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PubMed1967

Visual resolution when light enters the eye through different parts of the pupil.

1. Threshold contrasts for resolution of sinusoidal gratings imaged on to the retina through a decentred 2 mm pupil were measured.2. No loss in resolution was found when the pupil was decentred parallel to the lines of the gratings. A loss in resolution by a factor of 3 occurred when the pupil was decentred by 3 mm perpendicular to the lines of the gratings.3. The effects of focus on the threshold contrast for a grating viewed through a centred and decentred pupil were used to show that at least a portion of the loss in resolution is due to optical aberrations.4. Using a neon-helium gas laser as a coherent light source, interference fringes were produced on the retina directly. Threshold contrasts for resolution of the fringes were determined for different positions of entry of the beams of light through the pupil. When the Stiles-Crawford brightness effect was compensated for, no loss in resolution was found to occur for decentred entry of the beams.5. It is concluded that the off-axis loss of visual acuity is wholly due to optical aberrations in the eye.6. The ratios between the threshold contrasts for sinusoidal gratings and for interference fringes are used to calculate the optical transfer functions of the off-axis aberrations of the eye.

Humans↗
PubMed2001

Effect of rotation and translation on the expected benefit of an ideal method to correct the eye's higher-order aberrations.

An ideal correcting method, such as a customized contact lens, laser refractive surgery, or adaptive optics, that corrects higher-order aberrations as well as defocus and astigmatism could improve vision. The benefit achieved with this ideal method will be limited by decentration. To estimate the significance of this potential limitation we studied the effect on image quality expected when an ideal correcting method translates or rotates with respect to the eye's pupil. Actual wave aberrations were obtained from ten human eyes for a 7.3-mm pupil with a Shack-Hartmann sensor. We computed the residual aberrations that appear as a result of translation or rotation of an otherwise ideal correction. The model is valid for adaptive optics, contact lenses, and phase plates, but it constitutes only a first approximation to the laser refractive surgery case where tissue removal occurs. Calculations suggest that the typical decentrations will reduce only slightly the optical benefits expected from an ideal correcting method. For typical decentrations the ideal correcting method offers a benefit in modulation 2-4 times higher (1.5-2 times in white light) than with a standard correction of defocus and astigmatism. We obtained analytical expressions that show the impact of translation and rotation on individual Zernike terms. These calculations also reveal which aberrations are most beneficial to correct. We provided practical rules to implement a selective correction depending on the amount of decentration. An experimental study was performed with an aberrated artificial eye corrected with an adaptive optics system, validating the theoretical predictions. The results in a keratoconic subject, also corrected with adaptive optics, showed that important benefits are obtained despite decentrations in highly aberrated eyes.

Eye↗
PubMed2005

[Neoliberal reforms in health services in Latin America: a critical view from two case studies].

Neoliberal reforms have promoted privatization and decentralization as strategies to improve equity, efficiency, and the quality of health services. In this piece the impact of these reforms in Latin America is critically analyzed, and the impacts of privatization in Colombia and of decentralization in Mexico are detailed. These two cases show that after 10 years of privatization in Colombia and 20 years of decentralization in Mexico the reforms have had the opposite of the desired effect: They have not improved equity, have increased health expenditures, have not increased efficiency, and have not shown a positive impact on quality. Public health programs in Colombia have deteriorated, while decentralization in Mexico has had a very high cost, without achieving the proposed objectives. It is officially accepted that decentralization in Mexico has increased inequity, and that new reforms implemented in 2003 promote vertical programs. Health systems based on regulated competition are not the most suitable ones for Latin America. Latin American countries should improve their health systems in line with the principles stated in the Declaration of Alma Ata and according to their own national experiences.

Colombia↗
PubMedDate not supplied

Treatment of previous decentered excimer laser ablation with combined myopic and hyperopic ablations.

