Refractive changes in diabetic patients during intensive glycaemic control

Abstract

Aims-To evaluate the clinical course and the characteristics of transient refractive error occurring during intensive glycaemic control of severe hyperglycaemia. Methods-28 eyes of patients with persistent diabetes were included in this prospective study. During the observation period, patients underwent general ophthalmological examination and A-mode scan ultrasonography was performed at each examination-at days 1, 3, and 7, and then once every week or every other week until recovery of hyperopia. Results-A transient hyperopic change occurred in all patients receiving improved control after hyperglycaemia. Hyperopic change developed a mean of 3.4 (SD 2.0) days after the onset of treatment, and reached a peak at 10.3 (6.1) days, where the maximum hyperopic change in an eye was 1.47 (0.87) D (range 0.50-3.75 D). Recovery of the previous refraction occurred between 14 and 84 days after the initial assessment. There was a positive correlation between the magnitude of the maximum hyperopic change and (1) the plasma glucose concentration on admission (p<0.01), (2) the HbA 1c level on admission (p<0.005), (3) the daily rate of plasma glucose reduction over the first 7 days of treatment (p<0.001), (4) the number of days required for hyperopia to reach its peak (p<0.001), and (5) the number of days required for the development and resolution of hyperopic changes (p<0.0001). There was a negative correlation between the maximum hyperopic change of an eye and baseline value of refraction (p<0.01). During transient hyperopia, no significant changes were observed in the radius of the anterior corneal curvature, axial length, lens thickness, or depth of anterior chamber. Conclusions-The degree of transient hyperopia associated with rapid correction of hyperglycaemia is highly dependent on the rate of reduction of the plasma glucose level. A reduction of refractive index in intraocular tissues, especially in lens, appears to be responsible for this hyperopic change. (Br J Ophthalmol 2000;84:1097-1102 Patients with diabetes mellitus (DM) can develop various ocular complications including cataract, optic neuropathy, uveitis, and keratopathy as well as retinopathy. In addition, transient refractive error occurs during the course of DM and is associated with treatment induced changes in the plasma glucose concentration.

Acute Incapacitating Hyperopia during Hypoglycemic Treatment

“…Many authors, who investigated the effect of acute changes in plasma glucose level, have reported that decreasing plasma glucose levels cause hyperopic changes [1,5,6]. Although some conflicting reports are there, recently, several papers have reported an abrupt reduction in plasma glucose in diabetic patients with marked hyperglycaemia induced transient hyperopia [1,2,4]. It has been seen that the degree of hyperopia is highly dependent on the magnitude of the change in plasma glucose concentration [2].…”

“…Although some conflicting reports are there, recently, several papers have reported an abrupt reduction in plasma glucose in diabetic patients with marked hyperglycaemia induced transient hyperopia [1,2,4]. It has been seen that the degree of hyperopia is highly dependent on the magnitude of the change in plasma glucose concentration [2].…”

“…The difference in osmotic pressure results in the influx of water from the aqueous humour into the lens, causing lenticular Introduction P atients with diabetes mellitus can develop various ocular complications such as cataract, retinopathy, optic neuropathy, uveitis, and keratopathy etc. In addition, transient refractive error occurs during the course of diabetes mellitus and is associated with treatment induced changes in the plasma glucose concentration [1,2]. The association of myopia with hyperglycaemia and hyperopia with hypoglycaemia have been reported in diabetic patients [3].…”

“…There are studies which show that an abrupt reduction in plasma glucose in diabetic patients with marked hyperglycaemia, induce transient hyperopia [1,2,4]. It has been seen that the degree of hyperopia is highly dependent on the magnitude of the change in plasma glucose concentration [2]. Patients may get alarmed and may request for change of glasses but fresh prescription should be given only when the refraction stabilises, otherwise, the glasses thus prescribed will soon become inadequate.…”

Optical quality of the diabetic eye: a review

“…Other researchers, however, observed that the lens thickness did not increase significantly and the anterior chamber depth did not decrease significantly during hyperopic changes, explaining why this hypothesis cannot be confirmed without knowing the effects of each of these contributing factors in the power of the lens (thickness, curvature of anterior and posterior surfaces, refractive index of the aqueous humour lens, and vitreous body), as an increase in lens thickness resulted in myopic changes by reducing the radius of curvature. 51 The human lens continues to grow throughout life due to the addition of new fibres, becoming thicker and more convex; in addition, the refractive index of crystalline lens undergoes changes due to ageing and cataract development. In patients with DM, the lens has been found thicker and more convex compared with healthy subjects.…”