Thursday, January 25, 2018

Side and stomach sleepers: Faring worse with dry eye... and possibly MGD?

A study by Hank Perry et al (OCLI) was published in Cornea last year showing that dry eye patients who sleep on their side or face down have more dry eye than those who sleep on their backs:
A statistically significant difference was shown with back sleeping compared with left side sleeping using lissamine green staining (analysis of variance, P = 0.005). The Ocular Surface Disease Index score was also found to be elevated in patients who slept on their right or left side (36.4 and 34.1, respectively) as opposed to back sleepers (26.7) with P < 0.05. 
That was not nearly so startling as Dr Perry's comments about MGD in an article in this month's EyeWorld, because while the study results specifically stated that there was no statistically significant correlation between sleep position and degree of MGD, Dr Perry and colleagues clearly feel sleep position really does matter to the meibomian glands. For example:
The authors theorized that the problem is a mechanical one. The glands are fairly delicate and they function perfectly when there is nothing compressing them, but if you compress the glands, you have a direct effect on their ability to function, and this in turn leads to increased inflammation in the glands with eventual dropout and increasing severity of meibomian gland dysfunction.
Quite a theory.

This is a topic of keen interest to me. At the Dry Eye Shop we work daily to try to help people find dry eye products - not just gels and ointments but goggles, masks, shields, patches and tapes - that can increase the moisture in their eyes overnight without disrupting their sleep patterns. Their choice of products in many cases is limited by their sleep style - for reasons of safety as much as comfort.

Many people, for example, come to us after a doctor's referral and ask for a mask or goggle that will hold their lids down. This always concerns me, for reasons such as:
  • If the lids aren't fully closing, what will happen if the mask slips? They might be at risk of a corneal abrasion.
  • If they sleep on their side or stomach, won't it press on their eyes and give them blurry vision in the morning, or worse?
  • If they adjust the mask or goggle too tightly, might it not press dangerously on their eyes, even if they sleep on their back?
  • Et cetera.
So, in my personal recommendations, I have found myself trending more and more towards encouraging people to employ tools that will, without pressing on or even touching their eyelids, block air movement and hold moisture over their eyes.

Examples include:

  • the vaulting shields made by Eye Eco (EyeSeals 4.0, Onyix and Quartz), which, though flexible, will vault the eyes unless pressed down;
  • bubble type bandages like NITEYE and Ortolux, which are stiff enough to hold up to some pressure and keep anything from touching the eyes; 
  • post surgical shields such as the LASIK goggle, in extreme cases such as patients with floppy eyelid syndrome, where they must have secure, rigid protection to prevent literally rubbing the eyes (and corneas) on the bedding, or unconsciously rubbing the eyes with their hands during sleep.
In the cases where their doctor insists the lids be held shut, I encourage them to use skin-friendly silicone medical tapes or EyeLocc strips as opposed to masks or Tranquileyes. (To be clear - I think that if you're willing to put in the extra work to customize thickness of the Tranquileyes pads to get a very light pressure, it can work quite well for back sleepers - yet the safety factors remain a concern because they're so patient-specific.)

Then of course there are a host of special cases. Fibromyalgia, multiple chemical sensitivities and innumerable others introduce complicating factors that make the night solutions require ever more creativity. Nevertheless, it can be done!

But to return to the point of the study and the news report in EyeWorld: Is it really possible that physical compression of the meibomian glands from your sleep style could have a direct knock-on effect on your meibomian glands?

I eagerly await solid medical studies to answer this question.


Dry eye and conjunctivochalasis - a little reminder

The authors of this recent abstract underscore how commonly CCH (i.e. folds or wrinkling of the eye surface) and dry eye go hand in hand:

The Location of Conjunctivochalasis and Its Clinical Correlation with the Severity of Dry Eye Symptoms.

Background: We aimed to investigate the clinical importance of conjunctivochalasis (CCH) and, further, to implement a new CCH classification system. 
Methods: 60 eyes of patients with whom, upon clinical examination, CCH was diagnosed were investigated for the presence of symptoms and signs characteristic of dry eye. The eyes were grouped based on two stages of severity, Stage 1 (minimal/mild) and Stage 2 (medium/severe), for each nasal, middle, and temporal position, and on the extent of CCH folds in each site. 
Results: In 40 (66.6%) out of 60 eyes, symptoms and signs of CCH were manifest: pain in 25 (41.6%), epiphora in 25 (41.6%), and lacrimal punctum obstruction from conjunctival folds in 22 (36.6%) eyes. Depending on the position of CCH, a greater percentage of symptoms appeared in Stage 2 in the nasal position (78.9%), followed by middle (68.7%) and temporal positions (60%). When TBUT values were compared, statistically significant differences were found proportional to grading (p < 0.001) and position (nasal more severe than temporal, p < 0.001), and such differences were also found when TBUT values of all eyes were compared with those of symptomatic eyes (p = 0.01) and with those of symptom-free eyes (p = 0.002). 
Conclusions: CCH is a rather frequent and commonly unrecognized condition that should always be considered in differential diagnoses of dry eye.
Dalianis G1, Trivli A2, Terzidou C3.
Medicines (Basel). 2018 Jan 22;5(1).