PURPOSE: Decentration of the ablation zone is an occasional complication of excimer laser refractive surgery. We describe a technique to recenter the ablation zone without changing the refractive status obtained by the first surgery. METHODS: Sixteen eyes of 14 patients had moderate or marked ablation decentration after previous excimer laser surgery for myopia, but with only minor residual refractive error. Five eyes had spectacle-corrected visual acuity loss and all these patients reported various symptoms such as halos, ghost images, or night driving difficulties. To recenter the ablation zone without changing the refraction, a combination myopic and hyperopic treatment was used. The hyperopic treatment was decentered toward the initial decentered myopic ablation. A myopia ablation of near equal dioptric value was then added, but decentered in the opposite direction. The Bausch & Lomb Technolas Keracor 217 laser was used. RESULTS: After the first retreatment, the centration of the ablation zone was improved in 15 of the 16 eyes. All eyes with initial spectacle-corrected visual acuity loss recovered lines of visual acuity. Subjective decrease of symptoms was described as follows: nil in one eye, mild in one eye, moderate in four eyes, and marked in ten eyes. A second retreatment was needed in five eyes: in two to improve centration and in three to correct residual ametropia. The only complication (one eye) was induced decentration 180 degrees away from the initial decentration with a 1-line spectacle-corrected visual acuity loss, and additional retreatment was required. CONCLUSION: A combination of decentered myopic and hyperopic ablation of an equivalent dioptric magnitude, each decentered 180 degrees apart, was a useful method to correct previous excimer laser treatment decentration, with minimal alteration of refractive status that was obtained by the initial surgery.

Adult↗
PubMed1988

A retrospective study of dropout rates from a community mental health centre and associated factors.

To ascertain if decentralization of mental health services, making them more accessible to the public, would be reflected in a decrease in the dropout rate, a comparison was made between dropout rates just prior to and immediately following decentralization. This involved examining 1350 closed files representing cases seen during a three-year period after decentralization and comparing the findings with those of a previous study of files of 588 cases seen during a year before decentralization. The dropout rate decreased from 46% to 43%; while statistically significant, this change was too small to be of any practical importance. However, analysis of demographic and clinical variables in the post-decentralization sample proved most interesting. On the whole, it confirmed the findings from previous investigations, i.e. dropouts tended to be younger, less well-educated, of low socioeconomic status (SES), and were most commonly diagnosed as having a personality disorder. Although some therapists had a comparatively large proportion of dropouts, this discrepancy may reflect the distribution of difficult cases rather than the effectiveness of the therapists.

Alberta↗
PubMedDate not supplied

Long-term results of various anterior capsulotomies and radial tears on intraocular lens centration.

BACKGROUND AND OBJECTIVE: To evaluate the long-term effects of various anterior capsulotomies and radial tears on intraocular lens (IOL) centration. MATERIALS AND METHODS: Ninety-five eyes of 87 senile cataract patients operated with extracapsular technique were evaluated in IOL tilt and decentration with a new method of measurement. According to the type of anterior capsulotomy and number of radial tears, five groups were constituted as, can opener, envelope, continous curvilinear capsulorrhexis (CCC), CCC with one radial tear (relaxing incision at quadrant 12), and CCC with two relaxing incisions (relaxing incisions at quadrants 6 and 12), respectively. RESULTS: Early decentration and tilt in groups CCC and CCC with one radial tear were significantly lower than the other groups (P < 0.05). Late decentration and tilt in the CCC group were significantly lower than the other groups (P < 0.01). Highest values of tilt and decentration were determined in envelope capsulotomy. Additional symmetric relaxing incision at quadrant 6 revealed no effect on the prevention of decentration and tilt compared to one relaxing incision. CONCLUSION: CCC with one radial tear is not ideal but sufficient for IOL centration. All other anterior capsulotomy techniques, other than intact CCC, do not guarantee the IOL centration.

Aged↗
PubMed2006

Outpatient management of deep venous thrombosis: 2 models of integrated care.

OBJECTIVE: To describe and evaluate the impact, effectiveness, and safety of 2 models of outpatient deep venous thrombosis (DVT) management. STUDY DESIGN: Observational health-records survey conducted in 2 community hospitals using a comparative design. METHODS: The model centered around the emergency department (ED) was studied from April 15, 1997, through December 31, 1999; the decentralized model was studied from July 15, 2002, through March 15, 2004. The effect of the decentralized model on processes of care was determined by comparing the percentages of patients who were managed by office-based primary care providers under the 2 models. Two-week clinical outcomes also were compared, including symptomatic pulmonary embolism, symptomatic progression of index DVT, new DVT, major bleeding, minor bleeding, and death. RESULTS: During the study periods, 187 and 254 outpatients were enrolled in the ED-centered model and the decentralized model, respectively. Under the ED-centered model, 17 (22.1%) of 77 patients who presented to the primary care providers' offices on weekdays before 1:30 PM (on-hours) were managed exclusively within the clinic setting. Under the decentralized model, 78 (91.8%) of 85 patients who presented on-hours were managed within the clinics--a difference of 69.7 absolute percentage points (95% confidence intervals, 58.7%, 80.7%; P < .001). The models had comparable 2-week clinical outcomes. CONCLUSIONS: The decentralized model for outpatient DVT management allowed more primary care clinic patients to receive their initial care exclusively in the clinic setting. There was no significant difference between the models in short-term effectiveness of therapy and patient safety.

