The Impact of Lens Vault on Visual Acuity and Refractive Error: Implications for Management of Primary Angle-closure Glaucoma

Ophthalmological examination and imaging features that better predict risk of Angle Closure in siblings

OBJECTIVE

Characteristics of individuals with angle closure may be useful in targeted screening of family members. Here, we assess if findings gathered during examination and imaging of patients with a known angle closure diagnosis (probands) could better determine the risk of angle closure in the patients' siblings.

DESIGN

Cross-sectional study of patients with known angle closure and their siblings.

SUBJECTS

Participants, and Controls: South Indian patients (probands) 30 years and older with open angles, suspect primary angle closure (PACS), or primary angle closure/primary angle closure glaucoma (PAC/PACG), and a biological sibling age 30 years or older (n=292 proband/sibling pairs).

METHODS

Demographic data, relevant ocular history, and a comprehensive ophthalmic examination with Anterior Segment Optical Coherence Tomography (ASOCT) were obtained. Three clinically relevant models were created to analyze the contribution of specific proband factors in predicting sibling angle closure diagnosis, using demographic (age, gender), ocular exam (gonioscopy, optic nerve exam, visual acuity, intraocular pressure [IOP]), and ASOCT features to improve prediction beyond proband diagnosis alone evaluated by log likelihood ratio testing and statistical comparison of receiver operating characteristics (ROC).

MAIN OUTCOME MEASURES

Sibling angle closure diagnostic accuracy.

RESULTS

Demographic and ocular exam metrics did not improve the prediction of sibling angle closure for all three outcomes (sibling diagnosis: (1) PACS/PAC/PACG vs OA, (2) PAC/PACG vs PACS/OA, and (3) PAC/PACG vs PACS), adding no model improvement when compared to diagnosis alone. Models adding ASOCT metrics to the prior model including proband diagnosis, demographics and ocular exam measures led to significantly improved prediction of 2 of the 3 angle closure outcomes. Specifically, improvement was noted via likelihood ratio testing for prediction of PAC/PACG vs PACS/OA (p=0.01), or PAC/PACG vs PACS (p=0.001). For all 3 angle closure outcomes, ROC comparisons demonstrated significant improvement in AUC between the three models predicting sibling outcomes, demonstrating an increase in AUC with each successive nested model across all 3 sibling angle closure outcomes.

CONCLUSIONS

Structural features of eyes with angle closure may assist in stratifying the risk of angle closure in patients' siblings. Further studies should consider evaluating this approach to achieve more targeted screenings.

The ocular biometry characteristics of young patients with primary angle-closure glaucoma

Background

Although primary angle-closure glaucoma (PACG) mainly occurs in elderly people, diagnosis of PACG in young patients is not uncommon. So far, there is no article specialized on the ocular anatomical characteristics in these patients.In this study, ocular anatomical characteristics in young PACG patients are analyzed.

Methods

In this retrospective, comparative study, patients diagnosed with PACG and received ultrasound biomicroscopy (UBM) examination in our department were included. Patients were divided into two groups: a young group composed of patients ≤ 45 years and an old group composed of patients > 45 years. A-scan ultrasonography and ultrasound biomicroscopy (UBM) were used to measure ocular biometric parameters of patients in the two groups including axial length (AL), lens thickness (LT), central anterior chamber depth (ACD), anterior chamber width (ACW), angle opening distance 500 (AOD500), anterior chamber angle 500 (ACA500), iris thickness 1000 μm from the iris root (IT1000), iris thickness 500 μm from the iris root (IT500), trabecular-ciliary process angle (TCPA), trabecular-ciliary process distance (TCPD), scleral– ciliary process angle (SCPA), lens vault (LV), and pupil diameter (PD). Plateau iris (PI) and basal iris insertion were determined from UBM images, and the prevalence of PI and basal iris insertion were compared between the two groups. The incidence of postoperative malignant glaucoma (MG) was also determined in both groups and ocular anatomical predictors for the development of MG were evaluated in young PACG patients.

Results

One hundred fifteen patients were included into young group and 480 patients were included into old group. The young group had shorter TCPD, shorter AL, narrower TCPA, narrower SCPA thinner Lens compared to the old group. There were no significant differences in ACD, AOD 500, ACA500, LV, IT500, IT1000, PD or ACW between the two groups. The prevalence of PI was 22.6% in old group and 66.1% in young group (P < 0.001). More young PACG patients displayed basal iris insertion compared to old PACG patients (P < 0.001). 87 patients in the young group and 201 patients in the old group underwent trabeculectomy in our study. Among these patients, 21 young patients and 11 old patients developed MG after trabeculectomy (P < 0.001).

