Purpose: To introduce subepithelial pterygium pedicle (SPP) and to investigate the effect of SPP length on the anterior corneal curvature including keratometry and aberrations. Methods: In this single-center retrospective cohort, 72 eyes of 72 patients with primary nasal pterygium were analyzed using anterior segment (AS) swept-source optical coherence tomography (SS-OCT; Anterion). We evaluated SPP length, horizontal invasion length (HIL), and corneal profiles including keratometry, root mean square values for lower- and higher-order aberrations, and first- to fourth-order wavefront aberrations. Correlations between SPP length and these parameters were assessed after adjusting for HIL. The SPP cutoff for significant anterior horizontal tilt deterioration was determined using receiver operating characteristic (ROC) analysis and validated by analysis of covariance controlling for HIL. Results: SPP was detected in 57 of 72 eyes (79.2%), with a mean length of 842.3 ± 408.1 μm. A significant positive correlation was found between SPP length and HIL (r = 0.376, p = 0.001). After adjusting for HIL, SPP length remained significantly associated with anterior corneal horizontal tilt (p = 0.026), whereas no significant correlations were observed with other refractive or aberration parameters. ROC curve analysis identified an SPP length of approximately 850 μm as the threshold for predicting anterior horizontal tilt ≥3.65 μm. Consequently, this cutoff significantly differentiated subgroups after adjusting for HIL, showing a marked increase in horizontal tilt in eyes with SPP ≥850 μm (p = 0.016), indicating mechanical distortion. Conclusions SPP length, a subepithelial microstructural parameter visualized by AS SS-OCT, independently correlates with anterior horizontal tilt after adjustment for HIL. This finding suggests that SPP length serves as a microstructural indicator of horizontal mechanical corneal distortion in eyes with pterygium.

Purpose: To characterize perioperative changes in posterior corneal curvature (PCC) following pterygium excision using anterior segment (AS) swept-source optical coherence tomography (SS-OCT), and to identify the critical threshold of horizontal invasion length (HIL) predicting significant PCC alterations. Methods: This retrospective cohort study included 85 eyes of 77 patients with primary nasal pterygium. PCC parameters, including posterior keratometry (K) average, posterior steep K, posterior flat K and posterior corneal astigmatism, were measured preoperatively and postoperatively using AS SS-OCT (Anterion). Perioperative PCC changes were analyzed in relation to HIL and postoperative duration. Subgroup analyses were performed to identify the HIL cutoff value associated with statistically significant changes in posterior K average. Results: Significant postoperative flattening was observed in both posterior K average (from –6.27 ± 0.24 to –6.23 ± 0.23 diopters [D], p < 0.001) and posterior flat K (from –6.14 ± 0.23 to –6.09 ± 0.23 D, p < 0.001), accompanied by a significant increase in posterior corneal astigmatism (from –0.25 ± 0.12 to –0.29 ± 0.17 D, p = 0.003). The magnitude of posterior flattening showed a significant positive correlation with HIL (r = 0.384, p < 0.001) but was not correlated with postoperative duration (p = 0.428). In subgroup analysis, eyes with HIL ≥3.5 mm exhibited a significant change in posterior K average (p < 0.001), whereas those with HIL <3.0 mm and HIL <3.5 mm showed no significant change (p = 0.065 and p = 0.443, respectively). Conclusions Pterygium excision leads to significant posterior corneal flattening proportional to HIL, with 3.5 mm identified as a clinically relevant cutoff. Although the refractive impact may be subtle, surgeons should be aware of these posterior corneal changes as a consistent morphological response, especially in eyes with HIL ≥3.5 mm.

