Jonathan S. Pointer

The presbyopic add. II. Age-related trend and a gender difference

New transverse clinical data are presented which confirm and extend earlier results to be found in the literature describing the time course of presbyopia-as indicated by the magnitude of the binocular spectacle add--in normally sighted male and and female Caucasian subjects. An initial steep increase in add requirement beginning in the early forties becomes relatively slower but still of significance beyond the mid-fifties. This observation is correlated with the age-related progressive decline in the amplitude of accommodation, itself a consequence of physiological changes in the crystalline lens and capsule. The continuing need for an increase, albeit at a reduced rate, in the positive near supplement beyond the mid-to-late fifties-by which time little or no useful accommodation is available-is now attributed to the visually disruptive effects within the high spatial frequency domain of progressive age-related lenticular changes. The magnification afforded by the positive add increases spatial grain and thereby enhances visibility of detail in an ageing visual system free of any gross senile visual pathology. A small but consistent gender difference is revealed in presbyopic corrections: physiological and physical bases are suggested for the observation that females require an add of greater magnitude than their age-matched male counterparts.

Sighting dominance, handedness, and visual acuity preference: three mutually exclusive modalities?

It is tempting, even perhaps for the clinician, to assume prima facie that an individuals handedness is indicative of other lateral asymmetries, including ocular (sighting) dominance and preferred monocular acuity. An analysis of new data relating to these three modalities, as collated from counter‐balanced groups of normally sighted male and female children and adults examined in optometric practice, confirms the general fallacy of this assumption and considers why it is such a persistent misconception. The degree of association between the three modalities in right‐preferent individuals is revealed as statistically no greater than chance. On the basis of this study, estimates of right‐sided hand, eye and/or acuity congruency are derived for the information of the clinician in the prescribing environment of the consulting room.

A 6‐year longitudinal optometric study of the refractive trend in school‐aged children

This report describes the analysis of the refractive data of optometric patients examined annually between the ages of 7 and 13 years. The results indicate a declining hypermetropic/increasing myopic refractive trend in 73% of the 41 individuals who attended over the entire 6 years of the investigation: overall, there was a mean rate of change of −0.09 D pa. Annual myopic incidence values of between 3.5 and 12% were found, resulting in a rise in myopic prevalence in this clinical population from 5 to nearly 40% over the course of the study. For the refractive classification adopted here, the juvenile myopic patients emerged from a pool of previously emmetropic subjects: the proportion of hypermetropic patients remained approximately stable over the 6 years reviewed.

The absence of lateral congruency between sighting dominance and the eye with better visual acuity

The notion that in subjects with normal binocular vision (i.e. non‐strabismic cases) the eye showing sighting dominance will also most likely be that individuals better‐sighted eye has proved to be persistent. A review and analysis of the literature has now demonstrated, across several population groups, the fallacy of this belief. In fact, the occurrence of lateral congruency between sighting dominance and the eye with better visual acuity is at a statistical level no greater than chance would predict. Some clinical implications of this outcome are considered.

The presbyopic add. I. Magnitude and distribution in a historical context

The presbyopic addition or ‘add’ is the (binocular) spherical positive power supplement super‐imposed on any distance refractive correction to counter near vision difficulties associated with the physiological age‐related loss of accommodation and consequent recession of the near point: its necessity is first encountered in middle age. The continuous (linear) ascending trend in near lens power versus increasing age advocated since the seventeenth century is at odds with the twentieth‐century clinical observation that there is a deceleration in add requirement beyond an individuals mid‐fifties. It is shown here that this difference is reconciled – in broadly qualitative terms if not in magnitude – when typical clinical near addition data are superimposed on the accepted distance hypermetropic refractive base recorded from early middle age onwards: a continuous rising function is produced spanning most of the three decades beyond 40 years of age. This result is considered in the context of the age markings found on certain eighteenth‐century antique near vision glasses and the recommendations attached to the self‐selection of ready‐made reading glasses in the late twentieth century.

The presbyopic add. III. Influence of the distance refractive type

The possibility of the distance refractive type-emmetropia, hypermetropia or myopia-influencing the magnitude and rate of change of the presbyopic add does not seem to have received systematic consideration. To address this possibility a further series of transverse clinical data on the progression of the presbyopic add is presented. Analysis of these data reveals the influence of the distance refractive type on the presbyopic progression. Hypermetropes appear to show a two-phase rise in add requirement whereas emmetropes follow a linear and myopes a curvilinear path over the four decades between 41 and 80 years of age. Nevertheless the magnitude of the binocular add requirement at a given age for each of the three refractive types is very similar and all three classes maintain an increasing requirement with advancing age.

The far interpupillary distance. A gender‐specific variation with advancing age

A knowledge of the magnitude of the far interpupillary distance (FIPD) in relation to a specific population is of clinical, practical and theoretical interest. A FIPD database is presented here, comprising material collated from the spectacle dispensing records of n=1800 subjects seen in routine optometric practice. All measurements were taken by the author on healthy Caucasian (white, Northern European) males and females. The data were equi‐partitioned either across three age bands (16–25, 26–40, 41–65 years: mixed refractive types, total n=900) or between the three distance refractive types (emmetropia, hypermetropia, myopia: all subjects aged between 41–65 years, total n=900).

Habitual vs optimal distance visual acuity.

Purpose:  The maintenance of a good level of vision is desirable for developmental and social reasons; it is also a requirement that should not be overlooked in the clinical research environment. This study set out to quantify and analyse any difference between ‘habitual’ (pre‐sight test) and ‘optimal’ (post‐refraction) distance visual acuity in an optometric population. It is intended that the outcome of this work will inform not only clinicians but also those undertaking vision research.

Gender-related optical aspects of the onset of presbyopia.

Evidence is presented which substantiates the frequent clinical impression that female optometric patients require their first reading prescription at a slightly earlier age than males. Furthermore newly presbyopic females require an initial add of slightly greater magnitude than age‐matched males. A high (>+1.50 D) first add requirement is revealed as a predominantly male characteristic, an outcome attributable essentially to their often relatively later age of presentation for an initial presbyopic refractive examination.

The interpupillary distance in adult Caucasian subjects, with reference to ‘readymade’ reading spectacle centration

Citation information: Pointer JS. The interpupillary distance in adult Caucasian subjects, with reference to ‘readymade’ reading spectacle centration. Ophthalmic Physiol Opt 2012, 32, 324–331. doi: 10.1111/j.1475‐1313.2012.00910.x