Aged↗
PubMedDate not supplied

Are reproductive health NGOs in Uganda able to engage in the health SWAp?

This paper explores the ability for reproductive health (RH) non-governmental organizations (NGO) in Uganda to survive in the context of SWAp and decentralization. The authors argue that, contrary to the perceptions that this context may increase NGO's financial vulnerability, a SWAp and a decentralized system may provide an opportunity that should be embraced by NGOs to enhance their sustainability and effectiveness by reducing their current dependency on donor funding. The paper discusses the systemic weaknesses of many NGOs that currently make them vulnerable, and observes that unless these weaknesses are addressed, such NGOs will lose their space in the SWAp and decentralization arena. The authors suggest that NGOs need to recognize the opportunities that participating in public-private partnerships through a SWAp can offer them for long-term and significant funding. They need also to develop their capacity to pro-actively participate in a SWAp and decentralized context by becoming more entrepreneurial in nature, through re-orienting their organizational philosophies and strategic planning and budgeting so as to be able to partner effectively with the public sector in accessing funds made available through health sector reform.

Entrepreneurship↗
PubMed1992

The influence of pelvic nerve transection on the neuromuscular system of the canine urinary bladder.

We previously reported that bladder overdistension led to denervation and subsequent supersensitivity of the detrusor muscle to acetylcholine. Therefore, to exclude the influence of bladder overdistension, we produced a low-pressure bladder in female mongrel dogs using an indwelling urethral catheter, and performed pelvic neurectomy (decentralization). We examined the effects of decentralization on the neuromuscular system of the bladder. The contraction response levels of bladder strips in dogs 1 and 2 weeks after neurectomy was low, and significantly different from that of bladder strips in the control group. The dose-response curves of dogs 4 and 8 weeks after neurectomy showed a shift to the left when compared to those of the control group, indicating a significant increase in sensitivity of the bladder strips. Many cholinergic terminal and varicosity profiles had a normal ultrastructure in all of the groups subjected to neurectomy, while some had degenerating profiles representing clear axoplasm without any recognizable organelles. Microphotographs of bladder obtained from dogs with spontaneous catheter loss showed degenerating axons, which were observed more frequently than in bladders kept empty with indwelling urethral catheters. Micturition in the dogs with spontaneous catheter loss was achieved by overflow incontinence without catheterization. These findings suggest that post-synaptic nerve degeneration may be augmented by impairment of micturition, followed by decentralization. Our observations also suggest that post-synaptic nerve degeneration (denervation) plays an important role in the increased sensitivity of the detrusor muscle to acetylcholine in the parasympathetically decentralized urinary bladder, whether denervation is due to trans-synaptic degeneration or impairment of micturition.

Acetylcholine↗
PubMed1985

Synthesis and utilization of catecholamines in the rat superior cervical ganglion following changes in the nerve impulse flow.

The nerve impulse flow to the noradrenaline nerve cell body region of the superior cervical ganglion and to the noradrenaline nerve terminals of the salivary glands was decreased and increased by decentralization and pre-ganglionic electrical stimulation, respectively. The concentrations of dopamine, noradrenaline, and their primary deaminated metabolites (DOPAC, DOPEG) in the ganglion were not changed during the first day after the decentralization but were increased following preganglionic stimulation, particularly that of DOPAC. The disappearances of dopamine and noradrenaline after alpha-methyltyrosine and the disappearance of noradrenaline after inhibition of the dopamine-beta-hydroxylase were not changed by decentralization or stimulation. The accumulation of dopamine following inhibition of the dopamine-beta-hydroxylase was somewhat lowered by decentralization and was markedly enhanced by stimulation. In the noradrenaline nerve terminals of the salivary glands, preganglionic sympathetic stimulation decreased and increased the concentration of noradrenaline and dopamine, respectively. Thus, nerve impulses stimulated the tyrosine hydroxylase activity in the cell body region and the axon terminals of the noradrenaline neurons but they increased the utilization of noradrenaline only in the terminals.

