Effect of Trabeculectomy on Mean and Centroid Surgically Induced Astigmatism

This study aimed to investigate the arithmetic mean of surgically induced astigmatism (M-SIA) and the centroid of surgically induced astigmatism (C-SIA) after standard trabeculectomy. We comprised 185 eyes of 143 consecutive patients (mean age ± standard deviation, 67.7 ± 11.6 years) who underwent trabeculectomy and completed at least a 3-month routine follow-up. In all cases, the scleral flap was made at the nasal-superior location. Corneal astigmatism was measured with an automated keratometer. We calculated the M-SIA and the C-SIA using vector analysis and applied the astigmatism double angle plot. The magnitude of corneal astigmatism increased significantly, from 1.17 ± 0.92 D preoperatively to 1.77 ± 1.05 D postoperatively (paired t-test, p < 0.001). The M-SIA was 1.12 ± 0.55 D, and the C-SIA was 0.73 D @64° ± 1.02 D in the right eye group, and the M-SIA was 1.08 ± 0.48 D and the C-SIA was 0.60 D @117° ± 1.03 D in the left eye group. The C-SIA showed an astigmatic shift toward the nasal-superior location of the scleral flap creation. Our results revealed that trabeculectomy induced the SIA in the direction of the scleral flap location and that the C-SIA was much lower than the M-SIA in eyes undergoing trabeculectomy.

Usage of E-Polytetrafluoroethylene (e-PTFE) Membrane for Managing Trabeculectomy Flap- Related Over-Filtration Due to Unavailability of Scleral Patch Graft during Nation-Wide Lockdown

Scleral flap tears during trabeculectomy are difficult to repair in a predictable fashion. Donor scleral flap reinforcements are commonly preferred for managing trabeculectomy flap-related over-filtration, leading to shallow anterior chamber (AC). Due to the advent of COVID-19 lockdown, especially in the initial phases, eye banking activities almost came to a standstill, with almost no corneal and/or scleral tissue retrievals. Hence, in this manuscript we have presented a mini case series with follow-up of two of our cases; where Gore-Tex (e-polytetrafluoroethylene) implant was used as an alternative to scleral patch graft, for managing trabeculectomy flap-related over-filtration, with their pros and cons. Though Gore-Tex implant stability in both cases were contentious, it still served the purpose of managing the flap-related over- filtration and subsequent shallow AC.

A Modified Intrascleral Intraocular Lens Fixation Technique Using 27-Gauge Blunted Needles with Fewer Intraocular Manipulations

A new method for intraocular lens (IOL) fixation in the scleral tunnel using two common 27G blunted needles and an ultrathin 30G needle with fewer intraocular manipulations was developed. Half-depth scleral flaps were prepared, and vertically angled sclerotomies were performed under each scleral flap, 2 mm from the limbs with a 20G microblade or a 26G needle. Two bent 27G blunted needles connected the sclerotomy and corneoscleral incisions. One haptic was inserted into this bent 27G blunted needle extraocularly and extruded through the sclerotomy site. Each haptic was inserted into the lumen of the preplaced ultrathin 30G needle and buried into the scleral tunnel. In this retrospective study, we reviewed the outcomes of this new technique in patients with at least 3 months’ follow-up data. Iris capture of the IOL was not observed in any case, and IOL repositioning was not performed either. Astigmatism induced by intraocular aberration was almost as same as that with other methods. Our technique can be performed in any operation room without any extra instruments. This trial is registered with UMIN000044350.

Results of Rectangular and Triangular Shaped Scleral Flaps in Trabeculectomy in Terms of Control of Intra Ocular Pressure (IOP) and Complications

