One year structural and functional glaucoma progression after trabeculectomy

Abstract

We evaluated the changes in visual field mean deviation (VF MD) and retinal nerve fibre layer (RNFL) thickness in glaucoma patients undergoing trabeculectomy. one hundred patients were examined with VF and spectral-domain optical coherence tomography (OCT) before trabeculectomy and 4 follow-up visits over one year. Linear mixed models were used to investigate factors associated with VF and RNFL. VF improved during the first 3 months of follow-up (2.55 ± 1.06 dB/year) and worsened at later visits (−1.14 ± 0.29 dB/year). RNFL thickness reduced by −4.21 ± 0.25 µm/year from 1st month of follow-up. Eyes with an absence of initial VF improvement (β = 0.64; 0.30-0.98), RNFL thinning (β = 0.15; 0.08-0.23), increasing intraocular pressure (IOP; β = −0.11; −0.18 to −0.03) and severe glaucoma (β = −10.82; −13.61 to −8.02) were associated with VF deterioration. Eyes with VF deterioration (β = 0.19; 0.08-0.29), increasing IOP (β = −0.09; −0.17 to −0.01), and moderate (β = −6.33; −12.17 to −0.49) or severe glaucoma (β = −19.58; −24.63 to −14.52) were associated with RNFL thinning. Changes in RNFL structure and function occur over a 1-year follow-up period after trabeculectomy.Early VF improvement is more likely to occur in patients with mild/moderate glaucoma, whereas those with severe glaucoma show greater decline over one year. Our findings indicate that progression is observable using OCT, even in late-stage glaucoma.Clinically, reduction of intraocular pressure (IOP) remains the only proven treatment for glaucoma 1-3 . Landmark glaucoma randomized clinical trials have confirmed the value of lowering IOP in delaying visual field (VF) progression 1-5 . Interestingly, recent studies 6-8 have reported that the surgical lowering of IOP in glaucoma can result in the improvement of VF, which lends support to the preliminary data reported by Katz and Spaeth, who demonstrated reversal of structural change and field loss in newly diagnosed patients after commencement of treatment 9,10 .Apart from functional changes, others have examined structural changes after trabeculectomy and their potential association with functional changes. The association between structural glaucomatous damage with VF decline after trabeculectomy is complex. The MoreFlow Medical Research Council 5-Fluorouracil (5-FU) study reported that out of 250 eyes, 20 eyes showed structural progression, 35 eyes showed VF progression, and 15 eyes showed both over a five years period 11 . In the Collaborative Initial Glaucoma Treatment Study (CIGTS), VF worsening was significantly associated with enlargement of the optic cup, but reversal of cupping was not associated with improvement of the VF 12 . Other studies reported an early increase in retinal nerve fiber layer (RNFL) thickness after trabeculectomy, but did not investigate the relation with VF changes [13][14][15][16][17] . Also, these studies have used the older time-domain optical coherence tomography (OCT) 14,16 , stereoscopic optic disc photographs 12,15 scanning laser polarimetry 17 , or Heidelberg Retina Tom...

Long-Term Follow-Up After Successful Trabeculectomy: A Case Report of Reversal of Cupping and Recovery of Visual Field Progression

“…These findings suggest that TLE is advantageous when patients are young and at the early stage of glaucoma. This is supported by a recent report that early visual field improvement after TLE is more likely to occur in patients with mild/moderate glaucoma, whereas the visual field of patients with severe glaucoma will tend to decline greatly over one year [16]. This is consistent with our case report: the patient was 35 years old and with moderate glaucoma (MD = −9.59) at the time of TLE.…”

Functional Monitoring after Trabeculectomy or XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography and Visual Field Indices—A Retrospective Comparative Cohort Study

“…Other groups demonstrated results as regards RNFL development that are closer to the findings shown here. Chua et al found a decrease in the mean RNFL thickness of −4.2 ± 0.3 µm/year during the first year after TE in 105 eyes [ 45 ]. Similar to our results as regards RNFL thickness and visual field indices, Kim et al demonstrated a significant RNFL thickness reduction, but no concomitant change in the mean deviation of standard automated perimetry after 12 months of follow-up after TE or Ahmed glaucoma valve implantation [ 46 ].…”

Two Year Functional and Structural Changes—A Comparison between Trabeculectomy and XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography

“…Some authors stated no significant changes of RNFL thickness after TE in short follow-up periods of 6 to 12 months [ 22 , 25 , 26 ]. However, other studies showed significant RNFL changes for 12 to 18 months after different glaucoma surgeries [ 23 , 24 , 27 ]. Kim et al found a significant RNFL thinning 12 months after TE or Ahmed valve implantation.…”