Retinal acetylcholine content in normal and myopic eyes: a role in ocular growth control?

Retinal neurotransmitters are known to play a role in postnatal ocular development and eye growth. The success of muscarinic antagonists in blocking form-deprivation myopia has implicated retinal acetylcholine in the control of ocular growth. The present study investigated whether steady-state content of acetylcholine (ACh) and its metabolite choline (Ch) are altered in the retina of eyes developing axial myopia, in both tree shrews and chicks. Retinal ACh and Ch content were measured using reverse-phase high-performance liquid chromatography. Posterior and anterior retinal samples were analyzed from myopic (form deprived) and control eyes as well as age-matched normal eyes. Normative data on retinal neurotransmitter content demonstrated that chick retinas contained less than half the ACh and Ch neurotransmitter content of tree shrews when normalized to retinal protein (ACh: 61 +/- 3 vs. 130 +/- 6 ng, Ch: 131 +/- 5 vs. 347 +/- 25 ng). There was no significant difference in either ACh or Ch content between myopic and contralateral control eyes in either tree shrews or chicks, irrespective of the degree of myopia. This finding was consistent for both posterior, anterior, and consequently whole retinal samples. In contrast, dopamine and DOPAC contents were found to be reduced in myopic compared to control eyes of the same tree shrews (dopamine -6.9% and DOPAC -15.5%) and chicks (dopamine -12.3% and DOPAC -28.2%). These findings demonstrate that, contrary to dopamine and DOPAC content, steady-state retinal acetylcholine and choline content is not significantly altered during myopia development.     

Diet and cataract: a case–control study

We conducted a case–control study to assess the association between diet and risk of cataract in Athens, Greece. Totals of 314 cases and 314 frequency-matched controls of both sexes, aged 45–85 years and attending the ophthalmology department of a major teaching hospital in Athens, Greece, were included in the study. All participants were interviewed using a semi-quantitative food-frequency questionnaire, covering the average frequency of consumption of about 120 food items. Analyses were conducted through multiple logistic regression. The analysis was carried out taking cataract as a general outcome (all types of cataract combined) and repeated by the specific type of cataract. We found significant inverse associations of cataract with dietary consumption of fish (OR = 0.69, p < 0.001), vegetables (OR = 0.47, p < 0.001), fruits (OR = 0.53, p < 0.001), and potatoes (OR = 0.76, p = 0.004), while consumption of meat was positively associated with cataract (OR = 1.46, p = 0.001). High intake of total fat (OR = 2.00, p < 0.001) and cholesterol (OR = 1.65, p < 0.001) increased the risk of cataract. There was a protective association between cataract risk and intake of carbohydrates (OR = 0.39, p < 0.001), carotene (OR = 0.56, p < 0.001), vitamins C and E (OR = 0.50, p < 0.001 and OR = 0.50, p < 0.001 respectively). We identified an association between the risk of cataract and several food groups and nutrients. Diets rich in fruits, vegetables, fish, pulses and starchy foods may protect against cataract. In addition, high intake of vitamins C and E and carotene with reduction of intake in total fat and cholesterol may be beneficial. Dietary advice along these lines may provide adequate public health guidelines for the delay of age-related cataract.     

Frequency and risk factors of narrow angles in patients with pseudoexfoliation: a case–control study

International Ophthalmology - To determine the frequency and risk factors of narrow angles in pseudoexfoliation (PXF) patients. A prospective case–control study was conducted during the...     

Motion sharpening and contrast: gain control precedes compressive non-linearity?

Blurred edges appear sharper in motion than when they are stationary. We (Vision Research 38 (1998) 2108) have previously shown how such distortions in perceived edge blur may be accounted for by a model which assumes that luminance contrast is encoded by a local contrast transducer whose response becomes progressively more compressive as speed increases. If the form of the transducer is fixed (independent of contrast) for a given speed, then a strong prediction of the model is that motion sharpening should increase with increasing contrast. We measured the sharpening of periodic patterns over a large range of contrasts, blur widths and speeds. The results indicate that whilst sharpening increases with speed it is practically invariant with contrast. The contrast invariance of motion sharpening is not explained by an early, static compressive non-linearity alone. However, several alternative explanations are also inconsistent with these results. We show that if a dynamic contrast gain control precedes the static non-linear transducer then motion sharpening, its speed dependence, and its invariance with contrast, can be predicted with reasonable accuracy.     