Purpose: To determine the corneal stabilization timeline after pterygium excision adjusted for horizontal invasion length (HIL). Methods: In this single-center retrospective cohort study, we analyzed 88 eyes of 80 patients with nasal or temporal primary pterygium who underwent excision and perioperative evaluation with anterior segment (AS) swept-source optical coherence tomography (SS-OCT; Anterion). Anterior simulated mean keratometry (SimKmean; 3-mm ring) and HIL were measured on AS SS-OCT. Keratometric stabilization was assessed at postoperative cutoffs of 8, 12, 16, 20, and 24 weeks using analysis of covariance (ANCOVA) with HIL as a covariate. Subgroup analysis was performed after stratifying by the median HIL (3.82 mm). Results: Mean anterior SimKmean increased from 42.95 ± 1.79 diopters (D) preoperatively to 43.73 ± 1.53 D postoperatively (p < 0.001). Preoperative HIL correlated positively with the perioperative SimKmean change (r = 0.728, p < 0.001). While postoperative duration showed no significant unadjusted correlation with keratometric change (r = −0.133, p = 0.218), partial correlation controlling for HIL was negative (r = −0.248, p = 0.021), indicating diminishing change over time after severity adjustment. ANCOVA demonstrated significant stabilization at 16 weeks (p = 0.036). In the HIL ≥3.82 mm subgroup, SimKmean change was greater before 20 weeks than after 20 weeks (1.73 ± 1.59 D vs. 0.59 ± 0.74 D, p = 0.030), whereas no significant time-point differences were found for HIL <3.82 mm. Conclusions Corneal keratometric stabilization after pterygium excision depends on preoperative HIL. A minimum of 16 weeks is recommended before cataract surgery planning, with at least 20 weeks for eyes with HIL ≥3.82 mm.

Purpose: This study aims to determine whether the translucency-based clinical grade of pterygium shows independent relationships with anterior and posterior corneal curvature and anterior wavefront aberrations, with adjustment for horizontal invasion length (HIL) measured by anterior segment (AS) swept-source optical coherence tomography (SS-OCT). Methods: This study involved 53 eyes from 51 patients diagnosed with primary nasal pterygium. The clinical grade of the pterygium was evaluated using T grade based on the fibrovascular translucency. AS SS-OCT (Anterion, Heidelberg Engineering) provided HIL (in millimeters), thickness (in micrometers), anterior/posterior keratometry at the 3.0-mm ring, and anterior corneal wavefront metrics within a 6.0-mm zone. The device was also used to evaluate the magnitudes for the individual first-to fourth-order aberrations of the anterior corneal fields. Also, the fourth- to seventh-order root mean square (RMS), RMS lower-order aberration (LoA), and RMS higher-order aberration (HoA) values were collected. For statistical analysis, Spearman rank correlation test and Pearson correlation test were performed, along with partial correlation test adjusted for HIL. Results: The mean age of subjects was 59.3 ± 11.4 years, and 51.0% were female. T grade correlated positively with HIL. HIL showed strong associations with anterior simulated keratometry (Sim K) average, anterior Sim K steep, anterior Sim K flat, and anterior corneal astigmatism—but not with posterior corneal parameters. HIL also showed significant correlations with multiple anterior corneal wavefront parameters. After adjustment for HIL, T grade remained independently correlated with anterior Sim K flat, RMS LoA, and defocus; no significant relationships were observed with other Zernike terms or posterior metrics. Additionally, T grade was positively correlated with pterygium thickness. Conclusions T grade adds independent, complementary information (associations with flat keratometry, LoA RMS, and defocus) even after controlling for HIL. Incorporating T grade into preoperative assessment may improve estimation of optical burden and surgical prognosis.