Animals↗
PubMed1980

The school as a force for community change in Tanzania.

In newly independent countries where traditional theories of educational policy have continued to be followed, education has persisted as little more than a sophisticated mechanism for the recruitment of elites, and there has been an increased dependence on the advanced industrial nations for aid, experts, and educational models. Tanzania, however, has attempted to break away from traditional strategies, and the author here describes and analyzes the impact of 2 of the most far-reaching reforms--Education for Self-Reliance and Decentralization--on national goals and policies. President Nyerene enunciated the objectives for Education for Self-Reliance in 1967 as relating education to rural life, correcting the elitist bias of education, and changing negative attitudes among students towards agriculture and rural life. 5 major programs of reform covering primary and secondary education, teacher and higher education, and examinations were to be pursued, ensuring a closer integration of schools with local communities; e.g., through school farms and cooperative shops, and making curricula directly relevant to local needs. A policy of Decentralization is being implemented, allowing, theoretically at least, a much greater participation at the community level in decisionmaking. In primary and adult education this has already been effected to some extent, though there is evidence to suggest that decentralization in some regions and districts has resulted in the creation of local bureaucratic machinery for control, defeating the intentions of the reform. Decentralization of secondary and teacher education is likely to follow, leaving only higher education centrally controlled for manpower training and allocation purposes. Finally the author discusses the question of the transferability of the Tanzanian reforms.

Africa↗
PubMed2001

[Morphological results after eccentric perforating keratoplasty].

OBJECTIVE: Due to unfavourable optical and immunological conditions, an eccentric position of the corneal transplant is limited to curative or tectonic indications. The purpose of this study was to assess the morphological results of eccentric homologous penetrating keratoplasty (PK) with respect to diagnosis as well as position and size of the corneal graft. PATIENTS AND METHODS: In our retrospective study, 122 cases of eccentric homologous PK in 96 eyes between 01/1989 and 10/1997 were included, which in 104 patients was necessary because of a corneal ulcer (36 previous PK, 21 areactive/rheumatic, 20 herpetic, 15 bacterial, 12 other). Elective PK was performed on 6 eyes with corneal scars, 7 eyes with ectatic corneal diseases (ECT) and 5 others. Using postoperative slides the following parameters were quantified: the graft diameter (GD) and transparency, the distance of the geometric centre of the cornea from the central trephination margin (ABS) as well as from the geometric centre of the graft (decentration, DEZ). Of these, 17 grafts were classified as eccentric peripheral keratoplasty (EPK) with the optical axis through the host cornea and 67 as eccentric central keratoplasty (ECK) with the optical axis through the graft. RESULTS: The average follow-up period was 25 months. In EPK (ulcers only, 5.0 +/- 1.7 mm) the mean GD was significantly lower than in ECK (78% ulcers, 7.0 +/- 1.3 mm) (p < 0.001). The decentration of EPK (3.5 +/- 1.1 mm) was significantly higher than for ECK (1.4 +/- 0.8 mm, p < 0.001). ABS of EPK was +1.3 +/- 0.9 mm and for ECK was -2.0 +/- 1.0 mm. Of the grafts in EPK and ECK 46%/57%, respectively were crystal clear, 18%/15% respectively showed minor decompensation and 36%/28% were completely cloudy. In cases of ulcers/scars/ECT/others, 45%/75%/100%/75% were crystal clear, respectively, 18%/25%/0%/0% showed minor decompensation and 37%/0%/0%/25% were completely cloudy. With increasing stages of cloudiness, the mean graft decentration increased from 1.4 +/- 1.1 mm (crystal clear) to 1.7 +/- 1.2 mm (minor decompensation) and 2.2 +/- 1.4 mm (completely cloudy). Transplants with greater GD (p = 0.04) and ABS (p = 0.01) were significantly more often clear. Ulcers were significantly more cloudy than scars/ECT (p < 0.01). The position of the graft and its cloudiness was not significantly correlated. CONCLUSION: The diagnosis leading to eccentric PK seems to have the greatest impact on long-term graft transparency. Our results indicate that an increasing decentration of the graft is not inevitably associated with an increasing probability of clouding. A central penetrating repeat keratoplasty may be considered in the non-inflamed interval after eccentric tectonic mini-keratoplasty.

