Étude des atteintes de la surface oculaire chez les patients diabétiques

[Clinical profile of corneal sensitivity in diabetic patients: A case-control study]

PURPOSE

To evaluate the corneal sensitivity of black diabetic patients and identify factors associated with changes in corneal sensitivity.

METHODOLOGY

We conducted a cross-sectional comparative case-control study at the National Obesity Center of the Yaounde Central Hospital and the Djoungolo District Hospital from March 1 to July 31, 2022. Corneal sensitivity was measured using the Cochet-Bonnet esthesiometer in all diabetic patients over 18 years of age, matched for age and sex to a clinically healthy control population. Data were analyzed using SPSS version 23.0 software. A P-value of less than 5% was considered significant.

RESULTS

A total of 111 diabetic and 111 non-diabetic patients participated in the study. The mean age was 53.46±12.74 years for diabetics and 52.85±11.77 years for non-diabetics (P=0.901). The mean duration of diabetes was 6.4±5.30 years. Corneal sensitivity in diabetics was lower (44.56±9.59mm) compared to non-diabetics (53.59±6.30mm) with a statistically significant difference (P=0.000). Factors associated with decrease in corneal sensitivity in diabetics were duration of diabetes and poor glycemic control.

CONCLUSION

Decrease in corneal sensitivity related to diabetes is a complication to be systematically screened for during the ophthalmologic follow-up of diabetic patients.

Influence of diabetes mellitus on anterior segment of the eye

Diabetes mellitus (DM) has been emerging as one of the most serious health problems worldwide. Ocular complications of DM are currently one of the major causes of blindness in developed countries, among which diabetic retinopathy is relatively well studied and understood. However, although ocular surface complications of DM are common, diabetic complications of anterior segment of the eye, such as, cornea, conjunctiva, and lacrimal glands, are often overlooked. DM is associated with progressive damage to corneal nerves and epithelial cells, which increases the risk of anterior segment disorders including dry eye disease, corneal erosion, persistent epithelial defects, and even sight-threatening corneal ulcer. In this review, the authors will discuss the association of DM with disorders of anterior segment of the eye. Studies indicating the value of corneal nerve assessment as a sensitive, noninvasive, and repeatable biomarker for diabetic neuropathy will also be introduced. In addition, treatment modalities of anterior segment disorders associated with DM is discussed. The studies introduced in this review suggest that early and periodic screening of the anterior segment of the eye, as well as the retina, is important for the optimal treatment of DM.

Diabetes and contact lens wear

The literature suggests that diabetic patients may have altered tear chemistry and tear secretion as well as structural and functional changes to the corneal epithelium, endothelium and nerves. These factors, together with a reported increased incidence of corneal infection, suggest that diabetic patients may be particularly susceptible to developing ocular complications during contact lens wear. Reports of contact lens-induced complications in diabetic patients do exist, although a number of these reports concern patients with advanced diabetic eye disease using lenses on an extended wear basis. Over the past decade or so, there have been published studies documenting the response of the diabetic eye to more modern contact lens modalities. The results of these studies suggest that contact lenses can be a viable mode of refractive correction for diabetic patients. Furthermore, new research suggests that the measurement of tear glucose concentration could, in future, be used to monitor metabolic control non-invasively in diabetic patients. This could be carried out using contact lenses manufactured from hydrogel polymers embedded with glucose-sensing agents or nanoscale digital electronic technology. The purpose of this paper is to review the literature on the anterior ocular manifestations of diabetes, particularly that pertaining to contact lens wear.

Corneal sensitivity is related to established measures of diabetic peripheral neuropathy

PURPOSE

The objective was to investigate the association between corneal sensitivity and established measures of diabetic peripheral neuropathy (DPN).

METHODS

Corneal sensitivity was measured in 93 individuals with diabetes, 146 diabetic individuals without neuropathy and 61 control individuals without diabetes or neuropathy using a non-contact corneal aesthesiometer at the baseline visit of a five-year longitudinal natural history study of DPN. The correlation between corneal sensitivity and established measures of neuropathy was estimated and multi-dimensional scaling was used to represent similarities and dissimilarities between variables.

RESULTS

The corneal sensitivity threshold was significantly correlated with a majority of established measures of DPN. Correlation coefficients ranged from -0.32 to 0.26. Using multi-dimensional scaling, non-contact corneal aesthesiometry was closer to the neuropathy disability score, diabetic neuropathy symptom score and Neuropad and most dissimilar to electrophysiological parameters and quantitative sensory testing.

CONCLUSION

Corneal sensitivity, although not strongly related, is associated with other functional measures of DPN and might provide a useful adjunct in identifying functional loss of small nerve fibre integrity.

Corneal markers of diabetic neuropathy

Diabetic neuropathy is a significant clinical problem that currently has no effective therapy, and in advanced cases, leads to foot ulceration and lower limb amputation. The accurate detection, characterization and quantification of this condition are important in order to define at-risk patients, anticipate deterioration, monitor progression, and assess new therapies. This review evaluates novel corneal methods of assessing diabetic neuropathy. Two new noninvasive corneal markers have emerged, and in cross-sectional studies have demonstrated their ability to stratify the severity of this disease. Corneal confocal microscopy allows quantification of corneal nerve parameters and noncontact corneal esthesiometry, the functional correlate of corneal structure, assesses the sensitivity of the cornea. Both these techniques are quick to perform, produce little or no discomfort for the patient, and are suitable for clinical settings. Each has advantages and disadvantages over traditional techniques for assessing diabetic neuropathy. Application of these new corneal markers for longitudinal evaluation of diabetic neuropathy has the potential to reduce dependence on more invasive, costly, and time-consuming assessments, such as skin biopsy.

Wavelike epitheliopathy after phacoemulsification: role of in vivo confocal microscopy

PURPOSE

The purpose of this report was to describe an uncommon wavelike epitheliopathy after phacoemulsification in a 59-year-old man with well-controlled diabetes mellitus.

METHODS

Retrospective case report.

RESULTS

A 59-year-old man with a history of well-controlled diabetes mellitus presented to us with irritation and blurring of vision in the right eye of 4-month duration after phacoemulsification with multifocal intraocular lens implantation. Slit-lamp examination revealed a wave-like epitheliopathy in the right cornea, extending nasally from the incision area. Corneal sensation was reduced. Confocal microscopy revealed reduced subbasal nerve plexus and unhealthy corneal epithelium. Topical application of preservative-free lubricants was advised. On follow-up examinations, it was observed that the disappearance of the epitheliopathy correlated with the regeneration of the nerve plexus, as shown by the in vivo confocal microscopy findings.

CONCLUSIONS

This is an isolated case report of a wavelike epitheliopathy after phacoemulsification. The regeneration of the subbasal nerve plexus correlating with the disappearance of the epitheliopathy suggests an element of neurotrophic corneal damage. Other probable mechanisms are discussed along with the in vivo confocal microscopy findings.