Purpose: To compare between the results of rectangular and triangular shaped scleral flaps in trabeculectomy for primary open angle glaucoma. Study design: Quasi experimental study Place and Duration of Study: Khalid eye clinic, Karachi, from July 2018 to June 2019. Methods: This study included 24 patients of either gender and age from 40 to 65 years. Patients with a diagnosis of primary open angle glaucoma refractory to medical treatment were included by convenient sampling technique. They were divided into two groups. Group A underwent trabeculectomy with rectangular shaped scleral flap whereas Group B underwent trabeculectomy with triangular shaped scleral flap. The main outcome measures were intraocular pressure reduction, anterior chamber depth and post-operative complications. All patients were followed up for a period of two months. Results: Mean age was 52.1± 6.72 years. Mean pre-operative intraocular pressure in group A was 24.4±2.13 mmHg and 23.5±1.64 mmHg in group B. Mean post-operative IOP was 11.6±1.51 mmHg in group A and 13.4±1.67 mmHg in group B with p-value of 0.11. Pre-operative anterior chamber depth (ACD) was grade 4 both groups. It remained same in all patients of group A but two patients of group B changed to grade 3 ACD. Two patients of group B developed hypotony on the first post-operative day. They did not require revision suturing and were managed conservatively. Conclusion: Both types of scleral flap are effective in reducing IOP but rectangular scleral flap reduced IOP more as compared to triangular scleral flap but the difference was not statistically significant. Keywords: Trabeculectomy, Intra ocular pressure, Open angle glaucoma.

Retrospective evaluation of two-year results with a filtering trabeculotomy in comparison to conventional trabeculectomy by exact matching

Background: To compare two-year results of a filtering trabeculotomy (FTO) to conventional trabeculectomy (TE) in open-angle glaucoma by exact matching. Methods: 110 patients received an FTO and 86 a TE. FTO avoided the need for an iridectomy due to a preserved trabeculo-descemet window anterior to the scleral flap. TE employed a trabecular block excision and iridectomy. Mitomycin C was used in both. FTO and TE were exact matched by baseline intraocular pressure (IOP) and the number of glaucoma medications. Complete and qualified success (IOP ≤18 mmHg and IOP reduction ≥ 30%, with or without medication) were primary endpoints. IOP, visual acuity (BCVA), complications and intervention were secondary endpoints. Results: 44 FTO were exact matched to 44 TE. The IOP baseline in both groups was 22.5±4.7 mmHg on 3±0.9 medications. At 24 months, complete success was reached by 59% in FTO and 66% in TE, and qualified success by 59% in FTO and 71% in TE. In FTO, IOP was reduced to 12.4±4.3 mmHg at 12 months and 13.1±4.1 mmHg at 24 months. In TE, IOP was 11.3±2.2 mmHg at 12 months and 12.0±3.5 mmHg at 24 months. Medications could be reduced at 24 months to 0.6±1.3 in FTO and 0.2±0.5 in TE. There were no significant differences between the two groups in IOP, medications, complications or interventions at any point. Conclusion: Modifying aqueous flow through a limited trabeculotomy in FTO yielded clinical outcomes similar to traditional TE but allowed to avoid an iridectomy.

Wick technique in subscleral and subconjunctival Ologen™ implantation with trabeculectomy in patients with high risk of failure

Introduction: Ologen™ is traditionally placed subconjunctivally during trabeculectomy, which limits its area of action. Subscleral implantation of Ologen has been described involving fashioning a gutter beneath the scleral flap. This, however, would not prevent fibrosis at the margins of the scleral flap. We describe a modified technique of Ologen® placement that has the potential to prevent scarring at the margins of the flap withoutthe need to fashion a gutter. Materials and methods: The study involved a retrospective review of patients who had undergone trabeculectomy with Ologen implantation by the wick technique between January 2015 and August 2016. Patients judged to be at high risk of trabeculectomy failure were operated with this technique. Results: A total of six patients with median age of 38.5 years were included in the study. The mean preoperative intraocular pressure (IOP) was 30.8 ± 7.3 mmHg, which reduced to 10.6 ± 2.2 mmHg 18 months after surgery. By 18 months postoperative, all patients had IOP in the low teens (two patients required additional topical medication). One patient had two episodes of hypotony that responded to steroids and cycloplegics. Another patient required two needlings to bring IOP under control. No other complications were noted. Ultrasound biomicroscopy done 3 months after surgery showed two pieces of Ologen in one patient. Conclusions: The results of our study show that this technique may be used effectively in patients at high risk of trabeculectomy failure. Further studies in a larger number of patients with diverse high-risk conditions are required before this technique is recommended for general use.

