Risk factors associated with age-related macular degeneration. A case-control study in the age-related eye disease study: Age-Related Eye Disease Study Report Number 3

OBJECTIVE

To investigate possible risk factors for age-related macular degeneration (AMD) in participants in the Age-Related Eye Disease Study (AREDS).

DESIGN

Case-control study.

PARTICIPANTS

Of the 4757 persons enrolled in AREDS, 4519 persons aged 60 to 80 years were included in this study. The lesions associated with AMD ranged from absent in both eyes to advanced in one eye.

MAIN OUTCOME MEASURES

Stereoscopic color fundus photographs of the macula were used to place participants into one of five groups, based on the frequency and severity of lesions associated with AMD. Participants with fewer than 15 small drusen served as the control group.

RESULTS

Staged model building techniques were used to compare each of the four case groups with the control group. Increased age was a consistent finding of all four of the case groups compared with the control group, and all the following associations were age adjusted. Persons with either intermediate drusen, extensive small drusen, or the pigment abnormalities associated with AMD (group 2) were more likely to be female, more likely to have a history of arthritis, and less likely to have a history of angina. Persons with one or more large drusen or extensive intermediate drusen (group 3) were more likely to use hydrochlorothiazide diuretics and more likely to have arthritis. Hypertension, hyperopia, presence of lens opacities, and white race were also found more frequently in this group as well as in persons with neovascular AMD (group 5). Only persons in group 5 were more likely to have an increased body mass index, whereas persons with geographic atrophy (group 4) as well as those in groups 3 and 5 were more likely to have completed fewer years in school or to be smokers. Those with geographic atrophy were also more likely to use thyroid hormones and antacids.

CONCLUSIONS

Our findings for smoking and hypertension, which have been noted in previous studies, suggest that two important public health recommendations, the avoidance of smoking and the prevention of hypertension, may reduce the risk of developing AMD. Other associations, such as those for hyperopia, lens opacities, less education, female gender, increased body mass index, and white race, which have been noted in other studies, are also seen in the AREDS population. The increased use of thyroid hormones and antacids in persons with geographic atrophy and the increased likelihood of arthritis or hydrochlorothiazide use in persons with one or more large drusen or extensive intermediate drusen have not been previously reported and need additional investigation.

Case-control study of the risk factors for age related macular degeneration. France-DMLA Study Group

AIM

A case-control study was initiated to determine the risk factors for the development of age related macular degeneration (AMD).

METHODS

Study participants, who were all white, aged 50-85 years, and were recruited from private ophthalmology practices. Each practitioner enrolled patients with bilateral AMD, who were then matched with controls for sex and age. Environmental factors and systemic and ocular histories were screened. All patients had bilateral red-free fundus photographs and fluorescein angiography. Photographs were classified into pigment epithelium alterations, drusen, geographic atrophy, and exudative AMD. Statistical analysis included the identification of risk factors for AMD. A multivariate analysis was performed at the end of the study. Analysis included the entire study population and was carried out for each stage of AMD.

RESULTS

1844 controls were compared with 1844 patients with AMD. Mean age was 71 years for controls and 72 for cases. Logistic regression identified six major risk factors for AMD (whole population): arterial hypertension (odds ratio (OR) = 1.28), coronary disease (OR = 1.31), hyperopia (OR = 1.33), light coloured irises (OR = 1.22), and lens opacities or previous cataract surgery (OR = 1.55). The significance of vascular risk factors was increased for late stages of AMD, especially the atrophic forms (coronary disease, OR = 3.19).

CONCLUSIONS

This large case-control study confirms some of the risk factors previously identified and may contribute to the determination of methods for prevention of AMD.