Wednesday, January 24, 2018

Two studies on manuka honey for blepharitis


1. Randomised masked trial of the clinical safety and tolerability of MGO Manuka Honey eye cream for the management of blepharitis.

BMJ Open Ophthalmol. 2017 Aug 4;

Craig JP1, Wang MTM1, Ganesalingam K1, Rupenthal ID1, Swift S2, Loh CS1, Te Weehi L1, Cheung IMY1, Watters GA1.

Abstract

OBJECTIVE:
To assess the clinical safety and tolerability of a novel MGO Manuka Honey microemulsion (MHME) eye cream for the management of blepharitis in human subjects. 
METHODS AND ANALYSIS:
Twenty-five healthy subjects were enrolled in a prospective, randomised, paired-eye, investigator-masked trial. The MHME eye cream (Manuka Health New Zealand) was applied to the closed eyelids of one eye (randomised) overnight for 2 weeks. LogMAR visual acuity, eyelid irritation symptoms, ocular surface characteristics and tear film parameters were assessed at baseline, day 7 and day 14. Expression of markers of ocular surface inflammation (matrix metalloproteinase-9 and interleukin-6) and goblet cell function (MUC5AC) were quantified using impression cytology at baseline and day 14. 
RESULTS:
There were no significant changes in visual acuity, eyelid irritation symptoms, ocular surface characteristics, tear film parameters and inflammatory marker expression during the 2-week treatment period in treated and control eyes (all p>0.05), and measurements did not differ significantly between eyes (all p>0.05). No major adverse events were reported. Two subjects experienced transient ocular stinging, presumably due to migration of the product into the eye, which resolved following aqueous irrigation. 
CONCLUSION:
The MHME eye cream application was found to be well tolerated in healthy human subjects and was not associated with changes in visual acuity, ocular surface characteristics, tear film parameters, expression of markers of inflammation or goblet cell function. The findings support future clinical efficacy trials in patients with blepharitis. 

2. Preclinical development of MGO Manuka Honey microemulsion for blepharitis management.

BMJ Open Ophthalmol. 2017 Aug 7

Craig JP1, Rupenthal ID1, Seyfoddin A1,2, Cheung IMY1, Uy B3, Wang MTM1, Watters GA1, Swift S3.

Abstract

OBJECTIVE:
To evaluate the in vitro antimicrobial effects of cyclodextrin-complexed and uncomplexed Manuka honey on bacteria commonly associated with blepharitis, and in vivo rabbit eye tolerability of a cyclodextrin-complexed methylglyoxal (MGO) Manuka Honey microemulsion (MHME). 
METHODS AND ANALYSIS:
In vitro phase: Bacterial growth inhibition was assessed by area under the growth curve (AUC) for Staphylococcus aureus, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for S. aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa with cyclodextrin-complexed and uncomplexed Manuka honey were determined. In vivo phase: Six rabbits were administered 20 µL of MHME (at 1:10 dilution) to the right eye (treated) and 20 µL of saline to the left eye (control) daily, for 5 days. Tear evaporation, production, osmolarity, lipid layer, conjunctival hyperaemia and fluorescein staining were assessed daily, before and 15 min after instillation. 
RESULTS:
In vitro phase: The relative AUC for cyclodextrin-complexed Manuka honey was lower than that of uncomplexed honey at both 250 and 550 mg/kg of MGO (both p <0 .05="" aeruginosa.="" all="" and="" assessed="" aureus="" both="" but="" changes="" control="" cyclodextrin-complexed="" either="" epidermidis="" eyes="" for="" had="" honey="" in="" lower="" mbc="" mic="" no="" not="" observed="" or="" p.="" p="" parameters="" phase:="" s.="" significant="" than="" the="" treated="" uncomplexed="" vivo="" were="">0.05). 
CONCLUSION:
Overall, antimicrobial potency of cyclodextrin-complexed Manuka honey was greater than uncomplexed honey. No significant immediate or cumulative adverse effects were observed with MHME application on rabbit eyes, supporting future conduct of clinical safety and tolerability trials in human subjects.