Intra-Operative Mounted Optical Coherence Tomography Findings Following Reversal of Optic Nerve Head Cupping in Childhood Glaucoma

Visco-Circumferential-Suture-Trabeculotomy Versus Rigid-Probe Viscotrabeculotomy in Neonatal-Onset Primary Congenital Glaucoma

PRCIS

Angle procedures are safe and relatively effective for neonatal onset PCG. Watchful delay in intervention to close to the second month of life is helpful in ensuring diagnosis and making surgery more successful and easier.

PURPOSE

The purpose of this study was to compare the surgical outcomes of visco-circumferential-suture-trabeculotomy (VCST) to rigid-probe double-entry viscotrabeculotomy (DEVT) and rigid-probe single-entry viscotrabeculotomy (SEVT) in infants with neonatal-onset primary congenital glaucoma (PCG).

DESIGN

This was a retrospective chart review.

PATIENTS AND METHODS

Retrospective chart review of 64 eyes of 64 infants with neonatal-onset PCG referred to Mansoura Ophthalmic Center in Mansoura, Egypt between February 2008 and November 2018. Study groups included VCST, DEVT, and SEVT, and follow-up covered 4 postoperative years. Complete (qualified) success was defined as intraocular pressure (IOP) ≤18 mm Hg and with 35% IOP reduction from baseline without (with) IOP-lowering medications or further surgical interventions, and without any sign of progression in corneal diameter, axial length, or optic disc cupping and without visual devastating complications.

RESULTS

The mean±SD age at presentation and at the surgery of the study children was 3.63±1.74 and 55.23±1.60 days, respectively. The mean±SD IOP and cup/disc ratio of all study eyes at presentation and at final follow-up were 34.91±0.82 mm Hg and 0.70±0.09 and 17.04±0.74 mm Hg and 0.63±0.08, respectively. Complete success was achieved in 54.5%, 43.5%, and 31.6% in the VCST, DEVT, and SEVT groups, respectively. A self-limited hyphema was the commonest complication in all groups.

CONCLUSIONS

Angle procedures are safe and marginally effective for the surgical treatment of neonatal-onset PCG, bringing IOP under control for at least 4 years of follow-up. Circumferential trabeculotomy as a first-line treatment has more favorable outcomes than rigid-probe SEVT. Rigid-probe viscotrabeculotomy offers an alternative to the noncompleted circumferential procedure.

Neuroretinal Rim Response to Transient Intraocular Pressure Challenge Predicts the Extent of Retinal Ganglion Cell Loss in Experimental Glaucoma

Purpose

To determine if the optic nerve head (ONH) response to transient elevated intraocular pressure (IOP) can predict the extent of neural loss in the nonhuman primate experimental glaucoma model.

Methods

The anterior chamber pressure of 21 healthy animals (5.4 ± 1.2 years, 8 female) was adjusted to 25 mm Hg for two hours followed by 10 mm Hg for an additional two hours. For the duration of IOP challenge the ONH was imaged using radial optical coherence tomography (OCT) scans at five-minute intervals. Afterward, a randomized sample of 14 of these subjects had unilateral experimental glaucoma induced and were monitored with OCT imaging, tonometry, and ocular biometry at two-week intervals.

Results

With pressure challenge, the maximum decrease in ONH minimum rim width (MRW) was 40 ± 10.5 µm at 25 mm Hg and was correlated with the precannulation MRW, Bruch's membrane opening (BMO) position, and the anterior lamina cribrosa surface position (P = 0.01). The maximum return of MRW at 10 mm Hg was 16.1 ± 5.0 µm and was not associated with any precannulation ONH feature (P = 0.24). However, healthy eyes with greater thickness return at 10 mm Hg had greater loss of MRW and retinal nerve fiber layer (RNFL) at a cumulative IOP of 1000 mm Hg · days after induction of experimental glaucoma. In addition, MRW and RNFL thinning was correlated with an increase in axial length (P < 0.01).

Conclusion

This study's findings suggest that the ONH's response to transient changes in IOP are associated with features of the ONH and surrounding tissues. The neural rim properties at baseline and the extent of axial elongation are associated with the severity of glaucomatous loss in the nonhuman primate model.