Adolescent↗
PubMed2007

A multilevel analysis on the determinants of regional health care expenditure: a note.

Health care in most countries is a rather "local good" for which the fiscal decentralization theory applies and heterogeneity is the result. In order to address the issue of multijurisdictional health care in estimating income elasticity, we constructed a unique sample using data for 110 regions in eight Organisation for Economic Co-operation and Development (OECD) countries in 1997. We estimated this sample data with a multilevel hierarchical model. In doing this, we tried to identify two sources of random variation: within- and between-country variation. The basic purpose was to find out whether the different relationships between health care spending and the explanatory variables are country specific. We concluded that to take into account the degree of fiscal decentralization within countries in estimating income elasticity of health expenditure proves to be important. Two plausible reasons lie behind this: (a) where there is decentralization to the regions, policies aimed at emulating diversity tend to increase national health care expenditure and (b) without fiscal decentralization, central monitoring of finance tends to reduce regional diversity and therefore decrease national health expenditure. The results of our estimation do seem to validate both these points.

Age Factors↗
PubMedDate not supplied

Visual simulation of retinal images through a decentered monofocal and a refractive multifocal intraocular lens.

PURPOSE: To evaluate the effect of decentration of a monofocal intraocular lens (IOL) and a refractive multifocal IOL on retinal image quality using a new visual simulation system. METHODS: Using a new visual simulation system, we performed visual simulation of a monofocal and a multifocal IOL at 5, 4, 3, 2, 1, and 0.4 m with several decentered IOL positions from 0 to 1.0 mm through a 3- or 4-mm aperture using Landolt visual acuity (VA) charts. The VA was estimated under each condition from the simulated retinal image. RESULTS: With a monofocal IOL, the image was affected minimally by decentration at 4 and 5 m; at 2 and 3 m, the image contrast decreased slightly with increased decentration. With the multifocal IOL, some loss of image contrast developed at all distances compared with the monofocal IOL; however, the images of the Landolt's rings were still recognizable under all conditions. CONCLUSIONS: Our results suggest that up to 1.0 mm of decentration of a monofocal and multifocal IOL would not greatly affect the retinal image quality.

Foreign-Body Migration↗
PubMed1984

Cholinesterase activity in the rat superior cervical ganglion: effect of denervation and axotomy.

Cholinesterase activity and its various forms in the superior cervical ganglion of the rat were studied after denervation, axotomy and double section. The response of this activity to various inhibitors was also studied. The specific activity of cholinesterase activity was 323 +/- 25 nmol/mg protein/min in homogenates of normal ganglia and the total enzyme activity was 78 +/- 5 nmol/ganglion/min. Axotomy produced approximately a 40% decrease in total activity in ganglia at 3 days compared to contralateral ganglia. Activity in the contralateral ganglia was also decreased by about 30% compared to normal ganglia. Decentralization alone for 3 days did not affect the specific or total cholinesterase activity. However, decentralization followed by axotomy 3 days later resulted in a greater loss in activity compared to axotomy and a significant change in the forms of cholinesterase. After chromatography on Sepharose 6B-100 columns, 3 forms (a, c, d) of cholinesterase activity could be separated from homogenates of single ganglia. The 3 forms had estimated molecular weights of 1,934,000, 129,000 and 59,000 daltons, respectively. A fourth form (b) presented as a shoulder and had an estimated molecular weight of 404,000 daltons. Decentralization or axotomy decreased forms a and d. A reduction in the proportion of form c was also observed in the axotomized ganglion. Decentralization followed by axomoty resulted in large decreases in forms a, b and c and complete loss of form d. Assay of the separated forms in the presence of the specific inhibitor of acetylcholinesterase, BW284C-51, indicated that the majority of the enzyme recovered after chromatography is acetylcholinesterase.

Acetylcholinesterase↗
PubMed1992

Plasticity of the sympathetic nervous system innervating the cerebral arteries in rats.

