Routine Refraction Research Articles

Prevalence of Amblyogenic Risk Factors in Congenital Nasolacrimal Duct Obstruction in a Developing Country

PURPOSE: Conventionally, congenital nasolacrimal duct obstruction (NLDO) has been treated as an entity with no bearing on development of visual acuity and routine refraction is not done considering the volume of patients in a in a developing Asian country like India. This research was designed to study the prevalence of amblyogenic refractive error in patients with congenital NLDO, as compared to an age-matched control group, in a developing country. METHODS: In this study, 89 patients with congenital NLDO and 78 patients as age matched controls, less than 4 years of age were included at a tertiary care centre in India. All underwent a complete ocular examination and risk factors for amblyogenic refractive error were noted based on the AAPOS guidelines. RESULTS: There was no gender predisposition and no significant difference between the two groups in terms of mode of delivery, orthoptic check-up, keratometry, axial length, fundus or anterior segment examination. Amblyogenic refractive error, as defined by the AAPOS guidelines, was found in 18 (20.5%) patients in the case group compared to 3 (3.8%) in the control group, and this was as follows: astigmatism in 10, anisometropia in 5, hyperopia in 3 subjects, and myopia in 1. These risk factors were not greater in children with unilateral NLDO compared to bilateral NLDO, but both were greater than their control group. There was also no significant difference found between the two groups in terms of distribution of anisometropia. CONCLUSIONS: The prevalence of amblyogenic refractive error in congenital NLDO was significantly higher than in the control group. Hence, a thorough evaluation is warranted in cases of congenital NLDO for early detection amblyogenic refractive error.

Central Corneal Thickness in Aphakic Children With Microcornea-Microphthalmia.

To study the central corneal thickness (CCT) in eyes with microcornea and aphakia and without glaucoma, compare it with normal controls, and correlate it with the measured intraocular pressure (IOP). The study was conducted on 62 eyes of 31 aphakic children with microcornea. Controls (20 children) were selected from age-matched children presenting for routine refraction. Detailed anterior-segment and fundus examinations were conducted. The CCT and the axial length were measured. Medical records of the study patients were reviewed for the stability of the ocular parameters over time to exclude glaucoma. The mean±SD age of the study patients and controls were 4.0 (±3.1, 1.0 to 12.0) and 3.1 (±2.7, 0.6 to 12.0) years, respectively. The mean±SD CCT, the corneal diameter, the measured IOP, the cup/disc ratio, and the axial length of the study patients and the controls were 667.01±72.90 μm, 8.9±0.8 mm, 10.9±5.7 mm Hg, 0.1±0.1, 20.35±2.90 mm and 545.22±28.14 μm, 11.7±0.5 mm, 5.3±1.8 mm Hg, 0.1±0.1, and N/A, respectively. The difference between the study eyes and the controls in the CCT and the measured IOP was statistically significant (P<0.05). Aphakic eyes with microcornea have thicker CCTs and greater measured IOPs than normal eyes. Hence, the measurement of CCT is recommended in the assessment of aphakic eyes with microcornea for possible glaucoma. The measured IOP, although a reliable parameter, in isolation does not provide a diagnosis of glaucoma and must be viewed in conjunction with other patient findings, such as the cup/disc ratio, the progression of which over time must be considered for a more solid diagnosis.

Increased Prevalence of Ametropia in Children With Neurofibromatosis Type 1 Disease

Neurofibromatosis type 1 disease is an autosomal dominant disorder associated with numerous ophthalmic and systemic manifestations. Organic causes of visual loss include optic pathway gliomas, orbital plexiform neurofibroma, and glaucoma. In this study, the authors analyzed the prevalence of ametropia as a cause for visual loss in children with neurofibromatosis type 1 disease younger than age 12 years compared to matched controls. Only children with normal neuroimaging were evaluated. Myopia, hyperopia, astigmatism, and anisometropia were all more common in children with neurofibromatosis type 1 disease; however, statistically significant differences were observed in mild myopia and astigmatism alone. A higher need for optical correction was found in children with neurofibromatosis type 1 disease (33.3% vs 17.1% of controls, P = .049). In conclusion, children with neurofibromatosis type 1 disease have a higher prevalence of ametropia, especially mild myopia and astigmatism, often requiring optical correction. Routine refraction screening is recommended for limiting preventable visual loss.

