artery were measured using the laser Doppler blood flow metre and IOP and systemic circulatory parameters were monitored in similar fashion. Analysis of variance was applied for intergroup comparisons. RESULTS: NB(ONH) and NB(CH) decreased significantly only in the phenylephrine-treated eyes in rabbits by maximum of 9 and 20%, respectively (P=0.0046 and 0.0009), despite IOP decrease. In humans, NB(ONH) decreased significant by maximum of 13% (P=0.0047) and resistive index in the retinal arteries increased by 10% (P=0.0067) unilaterally; whereas IOP, diameter, blood velocity, or blood flow of the arteries was not significantly changed. CONCLUSION: Topical phenylephrine could exert a significant unfavourable effect on circulation in the ONH, choroidal tissue, and retinal arteries in rabbits and normal young humans.

Population-based prevalence of optic disc haemorrhages in elderly Japanese.

PURPOSE: To estimate the population-based prevalence of disc haemorrhages (DHs) in an elderly Japanese population and evaluate related factors including optic disc morphology. PATIENTS AND METHODS: Colour fundus photographs were taken during the screening examination of the Tajimi Study, during which 3021 of 3870 eligible residents of the city aged 40 years or older were screened (response rate, 78.1%). All fundus photographs were graded by one masked examiner to determine the presence of DHs. RESULTS: Good quality fundus photographs were available for both eyes of 2761 subjects. DHs were found in at least one eye of 34 subjects (1.2%; 95% confidence interval (CI) 0.8-1.6%). The prevalence was 14.0% (95% CI, 8.0-19.9%), 9.7% (2.9-16.6%), and 0.4% (0.1-0.6%) in subjects with definitive glaucoma, glaucoma suspects, and subjects without glaucoma, respectively. Logistic regression analyses indicated that DHs were associated with glaucoma (P<0.001), glaucoma suspects (P<0.001), and older age (P=0.032). No Heidelberg Retina Tomograph parameters differed between subjects with and without DHs. CONCLUSIONS: The prevalence of DHs was 1.2% in an elderly Japanese population, which was similar to other population studies. In addition to glaucoma, older age was associated with higher prevalence of DHs.

Atypical retardation pattern in measurements of scanning laser polarimetry and its relating factors.

PURPOSE: To assess the prevalence of atypical retardation pattern (ARP) in scanning laser polarimetry (SLP) with variable corneal compensation (VCC) and enhanced corneal compensation (ECC), and to evaluate the factors relating to typical scan score (TSS). METHODS: Measurements of SLP-VCC, SLP-ECC, and the Humphrey field analyzer (HFA) were performed in 105 normal subjects and 82 open-angle glaucoma (OAG) patients. ARP was defined as an SLP image with TSS<80. RESULTS: Prevalence of ARP with SLP-VCC was 13.3 and 14.6% in normal and OAG eyes, respectively, and that with SLP-ECC (2.9% and 1.2%) was lower than SLP-VCC (P<0.009). TSS with SLP-VCC was significantly correlated with age (partial correlation coefficient (PCC)=-0.22, P=0.003) and refractive error (PCC=0.26, P<0.001) after adjusting for each other. TSS with SLP-ECC was significantly correlated with neither age nor refractive error (PCC=-0.02, P=0.788; PCC=0.10, P=0.177, respectively). In OAG eyes, mean deviation (MD) of HFA was significantly correlated with TSS with SLP-VCC and SLP-ECC (PCC=0.35, P=0.001; PCC=0.23, P=0.039, respectively). In SLP-VCC, MD was significantly correlated with retinal nerve fibre layer (RNFL) thickness only after excluding eyes with ARP (P<0.001). CONCLUSIONS: ARP in SLP-VCC measurements was found in more than 10% of normal or glaucomatous eyes, and TSS was significantly lower in older subjects, more myopic eyes, or eyes with more advanced glaucomatous damage. The presence of ARP disturbs the accuracy of RNFL thickness measurement by SLP-VCC. In SLP-ECC measurements, prevalence of ARP was considerably lower and TSS was not affected by age or refractive error, suggesting the advantages of ECC in clinical practices.

Ocular and systemic factors related to intraocular pressure in Japanese adults: the Tajimi study.