The cortex is in overall control of ‘voluntary' eye movement

The neural circuits that control eye movements are complex and distributed in brainstem, basal ganglia, cerebellum, and multiple areas of cortex. The anatomical function of the substrates implicated in eye movements has been studied for decades in numerous countries, laboratories, and clinics. The modest goal of this brief review is twofold. (1) To present a focused overview of the knowledge about the role of the cerebral cortex in voluntary control of eye movements. (2) To very briefly mention two findings showing that the accepted hierarchy between the frontal and the occipital sensory areas involved in sensory–motor transformation might not be so trivial to reconcile, and to interpret in the context of eye movement command. This presentation has been part of the 44th Cambridge Ophthalmological Symposium, on ocular motility, 3 September 2014 to 5 November 2014.Historically, in humans, the data describing the implications of cortical areas in controlling eye movement have been collected in patients with lesions or degenerative diseases, whereas in animal models, two ancient but still preferred tools, for the delineation of cortical regions, involved the two techniques of low-threshold current stimulation and the recording of extracellular activity.¹ More recently, ultrasonic² and transcranial magnetic stimulations,^{3, 4, 5} as well as functional magnetic resonance imaging, provided complementary results to better understand with noninvasive techniques how eye movements are controlled by the brain.^{6, 7}Within the frontal cortex, the cortical structures of the saccadic systems include; the frontal eye field (FEF) and its role in saccade and pursuit eye movement control, the supplementary eye field (SEF) and the dorsolateral prefrontal cortex (dlPFC). The SEF and the dlPFC are both involved in the decisional processes that is governing ocular motor behavior, such as when and how they inhibit an unwanted reflexive saccade. The SEF and the dlPFC are also having a role in making eye movement at a memorized location, as well as producing sequences eye movements. In the temporoparietal regions, the activity of the posterior parietal cortex is less implicated in movement execution per se but more involved in visuospatial integration and attention. Lastly, the anterior cingulate cortex appears to be mainly and indirectly involved in the control of externally guided eye movements and attentional mechanisms.As briefly introduced above, in the frontal lobe, three main areas are involved in eye movement control (Figure 1). The FEF is involved in the preparation and triggering of all saccades.⁸ In particular, FEF is involved in saccades generation, which are internally triggered toward a target already present (visually guided saccade), not yet present (predictive saccade), and no longer visible (memory-guided saccade) or located in the opposite direction (antisaccade). Despite some noticeable activity recorded in nonhuman primates, FEF region is believed to be less involved in the triggering of purely reflexive, visually guided saccades, which are externally triggered toward a stimulus appearing at a peripheral location. A subregion of FEF also controls pursuit eye movements, along with the cortex, the posterior temporoparietal areas,^{9, 10} and cerebellum.¹¹ In humans, studies using fMRI have delimited the location of the FEF mainly to the intersection between the precentral sulcus and the superior frontal sulcus, whereas the pursuit-related area to a deeper region along the anterior wall, the fundus, and the deep part of the posterior wall.¹⁰ In the precentral sulcus, aside the main locus of the FEF, located at the junction with the superior frontal sulcus, another locus of activation is often observed in fMRI studies along the lateral part of this sulcus and the adjacent portion of the precentral gyrus.¹² The specific role of this lateral locus remains to be determined, as it is activated both by single and combined eye and head movements.¹³Open in a separate windowFigure 1Supranuclear region implicated in the control of eye movements.As illustrated in Figure 2, the antisaccade paradigm permits to study intentional saccades that have to be made in the direction opposite to a suddenly appearing peripheral visual target.¹⁴ To generate these movements at least two mechanisms are believed to be required: the inhibition of the unwanted reflexive saccade to the target; and the consecutive triggering of an intentional correct antisaccade made in the direction opposite to the target. Prosaccades and antisaccades have been intensively studied in humans (fMRI) and monkeys single unit (SU). In all reports, stronger activation has been observed just before antisaccades in the FEF than in prosaccade.^{15, 16} All these studies, confirm that such intentional saccades require an early preparation of FEF in antisaccades but not in prosaccades. However and although FEF is active in antisaccade preparation, these results do not demonstrate that inhibition or relocation of misdirected reflexive prosaccades are organized within the FEF per se. In fact, activation of the dlPFC and/or the SEF were also recorded just before antisaccades.¹⁶ In that scenario, the inhibition of reflexive saccades by the dlPFC and/or SEF could be exerted via FEF or directly on the superior colliculus, without involving other cortical areas, via a prefrontocollicular tract.