Long-Term Stability of Sutured Scleral Fixation of a Posterior Chamber Intraocular Lens With 10-0 Polypropylene for More Than 30 Years

Purpose: We report the longest follow-up to our knowledge of stable scleral fixation of a posterior chamber intraocular lens (PC IOL) with 10-0 polypropylene sutures. Methods: A retrospective review is presented of a case with more than 30 years’ follow-up after performing sutured scleral fixation with 10-0 polypropylene suture using 2 sutures tied together under a scleral flap. One suture was a cow-hitch looped around the haptic, and the other suture was passed through the sclera to create the scleral fixation. Results: The scleral fixation with 10-0 polypropylene suture knots for both haptics of the PC IOL allowed central optic positioning with excellent vision for more than 30 years without suture breakage. Conclusions: Polypropylene sutures for scleral fixation of PC IOLs remained stable for more than 30 years with central positioning of the PC IOL, without exposure of the fixation suture knots through the conjunctiva, and without suture breakage.

A Comparison of Scleral Tunnel and Pericardial Graft Implantation Techniques in Patients undergoing Ahmed Glaucoma Valve Implantation

The purpose of this study was to compare the two methods autologous scleral flap (scleral tunnel) and pericardial patch graft of tube covered in Ahmed glaucoma valve (AGV) in refractory glaucoma with respect to the tube exposure, infection, level of Intraocular Pressure (IOP), and any other complications due to applications of each technique. A retrospective chart review of 113 eyes in 102 patients with refractory glaucoma who underwent ahmed glaucoma valve (AGV) implantation (39 eyes in scleral tunnel and scleral flap group &ldquo;first group&rdquo; and 74 eyes in pericardium graft group&rdquo; second group&rdquo;) was performed. The procedures in these eyes were performed between January 2007 and October 2015 in a tertiary eye care hospital in KSA. The mean age was 56 &plusmn; 19 (8 months- 83 years) in the Scleral tunnel group and 50 &plusmn; 27 (1- 78 years) in the Pericardium group (p = 0.023). Fifty-six males and 57 females were included in the study. Medians of the follow-up were 48 &plusmn; 25.5 months (3 &ndash; 89) for the Scleral tunnel group and 29 &plusmn; 21.4 months (2 &ndash; 92) for the Pericardium group, and it is statistically significant (P &lt; 0.001). According to the findings, preoperative diagnosis in the two groups included neovascular glaucoma (NVG) found in 21 eyes (53.8%) in the Scleral tunnel group versus 18 eyes (24.3%) in the Pericardium group (p = 0.009). Exposure of the valve was found in 15 eyes (20.27%) in Pericardium graft group versus 2 eyes (5.12%) only in scleral tunnel group (p = 0.002). These exposed valves lead to endophthalmitis in 5 cases in the second group and no single case in scleral tunnel group was detected (P &lt; 0.001). The postoperative IOP values were statistically insignificant in all different time periods. Scleral tunnel method has less exposure rate than the pericardium graft. The purpose of this study was to compare the two methods autologous scleral flap (scleral tunnel) and pericardial patch graft of tube covered in Ahmed glaucoma valve (AGV) in refractory glaucoma with respect to the tube exposure, infection, level of Intraocular Pressure (IOP), and any other complications due to applications of each technique. A retrospective chart review of 113 eyes in 102 patients with refractory glaucoma who underwent ahmed glaucoma valve (AGV) implantation (39 eyes in scleral tunnel and scleral flap group &ldquo;first group&rdquo; and 74 eyes in pericardium graft group&rdquo; second group&rdquo;) was performed. The procedures in these eyes were performed between January 2007 and October 2015 in a tertiary eye care hospital in KSA. The mean age was 56 &plusmn; 19 (8 months- 83 years) in the Scleral tunnel group and 50 &plusmn; 27 (1- 78 years) in the Pericardium group (p = 0.023). Fifty-six males and 57 females were included in the study. Medians of the follow-up were 48 &plusmn; 25.5 months (3 &ndash; 89) for the Scleral tunnel group and 29 &plusmn; 21.4 months (2 &ndash; 92) for the Pericardium group, and it is statistically significant (P &lt; 0.001). According to the findings, preoperative diagnosis in the two groups included neovascular glaucoma (NVG) found in 21 eyes (53.8%) in the Scleral tunnel group versus 18 eyes (24.3%) in the Pericardium group (p = 0.009). Exposure of the valve was found in 15 eyes (20.27%) in Pericardium graft group versus 2 eyes (5.12%) only in scleral tunnel group (p = 0.002). These exposed valves lead to endophthalmitis in 5 cases in the second group and no single case in scleral tunnel group was detected (P &lt; 0.001). The postoperative IOP values were statistically insignificant in all different time periods. Scleral tunnel method has less exposure rate than the pericardium graft.