Conclusions

Shorter AL, more anteriorly positioned ciliary body, higher prevalence of PI may be responsible for the etiology of young PACG patients. Our results suggest that shorter AL, shorter TCPD and narrower TCPA may be predictors for development of MG in young PACG patients after trabeculectomy.

Comparative Evaluation of Phacoemulsification Alone versus Phacoemulsification with Goniosynechialysis in Primary Angle-Closure Glaucoma: A Randomized Controlled Trial

PURPOSE

Comparative evaluation of phacoemulsification (phaco) alone versus phacoemulsification combined with goniosynechialysis (phacoGSL) in primary angle-closure glaucoma (PACG).

DESIGN

Prospective, randomized, parallel group, active controlled trial.

PARTICIPANTS

Patients with PACG.

METHODS

A total of 120 consecutive patients with PACG were screened, of whom 80 met inclusion criteria, with PACG uncontrolled on maximal hypotensive therapy and were recruited. Patients were randomized into 2 groups and underwent phaco alone in group 1 or phacoGSL in group 2. The patients were examined at baseline and at 1 week and 1, 3, and 6 months. The anterior chamber angle parameters on swept-source anterior segment OCT (SS-ASOCT) were noted at 1 and 6 months.

MAIN OUTCOME MEASURES

The primary outcome measure was intraocular pressure (IOP) reduction. A reduction in IOP of ≥ 20% from baseline IOP with or without medications was considered a success. Secondary outcome measures included change in the anterior chamber angle temporal parameters, angle-opening distance, trabecular-iris space area and scleral spur angle, surgical safety, visual acuity, and reduction in the number of glaucoma medications postoperatively.

RESULTS

The average age of patients was 58.77±8.14 years and 56.50±9.17 years in groups 1 and 2, respectively (P = 0.31). The mean baseline IOP was 29.48±6.76 mmHg and 30.72±3.88 mmHg in groups 1 and 2, respectively (P = 0.13). Success was obtained in 93.33% of patients in group 1 and 91.18% of patients in group 2 at 6 months (P = 0.39). Mean IOP was 13.17±1.66 mmHg and 13.21±1.97 mmHg at 6 months in groups 1 and 2, respectively (P = 0.001). The reduction in IOP was 55.32% and 56.99% at 6 months in groups 1 and 2 (P = 0.48). Significant widening of the angle parameters was noted at 6 months with an increase compared with baseline values in both groups. In multivariate analysis, the significant predictor of decrease in IOP was the higher baseline IOP.

CONCLUSIONS

Both phaco and phacoGSL are associated with a significant reduction in IOP along with a noteworthy widening of the anterior chamber angle parameters. Both procedures succeeded in reducing the necessity of glaucoma medications postoperatively in PACG eyes. There is no additional benefit of phacoGSL over phaco in PACG.

Anterior segment configuration as a predictive factor for refractive outcome after cataract surgery in patients with glaucoma

Background

To compare refractive outcomes after cataract surgery between patients with closed-angle and open-angle glaucoma and evaluate the influence of preoperative factors on refractive outcomes in patients with glaucoma.

Methods

Patients diagnosed with glaucoma and who underwent uncomplicated cataract surgery were enrolled in this retrospective observational study. We collected data including age, history of prior laser peripheral iridotomy and trabeculectomy, type of glaucoma, manifest refraction, intraocular pressure, axial length, and various anterior segment parameters using anterior-segment optical coherence tomography. Factors associated with unsatisfactory refractive outcome at postoperative 6 month were evaluated.

Results

A total of 143 eyes (143 subjects) were included. Of these, 49 and 94 had closed-angle and open-angle glaucoma, respectively. At postoperative-6 month evaluation, the mean absolute error (MAE) predicted by the SRK-II and SRK-T formulae was 0.67 ± 0.61 and 0.81 ± 0.66 diopters (D), respectively. The overall predictability of achieving within ± 1.0 D of target was 76.92 % and 72.73 %, respectively. At a cutoff value of 1.0 D for MAE, there was no statistical significant difference in refractive outcome between the closed-angle and open-angle glaucoma groups. Logistic regression modeling showed that large lens vault (LV) was a significant predictor of unsatisfactory refractive outcome after cataract surgery in patients with glaucoma.

Conclusions

When considering cataract surgery in patients with glaucoma, surgeons should recognize that the refractive outcomes may be unsatisfactory in eyes with large LV.