Have you gotten a retinal eye exam or Optical coherence tomography (OCT)? What is your retinal nerve fiber layer thickness? (RNFL) [and how has it changed over time?]

[Alex K Chen]

https://www.rapamycin.news/t/alex-k-chen-metabolic-cgm-progress-my-everything-in-longevity-thread/466/293?u=alexkchen

https://www.rapamycin.news/t/what-is-your-rnfl-thickness-retinal-nerve-fiber-layer-thickness-it-is-an-easily-measureable-indicator-of-brain-health/6131

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7086093/

Edited March 9, 2023 by InquilineKea

[Mike Lustgarten]

I'd make it a focus (ha, pun intended)-I had 20-20 vision (or better) my whole life, but a couple of years ago, lots of daily blurriness when reading, and only in my left eye is now common. I'm not sure what can be done to slow/rejuvenate it (for now), but trying to track/slow/prevent it at your age, Alex would be probably be a good idea. 

[Dean Pomerleau]

Mike have you been checked for a cataract? I had the same thing happened. Turned out to be a cataract. Surgery fixed it. 

[Mike Lustgarten]

Hey Dean, I haven't. With all the veggies that I eat, I'd be shocked to have a cataract, but an eye Dr visit is definitely on the horizon.

[Saul]

I've had a retinal exam, after a scare caused by a faulty diagnosis of a minor cataract problem as being AMD:  In fact, the macular part of both retinas (and in fact the whole retinas, both eyes) are fine.

Macular Degeneration is the leading cause of blindness; you can see an ophthalmologist to see if you have anything to worry about (probably not).

The bad news:  So far, in today's current level of knowlege, there is no cure for macular degeneration.

  --  Saul

 

[Alex K Chen]

I'll book an ophthalmologist for next week.

Given it's in one eye but not the other, I wonder if it's my tendency to lay down on my side and put pressure on one of my eyes (left eye) when tired).

[Saul]

Cataracts and/or macular degeneration can occur in only one eye.  I doubt that your (probably trivial) problem is caused by sleeping on one side rather than the other.  It probably is sufficient to visit a (good) optometrist (an ophthalmologist will usually be more expensive) to get information other than guesswork.

I can recommend a great optometrist here in Rochester, NY -- but I doubt that that would be useful to you.

(If you're in the US, a lot of stores that sell glasses offer a free eye exam by their in-store optometrist, to tey to sell you a pair of glasses.)

  --  Saul

 

[Saul]

Hmmm...

I may have spoken too soon.  It's good that you're going to see an ophthalmologist.

  --  Saul

 

[Alex K Chen]

Saw him. He said it's not a reason for concern, that it probably was a mark that existed since birth, but will re-schedule an exam 1 year from now to see if there's progression.

Another eye exam saw my right-eye-RNFL to be 105..

These both from an Optovue (https://thenoss.com/products/optovue-ivuenr-2nd-gen-oct) which appears to be 2nd generation (may be less accurate than 3rd generation scanners)

Quote

 

Results:

The mean optic disc area was 3.36 ± 0.64 mm² (range, 2.13–5.08 mm²), mean rim area was 2.49 ± 0.58 mm² (range, 1.20–3.62 mm²), and mean cup area was 1.10 ± 0.75 mm² (range, 0–3.07 mm²). The disc area showed significant positive correlation with the rim area, cup area, horizontal cup disc ratio, vertical cup disc ratio, cup disc area ratio, mean cup depth, and maximum cup depth (P < 0.001). Neither gender nor refractive error showed any significant difference in various ONH parameters. ONH parameters did not show significant change with age except for rim area which declined with the advancing age (r = –0.25, P < 0.001).

Conclusions:

The quantitative measurement of ONH topography obtained with this study provides a normative database for an Indian population with spectral OCT/SLO. As optic disc area influences ONH topography, disc size should to be considered when evaluating optic disc for progressive optic neuropathies such as glaucoma.

 

crap, do I have low rim area? Even https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808425/ says mean rim area of 1.44

As you can see below, there's a 10 micron difference in thickness measured on my right eye between different instruments... But "The GCC is defined as the sum of RNFL, GCL and IPL thickness measured from the inner limiting membrane to the IPL boundaries" so despite high correlation between GCC and RNFL, they're not the same..

Conclusions: RTVue-100 showed higher imprecision (or higher measurement variability) than Cirrus HD-OCT and 3D OCT-1000 RNFL measurements. Three-dimensional cube scanning with post-hoc data sampling may be a factor reducing imprecision.

 

Edited March 9, 2023 by InquilineKea

[Alex K Chen]

They said I have a little bit of Peripapillary atrophy (PPA) [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3017221/ ] around the optic nerve, but nothing to worry about.

[Alex K Chen]

Quote

 

Results: One hundred eighty-seven eyes of 187 normal subjects were analyzed. Mean age+/-standard deviation was 33.0+/-19.7 years (range, 5-75). Average RNFLT and RNFLT by quadrant demonstrated the tendency of RNFLT to decrease with increasing age, especially after age 50 years. Average RNFLT demonstrated a negative slope of 0.16 microm/year (95% confidence interval [CI], -0.1 to -0.24). By quadrant, the superior average (negative slope, -0.23 microm/year; 95% CI, -0.1 to -0.34) showed a maximum tendency to decline with age, whereas in the inferior quadrant (negative slope, -0.08 microm/year; 95% CI, 0.05 to -0.24), the age-related decay was minimal. Six clock-hour RNFLT had a least negative slope of -0.022 microm/year (95% CI, -0.08 to -0.1). Chi-square test results showed a significant inverse relationship between age and average RNFLT (P = 0.01).