Nanophthalmos with uveal effusion. A new clinical entity

Five patients exhibited the association of nanophthalmos and uveal effusion, apparently on a familial basis. Glaucoma, occurring in the fourth to sixth decades of life, required surgical intervention that was followed by the development of secondary retinal and choroidal detachment. Recognition of this syndrome is important because: (1) surgical procedures for glaucoma should be avoided, if possible, in order to prevent the development of uveal effusion; (2) retinal detachment surgical procedures are ineffective in uveal effusion and should be avoided, and (3) choroidal elevation occurring in the uveal effusion phase may be erroneously diagnosed as an intraocular tumor and unnecessary enucleation may follow.

Vortex vein decompression for nanophthalmic uveal effusion

Uveal effusion in nanophthalmic eyes probably is the result of choroidal congestion secondary to imparied vortex venous drainage through the thick sclera that is characteristic of nanophthalmos. Ten eyes with nonrhegmatogenous retinal detachment, occurring in nanophthalmic eyes, were treated by vortex vein decompression and, in some cases, drainage of choroidal and/or subretinal fluid with air injection into the vitreous cavity. Eight of the ten eyes showed reattachment of the retina after this procedure. There results support the hypothesis that choroidal congestion is the basic mechanism of nanophthalmic uveal effusion.

Prediction of amblyopia and squint by means of refraction at age 1 year

In this series amblyopia, uncorrectable by spectacles and occlusion, was highly likely (48%) if a child had +3.50 or more dioptres of meridional hypermetropia at age 1 year. 45% of children with this refraction also had a squint. All those who remained with severely defective acuity in spite of treatment had either +3.50 or more dioptres of meridional hypermetropia or 4 or more dioptres of meridional myopia at age 1 year. These children were identifiable in the 3.7% of the population at age 1 year who showed high refractive errors. Squint as such was not so accurately predictable. Of those children with squint 71% had less than +3.50 dioptres of meridional hypermetropia at age 1 year--an incidence of 4.4% of the population. Apart from two 'congenital myopes' only 16% of these had residual amblyopia after treatment, and their last known acuity was never less than 6/12. Astigmatism in infancy or later is not significantly associated with squint or amblyopia.

Prevalence and associations of anisometropia and aniso-astigmatism in a population based sample of 6 year old children

AIM

To study the distribution of anisometropia and aniso-astigmatism in young Australian children, together with clinical and ocular biometry relations.

METHOD

The Sydney Myopia Study examined 1765 predominantly 6 year old children from 34 randomly selected Sydney schools during 2003-4. Keratometry, cycloplegic autorefraction, and questionnaire data were collected.

RESULTS

Spherical equivalent (SE) anisometropia (> or =1 dioptre) prevalence was 1.6% (95% confidence interval (CI) 1.1% to 2.4%). Aniso-astigmatism (>or =1D) prevalence was 1.0% (CI: 0.6% to 1.6%). Both conditions were significantly more prevalent among moderately hyperopic (SE > or =2.0D) than mildly hyperopic (SE 0.5-1.9D) children. Myopic children (SE < or =-0.5D) had higher anisometropia prevalence. Neither condition varied by age, sex, or ethnicity. In multivariate analyses, anisometropia was significantly associated with amblyopia, odds ratio (OR) 29, (CI: 8.7 to 99), exotropia (OR 7.7, CI: 1.2 to 50), and neonatal intensive care unit (NICU) admission (OR 3.6, CI: 1.1 to 12.6). Aniso-astigmatism was significantly associated with amblyopia (OR 8.2, CI: 1.4 to 47), maternal age >35 years (OR 4.0, CI: 1.3 to 11.9), and NICU admission (OR 4.6, CI: 1.2 to 17.2). Anisometropia resulted from relatively large interocular differences in axial length (p<0.0001) and anterior chamber depth (p = 0.0009). Aniso-astigmatism resulted from differences in corneal astigmatism (p<0.0001).

CONCLUSION

In this predominantly 6 year old population, anisometropia and aniso-astigmatism were uncommon, had important birth and biometry associations, and were strongly related to amblyopia and strabismus.

Associated factors for age related maculopathy in the adult population in China: the Beijing eye study

BACKGROUND

To evaluate factors associated with the prevalence of age related maculopathy (ARM) in the adult Chinese population.