BACKGROUND: As intraocular pressure (IOP) and age are consistent risk factors of glaucoma, it is of special interest to know the association between IOP and possibly relating factors including age in Japan where a high prevalence of normal-tension glaucoma has been reported. The aim of this report was to evaluate the distribution of and factors related to applanation IOP in a population-based study in Japan. METHODS: A randomly sampled group of 3021 residents (response rate 78.1%) of Tajimi City, aged 40 years or older, underwent screening examinations including measurements of IOP with Goldmann applanation tonometry and central corneal thickness. RESULTS: Among right eyes without glaucoma, suspected glaucoma or other disorders which could affect correct IOP measurements, IOP averaged 14.6 (SD 2.7) and 14.5 (2.5) mm Hg in men and women, respectively, with no significant intergender difference (p = 0.342). Multiple regression analyses revealed that age was significantly negatively correlated with IOP (non-standardised beta (B) = -0.020/year, p = 0.0001). Higher body mass index (B = 0.14/BMI, p<0.0001), higher mean blood pressure (B = 0.022/mm Hg, p<0.0001), history of diabetes (p = 0.0019), thicker cornea (B = 0.014/microm, p<0.0001), higher myopia (B = 0.055/dioptres, p = 0.0043) and steeper corneal curvature (B = -0.72/mm, p = 0.0002) were also significantly correlated with higher IOP. CONCLUSIONS: In an adult Japanese population, applanation IOP averaged 14.5 mm Hg and was negatively correlated with age after adjusting for other related factors. A positive correlation between IOP and myopia was found.

Performance of GDx VCC in eyes with peripapillary atrophy: comparison of three circle sizes.

PURPOSE: A scanning laser polarimetry (GDx VCC) equips three different sized measurement circles. In eyes with peripapillary atrophy (PPA), the GDx measurement becomes inaccurate when the circle falls on PPA. The aim of this study was to evaluate performance of the three circles of GDx measurement in eyes with PPA. METHODS: Three different sized circles were compared regarding frequency of PPA, which fell on each circle in 282 open-angle glaucoma (OAG) eyes, reproducibility of GDx parameters in 24 normal and 22 OAG eyes, and ability to detect glaucoma in 50 normal and 50 OAG eyes. RESULTS: PPA was observed in 230 (82%) of 282 OAG eyes. PPA fell on the small circle (default setting), medium, and large circles in 119 (43%), 38 (14%), and 12 (4%) of the 280 OAG eyes. Reproducibility of GDx parameters was not significantly different among three circles in normal eyes (P>0.05), whereas coefficients of reproducibility of TSNIT average (P=0.006) and superior average (P=0.035) were smaller in the smaller circles in OAG eyes. GDx parameters significantly correlated (P<0.001), but were significantly different (P<0.05) between the small and medium circles. The area under receiver operating characteristic curves for dividing OAG from normal eyes using GDx parameters was similar between the small and medium circles. CONCLUSIONS: If the medium circles were used, obstructing influences of PPA on GDx measurement could be avoided more often in Japanese OAG eyes with similar reproducibility and comparable ability to detect glaucoma compared to those with the default small circle.

Topical application of autologous serum for the treatment of late-onset aqueous oozing or point-leak through filtering bleb.

PURPOSE: To evaluate the efficacy of topical autologous serum application to stop aqueous oozing or point-leak through filtering bleb after trabeculectomy. PATIENTS AND METHODS: A total of 21 consecutive eyes with oozing and 21 eyes with a point-leak through a functional bleb after trabeculectomy with 5-fluorouracil or mitomycin C were enrolled in this randomized, case-control study. In eyes randomly assigned to the serum group, an antibiotic and the autologous serum, which was sterilely diluted to 20% with physiological saline, were topically applied four times a day for up to 12 weeks. In eyes assigned to the control group, the antibiotic alone was applied according to the same protocol. Intraocular pressure (IOP) and the presence of oozing or a point-leak were tested before and every 2 weeks after starting the treatments. RESULTS: In the serum and control groups, oozing stopped in 62.5 and 0% of eyes, respectively (P=0.003), and point-leaks stopped in 27.3 and 18.2%, respectively (P>0.9). IOP significantly increased from 10.0+/-3.2 (mean+/-standard deviation) to 11.8+/-3.3 mmHg in eyes in which oozing stopped (P=0.066), and from 11.4+/-2.7 to 15.4+/-2.3 mmHg in eyes in which a point-leak stopped (P=0.042). CONCLUSIONS: Autologous serum application was significantly effective to stop aqueous oozing but not point-leaks. Stopping oozing or point-leaks was significantly associated with an increase in IOP.

Corneal irregular astigmatism and contrast sensitivity after photorefractive keratectomy.