Purpose: We report a case of bilateral nasal and temporal four-site scleromalacia following cosmetic conjunctivectomy, successfully managed with simultaneous restoration surgery at all four sites using autologous tragal perichondrium and preserved scleral graft.Case summary: A 56-year-old woman who underwent cosmetic conjunctivectomy on both eyes 15 years earlier, presented with intermittent eye pain. Examination revealed scleromalacia with calcium plaques in all four nasal and temporal scleral areas. The most extensive avascular area was in the nasal region of the right eye, and the most prominent uveal exposure was in the nasal area of the left eye. Considering the lesion and exposure sizes of the avascular zone and uvea exposure, preserved sclera was transplanted to the temporal and nasal areas of the right eye, while autologous tragal perichondrium was transplanted to the nasal area of the left eye. Tenon's capsule vessels were fixed with pedicle flaps in all four surgical areas for vascularization. Frozen amniotic membrane was transplanted in the nasal area of the left eye, where the conjunctival defect was substantial, and in the lateral area of the left eye, where no graft was used. The conjunctival epithelium was closed using autologous conjunctival flaps in all four areas. Post-surgery, successful engraftment and vascularization of the graft materials were observed in both eyes. Conclusions Even with multiple areas of scleromalacia in both eyes, successful results can be achieved during simultaneous surgery if an appropriate graft material is selected and the surgery is performed utilizing principles of tissue restoration.

Purpose: To analyze anterior, posterior, and total corneal refractive profiles and thickness using anterior segment (AS) sweptsource optical coherence tomography (SS-OCT) in Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) patients. Methods: This retrospective study compared 23 eyes from 14 patients with SJS/TEN with 23 eyes from 14 age- and sexmatched controls. AS SS-OCT measured corneal refractive profiles and pachymetry. Parameters included anterior, posterior, and total corneal power values, posterior to anterior curvature ratio, maximal corneal power, and thickness profiles. The SJS/TEN group was subdivided based on corneal opacity presence (subgroup A) or absence (subgroup B). Results: The SJS/TEN group showed significantly higher corneal astigmatism and maximal corneal power values for both anterior and posterior curvatures. Steep total corneal power and total corneal astigmatism were higher in the SJS/TEN group. The thinnest corneal thickness was lower, and its distance from the corneal vertex was greater in the SJS/TEN group. Subgroup analysis revealed that these differences were primarily attributed to the presence of corneal opacity. Additionally, automated keratometry of the anterior corneal surface showed significantly higher values, including steep, flat, and average keratometry and corneal astigmatism, in the SJS/TEN group. Conclusions AS SS-OCT shows significant alterations in both anterior and posterior corneal curvatures in patients with SJS/TEN. These findings emphasize the importance of considering posterior corneal curvature changes in pre-cataract surgery assessments and contact lens prescriptions for patients with SJS/TEN.

Purpose: This study evaluated the objective changes in the contralateral eye after unilateral cataract surgery. Methods: The study was designed as retrospective observational study. It included 44 patients who underwent unilateral cataract surgery. Collected data were uncorrected and corrected visual acuity, spherical equivalent, intraocular pressure, contrast sensitivity (CS), stereoacuity, and anterior segment optical coherence tomography parameters. Data were collected preoperatively, and 1 week and 1 month postoperatively for each eye. Results: Following unilateral cataract surgery, the pupil size of the fellow eye decreased from 3.46 mm to 3.17 mm (postoperative week 1, p = 0.003) and 3.08 mm (postoperative month 1, p < 0.001). Anterior chamber depth of the fellow eye increased significantly from 3.16 mm to 3.27 mm (postoperative week 1, p = 0.005) and 3.26 mm (postoperative month 1, p = 0.001). Uncorrected distance visual acuity (UDVA) of the fellow eye improved significantly at postoperative week 1 (p = 0.042) and postoperative month 1 (p = 0.044). Change of UDVA of the fellow eye at postoperative month 1 was significantly correlated with that of the treated eye (p = 0.039). Conclusions Anterior chamber structures changed and UDVA improved in the contralateral eye after unilateral cataract surgery in our cohort. Because fellow eyes were positively affected by monocular cataract surgery, it would be good information if planning for unilateral cataract surgery due to inevitable reasons.

Background: Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. Methods: We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition. Results: Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways. Conclusion We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.

Background: Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. Methods: We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition. Results: Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways. Conclusion We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.