¹⁷Open in a separate windowFigure 2Saccade and saccadic paradigms.SEF is located on the medial surface of the superior frontal gyrus.¹⁶ In humans, SEF is located in the upper part of the para-central sulcus (Figure 1). Anatomically SEF appears to be a critical node in the oculomotor circuit. SEF is connected with all areas involved in eye movement control—the FEF, the dlPFC, the anterior cingulate cortex (ACC), most of the parietal cortex, and also deep oculomotor structures in the brainstem. Electrical stimulation in monkey and lesion studies in humans have demonstrated that SEF is involved in motor program comprising a saccade combined with a body movement.¹⁸ In SU-recording studies in monkey, using a saccade sequence, it was demonstrated that the SEF neurons are also involved in the coding of temporally ordered saccadic eye movements.¹⁹ In the same vein, a recent TMS study in humans has shown that stimulation applied over the SEF resulted in a disruption of the saccade order in a double-step paradigm (comprising a sequence of two successive saccades). Altogether, these results validate that the SEF control and have an important role in motor preparation rather than motor program by itself, even when they are limited to a single saccade.⁸Slightly more rostral and lateral than the SEF (dlPFC Figure 1), the dlPFC is involved in saccade inhibition,²⁰ but see,²¹ as well as, short-term spatial memory and in decision processes.²² Human and nonhuman primates studies have demonstrated that the dlPFC, and, more particularly, area 46 of Brodmann and the adjacent Brodmann area 9, both located in the middle frontal gyrus, are involved in the control of memory-guided saccades.²³ Aside its role in memory-guided saccades the dlPFC is also involved in the control of predictive saccades.²⁴ These results in conjunction with those referred to above suggest that the dlPFC has a crucial role in decisional processes governing eye movement behavior, preparing intentional saccades by inhibiting unwanted reflexive saccades (inhibition), maintaining memorized information for forthcoming intentional saccades (short-term spatial memorization), or facilitating intentional anticipatory saccades (prediction), depending upon current external environmental and internal circumstances.All these decisional rules that are important in guiding or inhibiting future responses are believed to be exerted through inhibitory interactions between neurons in the dlPFC, FEF, SEF, and parietal regions. In particular, the control of the timing during cognitive operations might be thereby shaped by the temporal flow of information between FEF, SEF, and dlPFC.²⁵In the parietal lobe, the location and function of subregions involved in eye movements and attention have been studied intensively, but are still not so well known.^{26, 27} The parietal lobe and more particularly its posterior part, the PPC, are involved in the control of saccades and attention. In humans and nonhuman primates, the PPC includes the intraparietal sulcus (IPS) extending from the post-central sulcus anteriorly to the parieto-occipital sulcus posteriorly (Figure 1). The anatomy of the IPS is not trivial to compare across subjects and species, being relatively variable from one subject to another.²⁸ The human parietal-eye-field (PEF) corresponds to the lateral intraparietal area of the monkey. The lateral intraparietal area is involved in the control of saccades, but also in attentional processes. Furthermore, low threshold of electrical stimulation of this area in the monkey or human results in a simple shift of visual attention (without eye movement), whereas stronger stimulation results in a saccade.^{29, 30, 31} These results emphasize in PPC but also in other brain regions, the close but distinct circuits existing between saccades and attention, even in the same area.^{32, 33, 34} The PEF appears to be located along the IPS, within the sulcus, in its posterior half, adjacent laterally to the anterior part of the angular gyrus (Brodmann area 39) and medially to the posterior part of the SPL (Brodmann area 7).As it has been noticed in SEF, the activation of the PEF is also modulated by head position. The PEF projects to both the FEF and the superior colliculus (Figure 1). In the monkey, these two projections appear to be qualitatively different, with a more visual involvement for the parieto-FEF projection and a more saccadic involvement for the parietosuperior colliculus projection. The parieto-FEF projection is believed to be mainly involved in visual processing, whereas the parietocolliculus projection is more involved in express saccades.³² The results of studies in patients with lesions affecting the posterior part of the internal capsule, damaging the direct parietocollicular tract originating in the PEF, are in accordance with the experimental results and confirm that the PEF is crucial for reflexive saccade generation, but not for intentional saccade generation. The latter depends mainly upon FEF, SEF, and dlPFC activities.²⁵Finally, the cingulate cortex, which is not per se an oculomotor area, has also been found to have an important role in the control of voluntary saccades. In particular, the rostral part of the cingulate cortex is involved in intentional saccade control, but not in reflexive saccade control. The dorsal bank of the ACC is involved, via direct connections to SEF, in preparing all the frontal ocular motor areas involved in intentional saccade control to act in the forthcoming motor behavior. The dlPFC is also connected to ACC.^{35, 36}     

