Changes of Subjective Symptoms and Tear Film Biomarkers following Femto-LASIK

Tear Proteins Altered in Patients with Persistent Eye Pain after Refractive Surgery: Biomarker Candidate Discovery

Some patients develop persistent eye pain after refractive surgery, but factors that cause or sustain pain are unknown. We tested whether tear proteins of patients with pain 3 months after surgery differ from those of patients without pain. Patients undergoing refractive surgery (laser in situ keratomileusis or photorefractive keratectomy ) were recruited from 2 clinics, and tears were collected 3 months after surgery. Participants rated their eye pain using a numerical rating scale (NRS, 0-10; no pain-worst pain) at baseline, 1 day, and 3 months after surgery. Using tandem mass tag proteomic analysis, we examined tears from patients with pain [NRS ≥ 3 at 3 months (n = 16)] and patients with no pain [NRS ≤ 1 at 3 months (n = 32)] after surgery. A subset of proteins (83 of 2748 detected, 3.0%) were associated with pain 3 months after surgery. High-dimensional statistical models showed that the magnitude of differential expression was not the only important factor in classifying tear samples from pain patients. Models utilizing 3 or 4 proteins had better classification performance than single proteins and represented differences in both directions (higher or lower in pain). Thus, patterns of protein differences may serve as biomarkers of postsurgical eye pain as well as potential therapeutic targets.

Changes of Subjective Symptoms and Tear Film Biomarkers Following Lenticule Extraction

PURPOSE

To investigate the influence of lenticule extraction on subjective symptoms and objective biomarkers of dry eye and to clarify relationships between markers and find indicators for subjective symptoms after lenticule extraction.

METHODS

Right eyes of myopic patients undergoing lenticule extraction surgery (n = 35) were examined preoperatively and 5 and 90 days postoperatively using established clinical dry eye examination methods (tear film break-up time [BUT], Schirmer test, lissamine green and fluorescein staining, and Ocular Surface Disease Index (OSDI) questionnaire). A patient subset was also examined after 1 year (n = 14). Tear samples were eluted from Schirmer strips and then measured with enzyme-linked immunosorbent assays (calcitonin gene-related peptide (CGRP), interleukin-1β, IL-6, IL-8, matrix metallopeptidase 9 [MMP-9], nerve growth factor, and tumor necrosis factor-α). Postoperatively, unpreserved ofloxacin and dexamethasone eye drops were given (four times a day for 10 days).

RESULTS

BUT decreased at days 5 (P = .023) and 90 (P = .025). Lissamine green staining increased at day 90 (P = .036). OSDI values increased at day 5 (total values, vision-related function, ocular symptoms, all P < .001, but not environmental triggers) and at day 90 (vision-related function, P = .017). A downregulation of CGRP (P = .006) and MMP-9 levels (P = .042) was observed on day 5 compared to day 90.

CONCLUSIONS

Due to incongruity of patient symptoms, clinical signs, and tear protein changes, no predictive indicator was found, but some patients reported increased discomfort. Changes after lenticule extraction are not exclusively due to dry eye. [J Refract Surg. 2023;39(9):597-604.].

Increased Angiopoietin-1 and -2 levels in human vitreous are associated with proliferative diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a frequent complication of diabetes mellitus and a leading cause of blindness in adults. The objective of this study was to elucidate the diabetic retinopathy pathophysiology in more detail by comparing protein alterations in human vitreous of different diabetic retinopathy stages.

METHODS

Vitreous samples were obtained from 116 patients undergoing pars plana vitrectomy. Quantitative immunoassays were performed of angiogenic factors (VEGF-A, PIGF, Angiopoietin-1, Angiopoietin-2, Galectin-1) as well as cytokines (IL-1β, IL-8, IFN-γ, TNF-α, CCL3) in samples from control patients (patients who don't suffer from diabetes; n = 58) as well as diabetes mellitus patients without retinopathy (n = 25), non-proliferative diabetic retinopathy (n = 12), and proliferative diabetic retinopathy patients (n = 21). In addition, correlation analysis of protein levels in vitreous samples and fasting glucose values of these patients as well as correlation analyses of protein levels and VEGF-A were performed.

RESULTS

We detected up-regulated levels of VEGF-A (p = 0.001), PIGF (p<0.001), Angiopoietin-1 (p = 0.005), Angiopoietin-2 (p<0.001), IL-1β (p = 0.012), and IL-8 (p = 0.018) in proliferative diabetic retinopathy samples. Interestingly, we found a strong positive correlation between Angiopoietin-2 and VEGF-A levels as well as a positive correlation between Angiopoietin-1 and VEGF-A.

CONCLUSION

This indicated that further angiogenic factors, besides VEGF, but also pro-inflammatory cytokines are involved in disease progression and development of proliferative diabetic retinopathy. In contrast, factors other than angiogenic factors seem to play a crucial role in non-proliferative diabetic retinopathy development. A detailed breakdown of the pathophysiology contributes to future detection and treatment of the disease.