OBJECTIVE: To investigate the relation between contrast sensitivity and corneal irregular astigmatism in eyes after photorefractive keratectomy (PRK). DESIGN: Prospective observational case series. PARTICIPANTS AND CONTROLS: Seventy-nine eyes without corneal haze 6 months or more after PRK and 30 normal control eyes. METHODS: Videokeratography was taken with TMS-1 (Computed Anatomy Inc. New York, NY), and contrast sensitivity for day and night vision was measured using a Multivision Contrast Tester 8000 (Vistech Consultants, Inc., Dayton, OH). MAIN OUTCOME MEASURES: Regular and irregular astigmatism (asymmetry and higher order irregularity components) were computed using Fourier series harmonic analysis of the videokeratography data. Area under the log contrast sensitivity function (AULCSF) was calculated from the contrast sensitivity data taken at five spatial frequencies. RESULTS: After PRK, AULCSFs were significantly smaller for day vision (P = 0.007, unpaired t test) and night vision (P = 0.020) compared with normal controls. AULCSFs for day vision were significantly negatively correlated with asymmetry (Pearson's correlation coefficient, R = -0.23, P = 0.049) and higher order irregularity (R = -0.33, P = 0.004) components but not with the regular astigmatism component (P > 0.3). AULCSF for night vision correlated significantly with asymmetry (R = -0.31, P = 0.013) and higher order irregularity (R = -0.30, P = 0.016) components but not with the regular astigmatism component (P > 0.3). CONCLUSIONS: Corneal irregular astigmatism after PRK significantly influences contrast sensitivity.

Effects of topical latanoprost on optic nerve head circulation in rabbits, monkeys, and humans.

PURPOSE: To evaluate the effect of topically administrated latanoprost on optic nerve head (ONH) circulation in Dutch rabbits, cynomolgus monkeys, and normal humans. METHODS: The ONH tissue blood velocity (NB(ONH)) was determined using the laser speckle method. Latanoprost (0.005%, 30 microl) was instilled into one eye, and vehicle into the other eye as a control. In rabbits, NB(ONH) was measured for 90 minutes after a single instillation and before and after a 7-day once-daily instillation regimen. In monkeys, NB(ONH) was measured before and after 1, 4, and 7 days of a once-daily instillation regimen. The effect of intravenous indomethacin on the latanoprost-induced NB(ONH) change was also studied in rabbits and monkeys. In humans, the time-course changes in NB(ONH) were measured for 4.5 hours before and after a 7-day once-daily instillation regimen. Intraocular pressure (IOP) and systemic parameters were simultaneously studied in each experiment. All measurements were performed by investigators masked to the experimental condition. RESULTS: Latanoprost significantly increased NB(ONH) 10% to 19% in treated eyes after a single instillation (P = 0.035) or 7-day instillation regimen (P = 0.035) in rabbits, after a 4-day (P = 0.035) or 7-day (P = 0.035) instillation regimen in monkeys, and after a 7-day (P = 0.013) instillation regimen in humans, whereas there were no significant changes in the vehicle-treated eyes in any of the experiments (P > 0.5). Pretreatment with indomethacin (5 mg/kg) abolished the NB(ONH) increase but not the IOP reduction in latanoprost-treated eyes in rabbits and monkeys. IOP remained unchanged in both eyes in rabbits (P > 0.4), whereas it significantly decreased only in latanoprost-treated eyes in monkeys (P < 0.05) and humans (P < 0.05). CONCLUSIONS: Topical latanoprost significantly increased ONH blood velocity only in treated eyes in rabbits, monkeys, and humans. This effect was independent of the IOP-reducing effect of latanoprost and probably was associated with local penetration of the drug and the production of endogenous prostaglandins.

Corneal irregular astigmatism after laser in situ keratomileusis for myopia.

AIMS: To quantitatively evaluate the changes in corneal irregular astigmatism after laser in situ keratomileusis (LASIK) in relation to the amount of laser ablation. METHODS: In 189 eyes of 116 patients undergoing LASIK for myopia, corneal topography was obtained before and 1 month after surgery. Using Fourier harmonic analysis of the topography data, corneal irregular astigmatism (asymmetry and higher order irregularity) was calculated. RESULTS: By surgery, asymmetry component significantly increased (p < 0.0001, Wilcoxon signed rank test), while higher order irregularity did not (p = 0.767). The increases in the asymmetry component significantly correlated with ablation depth (Spearman rank correlation coefficient r(s) = 0.440, p < 0.0001). No significant correlation was found between changes in higher order irregularity and ablation depth (r(s) = 0.137, p = 0.074). CONCLUSION: LASIK significantly increases the asymmetry component of the cornea which is dependent on the amount of laser ablation.