Ocular Response Analyzer and Goldmann Applanation Tonometry

Correlation of findings of the Reichert Ocular Response Analyzer (ORA) with Goldmann applanation tonometry (GAT). Observational, cross-sectional study. The study was conducted on 103 eyes of 56 patients, aged 41 to 78 years; average (±SD) 58.9 (±9.8) years attending the outpatient clinic of the Department of Ophthalmology, Alexandria University, for a routine refraction. Full ophthalmic examination including slit lamp biomicroscopy and GAT, then Reichert ORA utilization to obtain the intraocular pressure cornea corrected (IOPcc), the IOP Goldmann (IOPg), the corneal resistance factor (CRF), the corneal hysteresis (CH), and the central corneal thickness (CCT). Exclusion criteria included previous ophthalmic surgery and any corneal pathology. The mean (±SD) IOP GAT was 14.1 mm Hg (±3.0) (range: 8 to 22 mm Hg). The mean (±SD) IOPg, IOPcc, CRF, CH, and CCT was 15.5 (±4.0), 16.9 (±3.7), 9.6 (±2.0), 9.4 mm Hg (±1.7) and 540.8 (±32.6) μm, respectively. There was a significant correlation (P<0.0001) between IOP GAT and each of IOPg, IOPcc, and CRF; between IOPg and each of IOPcc, CRF, and CCT; between IOPcc and each of CRF and CH; and between CCT and each of CRF and CH at 0.01 level. The average (±SD) difference between IOP GAT and IOPg and IOPcc was -1.33 (±2.38) mm Hg and -2.81 (±2.66) mm Hg, respectively, and was statistically significant (paired t test in a 95% confidence interval). The ORA is valuable for the evaluation of IOP and corneal biomechanics. However its results are not to be used interchangeably with the GAT findings.

Evaluation of axis alignment system for correction of myopic astigmatism with the excimer laser

Purpose: To evaluate the efficacy of in situ axis alignment for the treatment of myopic astigmatism with an excimer laser.Methods: In this prospective clinical trial, 71 eyes with stable astigmatism of −1.00 to −6.00 diopters (D) with or without stable myopia of up to 10.00 D were randomized to receive excimer treatment of their astigmatic component aligned to the axis determined by subjective refraction (control group) or to have the alignment verified and altered if necessary by in situ alignment (axis alignment group). A VISX Twenty-Twenty excimer laser was used for the treatment. Patients were followed for 6 months.Results: In 85% of eyes in the axis alignment group, the axis of cylinder was different from that calculated by routine refraction. Pretreatment mean cylinder was −1.81 D ± 0.91 (SD) in the axis alignment group and −1.75 ± 0.60 D in the control group. At 6 months, an undercorrection of cylinder was seen in both groups; the mean residual cylinder was −0.70 ± 0.56 D in the axis alignment group and −0.59 ± 0.50 D in the control group. More than 80% of all eyes were within ± 1.00 D of plano and achieved an uncorrected visual acuity of 6/12 or better. A loss of two or more lines of best corrected visual acuity was recorded in three eyes.Conclusion: The in situ alignment technique did not produce better results of photoastigmatic refractive keratectomy than the routine axis alignment technique.

Parallel-testing infinity balance. Instrument and technique for the parallel testing of binocular vision.

Routine refraction involves a series of tests during which changes carried out in the latter part of the routine may alter parameters already considered to have been fixed. These earlier parameters, although thought to have been fixed, are therefore not always valid. No binocular testing device is presently available which allows the practitioner to be aware of how the changing of one parameter affects the others. The Parallel-Testing Infinity Balance (PTIB) has been designed to provide that tool. It is an adaptation of the Turville Infinity Balance. It has the potential for binocular balancing, including suppression, astigmatic distortion, image size and shape variation, and vertical and horizontal imbalances. There follows a discussion of its design and use.

