Intraocular Pressure Changes Following Corneal Cross-Linking in Patients With Keratoconus

Journal of Glaucoma · 2026-01-12

PRÉCIS: This retrospective study found significantly elevated IOP measurements in eyes with keratoconus after CXL at postoperative months 1 and 3, but not after 4.5 months, compared with both baseline and untreated fellow eyes. PURPOSE: To evaluate intraocular pressure changes after corneal collagen cross-linking in patients with keratoconus and compare intraocular pressure measurements across tonometry methods. METHODS: A retrospective chart review was performed of 405 patients (405 index eyes and 218 untreated fellow eyes) who underwent cross-linking between January 1, 2012, and January 1, 2024, at Duke Eye Center. Preoperative and postoperative intraocular pressure measurements were collected at ~1 month, 3 months, and ≥4.5 months postoperatively. Generalized estimating equation models included time point, tonometry method (iCare, Tonopen, Goldmann applanation tonometry), corticosteroid use, age, sex, and race. Wilcoxon rank-sum and sign-rank tests were used for tonometry method sub-analyses. RESULTS: In treated eyes, intraocular pressure significantly increased at 1 month (2.2 mmHg increase, P =0.001) and remained elevated at 3 months (1.1 mmHg increase, P <0.001), returning to baseline by ≥4.5 months ( P =0.168). No significant intraocular pressure change was observed in untreated fellow eyes at any postoperative time point. Tonopen measurements were consistently higher than iCare (all P <0.001). iCare measurements showed significant elevation at 1 month postoperatively ( P =0.005), and Tonopen measurements at 1 month and 3 months (both P <0.001). No elevation was observed beyond 3 months with any tonometry method. CONCLUSIONS: Corneal collagen cross-linking was associated with transient intraocular pressure elevations postoperatively that normalized by ≥4.5 months. Tonometry method significantly influences intraocular pressure measurements, with iCare having lower measurements compared with Tonopen. Awareness of this pattern is important when managing patients with risk factors for glaucoma after cross-linking.

Longitudinal Multimodal Imaging Findings Following Inadvertent 577 nm Laser Backscatter Exposure During Panretinal Laser Photocoagulation

Journal of VitreoRetinal Diseases · 2026-03-30

Purpose: To report an unusual case of retinal dysfunction in a treating ophthalmologist following inadvertent exposure to 577 nm yellow laser backscatter during panretinal photocoagulation. Methods: A single case was reviewed. Results: A 28-year-old physician was inadvertently exposed to 577 nm yellow laser backscatter while using an indirect ophthalmoscope to deliver panretinal laser photocoagulation for ischemic retinal disease. He immediately experienced bilateral after-images that persisted for 72 hours. Longitudinal multimodal retinal imaging revealed no structural abnormalities. Multifocal electroretinography (mfERG) performed soon after exposure demonstrated macular dysfunction in both eyes. At 18 months, mfERG amplitudes had normalized, but implicit times remained prolonged, consistent with persistent mild cone dysfunction. Conclusions: Inadvertent laser backscatter exposure can result in functional retinal changes without detectable structural abnormalities. This case underscores the importance of rigorous laser safety protocols for treating ophthalmologists during ophthalmic laser procedures.

Size Matters

American Journal of Ophthalmology · 2025-04-02 · 2 citations

The Efficacy and Safety of Trabeculectomy after Failed Primary Glaucoma Drainage Devices

Ophthalmology and Therapy · 2025-06-22

INTRODUCTION: Trabeculectomy is not usually considered for uncontrolled intraocular pressure (IOP) after glaucoma drainage devices (GDD) because of concern that the conjunctiva has been violated and future trabeculectomy surgery is likely to fail due to fibrosis. We examined the clinical outcomes of patients who underwent a trabeculectomy after failed primary GDD. METHODS: This is a cross-sectional study of all patients who had a glaucoma drainage implant that failed or was inadequate in lowering IOP and underwent a trabeculectomy in the same eye from January 2016 to December 2022. RESULTS: A total of 23 eyes in 22 patients met our criteria. Average IOP [± standard deviation (SD)] prior to trabeculectomy was 21.7 ± 9.3 on 3.2 ± 1.3 medications. The length of follow-up was between 0.3 and 5.0 years with an average follow-up time of 2.2 years. At 1 year (n = 16), IOP was 11 ± 1.9 mm Hg on 1.8 ± 1.5 medications. At 2 years, the average IOP was 11.8 ± 4.6 on 1.9 ± 1.4 medications. At all follow-up points, the decrease in IOP and medication was statistically significant compared with baseline (paired t-tests; p < 0.05). Most postoperative complications self-resolved with medical management (three early wound leaks, two late wound leaks, two instances of hypotony maculopathy, and one instance of cystoid macular edema). One early wound leak required surgical repair. One eye underwent an additional GDD surgery, and three eyes underwent bleb needling. In all, 20 (87%) eyes at final visit were within two lines of their baseline vision prior to trabeculectomy. No eyes progressed to having no light perception visual acuity or had an ocular infection. CONCLUSIONS: This study suggests that trabeculectomy after a GDD is an effective and safe option for IOP control and glaucoma medication reduction. In this small sample of surgical cases, complication and reoperation rates were comparable to published rates.