Factors affecting the forward shift of posterior corneal surface after laser in situ keratomileusis.

PURPOSE: To evaluate the anteroposterior movement of the corneal back surface after laser in situ keratomileusis (LASIK). DESIGN: Retrospective noncomparative case series. PARTICIPANTS: One hundred ninety-six eyes of 120 subjects with myopic refractive errors of -2.0 to -12.5 diopters. INTERVENTION: LASIK was performed. Corneal topography of the posterior corneal surface was obtained with the scanning slit topography system before and 1 month after surgery. MAIN OUTCOME MEASURES: The amount of forward shift of the posterior corneal surface was determined. Multiple regression analysis was used to assess the factors that affect the forward shift of the posterior corneal surface. RESULTS: After surgery, the posterior corneal surface displayed mean forward shift of 40.9 +/- 24.8 micrometer. Explanatory variables relevant to the forward shift of corneal posterior surface were, in the order of magnitude of influence, the amount of laser ablation (partial regression coefficient B = 0.561, P < 0.0001), preoperative corneal thickness (B = -0.176, P = 0.00096), and preoperative intraocular pressure (B = 1.676, P = 0.0053). Preoperative refraction and achieved myopic correction showed collinearity with the amount of laser ablation. CONCLUSIONS: LASIK induces a forward shift of the cornea. Eyes with thinner corneas, higher intraocular pressure, and higher myopia requiring greater laser ablation are more predisposed to the anterior shift of the cornea.

Topical latanoprost and optic nerve head and retinal circulation in humans.

The purpose of the present study was to study the effect of a single instillation of latanoprost on the human optic nerve head (ONH) and retinal circulation. Using laser-speckle tissue blood flow analysis, normalized blur (NB; a quantitative index of tissue blood velocity) was measured every 0.125 sec at a temporal ONH site free of visible surface vessels. Measurements were averaged for 3 cardiac cycles (NB(ONH)). Color Doppler Imaging (CDI) was also used to evaluate peak systolic blood velocity (PSV), endo-diastolic velocity (EDV), and resistive index (RI) in the central retinal artery (CRA) and mean blood velocity (MV) in the central retinal vein (CRV). One drop of 0.005% latanoprost was instilled into one eye and its vehicle into the other in eleven healthy volunteers in a double-blinded manner. Measurements of bilateral NB(ONH), CDI parameters, intraocular pressure (IOP), blood pressure (BP), and pulse rate (PR) were performed before, and 45, 90, 180, and 270 min after instillation. After a single instillation of latanoprost or the vehicle, there was no significant bilateral difference throughout the experimental period. The difference in NB(ONH) between that before and at each time point of measurement (delta NB(ONH)) in the latanoprost-treated eyes was significantly higher between 45 and 270 min after instillation than that in vehicle-treated eyes (P = 0.0003 to 0.0156); ANOVA for repeated measurements also revealed significant difference between both eyes (P < 0.00001). BP, PR, and NB(ONH) in the eye that received only the vehicle, PSV, EDV, and RI in the CRA in both eyes, and MV in the CRV in both eyes changed little. Tissue blood velocity in the ONH increased at least temporarily following a single instillation of topical latanoprost. Although the mechanism of the increase is unclear, the effects of latanoprost on ONH tissue circulation in humans may have clinical implications.

Effect of topical unoprostone on circulation of human optic nerve head and retina.

The purpose of the present study was to study the effect of topical unoprostone on the circulation of human optic nerve head (ONH) and retina in normal subjects. Using laser-speckle tissue blood flow analysis, normalized blur (NB), a quantitative index of tissue blood velocity, was measured every 0.125 sec at a temporal ONH site, free of visible surface vessels. Measurements were averaged for 3 cardiac cycles (NB(ONH)). Color Doppler imaging (CDI) was also used to evaluate peak systolic blood velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) in the central retinal artery (CRA) and mean blood velocity (MV) in the central retinal vein (CRV). For baseline comparison (Day 0), recordings of bilateral NB(ONH) and intraocular pressure (IOP), blood pressure (BP), and pulse rate (PR) were recorded in healthy volunteers before, and 45, 90, 180, and 270 min after instillation of one drop of unoprostone vehicle. On Day 1 (the day after baseline measurements), and twice daily for 7 days, one drop of 0.12% unoprostone was instilled into one eye and its vehicle into the other in a double-blinded manner. Measurements as on Day 0 were recorded on Days 1 and 7. CDI measurements were performed before and at 45 and 180 min after morning instillation on Days 1 and 7. During baseline recordings, there were no significant changes in any parameters. After administration of topical unoprostone, IOP was significantly lower bilaterally with more reduction in the unoprostone-treated eyes on Day 7. On Day 7, the NB(ONH) of the unoprostone-treated eyes was significantly higher 45 min after instillation than baseline (P = 0.035 with Bonferroni's correction). Analysis of variance for repeated measurements also revealed significant difference between Day 0 and Day 7 (P = 0.0017). BP, PR, NB(ONH) in the eye that received only the vehicle, PSV, EDV, and RI in the CRA in both eyes, and MV in the CRV in both eyes changed little. Tissue blood velocity in the ONH increased, at least temporarily, following instillation of unoprostone twice daily for 7 days. Although the clinical implication of the increase is unclear, the effects of topical unoprostone on human ONH circulation deserve further consideration.