METHODS

The Beijing Eye Study, a population based prevalence study, included 4439 out of 5324 subjects from a rural area and an urban region of greater Beijing, aged 40+ years and invited to participate (response rate 83.4%). Fundus photographs were graded using the Wisconsin Age-Related Maculopathy Grading system. The following parameters were graded: drusen size, drusen type, and the area covered by drusen; pigmentary abnormalities; geographic atrophy; and exudative ARM.

RESULTS

Fundus photographs were available for 8655 eyes of 4376 (98.6%) subjects. Early age related macular degeneration (ARD), late ARD, and exudative ARD, respectively, were present in 1.4%, 0.20%, and 0.10% of the subjects. In a binary logistic regression analysis, early ARM was statistically associated with age (p<0.001; 95% CI: 1.04 to 1.08), hyperopic refractive error (p = 0.008; 95% CI: 1.04 to 1.28), rural region (p<0.001; 95% CI: 0.17 to 0.49), and lower level of education (p = 0.01; 95% CI: 1.07 to 1.65). Early ARM was not significantly associated with the optic disc size (p = 0.42), and size of beta zone of peripapillary atrophy (p = 0.28), the self reported diagnosis of diabetes mellitus (p = 0.39; OR: 1.37; 95% CI: 0.66 to 2.85), amount of cortical cataract (p = 0.72), subcapsular cataract (p = 0.98), nuclear cataract (p = 0.26), sex (p = 0.23), cataract surgery (p = 1.0; OR: 0.96; 95% CI: 0.13 to 6.95), glaucomatous optic nerve damage (p = 0.77; OR: 0.62; 95% CI: 0.15 to 2.52), and history of smoking (p = 0.66; OR: 1.14; 95% CI: 0.65 to 2.00).

CONCLUSIONS

Hyperopic refractive error besides age was the single most important risk factor for ARM in adult Chinese. Other associated factors were rural region and lower level of education.

Emmetropisation in human infancy: rate of change is related to initial refractive error

Animal studies show that the rate of recovery from experimentally induced refractive errors is related to the level of ametropia induced. The present study examined the rate of emmetropisation occurring in a sample of 22 human infants refracted by near retinoscopy during the first six months of life and then again between 12 and 17 months old. None of the subjects were myopic. Regression analysis revealed that emmetropisation occurred more rapidly in the presence of high refractive errors (P < 0.005 and P = 0.001 for hyperopia and astigmatism respectively). These data confirm the findings of the animal studies and suggest that non-reducing hyperopia and astigmatism in the second year of life may require correction.

Outcome in refractive accommodative esotropia

AIM

To examine outcome among children with refractive accommodative esotropia.

METHODS

Children with accommodative esotropia associated with hyperopia were included in the study. The features studied were ocular alignment, amblyopia, and the response to treatment, binocular single vision, requirement for surgery, and the change in refraction with age.

RESULTS

103 children with refractive accommodative esotropia were identified. Mean follow up was 4.5 years (range 2-9.5 years). 41 children (39.8%) were fully accommodative (no manifest deviation with full hyperopic correction). The remaining 62 children (60.2%) were partially accommodative. At presentation 61.2% of children were amblyopic in one eye decreasing to 15.5% at the most recent examination. Stereopsis was demonstrated in 89.3% of children at the most recent examination. Mean cycloplegic refraction (dioptres, spherical equivalent) remained stable throughout the follow up period. The mean change in refraction per year was 0.005 dioptres (D) in right eyes (95% CL -0. 0098 to 0.02) and 0.001 D in left eyes (95% CL -0.018 to 0.021). No patients were able to discard their glasses and maintain alignment.

CONCLUSIONS

Most children with refractive accommodative esotropia have an excellent outcome in terms of visual acuity and binocular single vision. Current management strategies for this condition result in a marked reduction in the prevalence of amblyopia compared with the prevalence at presentation. The degree of hyperopia, however, remains unchanged with poor prospects for discontinuing glasses wear. The possibility that long term full time glasses wear impedes emmetropisation must be considered. It is also conceivable, however, that these children may behave differently with normal and be predestined to remain hyperopic.