Correlation between presbyopia, age and number of births of mothers in the Kumasi area of Ghana

There is an assumption in Ghana that motherhood has an effect on presbyopia. This study thus attempts to correlate the relationship between presbyopia, age and number of births of mothers in the Kumasi area of Ghana. The data were compiled from records of patients who attended routine eye examinations and refraction tests at the Morny Optical Centre, Kumasi, during the last quarter of 1993. Presbyopia in males and females, and those of mothers and childless female adults for particular age groups were compared. Correlations were found between age and reading additions for both sexes, and presbyopia occurs at a younger age than published. This preliminary study does not indicate any inter-dependence of births on female presbyopia. Further studies with select data may be required to confirm the above findings.

Apparatus for Routine Refraction Measurements of Layers of Lacquers with Digital Reading

Apparatus for Routine Refraction Measurements of Layers of Lacquers with Digital Reading

Intermediate Sex-Linked Retinitis Pigmentosa

Recent advances in the therapeutic armamentarium of the ophthalmologist have simplified a number of problems concerned with ocular infection and inflammation. There remains, however, an increasing incidence of developmental, metabolic, and involutional disease to challenge the ophthalmic physician. It is becoming evident that the role of the gene looms ever more significant in the etiology of a large proportion of these latter entities. It is apparent, therefore, that the ability to recognize the states of gene-determined pathological ocular traits is most important both from the diagnostic and from the prognostic viewpoint. This study resulted from the recognition by one of us (R. L. W.) of the female carrier state of intermediate sex-linked choroidoretinal degeneration (a tapetal-like retinal luster) during the course of a routine refraction being performed in the ophthalmological outpatient service of the Wayne County General Hospital. It is proposed to present herein an additional family which exhibits

The Turville Infinity Balance Technique, and Its Application. to Routine Refraction

The Turville Infinity Balance Technique, and Its Application. to Routine Refraction

The Turville Infinity Binocular Balance Test

To summarise: The Turville method of subjective refraction was applied to 215 consecutive patients. The prescription determined by this method was given each patient regardless of the results of other tests and even against the writer's judgment in some cases. In slightly less than 10 per cent, of these subjects the prescription departed significantly from that which would have been given ordinarily. The prescription was changed in three out of these 21 cases at a subsequent date, two because of binocular difficulties arising from the incorporation of vertical prism and the third because some latent hypermetropia became manifest. A significant departure was assumed to be more than a 0.50 D. difference in the sphere, more than a 0.25 D. difference in the cylinder, 10d̀ or more difference in the axis of the cylinder, and/or the incorporation of prism power in the prescription.After using the Turville method for over one year, the writer's enthusiasm for it, as an addition to routine refraction, is greater rather than less. Of course, it is not a sure‐fire, fool‐proof method of satisfying every patient. It is an important addition to routine refraction, perhaps as important as the flip cross cylinder. The writer no longer applies the results blindly as was done during the testing period, but be now modifies the prescription as indicated by the other tests and sometimes by intuition only based on previous experience.

TREATMENT OF PEDICULOSIS CILIARIS WITH ANTICHOLINESTERASE AGENTS

NEW DRUGS for the treatment of pediculosis ciliaris cannot be said to be especially needed. The time-honored ammoniated mercury has proved itself effective when used liberally enough. Yet it is of considerable interest, and may be of some practical usefulness, to know that the common physostigmine in the standard concentrations used for the treatment of glaucoma is just as effective as ammoniated mercury, if not more so. Tetraethylpyrophosphate, and presumably many other anticholinesterase compounds, are also effective. A case in which we had an opportunity to study the effect of physostigmine and tetraethylpyrophosphate is reported. REPORT OF CASE E. B., a woman aged 49, during routine refraction, was noted to have blepharitis. In reply to questioning, she stated she had had severe itching of the lids, especially at night. Gross examination showed black discoloration of the eyelashes and loose, tiny black dots on the cheeks below the lashes. The first

