Assessing the role of systemic inflammation in the etiopathogenesis of advanced stage keratoconus

Pachychoroid pigment epitheliopathy in keratoconic eyes

PURPOSE

To report the association between keratoconus (KC) and pachychoroid pigment epitheliopathy (PPE). As secondary outcome, we explored the relation between subfoveal choroidal thickness (SFCT) and topometric indexes.

METHODS

Retrospective, observational, cross-sectional, case-control study. Multicentric study including patients with KC and healthy controls. Each subject underwent a complete ophthalmological visit, Placido-based corneal topography, Scheimpflug corneal tomography and spectral-domain OCT (SD-OCT) with the enhanced depth imaging (EDI) mode on. Linear mixed models (LMM) were employed for comparison between groups, and to examine the impact of different topometric factors on SFCT. KC stages were defined according to Belin grading.

RESULTS

Overall, 56 eyes from 35 KC patients and 52 eyes from 27 healthy, age- and axial length-matched control subjects were included in the study. PPE was found in 10 (17.9%) eyes from 8 KC patients, whereas was absent in all healthy controls. SFCT was statistically significantly higher in keratoconic eyes (median: 390 µm; interquartile range (IQR): 339 - 425 µm) compared to healthy eyes (median: 240 µm; IQR: 200 - 288 µm) (p < 0.001). SFCT did not differ across different KC stages and between keratoconic eyes with and without PPE.

CONCLUSIONS

PPE is a relatively frequent finding in eyes with KC, being present in about 1 out of 6 cases, regardless of disease stage.

KEY MESSAGES

What is known: Keratoconus (KC) is a corneal disorder commonly associated with other chorioretinal abnormalities. It is well known that keratoconic eyes display increased choroidal thickness, and the rare association between KC and central serous chorioretinopathy (CSC) has already been reported in the literature.

WHAT IS NEW

We identified an association between KC and pachychoroid pigment epitheliopathy (PPE), a precursor or forme fruste of pachychoroid diseases, such as CSC. PPE presence is independent from corneal parameters and is observed in about 1 out 6 KC eyes.

Evaluation of neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and mean platelet volume levels in pediatric keratoconus patients

PURPOSE

To examine the level of neutrophil-lymphocyte ratio and platelet-lymphocyte ratio in the pediatric patient group with keratoconus.

METHODS

Patients aged 5-18 years with a diagnosis of keratoconus followed by the corneal department and children in the similar age group who were determined as controls were included in the study. Their topographies were evaluated. In both groups, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and mean platelet volume (MPV) were measured.

RESULTS

The study group consisted of children aged 15 ± 1.4 years and the control group 13 ± 1.3 years of age. The mean central corneal thickness of the patients in the patient group was 445.64 μm, and in the control group was 532.25 μm. The NLR was 3.37 ± 1.04 in the patient group and 2.31 ± 0.82 in the control group. The PLR was significantly increased in the KC group (147.54 ± 41.36) than in the control group (118.71 ± 27.11) (P = 0.042). MPV in the patient group was 12.18 ± 2.76 and 7.00 ± 1.37 in the control group. This value was found to be statistically significant (P = 0.047) when the control group and the patient group were compared.

CONCLUSION

Platelet/lymphocyte ratio and mean platelet volume, which are thought to be new markers of systemic inflammation, may be new indices in keratoconus in pediatric patients.

Bowman Layer Onlay Grafting as a Minimally Invasive Treatment for the Most Challenging Cases in Keratoconus

PURPOSE

To analyze the clinical outcomes after Bowman layer (BL) onlay grafting for the treatment of progressive, advanced keratoconus.

DESIGN

Prospective, interventional case series.

METHODS

Twenty-one eyes underwent BL onlay grafting. After removing the epithelium, a single or double BL graft was "stretched" onto the corneal surface, allowed to dry-in, and a soft bandage lens was placed until the graft was re-epithelialized. Best spectacle- and/or best contact lens-corrected visual acuity (BSCVA/BCLVA), corneal tomography, and postoperative complication rates were analyzed for the total group and 2 subgroups (group 1: preoperative maximum keratometry [Kmax] <69 diopters [D; n = 7); group 2: preoperative Kmax ≥69 D [n = 14]). Follow-up ranged from 6 to 36 months (mean 21 ± 11 months).

RESULTS

All 21 surgeries were uneventful. Overall, Kmax changed from 76 ± 12 D preoperatively to 72 ± 9 D at 6 to 36 months postoperatively (P = .015). Kmax decreased by 6 D in group 2 (P = .002) but did not change in group 1. Average BSCVA remained stable for group 1 and improved from preoperatively 0.8 ± 0.4 to 0.4 ± 0.2 logarithm of the minimum angle of resolution postoperatively in group 2 (P = .032); BCLVA remained stable (P > .05). Within the first postoperative weeks, 2 eyes required BL graft repositioning after inadvertent bandage lens removal and 4 eyes underwent BL retransplantation for incomplete re-epithelialization. One eye underwent BL regrafting 12 months postoperatively after traumatic corneal erosion. All eyes showed a completely re-epithelialized graft at the last available follow-up.

CONCLUSIONS

BL onlay grafting is a completely extraocular, minimally invasive surgical technique, providing up to -6 D of corneal flattening in eyes with advanced progressive keratoconus, allowing for continued (scleral) contact lens wear and therefore preserving the BCLVA.

The Diagnostic Value of Neutrophil to Lymphocyte Ratio as an Effective Biomarker for Eye Disorders: A Meta-Analysis

The neutrophil to lymphocyte ratio (NLR) reflects a dynamic relationship between the innate (neutrophils) and adaptive (lymphocytes) cellular immune response. This systematic review and meta-analysis was conducted to critically evaluate the literature regarding the use of the NLR as a reliable means to detect several ocular disorders. Our study was registered with the PROSPERO (ID: CRD42022314850). Three databases, including PubMed, Embase, Scopus, and the Web of Science, were searched on September 9, 2022, with no restrictions on the article's language. Finally, 32 articles were recognized as eligible for our meta-analysis. We found that patients with eye diseases had significantly elevated levels of NLR in comparison to healthy controls (SMD =0.53, 95% CI =0.35-0.71, P < 0.001). In subgroup analysis, patients with keratoconus (SMD =0.69; 95% CI =0.33-1.05, P < 0.001), glaucoma (SMD =0.56, 95% CI =0.25-0.87, P < 0.001), pterygium (SMD =0.14; 95% CI =0.01-0.26, P < 0.001), and idiopathic epiretinal membrane (SMD =0.14; 95% CI =0.01-0.26, P < 0.001) had higher levels of NLR compared to healthy controls. However, NLR levels of patients with dry eye disease were similar to healthy controls (SMD =0.32, 95% CI = -0.49-1.13, P = 0.435). It can be said that NLR is a valuable marker of systemic inflammation, which is significantly increased in many eye disorders, suggesting that inflammation plays a key role in the pathophysiology of these diseases.