Relationship between refraction and prevalent as well as incident age-related maculopathy: the Rotterdam Study

PURPOSE

To study the relationship between baseline spherical equivalents (SphE) of refraction and prevalent as well as incident age-related maculopathy (pARM and iARM, respectively).

METHODS

The study was performed as part of the Rotterdam Study, a population-based, prospective cohort study. The SphE (in diopters), measured with autorefraction and subjective optimization, was recorded in 6209 subjects aged 55 years or more. Aphakic or pseudophakic eyes at baseline were excluded. Stereoscopic transparencies of the macular region were graded according to the International Classification and Grading System. ARM was defined as large soft drusen with pigmentary changes, or indistinct drusen, or atrophic or neovascular age-related macular degeneration (AMD). For the prevalence analyses, ARM was classified into no, p(early)ARM, or pAMD, and in each subject the eye with the most advanced ARM and the corresponding refraction was selected. After a mean 5.2 years of follow-up, 4935 subjects had complete data for these incidence analyses. In each subject, the eye with iARM was selected.

RESULTS

The age- and gender-adjusted odds ratio (OR) of pARM (n = 536) for every diopter of progress toward hyperopia was 1.09 (95% confidence interval [CI]1.04-1.13). For p(early)ARM (n = 440) the OR was 1.09 (1.04-1.14) and for pAMD (n = 96) the OR was 1.09 (1.00-1.19). Baseline refraction was significantly associated with increased risk of iARM (n = 497). For each diopter of progress toward hyperopia the OR was 1.05 (95% CI 1.01-1.10). Additional adjustments for smoking, atherosclerosis, and blood pressure did not alter the relationship.

CONCLUSIONS

These population-based incidence data confirm results from prevalence and case-control studies that there is an association between hyperopia and ARM.

Hereditary posterior microphthalmos with papillomacular fold and high hyperopia

Five patients had a bilateral hereditary ocular syndrome composed of posterior microphthalmos with a papillomacular fold and high hyperopia. Anterior segment dimensions were near normal; the vitreous compartment was markedly fore-shortened. A papillomacular retinal fold extending from the center of the fovea toward the optic nerve head was present. Visual acuity ranged from 0.05 (20/400) to 0.6 (20/33); refractive errors ranged from + 11.25 to + 17.50 diopters. An autosomal recessive pattern of inheritance is postulated.

Refractive development in children with Down's syndrome: a population based, longitudinal study

AIMS

To study the refractive development in children with Down's syndrome longitudinally.

METHODS

An unselected population of 60 children with Down's syndrome was followed with repeated retinoscopies in cycloplegia for 2 years or more (follow up 55 (SD 23) months). Accommodation was assessed with dynamic retinoscopy.

RESULTS

From longitudinal spherical equivalent values of the right eye, three main categories of refraction were defined: stable hypermetropia (<1.5 D difference between the first and last visit) (n=34), increasing hypermetropia ("hypermetropic shift"; >/=1.5 D difference) (n=11), and decreasing hypermetropia/development of myopia ("myopic shift"; >/=1.5 D difference) (n=9). Patients with anisometropia (n=6) were evaluated separately. In the stable hypermetropia group three sublevels were chosen: low (</=+2.0 D at the last visit), moderate (+2.25 to + 4.0 D), and high (>+4.0 D). An accommodation weakness was found in 55% of the children. Accommodation weakness was significantly less frequent in the stable, low grade hypermetropia group (22%) than in all the other groups (p=0.008). The frequency of astigmatism >/=1.0 D at the last visit was 57%, the direction of axis being predominantly "with the rule." All the eyes with oblique astigmatism had a side specific direction of axis; the right eyes belonging to the 135 degrees axis group and the left eyes to the 45 degrees axis group.

