Warm compress application induces transient visual degradation

[Scout]

http://www.ncbi.nlm.nih.gov/sites/en...ubmed_RVDocSum

Optometry and Vision Science. 2007 Jul;84(7):580-587.

Warm Compress Induced Visual Degradation and Fischer-Schweitzer Polygonal Reflex.

Solomon JD, Case CL, Greiner JV, Blackie CA, Herman JP, Korb DR.

Schepens Eye Research Institute, Boston, Massachusetts (JDS, JVG), Korb Associates, Boston, Massachusetts (CLC, CAB, DRK), Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts (JVG), and Pittsfield Eye Associates, Pittsfield, Massachusetts (JPH).

PURPOSE.: To document adverse visual effects of warm compress therapy and determine potential etiologies in subjects with dry eye symptoms. METHODS.: Subjects (n = 24) with dry eye symptoms were recruited. Group 1 (n = 13): baseline measurements for each eye included subjective blur, visual acuity (VA), autorefraction (AR), corneal topography (CT), central corneal curvature (CCC), lipid layer thickness (LLT), and evaluation for corneal striae and edema. A warm, moist compress (44.4-45 degrees C) was applied with gentle pressure for 30 min to the closed eyelids of the randomized experimental eye; nothing was applied to the contralateral control eye. Subjective blur, VA, AR, CT, CCC, and LLT were evaluated for each eye at 5, 15, and 30 min and 5 min after application. Striae and edema were assessed for each eye at 30 and 5 min after application. Group 2 (n = 11): the above warm compress protocol was repeated to investigate the Fischer-Schweitzer polygonal reflex at the times stated. RESULTS.: At 5 and 30 min, 71% and 88% of all subjects experienced increased subjective blur and decreased VA. At 30 min: Group 1: Of 13 experimental eyes: 13 experienced subjective blur; nine exhibited a VA decrease >/=2 lines (mean = 3.4 +/- 0.7). For the control eye, two subjects reported blur and none exhibited decreased VA. The findings for AR, CT, CCC, LLT, striae and edema did not correlate with blur or with VA decline. Group 2: Of 11 experimental eyes: 10 exhibited the polygonal reflex compared with 0 controls (p < 0.001); eight exhibited subjective blur; seven exhibited VA decrease >/=2 lines (mean = 2.9 +/- 0.9). The polygonal reflex correlated positively to visual blur (r = 0.88, p = 0.04) and to VA decrease (r = 0.79, p = 0.1). CONCLUSIONS.: Warm compress application induces transient visual degradation. Although there was no correlation between visual degradation and AR, CT, CCC, LLT, or the presence of striae or corneal edema, visual degradation correlated positively with the polygonal reflex, which was observed following warm compress application.

PMID: 17632305 [PubMed - as supplied by publisher]

[Fred2]

Bumping this because it's scary and I'm hoping people have more info on it.

Are there any reports or studies done suggesting there is any chance of such degradation becoming permanent?

What is this Fischer-Schweitzer polygonal reflex? I've not been able to find any info on it.

[kitty]

Here is mention of this study in Rebecca's blog:

http://dryeyedigest.blogspot.com/200...ed-vision.html

Here is an article that discusses the Fischer-Schweitzer mosaic http://www.otmagazine.co.uk/articles...orris_5506.pdf:

"Fischer-Schweitzer mosaic This condition is characterised by the appearance of a series of minute lines or furrows giving the impression of a ‘wrinkled’
cornea (Figure 1). They involve Bowman’s membrane and fluorescein collects in the furrows giving the characteristic picture."
The article refers to pressure placed on the cornea by RGP lenses. I believe this reflex has to do with the way the cells form a matrix when pressure is applied. I'm sure someone should be able to give you a more simple explanation. But the short response to your concern is, I suspect, that this is the cornea's natural response to having pressure applied to it. It is transient and is not of concern. I think it might be the reason I would wake with blurred vision after sleeping in the tranquil eyes goggles. When I used them with the standard inserts, they pressed against my eye, similar to the way a compress would. Several hours after removal, my vision returned to normal. I might be off base but I'm taking a shot!

[stella]

You dont get this with steaming so presumably it is due to pressure on the eyeball rather than heat

[Fred2]

Thanks for your responses, guys!

You dont get this with steaming so presumably it is due to pressure on the eyeball rather than heat

You don't get the Fischer-Schweitzer mosaic or the visual degradation? Could you link me up with a source on that?

I figured that the vision degradation was due to the oils flowing, too, but I wish we had a definite authoritative answer on this.

Here's another frightening paper:

Effect of warm compress therapy from hard-boiled eggs on corneal shape.

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

Both treatments 1 and 3 affected the SAI (surface asymetry index) and SRI (surface regularity index). There was no significant change on other corneal parameters from treatments. CONCLUSION: Because it is difficult to standardize the pressing force, it is recommended to place the hard-boiled egg close to, but not touching, the eyelid during warm compress therapy. The temperature rise from this treatment protocol should be large enough to melt the meibomian gland secretions without distorting the corneal shape.

I wonder, though, whether these changes in corneal shape might be a result of the Fischer-Schweitzer mosaic. If it isn't then the only effective treatment for MGD carries the risk of deforming your cornea.

This is also cause for concern:

Corneal heat and stretch method and apparatus

http://www.patentstorm.us/patents/60...scription.html

The present invention exploits the creep properties of the collagen fibrils in the cornea for therapeutic purposes, in the temperature range from just above normal physiological temperature to the thermal shrinkage temperature of collagen. Creep resulting from specific applications of sufficient stress and sufficient temperature for sufficient time leads to a permanent new shape of the cornea. If the creep is concentrated primarily in the paracentral and peripheral cornea (the annular region from 4 mm to 11 mm diameter) and in the circumferential direction, then the central cornea flattens, thus reducing the dioptric power of the cornea, tending to correct myopia. On the other hand, if the creep is concentrated in the paracentral and peripheral cornea and is primarily in the radial direction, the central cornea steepens (becomes more curved), thus increasing the dioptric power of the cornea, tending to correct hyperopia. If creep is concentrated primarily in the paracentral cornea and in the circumferential direction, but restricted to the vicinity of a particular meridian, the curvature of the central cornea becomes flatter in the central segment of that meridian, tending to correct astigmatism where said meridian is too steep.

I haven't had the time to read this carefully, and I'll have to leave it for tomorrow because my eyes are quite dry, but I suspect there's much to be learned there.

Does anybody know what the safe range of temperatures for the cornea is and what kind of pressure is necessary to change it's shape (the article I quoted from suggests that the weight of an egg is sufficient, but, as I said, there's a chance that the changes they measured were due to the Fischer-Schweitzer mosaic)?

I hope we can work this out.

PS
On an unrelated note, the last link talks about a very interesting idea for treating myopia, hyperopia and astigmatism. Does anybody know whether this has ever been done? The patent for the device that's supposed to do this was issued in 2000.