Investigation of children’s habits of smartphone usage and parental awareness of myopia control in underdeveloped areas of China

AIM: To investigate the behaviors of smartphone usage and parental knowledge of vision health among primary students in the rural areas of China. METHODS: In this school-based, cross-sectional study, a total of 52 606 parents of students from 30 primary schools in the Xingguo County were investigated through an online questionnaire from July 2020 to August 2020. The self-designed questionnaire contained three parts: the demographic factors of both children and parents, parental knowledge and attitude toward myopia, and the preventive treatment of myopia. RESULTS: A total of 52 485 appropriately answered questionnaires were received, showing an effective response rate of 95.1%. The average age of the primary students was 10.1±0.98y and the prevalence of myopia among the primary students was 40.3%. The age of myopia occurrence in elementary students was significantly correlated with the parents’ educational level (95%CI: 0.82-0.98, P=0.013), children’s gender (95%CI: 1.08-1.20, P<0.001), school location (county or countryside) (95%CI: 0.59-0.66, P<0.001), children’s smartphone ownership (95%CI: 1.09-1.26, P<0.001), and the average time spent on smartphone per day (95%CI: 0.78-0.88, P<0.001). School location in the county town, high family income, and high parents’ educational level significantly affected both parents’ myopia awareness and children’s vision-threatening behaviors (P<0.01). Left-behind children showed a higher incidence of vision-threatening habits than those who lived with their parents (P<0.01). CONCLUSION: The results reveal the current situation of myopia development among rural primary school students and their parents. This survey will serve as a guidance for designing myopic prevention policies in the rural areas of China.     

【In Press】Comparison of myopia control between toric and spherical periphery design orthokeratology in myopic children with moderate-to-high corneal astigmatism

AIM: To compare clinical results between toric and spherical periphery design orthokeratology (ortho-k) in myopic children with moderate-to-high corneal astigmatism. METHODS: This retrospective study enrolled 62 eyes of 62 subjects using toric ortho-k lenses. These subjects were assigned to the toric group. Based on the one-to-one match principle (same age, proximate spherical equivalent and corneal astigmatism), 62 eyes of 62 subjects were enrolled and included in the spherical group. At one-year follow-up visit, visual acuity, corneal astigmatism, treatment zone decentration, axial elongation and adverse reaction were compared between these two groups. RESULTS: At the one-year visit, corneal astigmatism was significantly lower in the toric group (1.22±0.76 D) than in the spherical group (2.05±0.85 D) (P=0.012). The mean magnitude of the treatment zone decentration was 0.62±0.42 mm in the toric group and 1.07±0.40 mm in the spherical group (P=0.004). Axial elongation was significantly slower in the toric group (0.04±0.13 mm) than in the spherical group (0.09±0.13 mm) (P=0.001). The one-year axial elongation was significantly correlated with initial age (r=-0.487, P<0.001) and periphery design of ortho-k lens (r=0.315, P<0.001). The incidence of corneal staining was lower in the toric group (8.1%) than in the spherical group (19.4%) (P<0.001). CONCLUSION: Toric periphery design ortho-k lenses may provide lower corneal astigmatism, better centration, slower axial elongation and lower incidence of corneal staining in myopic children with moderate-to-high corneal astigmatism.     

Is glaucoma blindness a disease of deprivation and ignorance? A case–control study for late presentation of glaucoma in India

Aim:

The aim was to identify the presenting symptoms and social risk factors for late presentation of primary glaucoma in newly diagnosed cases.