CONCLUSION

A stable, low grade hypermetropia was significantly correlated with a normal accommodation. Accommodation weakness may be of aetiological importance to the high frequency of refractive errors encountered in patients with Down's syndrome. A striking right-left specificity in the oblique astigmatic eyes suggests that mechanical factors on the cornea from the upward slanting palpebral fissures may be a major aetiological factor in the astigmatism.

Photorefractive keratectomy in pediatric patients

This article reports the results of photorefractive keratectomy in nine patients between 10 and 15 years of age who were treated for the following refractive errors: unilateral myopia, post intraocular lens myopia, and unequal hypermetropia with amblyopia. Visual acuity improved and spectacle correction decreased in all patients. There was significant visual improvement with pleoptic treatment in one amblyopic hypermetropic patient.

Early-onset accommodative esotropia

Twenty-one patients had esotropia diagnosed before age 12 months. In all of these patients esotropia was eliminated, at least initially, by antiaccommodative therapy consisting of either full hypermetropic spectacles or miotics, or both. Clinical findings evaluated in these patients were comparable to similar clinical factors studied in a larger series of patients with accommodative esotropia, most with onset after 12 months of age. In approximately 50% of these patients early-onset accommodative esotropia deteriorated to a nonaccommodative esotropia that required surgery despite aggressive antiaccommodative therapy. All but one of the surgically treated patients continued to need hypermetropia spectacles postoperatively to maintain alignment.

Infant vision screening predicts failures on motor and cognitive tests up to school age

In a population-based infant vision screening programme, 5295 infants were screened and those with significant refractive errors were followed up. To assess the relationship between the development of vision and other domains, we report a longitudinal study comparing infants with significant hyperopia, identified at age 9 months ('hyperopes') with infants with normal refractions ('controls'). Children are included who completed at each age a broad set of visual, cognitive, motor and language measures taken over a series of follow-up visits up to age 5.5 years. Hyperopes performed significantly worse than controls on the Atkinson Battery of Child Development for Examining Functional Vision at 14 months and 3.5 years and the Henderson Movement Assessment Battery for Children at 3.5 and 5.5 years. The Griffiths Child Development Scales, MacArthur Communicative Development Inventory and British Picture Vocabulary Scales showed no significant differences. Exclusion of those infants who became amblyopic and strabismic did not substantially alter these results, suggesting that the differences between groups were not a consequence of these disorders. These results indicate that early hyperopia is associated with a range of developmental deficits that persist at least to age 5.5 years. These effects are concentrated in visuocognitive and visuomotor domains rather than the linguistic domain.

Relationship of idiopathic preretinal macular fibrosis to posterior vitreous detachment

Of 100 consecutive cases of spontaneous posterior vitreous detachment, 20 patients had bilateral posterior vitreous detachments, and 50 patients experienced light flashes just before, or at the moment, that they noticed a floating opacity. Most patients had no loss of vision at the time. A prominent provoking factor rarely caused the detachment. In five cases there were hemorrhages at the disk where the posterior attachment of the vitreous body was torn from the disk margin. Six peripheral retinal holes were found in patients with posterior vitreous detachments and in four, the holes were fresh and three were associated with fresh blood in the peripheral vitreous body. There was no attachment between the posterior face of the receding vitreous body and the macular region. There were no macular pathologic findings in this study and there was no secondary pathology anywhere near the macula at the posterior pole. Spontaneous preretinal macular fibrosis did develop in two cases after posterior vitreous detachment, but only after more than two years and in the absence of any vitreoretinal adhesion.

