Long Anterior Lens Zonules and Intraocular Pressure

Abstract

PurposeTo investigate the relation between intraocular pressure (IOP) and the idiopathic long anterior zonule (LAZ) trait.MethodsPatients presenting for primary eye care were examined for LAZ, identified as radially oriented zonular fibers with central extension >1.0 mm beyond the normal anterior lens insertion zone (estimated via slit lamp beam length). Ocular, systemic health, and lifestyle data were collected via comprehensive exam and questionnaire. Multivariate regression was used to assess the relationship between IOP (Goldmann) and LAZ.ResultsThere were 2169 non-LAZ and 129 LAZ subjects (mean age: 49.8 ± 15.0 vs. 62.6 ± 10.2 years; 63.6% vs. 76.0% female; 83.2% vs. 91.5% African American). Right eyes with >trace LAZ (n = 59 of 110) had higher unadjusted mean IOP than control eyes (16.4 ± 3.3 vs. 15.0 ± 3.3 mm Hg, P = 0.005), and with control for numerous factors, LAZ eyes had an average IOP of approximately 1.3 ± 0.4 mm Hg higher (P = 0.003) than non-LAZ eyes. Final model covariates included sex (P = 0.001); spherical-equivalent refractive error (D; P < 0.0001); body mass index (kg/m2; P < 0.001); presence of diabetes (P < 0.001); having >high school education (P < 0.001); systolic blood pressure (mm Hg; P < 0.0001); being an ever smoker (P = 0.006); and having history of any site cancer (P = 0.01).ConclusionsThe LAZ trait, with potential prevalence near 2%, was associated with a higher IOP. This observation is consistent with the hypothesis that the trait is a marker for underlying mechanisms that elevate glaucoma risk.

Krukenberg’s Spindles Strongly Suggest Long Anterior Zonule Associated Pigment Dispersion Mechanism in Older Patients

“…For this study, we analyzed a dataset collected for an ongoing investigation, which has been described previously. 20 Data collection for the current analysis extended from October 2011 through November 2018, and the overall goal of the larger investigation has been to assess ocular and general health associations with the LAZ trait. Potential subjects for this investigation included consecutive patients who presented for regularly scheduled examination by one of nine attending doctors in the primary eye care service of an urban teaching facility in Chicago, Illinois, USA.…”

“…34 Further detail on LAZ morphology and detection is presented elsewhere. 11,20,26,35 To ensure definitive LAZ cases, we excluded subjects with < 5 LAZ fibers. 20,26,35 To provide estimation of the number/density of LAZ, investigators used the following arbitrary scale based on countable LAZ fibers: grade trace = 0 to 4, grade 1+ = 5 to 9, grade 2+ = 10 to 19, grade 3+ = 20 to 49, and grade 4+ = ≥ 50.…”

“…17,18 The other variety, which has unknown etiology, most frequently occurs among hyperopic women with age > 50 years. 10,19,20 In addition to LAZ's importance to cataract surgery due to anterior capsular zonule-free zones often being ≤ 3 mm, [21][22][23][24][25][26][27][28] it has been shown that people with idiopathic LAZ have a higher IOP than people without the trait. 20 There is also the suggestion that LAZ could signal higher risk for narrow-and open-angle forms of glaucoma.…”

“…10,19,20 In addition to LAZ's importance to cataract surgery due to anterior capsular zonule-free zones often being ≤ 3 mm, [21][22][23][24][25][26][27][28] it has been shown that people with idiopathic LAZ have a higher IOP than people without the trait. 20 There is also the suggestion that LAZ could signal higher risk for narrow-and open-angle forms of glaucoma. 17,20,[29][30][31][32][33] Given the importance of KS presence as a sign of pigment dispersion processes and its possible under-recognition as an indicator of LAZ-associated PDS, we further investigated this relationship among our patient population.…”

“…20 There is also the suggestion that LAZ could signal higher risk for narrow-and open-angle forms of glaucoma. 17,20,[29][30][31][32][33] Given the importance of KS presence as a sign of pigment dispersion processes and its possible under-recognition as an indicator of LAZ-associated PDS, we further investigated this relationship among our patient population.…”