Materials and Methods:

It was a case-control study in a tertiary eye care center in Maharashtra, India. Newly diagnosed patients with primary glaucoma were classified as cases (late presenters) where there was no perception of light in one eye or severe visual field loss affecting an area within 20° of fixation or a cup–disc (C:D) ratio ≥0.8 and controls (early presenters), presenting relative scotoma within 20° of fixation or a C:D ratio <0.8, but >0.5. All patients underwent a comprehensive ocular examination including gonioscopy, perimetry, and detailed family and social history. Occupation, education, and socioeconomic status were graded. SPSS version 12.0 was used, and univariate and multivariate logistic regression analysis was performed.

Results:

Gradual progressive painless loss of vision was the commonest symptom (175, 87.5%). Primary angle closure glaucoma was more common in females (P = 0.001) and lower socioeconomic groups (P = 0.05). Patients who were less educated were more likely to have late presentation of glaucoma (P < 0.001, odds ratio = 0.07; 95% CI, 0.02–0.25). Knowledge of family history of glaucoma (P = 0.80, odds ratio = 1.16; 95% CI, 0.36–3.71) and eye clinic attendance in past 2 years still resulted in late presentation (P = 0.45, odds ratio = 1.34, 95% CI, 0.63–2.82).

Conclusion:

Lack of education and awareness of glaucoma were major risk factors for late presentation.     

Lateral thinking – Interocular symmetry and asymmetry in neurovascular patterning,in health and disease

No biological system or structure is likely to be perfectly symmetrical, or have identical right and left forms. This review explores the evidence for eye and visual pathway asymmetry, in health and in disease, and attempts to provide guidance for those studying the structure and function of the visual system, where recognition of symmetry or asymmetry may be essential.The principal question with regards to asymmetry is not ‘are the eyes the same?’, for some degree of asymmetry is pervasive, but ‘when are they importantly different?’. Knowing if right and left eyes are ‘importantly different’ could have significant consequences for deciding whether right or left eyes are included in an analysis or for examining the association between a phenotype and ocular parameter. The presence of significant asymmetry would also have important implications for the design of normative databases of retinal and optic nerve metrics.In this review, we highlight not only the universal presence of asymmetry, but provide evidence that some elements of the visual system are inherently more asymmetric than others, pointing to the need for improved normative data to explain sources of asymmetry and their impact on determining associations with genetic, environmental or health-related factors and ultimately in clinical practice.     

The Study of G6PD in Erythrocyte and Lens in Senile and Presenile Cataract

The G6PD activity of erythrocytes in 113 male patients with senile and presenile cataract and 86 controls, and G6PD activity of lens in 30 patients with senile cataract and 42 controls were reported. The cataractous group had higher frequency of G6PD deficiency and lower average G6PD level in erythrocytes and lenses, but with out statistical significance. The frequency of G6PD deficiency of erythrocytes in presenile cataractous group was higher than that of senile cataractous group but with no statistical significance too. However, the average G6PD level of erythrocytes in presenile cataractous group was lower than that of senile cataractous group and with statistical significance (P<0.05). The G6PD activity of lenses only presenile in the cortex and have a positive correlation with that of erythrocytes. There was a case with deficiency of G6PD both of erythrocytes and cataractous lenses in both eyes. The results indicate that the deficiency of G6PD might be one of the cataractous pathogenetic factor for presenile cataract. Measurement of G6PD activity of erythrocytes among population might be of significance in finding the risk factor for cataract.     

Coagulase-negative Staphylococci in Conjunctivitis and Blepharitis

Coagulase-negative staphylococcus (C-NS) are regarded asnormal flora of the lids and conjunctiva.The ability of these organisms tocause conjunctivitis and blepharitis can be overlooked or disregarded.Toelucidate the role of individual C-NS species in these eye diseases wecompared Staphylococcus sp.isolated from the conjunctiva and lids of 50healthy volunteers with 248 strains of Staphylococcus isolated frompatients with staphylococcal conjunctivitis or blepharitis.S.epidermidiswas the most frequent species isolated from the conjunctiva and lids ofboth groups.S.aureus was isolated only from infected patients.Noindividual C-NS species was found to be significantly associated with eyedisease,but the colony count of C-NS after isolation was a useful indicatorof conjunctivitis and blepharitis.The ability of Staphylococcus to fermentmannitol or mannose was associated with isolates only from infectedpatients.Eye Science 1993:9:129-135.     