Ocular findings in Kenny's syndrome

In 1966, Kenny described two patients with an unusual congenital syndrome including dwarfism, thickened long bone cortex, transient hypocalcemia, and normal intelligence. These and other patients previously were incorrectly described as "myopic". Ocular findings in four subjects ranged from uncomplicated nanophthalmos with hyperopia to extreme pseudopapilledema, vascular tortuosity, and mucular crowding. Postmortem findings from one patient showed calcium deposits demonstrable only by special histochemical stains that were distributed uniquely in the cornea. This distribution differed greatly from the pattern seen in band keratopathy. Retinal calcification was also an unusual feature. Because one patient exhibited a pseudodoubling of the optic papilla, the literature was reviewed. We conclude that no convincing case of true doubling of the optic nerve has been described. Ophthalmologists should be alert for undiagnosed electrolyte abnormalities, especially hypocalcemia, in patients with Kenney's syndrome.

Acute acquired comitant esotropia: a prospective study

PURPOSE

To define the clinical characteristics of patients presenting with acute onset esotropia and features suggestive of possible underlying central nervous system pathology. To assess the prognosis for the return of binocular function and to consider the most appropriate management.

METHODS

A prospective clinical study was carried out of all patients presenting to the department of paediatric ophthalmology at a university teaching hospital over the period January 1994 to April 1997. Each patient underwent a full ophthalmological examination (including assessment of sensory status). All patients were referred to a paediatric neurologist for examination and CT and/or MRI scan.

RESULTS

Ten patients presented during the study period. Uncorrected hypermetropia and/or decompensated monofixation syndrome were the commonest aetiological factors. One patient was found to have a cerebellar tumour. In 5 patients prescription of the full hypermetropic correction alone was sufficient to restore binocularity. Five patients required bilateral medial rectus recession. Binocular function was restored in all cases--in 5 cases with bifoveal fusion.

CONCLUSION

Decompensation of a pre-existing phoria or monofixation syndrome appears the commonest aetiology. Prescription of the full hypermetropic correction found at cycloplegic refraction forms an essential part of initial management. No single clinical sign can reliably indicate the rare patient harbouring a tumour. A high index of suspicion should be maintained and neuro-imaging considered in the absence of expected findings such as hypermetropia or fusion potential or in the presence of atypical features or neurological signs.

Choroidal folds

We documented the presence of choroidal folds in a series of 59 eyes. Fifteen separate conditions were established as causes of the choroidal folds. Hyperopia was the most common cuase, although no definite etiology could be established in ten cases.

Photorefractive keratectomy to correct astigmatism with myopia or hyperopia

Excimer laser photorefractive keratectomy as a means to flatten the central cornea has generated considerable interest. With this technique radial symmetric ablations can be performed to correct myopic refractive errors and excise superficial corneal pathology. We developed a technique that uses toric ablation to correct astigmatism. A new mask was designed for the MEL 60 Aesculap-Meditec excimer laser. The mask can be rotated regularly over 360 degrees. By varying the angular distances, the surgeon can increase ablation depth in any desired meridian. As a result, both cylindrical and spherical errors can be corrected in one procedure. Seventy-three eyes with either simple, myopic, mixed, or irregular astigmatism were treated. In each category of astigmatism, the surgery reduced the spherical component as well as the overall mean preoperative cylindrical refraction. Our findings suggest that this technique is a safe and effective procedure for correcting different types of astigmatism.

A longitudinal study of a population based sample of astigmatic children. I. Refraction and amblyopia

The refraction changes in 310 children with astigmatism greater than or equal to 1.0 D in at least one eye at one year of age were followed during a period of 3 years. At the age 4 years amblyopia was found in 23 children (7%). The refraction data of these children were compared to the rest of the sample. We found that an increasing astigmatism during the test period was associated with an increased risk to develop amblyopia. The majority of children (n = 280) showed a decrease of their astigmatism, whereas all cases with a marked amblyopia (V.A. less than 0.5) or binocular amblyopia, except one, had an increasing or unchanged astigmatism during the age period 1 to 4 years. Strabismus and oblique astigmatism at any time during the test period was also strongly related to amblyopia. The incidence of strabismus (1%) was unexpectedly low. The study also showed that independent of age there was no simple relationship between amblyopia and refraction errors measured at a single test session. The main conclusion of this study is that failure of emmetropization may play an important role in visual development.