Conclusions: Age-related retinal nerve fiber layer (RNFL) loss is not uniform in all the quadrants, with maximum loss in the superior quadrant, and seems to reach a maximum after the age of 50 years. Furthermore, it seems that inferior quadrant RNFL is more resistant to loss.

 

https://iovs.arvojournals.org/article.aspx?articleid=2127832

 

The most significant decrease was observed in the lower quadrants (0.575 μm/y; 95% CI, 0.733–0.416; linear regression analysis, P < 0.001), followed by the upper quadrants (0.488 μm/y; 95% CI, 0.646–0.330; linear regression analysis, P < 0.001), temporal quadrants (0.253 μm/y; 95% CI, 0.350–0.156; linear regression analysis, P < 0.001), and nasal quadrants (0.141 μm/y; 95% CI, 0.272–0.010; linear regression analysis, P = 0.035). Age-related RNFLT changes in the 4 quadrants are shown in Figure 2. 

Figure 1

View OriginalDownload Slide

 

Scatterplot showing overall group's mean RNFLT decrease with aging.

Figure 2

 

Quote

Other factors that possibly might account for the differences in RNFLT in earlier studies are refractive error and axial length. The RNFLT was reported to decrease as the severity of myopia increased, based on TD-OCT²³ and SD-OCT.⁵⁸ Leung et al.⁶⁵ reported that elongation of the globe in myopic eyes leads to mechanical stretching and thinning of the retina, which is associated with thin RNFL values. To minimize the effect of severe myopia and long axial length (>25 mm), all participants in our study were selected based on a spherical equivalent range of −1 to +1 D. 

I do have -4.5 level myopia (though it was as high as -5/-5.5 - there is SOME disagreement in eye exams depending on how they score "half right" rows)

Edited March 12, 2023 by InquilineKea

[Alex K Chen]

Quote

 

Two hundred and twenty eyes of 110 subjects were tested in the study. The overall average RNFL thickness was 104.17 ± 10.71 µm. The mean values of the RFNL thickness in the inferior, superior, nasal and temporal quadrants, and are summarized in Table 2. The mean RNFL thickness for the male and female subjects was 102.64 ± 10.22 µm and 107.73 ± 11.08 µm, respectively. There was a statistically significant difference (t = 3.30, P = 0.001) with the RNFL being thicker in females. The mean RNFL thickness by quadrants for the male and female subjects is summarized in Table 3. The gender difference between the mean measurements for the inferior and superior quadrants was statistically significant.

Table 2

Mean RNFL thickness by quadrant (n=220)

Quadrant	Mean±SD (µm)
Inferior	129.15±16.87
Superior	135.34±20.40
Nasal	85.10±23.60
Temporal	67.19±13.27

 

 

[Alex K Chen]

https://iovs.arvojournals.org/article.aspx?articleid=2164005

 

Quote

results. The RNFL measurements were significantly lower in the high myopia group compared with those of the low-to-moderate myopia group at 12, 1, and 7 o’clock (right eye orientation). Apart from the temporal clock hours, significant correlations were evident between RNFL measurements and the axial length and spherical equivalent. The average RNFL thickness decreased with increasing axial length (r = −0.314, P = 0.001) and negative refractive power (r = 0.291, P = 0.002). A significant proportion of myopic eyes were classified as outside normal limits, with reference to the normative database. The most frequently abnormal sector was at 2 o’clock, where 16.5% of myopic eyes were outside normal limits.

Quote

The average RNFL thickness in highly myopic eyes was 100.69 ± 10.36 μm, which was significantly thinner than that in low-to-moderately myopic eyes (107.49 ± 12.74 μm; P = 0.003).

^well that's inconsistent from the other studies (even at younger ages), need standardization across instruments

Edited March 9, 2023 by InquilineKea

[Alex K Chen]

Quote

 

RESULTS—Neuroretinal rim area declined at the rate of between 0.28% and 0.39% per year. Vertical optic cup diameter and optic cup area increased with age. The mean cup/disc diameter ratio increased by about 0.1 between the ages of 30 and 70 years.

 

 

[Alex K Chen]

Why is RNFL thickness highest in ST (superior-temporal) and IT (inferior-temporal) quadrants? And lowest in TL and TU?

https://www.mdpi.com/2076-3921/9/6/494

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5824084/

Quote

Overall RNFL thickness decreased 7 microns for every 1 mm of axial length, and 3 microns for every 1 Diopter sphere

...and I'm 4.5 Diopters, so that's.. uhh.. 13.5 micron decrease? depends on the paper...

Edited March 9, 2023 by InquilineKea

[Alex K Chen]

https://www.tandfonline.com/doi/abs/10.1080/10550887.2020.1754109?journalCode=wjad20&

-> wow, what a solution (cannabis). And this is in those with cannabis use disorder, who most likely abuse/mis-use it. Imagine for cannabinoids supplemented the healthy way. damnit I have to try more.

https://www.frontiersin.org/articles/10.3389/fnagi.2019.00069/full

-> this is why it's important for BRAIN HEALTH, and may be the easiest way to measure brain health changes each year....

 

Edited March 9, 2023 by InquilineKea

[Alex K Chen]

Bryan Johnson looks into https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5782455/ . Need to look more into that

[Alex K Chen]

I just looked into my 2014 results. Damnit I refused eye dilation then so the results are not super-interesting.

[Alex K Chen]

https://elifesciences.org/articles/82364

[Alex K Chen]

this is the successor

 

 

[Alex K Chen]

I wonder if https://onlinelibrary.wiley.com/doi/10.1111/acel.12005

is related

[Alex K Chen]

https://www.sciencedirect.com/science/article/pii/S2214647416300186