News and Notes

<h3>GENERAL NEWS</h3><h3>Graduate Course of the Gill Memorial Eye, Ear and Throat Hospital.</h3> —The twentieth annual spring graduate course of the Gill Memorial Eye, Ear and Throat Hospital will be held at Roanoke, Va., on April 7 to 12, 1947. One of the guests of honor, Dr. A. J. Ballantyne, Glasgow, Scotland, will speak on April 7, at 8 p. m., on "Clinical Research and Medical Practice." The regular sessions on the eye will be held on April 10 to 12, and the list of speakers is as follows : Dr. Eugene M. Blake : "Pathology of Glaucoma," "Choice of Operations in Glaucoma," "Unilateral Exophthalmos," "Fundus Changes in Blood Dyscrasias." Dr. Wiliam T. Hunt : "Essential Points in Routine Refraction," "Ocular Therapeutics," "Management of Cases of Lateral `Phoria' and `Tropia,' " "The Near Point Examination." Dr. Arthur J. Bedell : "Retinopathy of Hypertension," "Fundus Changes in Myopia," "Anomalies of the Fundus," "Differential Diagnosis of Optic

DI-N-BUTYLCARBAMINOYLCHOLINE SULFATE

Carbaminoylcholine chloride (doryl) does not affect the surface tension of water. Recently, we have synthesized surface-active derivatives of this compound by replacing the hydrophilic NH 2 group with water-insoluble amines, e. g., di-n-butylamine (fig. 1). This change in molecular structure and surface activity reverses the effects of the drug on the intraocular muscles. While the effects of carbaminoylcholine chloride simulate those of stimulation of the parasympathetic nerves, i. e., miosis and cyclotonia, the action of the new surface-active derivatives simulates that of paresis of the parasympathetic nerves, i. e., mydriasis and cycloplegia. Synthesis and preliminary studies of the pharmacologic action of the new drugs on the eyes have been reported previously. 1 A more detailed investigation of the new class of drugs is the basis of this report. It was our purpose to synthesize an improved cycloplegic and mydriatic drug for use in routine refraction and internal examination. For this

VITAMIN C AND THE AGING EYE

In the course of routine refraction tests on a number of patients at the Hastings State Hospital during the late summer months of 1937, clouding of the optic media associated with more or less impaired vision was noted in an undetermined percentage of cases; apparently this was a precursor of senile cataract, a concomitant feature of early cataract or a morbid condition per se. The patients ranged in age from 41 to 73 years, represented both sexes and included workers and nonworkers. None was a newcomer to the institution. Only a small percentage of this group could be classed as actually senile. In view of references in the literature within the past few years to changes in the vitamin C content of the lens and of other structures of the eye in cataractous conditions (to be discussed later in this paper) and in view also of the combination of circumstances

Value of Muscle-Balance Tests in Routine Refraction

Value of Muscle-Balance Tests in Routine Refraction

REFRACTION CHANGES IN THE EYES OF CHILDREN UNDER SIX YEARS OF AGE

It has been the common belief among ophthalmologists that the refractive changes in the eyes of children occur in the direction of myopia. As this has not been my impression during routine refraction, it was decided to make a survey of a group of cases in which more than one refraction was done under atropine. The cases reported are from the private practice of Dr. E. V. L. Brown and myself and from the Max Epstein Clinic of the University of Chicago. There are 124 children in this group, all under 6 years of age. The youngest patient was 10 months old and the oldest 5½ years of age. In 60 per cent of these cases several refractions were done from six to twelve months apart. The final reading was used in this report. The average age of the entire group was 3.95 years when the first determination was made

The Importance of Heterophoria Tests in Routine Refraction

The mutual relations of heterophoria with errors of accommodation are discussed. A distinction is made between accommodative convergence and fusional convergence. The significance of various forms and manifestations of heterophoria are considered. Presented in the Section on Ophthalmology of the American Medical Association, at the St. Louis Meeting, May, 1922.