What Are Normal IOP Values at Higher Elevations?

As I mentioned in a prior post, my IOP seems to have been trending downward consistently. The only question in regard to that trend was the last IOP check at an altitude of 8000 feet above sea level. Most of my IOP measurements were done at sea level.

I understood my ophthalmologist to tell me that the normal IOP range was shifted higher at significantly higher elevations. I have not been able to confirm this from published research, however. He said that the 'average' (note: he didn't specify mean or median) IOP at 8000 ft elevation is 21.

The following article discusses the correlation between IOP and the altitude at one's place of residence.

High Altitude and the Eye: A Case Controlled Study in Clinical Ocular Anthropometry of Changes in the Eye. [PMID: 16351567 PubMed]

The intraocular pressure was measured by a Goldman aplanation tonometer mounted on a Haag-Streit BM-9000 slit lamp at a single clinic location with an altitude in between the higher and lower altitudes. The higher altitude natives of Lahaul–Spiti had significantly lower pressures compared to the Kinnaur natives (t 3.215, p = 0.002).

After reading this paper, I realized it doesn't answer the question I was asking. I have been unable to confirm what I understood, so for now, I'll assume I understood correctly that the normal IOP range is shifted higher when measured at 8000 ft elevation. This implies that my last IOP values of

Left 19; Right 17

which were taken at the 8000 ft elevation should be considered to be lower than the prior values (left 18; right 18) taken at sea level.

Rationale: 

If the 'average' IOP at sea level is 15 and my IOP values were 18, then I was 3 points above average.

If the 'average' IOP at 8000 ft elevation is 21 and my IOP values were 17 and 19, then I was approximately 3 points below average at this time. 

However, there are too many unknowns at this point to make solid conclusions. For example, the issue of acclimation probably plays a role.

I am simply going to assume (and hope) that my IOP is indeed continuing to trend downward.