Do scleral flap dimensions influence reliability of intraocular pressure control in experimental trabeculectomy?

AIM: To compare the effect on intraocular pressure (IOP) of large vs small scleral flap size during trabeculectomy using adjustable sutures. METHODS: Trabeculectomy operations were performed on nine donor human eyes connected to a constant flow infusion with real-time IOP monitoring. Large scleral flaps (4 x 4 mm, 16 mm(2), n=12) or small scleral flaps (3 x 2 mm, 6 mm(2), n=9) were constructed over 0.76 mm(2) sclerostomies. For each procedure, equilibrium IOP was measured following tight closure with two four-throw adjustable 10-0 nylon sutures. RESULTS: Five scleral flaps were thin or poorly constructed; four of these were in the initial seven procedures, implying learning effect. These had a mean absolute IOP of 7.6 mmHg (range 2.7-12.4 mmHg) and mean relative IOP of 28.3% of baseline (range 10-45.8%) after closure. In the remaining 16 good quality procedures, mean IOP was 1.3 mmHg (range 0-3.4 mmHg) after sclerostomy, confirming minimal outflow resistance before closure. Following flap closure mean IOP was 20 mmHg (SD 4.4, range 15.5-29.3 mmHg) for large (n=8), and 18.7 mmHg (SD 3.6, 15.9-25.8 mmHg) for small (n=8) flaps (unpaired t-test, P=0.26). Mean IOP (% baseline) was 71.6% (SD 8.4, range 60.6-86.6%) and 66% (SD=12.7, 46.8-86.6%) for large and small flap groups, respectively (unpaired t-test, P=0.2). CONCLUSIONS: Well-constructed scleral flaps of both sizes were able to support an average IOP at least two-thirds of baseline, and both had similar absolute IOP levels. Errors in flap construction resulted in loss of IOP control. Smaller flap size does not appear to compromise control of early postoperative IOP using adjustable sutures.     

Changes in corneal sensation following 20 and 23?G vitrectomy in diabetic and non-diabetic patients

Purpose

To evaluate the changes in corneal sensation (CS) following two different port sizes vitrectomy in diabetic and non-diabetic patients.

Patients and Methods

Patients prepared for pars plana vitrectomy were randomly assigned to four groups: diabetics to either 20 G or 23 G and non-diabetics to either 20 G or 23 G vitrectomy systems. CS was measured using the Cochet-Bonnet aesthesiometer at baseline preoperatively, and at 1 day, 1 week, and 1 month postoperative.

Results

A total of 40 eyes of 40 patients were included in this study; 20 patients (20 eyes) in each of the 20-G and 23-G groups. The mean age was 55.51±10 years and male/female ratio was 2:3. There were no significant difference between CS at baseline, and at 1 day, 1 week, and 1 month between both the 20-G and 23-G groups. There were significant drops in CSs at 1 day and 1 week for both groups (20 G and 23 G) with incomplete recovery for the 20-G group and complete recovery for the 23-G group. Comparing the two diabetic subgroups (20 G and 23 G) and two non-diabetic subgroups (20 G and 23 G), there were no significant differences in CS between subgroups. Diabetics'' eyes had lower CSs throughout the study period in the 20-G and 23-G groups, which was significant at day1 and week 1 postoperatively.

Conclusion

The vitrectomy procedure showed reduction in CS in the postoperative period with minimal nonsignificant difference between 20 G and 23 G systems. However, diabetics'' eyes showed compromised CS preoperatively and a further significant reduction for 1 month postoperatively compared with non-diabetics.     

Development of PVEP in Infants and Children

The development of components of VEP was studied in 150 infants and children between 2 weeks and 9 years of age participated as subjects. Ten adult subjects, 25 ito 35 years of age were also studied. The results indicated that the VEP had a simple wave form, consisting of only a slowly rising positive wave to 140‘, 70‘ and 35‘ checks from infants of 2 to 8 weeks following birth. P_1 wave appeared in response to 17.5‘ check stimulus at 10 weeks following birth. The latencies of P_1 components shortened d...     

Risk factors for exudative age-related macular degeneration in a large French case–control study

Purpose

The purpose of the CAP (Creteil AMD PHRC-funded) Study was to analyze risk factors of exudative age-related macular degeneration (AMD) in a large French case–control population.

