In this retrospective observational case series, investigators examined the relationship of macular thickness (via optical coherence tomography, OCT) to retinopathy severity in patients with diabetes and no clinically detectable macular edema.

The study included 383 eyes of 383 patients of a private retina practice, including 100 normal eyes of patients who did not have diabetes, 100 eyes of patients with diabetes without retinopathy, 100 eyes of patients with diabetes and mild-to-moderate retinopathy, 35 eyes of patients with diabetes who had severe nonproliferative or proliferative retinopathy and 48 eyes of patients with diabetes with regressed proliferative retinopathy. Main outcome measures included central subfield mean thickness (CSMT), inner and outer zone measurements and total macular volume.

CSMTs were 208 +/- 22 (standard deviation, SD), 198 +/- 25, 204 +/- 26, 224 +/- 38 and 205 +/- 27 microns for normals, eyes of diabetics without retinopathy, eyes with mild-to-moderate nonproliferative retinopathy, eyes with severe nonproliferative to proliferative retinopathy and eyes with regressed proliferative retinopathy, respectively. For all groups, mean CSMT was greater in men than in women. Statistically significant differences by gender were observed for controls (mean difference 12 microns), diabetes patients without retinopathy (mean difference 14 microns) and diabetes patients with mild-to-moderate nonproliferative retinopathy (mean difference,18 microns). For increasing retinopathy severity, the probability of macular thickening detected by OCT but not detected by clinical examination increased. Fifteen percent of eyes with severe nonproliferative or proliferative retinopathy and no clinically detected edema had OCT-measured macular thickening.

The authors concluded that, because OCT measurements were gender-dependent, gender balance or statistical adjustment for gender imbalances of compared groups in OCT studies of diabetic macular edema is important. As retinopathy severity increases, the probability of subclinical edema rises. Except for an individual baseline measurement, possibly useful for longitudinal comparison, the data suggests that there is little reason to obtain OCT routinely in eyes with diabetes and no retinopathy or mild-to-moderate diabetic retinopathy when clinical examination fails to show macular edema.

This study by Swiss researchers compared the effects of different upper eyelid procedures on corneal topography.

Eighty-two eyes of 43 patients with various degrees of dermatochalasis or ptosis underwent computed corneal topography before surgery and at three months after surgery. Patients were divided into groups depending on the extent of surgery. Thickness of the central cornea was also correlated with the change in astigmatism.

Mean changes in total astigmatism of 0.25 diopters (D) after ptosis surgery and 0.21D after blepharoplasty were observed, with reduction of large fat pads, compared with 0.09D in patients after skin-only blepharoplasty. A correlation was also observed between corneal thickness and change in astigmatism of more than 0.2 cylinders after ptosis surgery. Postoperative astigmatic axis changes were not systematic.

The findings emphasize the importance of advising patients, especially those with ptosis and severe dermatochalasis, that upper eyelid repositioning procedures may induce vision changes.