Regular and irregular astigmatism after superior versus temporal scleral incision cataract surgery.

OBJECTIVE: To evaluate the effect of superior and temporal scleral incisions on regular and irregular astigmatism in small incision cataract surgery. DESIGN: Prospective, randomized, comparative clinical trial. PARTICIPANTS: One hundred seventy-four eyes of 87 patients with bilateral cataracts scheduled to undergo routine cataract surgery. METHODS: One eye of each patient was randomly assigned to the superior incision group, and the contralateral eye was allocated to the temporal incision group. Phacoemulsification and intraocular lens implantation were performed through an unsutured 4.1-mm scleral incision. Patients were examined 1 day and 1, 3, and 6 months after surgery. MAIN OUTCOME MEASURES: Surgically-induced regular astigmatism calculated with vector analysis method, irregular astigmatism obtained by Fourier analysis of videokeratography data, and uncorrected and corrected visual acuity. RESULTS: Postoperatively, the superior incision group showed slight against-the-rule astigmatic changes, whereas slight with-the-rule astigmatism was seen in the temporal incision group. The amount of against-the-wound astigmatism and absolute value of length of the induced vector did not differ significantly between groups (P > 0.05, paired t test). In both groups, irregular astigmatism 1 day after surgery was significantly greater than the preoperative levels (P < 0.001), but not thereafter. No significant intergroup difference was observed in the amount of irregular astigmatism at any postoperative visits (P > 0.05). There was no significant difference in uncorrected and corrected visual acuity between groups postoperatively (P > 0.05, chi-square test). CONCLUSIONS: In small scleral incision cataract surgery, superior and temporal approaches are comparable in terms of visual rehabilitation and induction of regular and irregular astigmatism.

Effects of pterygium on corneal spherical power and astigmatism.

OBJECTIVE: To evaluate prospectively the corneal refractive status before and after pterygium surgery and its relationship with preoperative pterygium size. DESIGN: Prospective, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: One hundred thirty-six eyes undergoing primary pterygium removal surgery. MAIN OUTCOME MEASURES: Corneal spherical power, astigmatism, surface regularity index (SRI), and surface asymmetry index (SAI) before and after surgery, and the preoperative pterygium size. RESULTS: Before surgery, pterygium size significantly correlated with spherical power (Pearson's correlation coefficient, r = -0.370, P < 0.001), astigmatism (r = 0.600, P < 0.001), SRI (r = 0.367, P < 0.001), and SAI (r = 0.387, P < 0.001). The surgery significantly increased spherical power of the cornea, whereas astigmatism, SRI, and SAI were significantly decreased by the surgery (P < 0.01, paired t test with Bonferroni's correction of P value for multiple comparison). Surgically induced changes in spherical power (r = 0.598, P < 0.001) and astigmatism (r = 0.653, P < 0.001) significantly correlated with the preoperative pterygium size. Precise prediction of the magnitude of refractive changes based on the preoperative pterygium size was difficult. CONCLUSIONS: The presence of pterygium and its removal significantly influence the corneal refraction including spherical power, astigmatism, asymmetry, and irregularity, with the larger pterygium exerting the greater influence.

Changes in anterior and posterior corneal curvatures in keratoconus.