Patients and methods

One thousand and twenty-four patients with exudative AMD and 275 controls were recruited. Information about lifestyle, medical history, and dietary intake were collected. Associations of risk factors were estimated using logistic regression.

Results

After multivariate adjustment, CFH Y402H and ARMS2 A69S polymorphisms were associated with very high risk for exudative AMD (OR?=?6.21 and OR?=?11.7, respectively, p?<?0.0001). Risk for exudative AMD was increased in current smokers (OR?=?3.79, p?=?0.0003) and former smokers having quitted since less than 20 years ago (OR?=?2.30, p?=?0.002), but not in former smokers having quitted since 20 years or more ago (OR?=?0.81, p?=?0.43). Heavy smokers (at least 25 pack-years) were particularly at risk (OR?=?3.61, p?<?0.0001). Use of cooking oils rich in omega 3 fatty acids was significantly associated with a reduced risk of exudative AMD (OR?=?0.55, 95 % CI: 0.36–0.84, p?=?0.006), as well as a high consumption of fruits (OR?=?0.60, 95 % CI: 0.37–0.98, p?=?0.04), but not the consumption of fish, vegetables or oils rich in omega 6. High waist circumference was associated with increased risk for exudative AMD (OR?=?2.53, p?<?0.0001), but not hypercholesterolemia, hypertension, or body mass index.

Conclusions

The CAP Study confirms major genetic risk factors for exudative AMD. It further documents the high risk in heavy smokers and the long persistence of risk after smoking cessation, and the associations with waist circumference and fruit consumption. Furthermore, we observed an inverse correlation between AMD and cooking oils harboring a beneficial omega-3 fatty acid profile.     

Who needs myopia control?

Myopia has become a major visual disorder among school-aged children in East Asia due to its rising prevalence over the past few decades and will continue to be a leading health issue with an annual incidence as high as 20%-30%. Although various interventions have been proposed for myopia control, consensus in treatment strategies has yet to be fully developed. Atropine and orthokeratology stand out for their effectiveness in myopia progression control, but children with rapid progression of myopia require treatment with higher concentrations of atropine that are associated with increased rates of side effects, or with orthokeratology that carries risk of significant complication. Therefore, improved risk assessment for myopia onset and progression in children is critical in clinical decision-making. Besides traditional prediction models based on genetic effects and environmental exposures within populations, individualized prediction using machine learning and data based on age-specific refraction is promising. Although emerging treatments for myopia are promising and some have been incorporated into clinical practice, identifying populations who require and benefit from intervention remains the most important initial step for clinical practice.     

The Visual Deprivation and Increase in Axial Length in Patients with Cataracts

Purpose: To investigate the relationship between axial myopia and visual deprivation in patients with cataracts in their youth.Methods: Forty myopic eyes of 25 cases had long deprivation of form vision due to cataracts during their youth. The axial length was measured by A-Scan ultrasound.Results: The axial length is 2-6mm (mean: 3. 7mm) longer than the other eyes in 10 patients with unilateral cataracts. Fifteen cases with bilateral cataracts had 25-29mm of axial length (mean of the right eyes 26-8mm and the left eyes: 26. 7mm). Six cases with unilateral cataract had traumatic histotry at age from 2-9 years (mean: 5. 1 years) and the duration of visual deprivation due to cataract was from 8 to 30 years (mean; 12 years). Thirteen cases with dilateral congenital cataract had 17- 4 years(from 3 to 37 years) of visual deprivation. Concusion: The deprivation of form vision due to cataracts in childhood leads to in crease in axial length and myopia. Eye Science 1996; 12: 135- 137.     

Angioblasts in Adult and Its Role in Ocular Disorders Due to Neovascularization

Blood vessel formation includes vasculogenesis and angiogenesis. Traditionally vasculogenesis is believed to occur in embryo, forming blood vessels by the differentiation of angioblasts, while angiogenesis is defined as the formation of new blood vessels that originate from pre-existing vessels, which happens both in embryo and adult. However, recent studies on angioblasts have shown that new blood vessel formation due to angioblast differentiation, once was believed to happen exclusively in embryo, also occurs in adult. These findings not only help us to understand the pathogenesis of new blood vessel formation, but also provide some new clues to investigate new therapeutic target for the treatment of angiogenesis. Eye Science 2005 ;21:158-162.