Off the Cuff: OD of the Year

In a prospective, randomized, participant-masked, crossover clinical trial, 28 astigmatic participants were tested for the following conditions on different days: full sphero-cyl correction and undercorrection by 0.25, 0.50 and 0.75 DC, while maintaining spherical equivalence to ascertain the impact of altering cylinder (cyl) power and axis on vision in astigmatism. Axis was also misaligned between -30 degrees and +30 degrees, in 10-degree steps. For each configuration, monocular high- and low-contrast visual acuities (HCVA, LCVA) were measured at 6m, and participants rated vision clarity (one to 10), vision satisfaction (one to 10) and vision acceptability (yes/no). Linear mixed models were used to compare visual performance in the overall group and in low, medium and high cyl subgroups.

Undercorrecting cyl power affected all groups equally. Undercorrection by 0.75 DC was significantly different to full cyl power for all variables, while 0.25 DC undercorrection did not cause any significant decreases. Undercorrection by 0.50 DC was significantly different to full cyl power for HCVA and vision acceptability. Axis misalignment affected the cyl groups differently, with the greatest impact in the high cyl group, followed by the medium then the low-cyl group. Misalignment by ±30 degrees caused significant decreases in almost all cases, while misalignments by ±10 degrees or ±20 degrees caused significant decreases for some cyl groups and test variables.

Undercorrection of cyl by ≤0.50 DC while maintaining spherical equivalence had no significant effect on HCVA, LCVA, vision clarity or vision satisfaction, while the amount of axis misalignment that could be tolerated was dependent on the cyl power. Investigators wrote that the results might have practical ophthalmic applications, such as providing a rationale for reducing the total number of stock keeping units of toric contact lenses.

This study evaluated the effects of different contact lens (CL) replacement schedules and different CL materials on the ocular surface and tear function. Daily disposable hydrogel CLs were given to group 1 (n=22), daily disposable silicone hydrogel CLs were given to group 2 (n=25) and reusable silicone hydrogel CLs were given to group 3 (n=24). Tear function tests and inflammatory cytokine [interleukin (IL)-6, IL-8, IL-17A, and matrix metalloproteinase (MMP)-9] levels were evaluated before, and at one and three months after CL usage. Impression cytology was evaluated before and at three months after CL usage.

At the first and third months of CL usage, a statistically significant difference was determined between the groups in the levels of IL-6, IL-8 and IL-17A in tears, with the lowest levels in group 1 and the highest levels in group 3. At the third month of CL usage, the levels of these cytokines (in picograms/milliliter) were 6.06 ± 0.83, 78.18 ± 12.42, 61.69 ± 13.95 and 37.71 ± 5.95 in group 1; and 8.04 ± 0.89, 107.34 ± 14.40, 68.63 ± 13.72 and 46.26 ± 6.50 in group 3, respectively. A statistically significant decrease was determined over time in the Schirmer’s test in group 1, in only the tear breakup time in group 2, and in the tear breakup time and Schirmer’s test in group 3. A statistically significant increase was determined over time in the levels of IL-6, IL-8, IL-17A and MMP-9 in all groups. In the third month, a significant progression was observed in the Nelson grade in all groups.

Researchers concluded that the wear of daily disposable CLs could be considered to cause less damage to the ocular surface and less increase in proinflammatory cytokine levels.

This study evaluated the dry eye disease and meibomian gland dysfunction with meibography of Seborrheic Dermatitis patients. A hundred eyes of 50 patients with seborrheic dermatitis (group 1) and 100 eyes of 50 healthy individuals (group 2) were enrolled in this prospective study. A comprehensive ophthalmic examination including lid margin alterations and meibomian gland obstruction assessment, Ocular Surface Disease Index assessment, tear film break-up time test, corneal and conjunctival fluorescein staining assessment, and Schirmer’s test were performed on all subjects. In addition, upper and lower lids were evaluated for meibomian gland loss with non-contact meibography. The meibomian glands were graded from grade 0 (no loss of meibomian glands) to grade 3 (gland loss >2/3 of the total meibomian glands).

The mean ages of group 1 and group 2 were 29.1 ± 9.1 (range, 18 to 48) and 30.6 ± 6.3(range, 20 to 49) years, respectively. MGD (n=19, 34.5%), meibomian gland loss (36.4% ± 18.1), upper meiboscore (0.7 ± 0.8), lower meiboscore (0.6 ± 0.7) and DED (n=10, 18.2%) were significantly higher in the SD patients compared with the control participants. There was a significant relationship between age with meibomian gland loss, MGD and DED.

Researchers determined that seborrheic dermatitis might influence meibomian gland morphology and, as a result, cause meibomian gland dysfunction and dry eye disease. For this reason, they recommended that patients with seborrheic sermatitis be evaluated for meibomian gland dysfunction and dry eye disease, and start treatment when needed.