In order to investigate the neuroplasticity of the peripheral sympathetic nervous system innervating the cerebral blood vessels, we observed and traced the sprouting nerve fibers originating in the contralateral superior cervical ganglion (SCG) into the previously denervated cerebral arteries following unilateral excision of the SCG and/or decentralization of the contralateral SCG in young rats (4 weeks old). These nerve fibers were labeled anterogradely with wheat germ agglutinin-horseradish peroxidase or stained immunohistochemically with anti-tyrosine hydroxylase antibody. Eight weeks after the right SCG excision, reinnervating nerve fibers originating in the contralateral ganglion formed a circular pattern of nerve plexus only on the wall of the main cerebral arteries of the circle of Willis in the ganglionectomized side. However, the decentralization of the contralateral SCG, which was performed simultaneously with a unilateral SCG excision, prevented the nerve sprouting into the denervated regions. Unilateral decentralization of SCG itself failed to affect their distribution pattern or their density of nerve fibers originating in the ganglion. It is concluded that in the young rat the outgrowth of the sympathetic nerve fibers into the denervated cerebral arteries was strongly impeded by the disconnection of ganglion cells from the central nervous system, while the decentralization alone could not affect the innervation pattern of the postganglionic fibers which have been already built-up in the cerebral arterial system.

Animals↗
PubMed2005

Comparison of the stability of 1-piece and 3-piece acrylic intraocular lenses in the lens capsule.

PURPOSE: To compare the degrees of intraocular lens (IOL) decentration, tilt, and longitudinal movement; the refractive change; and anterior capsule contraction after cataract surgery between eyes with a 1-piece acrylic IOL with soft acrylic loops and eyes with a 3-piece acrylic IOL with rigid poly(methyl methacrylate) loops. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Fifty-six patients had implantation of a 1-piece acrylic IOL in 1 eye and a 3-piece acrylic IOL in the fellow eye. The degree of IOL decentration and tilt, the anterior chamber depth (ACD), and the area of anterior capsule opening were measured using Scheimpflug videophotography 3 days and 1, 3, and 6 months postoperatively. The postoperative refractive status was also examined. RESULTS: The mean degrees of decentration and tilt in the 1-piece IOL group were similar to those in the 3-piece IOL group throughout the follow-up. The ACD did not change after surgery in the 1-piece group but showed significant shallowing in the 3-piece group (P < .0001). The spherical equivalent (SE) did not change in the 1-piece group, while the SE had a significant myopic shift of approximately 0.4 diopter in the 3-piece group. The percentage of anterior capsule contraction was similar between the groups. CONCLUSIONS: The degree of IOL decentration and tilt and percentage of anterior capsule contraction in eyes with a 1-piece acrylic IOL with soft acrylic loops were similar to those in eyes with a 3-piece acrylic IOL. The longitudinal movement of the 1-piece IOL was less than the movement of the 3-piece IOL, resulting in less postoperative myopic shift.

Acrylic Resins↗
PubMed2006

The axial misalignment between ocular lens and cornea observed by MRI (I)--at fixed accommodative state.

Lens tilt and decentration relative to the corneal axis are two of the factors which cause aberration in human eyes. Although many techniques have been developed to quantitatively measure these factors, however, they are mostly confined in 2D observations. To extend the view from 2D to 3D, MR imaging technique becomes a good candidate due to its capability of 3D-image reconstruction and with fairly good spatial resolution for that purpose. In this study a total of six eyes of six young students at this Institute were examined by using a 1.5T MRI machine incorporating with a commercial 3-in. surface coil at Taipei Veterans General Hospital. From a 45 degrees flipped reflective mirror, the subject could focus to a target at a distance of 60 cm from the eye for MR imaging in monocular vision. Quadric surface models were used to fit cornea and lens surfaces in the post image processes. Tilts of the two lens surfaces and the decentration of lens centre with respect to corneal axis were determined through coordinate transformations. One month later, retest was carried out on five of the six subjects. The results show that the average tilts of anterior and posterior lens surfaces, and lens decentration are 3.7+/-2.5 degrees, 3.3+/-1.4 degrees and 0.11+/-0.07 mm (H), -0.06+/-0.38 mm (V), respectively, for the test; 2.1+/-2.4 degrees, 1.9+/-1.8 degrees and -0.02+/-0.28 mm (H), -0.45+/-0.28 mm (V) for the retest. No statistically significant difference (by Wilcoxon Signed Ranks test) is revealed for the tilts of both lens surfaces (p(phia)=0.375, p(phip)=0.225) and for decentration (p(H)=0.343, p(V)=0.345) between test and retest in this longitudinal observation. The surface shapes of the ocular anterior components do not seem to be unified by only one type but ellipsoid, elliptic paraboloid, hyperboloid and paraboloid are all possible. Changes in shape type in the ocular anterior components were also found when measured in a period of one month.

Accommodation, Ocular↗