OBJECTIVE: To quantitatively evaluate the changes in anterior and posterior corneal curvatures of eyes with keratoconus. DESIGN: Case-control retrospective and observational study. PARTICIPANTS: Thirty-one patients who were clinically diagnosed to have unilateral or bilateral keratoconus and 18 normal subjects. INTERVENTION: The anterior and posterior topographies were obtained using scanning-slit videokeratography and assessed by Fourier series harmonic analysis. MAIN OUTCOME MEASURES: Quantitative descriptors of the topography data, spherical power, regular astigmatism, and irregular astigmatism (asymmetry and higher order irregularity) components were compared between the anterior and posterior surfaces and among groups of clinically diagnosed keratoconus (33 eyes), keratoconus suspect (13 eyes), and normal subjects (36 eyes). RESULTS: Spherical power (P = 0.0003, Mann-Whitney U test with Bonferroni's correction of P values), regular astigmatism (P = 0.0166), and asymmetry (P = 0.0031) of the anterior surface were significantly greater in the keratoconus eyes than in the normal controls. For the posterior surface, spherical power (P<0.0001), regular astigmatism (P = 0.0143), asymmetry (P< 0.0001), and higher order irregularity (P = 0.0032) of the keratoconus group were significantly greater than those of the control group. The keratoconus suspect eyes, when compared with the normal controls, showed a significantly greater amount of spherical power (P = 0. 0166) and asymmetry (P<0.0001) in the anterior surface and spherical power (P <0.0001), regular astigmatism (P = 0.0244), asymmetry (P<0.0001), and higher order irregularity (P = 0.0276) in the posterior surface. All refractive components demonstrated statistically significant correlations between the anterior and posterior surfaces (P<0.0001, Spearman's rank correlation). CONCLUSIONS: Not only the anterior but also the posterior corneal curvature is affected in keratoconus. These changes are observed from the early stage of this disorder.

Effects of semotiadil, a novel calcium antagonist, on the retina and optic nerve head circulation.

The effects of semotiadil, a novel benzothiazine calcium antagonist, on the retinal and optic nerve head (ONH) tissue circulation were evaluated using the noninvasive laser speckle method. In urethane-anesthetized Dutch or albino rabbits, before and up to 90 min following intravenous injection of 400 microg/kg semotiadil fumarate (semotiadil group) or vehicle (control group), normalized blur value, a quantitative index of tissue blood velocity, in the retina (NB(retina)) or ONH (NB(onh)), was serially obtained with monitoring intraocular pressure (IOP) and systemic parameters: arterial pressure, pulse rate, arterial blood gas, and body temperature. There were no significant differences in IOP and the systemic parameters except arterial pressure between semotiadil and control groups during the experiments. Arterial pressure showed an acute and transient drop during the first 5 min after semotiadil administration. The time courses of the normalized blur value were significantly different between semotiadil and control groups in the retina (P = 0.0001, repeated measures two-way ANOVA), but not in the ONH (P = 0.6724). Changes in NB(retina) from the baseline in the semotiadil group was significantly greater than those in the control group 50 min or later after the administration (P < 0.0500, Mann-Whitney test). NB(onh) showed no significant differences between the two groups except during the first few min when arterial pressure acutely decreased in the semotiadil group. In conclusion, intravenously injected semotiadil increased the tissue blood velocity in the retina, but not in the ONH. This vascular selectivity in the ocular neural tissues differs from those of other calcium antagonists, such as nicardipine.

Quantitative analysis of regular and irregular astigmatism induced by pterygium.

PURPOSE: To quantitatively evaluate the influence of pterygium and its removal surgery on both regular and irregular corneal astigmatism. METHODS: In 19 eyes of 19 patients undergoing pterygium surgery, videokeratographic measurements were taken before and 1 month after surgery. Using Fourier harmonic analysis, dioptric data on mire rings were decomposed into spherical, regular astigmatism, and irregular astigmatism (decentration and higher order irregularity) components. The distance between the line of sight and the advancing edge of pterygium was measured, and the eyes were classified into two groups: large pterygium group (the distance <2.0 mm, n = 7) and small pterygium group (> or =2.0 mm, n = 12). Fifteen eyes of 15 subjects served as age-matched normal control eyes. RESULTS: Before surgery, the magnitudes of regular astigmatism and higher order irregular astigmatism showed significant correlation with the size of pterygium. Regular astigmatism, asymmetry, and higher order irregularity in the large pterygium group were significantly greater than those of normal control eyes. The pterygium removal surgery significantly improved these changes, but regular astigmatism and higher order irregularity in the large pterygium group still remained significantly greater than those in the normal control eyes. CONCLUSION: Pterygium induces a significant amount of regular and irregular astigmatism in proportion to its size. The removal surgery can improve these changes, but corneal distortion does not normalize completely in eyes with advanced pterygium.