Re: Zhou et al.: Incidence of acute cystoid macular edema after starting a prostaglandin analog compared with other classes of glaucoma medications (Ophthalmol Glaucoma. 2025;8:4-11)

Ophthalmology Glaucoma · 2025-04-19

The Role of Ocular Perfusion Pressure in the Pathogenesis of Glaucoma

2024-05-28

Although many risk factors, such as elevated intraocular pressure (IOP), have been implicated in the pathogenesis of open-angle glaucoma (OAG), the exact mechanisms remain unclear. There are 2 theories that have gained the most traction over time: the mechanical theory suggests that IOP directly damages the lamina cribrosa and retinal ganglion cell axons, whereas the vascular theory hypothesizes that insufficient ocular blood flow predisposes the optic nerve to damage, especially in the setting of increased IOP. 1 , 2 While these 2 theories are presented as distinct, they are not mutually exclusive, and in many clinical scenarios, both mechanisms may be at play.

Posterior Vitreous Detachment and Risk of Neovascular Glaucoma in Eyes with Prior Retinal Vascular Occlusions

Ophthalmology and Therapy · 2024-09-29 · 1 citations

INTRODUCTION: To investigate the impact of posterior vitreous detachment (PVD) on the risk of developing neovascular glaucoma (NVG) in eyes with occlusions of the retinal artery (RAO) or retinal vein (RVO). METHODS: Single-center retrospective case-control study of adults with a history of RVO/RAO. Cases (N = 101) who developed NVG were age and sex matched 1:2 to controls who did not develop NVG (N = 202). Multivariable logistic regression was used to estimate the association between history of PVD and risk of NVG while controlling for other related demographic or clinical factors. RESULTS: In initial bivariate analyses, there was no difference in risk of NVG based on eye, lens status, hypertension, history of panretinal photocoagulation (PRP), or retinal surgery (all p > 0.10), a borderline difference based on diabetic retinopathy (DR) (p = 0.06) and prior anti-vascular endothelial growth factor (anti-VEGF) treatment (p = 0.08), and a significant difference based on race/ethnicity, type of vascular event, and PVD status (all p < 0.05). In the final multivariable model, patients without PVD were significantly more likely to develop NVG (OR = 3.07, p = 0.0001) independent of the other covariates. Risk of NVG was greater in those with DR (OR = 1.98, p = 0.0440) and in those with central RVO vs. branch RVO/hemiretinal RVO (OR = 5.77, p < 0.0001). Non-White/Non-Hispanics (OR = 2.56, p = 0.0051) and Hispanics (OR = 3.65, p = 0.0288) were more likely than White patients to develop NVG. CONCLUSIONS: Progression to NVG after retinal vascular occlusion is more likely in Non-White/Hispanic patients, those with concomitant DR, and those with CRVO/CRAO. The absence of PVD increases the risk for NVG. Further studies are necessary to understand this relationship.

Diagnosing glaucoma progression with optical coherence tomography

Current Opinion in Ophthalmology · 2024-11-07 · 5 citations

PURPOSE OF REVIEW: Optical coherence tomography (OCT) is a widely used tool to diagnose and monitor glaucoma by objectively measuring the ganglion cell layer and the retinal nerve fiber layer (RNFL) thickness. The presence of RNFL thinning raises suspicion for glaucoma progression. Therefore, this review aims to discuss current approaches to using OCT for detecting glaucomatous change, limitations, and recent advancements. RECENT FINDINGS: Previously established approaches to determining glaucomatous progression on OCT include quantitative and qualitative methods. The most common quantitative methods include event-based and trend-based analysis. Decreasing RNFL thickness or loss of the ganglion cell layer are indicative of glaucomatous changes. However, interpretation of OCT scans is strongly impacted by artifacts, which can be because of epiretinal membrane or posterior vitreous detachment. Race and aging also may impact interpretation of RNFL progression. More recent research focuses on loss of the RNFL because of the effects of systemic conditions. Given the limitations in the current approaches, recent advancements indicate a promising role for artificial intelligence in determining true glaucomatous progression. SUMMARY: This review highlights current approaches to identifying glaucoma progression on OCT, limitations to these approaches, and the potential role for artificial intelligence.

Treatment of Primary Angle-Closure Suspect

JAMA Ophthalmology · 2024-03-21 · 2 citations

This article discusses treatment options for suspects of primary angle-closure disease.

Optical Coherence Tomography Findings in Glaucoma With Coexisting Vitamin A Deficiency

Journal of Glaucoma · 2024-04-15

This case study reports on the presence of vitamin A deficiency in an adult with asymmetric normal tension glaucoma. The retinal OCT findings demonstrated not only expected loss of the outer retinal layers, typically seen in vitamin A deficiency, but also severe and bilateral loss of the inner retinal layers. After vitamin A supplementation, visual acuity, dark adaptation, and color vision normalized. The outer retinal layers had a restoration of thickness after vitamin A supplementation, but the inner layers did not change. This case is unique because it may give us an insight into the role of vitamin A on the inner retina and demonstrate the recovery of the outer retinal layers with vitamin A supplementation.