Comparison of Outcomes Following Glaucoma Drainage Tube Surgery Between Primary and Secondary Glaucomas, and Between Phakic and Pseudophakic eyes.

PURPOSE: To report outcomes of glaucoma drainage device (GDD) surgery based on primary or secondary glaucoma diagnosis and lens status. DESIGN: Single-center, retrospective, consecutive cohort study. METHODS: University of Florida patients aged 18 to 93 years who underwent nonvalved GDD surgery between 1996 and 2015 with a minimum of 1-year follow-up were examined. Of the 186 eyes of 186 patients enrolled, 108 had a primary glaucoma and 78 a secondary glaucoma diagnosis. Excluding 13 aphakic patients, 57 eyes were phakic and 116 pseudophakic. Mean intraocular pressure (IOP), mean number of medications, visual acuity (VA), surgical complications, and failure (IOP ≥18 mm Hg, IOP <6 mm Hg, reoperation for glaucoma, or loss of light perception) were the main outcome measures. RESULTS: No significant difference was noted in mean IOP and mean medication use (12.8 ±â€Š4.5 and 13.0 ±â€Š6.6 mm Hg on 2.0 ±â€Š1.2 and 1.5 ±â€Š1.1 medication classes, respectively), mean VA (1.08 ±â€Š0.98 and 0.94 ±â€Š0.89, respectively), failure, or numbers of complications and reoperations (P > 0.05) between eyes with primary and secondary glaucomas at up to 5 years postoperatively. Comparison of phakic and pseudophakic eyes showed a statistically significant higher success rate for the pseudophakic patient group at the ≥18 mm Hg upper limit and <6 mm Hg lower limit (P = 0.01), and significantly fewer eyes required reoperation to lower IOP (6.9% vs 23%). CONCLUSIONS: GDD surgery appears equally effective for secondary glaucomas as for primary glaucomas, and has a better outcome for pseudophakic eyes than phakic eyes.

Comparison of Outcomes of Glaucoma Drainage Implant Surgery With or Without Prior Failed Trabeculectomy.

PRECIS: A comparison of 186 glaucoma patients with mixed diagnoses who underwent nonvalved glaucoma drainage device (GDD) implant surgery showed similar long-term intraocular pressure (IOP), medication, and visual acuity (VA) outcomes between those with prior failed trabeculectomy surgery versus those without. PURPOSE: The purpose of this study was to evaluate whether prior failed trabeculectomy adversely affects the outcome of glaucoma tube surgery. PATIENTS AND METHODS: A total of 186 eyes of 186 patients who underwent a nonvalved GDD implant surgery by a single surgeon between 1996 and 2015 at a University practice were included. Patients were of mixed diagnoses and over 18 years old. Before the GDD surgery, 65 had a previous failed glaucoma filtering surgery and 121 had no prior glaucoma surgery. Demographic information, preoperative and postoperative IOP, medication, VA, and complications were collected from chart review. RESULTS: No significant difference was noted in mean IOP and mean medication use (13.0 and 12.6 mm Hg on 2.0 and 1.7 medication classes at 5 y postoperatively, respectively), mean VA and change in VA from baseline, or numbers of complications (P>0.05), between eyes that had a prior failed filtration surgery and those that had not. Kaplan-Meier plots for failure over 5 years using a lower limit of <5 mm Hg and an upper limit of ≥18, ≥15, or ≥12 mm Hg did not show a significant difference between groups. Subanalyses were performed to examine only primary glaucoma eyes and results were similar. Further group subanalyses comparing those with baseline IOP ≥25 or <25 mm Hg, age 65 and above or below 65 years and those specifically with Baerveldt 350 mm2 implants also did not show significant differences. CONCLUSION: Prior failed filtration surgery does not appear to affect the outcome of future GDD surgery.

Attaining Intraocular Pressure of ≤10 mm Hg: Comparison of Tube and Trabeculectomy Surgery in Pseudophakic Primary Glaucoma Eyes.

PURPOSE: The aim of this study is to evaluate whether trabeculectomy with antimetabolites or glaucoma drainage device (GDD) surgery is more likely to achieve an intraocular pressure (IOP) ≤10 mm Hg. DESIGN: Retrospective, nonrandomized, cohort study of pseudophakic, primary glaucoma patients. METHODS: 53 pseudophakic patients underwent trabeculectomy and 65 received GDD at the University of Florida by one surgeon between 1993 and 2015. The main outcome measures were mean IOP and percentage of patients obtaining an IOP ≤10 mm Hg for up to 5 years postoperatively. A subgroup undergoing a first time glaucoma surgery was also analyzed because there were more redo glaucoma procedures in the GDD group. RESULTS: Over 5 years, the mean annual IOP for the trabeculectomy eyes was between 6.9 and 7.8 mm Hg on an average of 0.2 medications, and that for GDD eyes was between 11.4 and 12.1 mm Hg on a mean of 1.6 to 1.9 medications (P < 0.002). A significantly higher percentage of trabeculectomy eyes than GDD eyes achieved a pressure of ≤10 mm Hg, for years 1 to 4 (P < 0.05). Visual acuity (VA) change was not statistically different between the groups, both for mean logMAR acuity and percentage of patients that lost ≥2 Snellen lines. Complication rates were similar between the groups. Postoperative VA change was similar for eyes achieving low IOP ≤5 mm Hg and those eyes with an IOP ≥10 mm Hg. CONCLUSIONS: Trabeculectomy provided significantly lower IOP for 5 years postoperatively in pseudophakic primary glaucoma patients, and was more likely to achieve an IOP ≤10 mm Hg.

The impact of conjunctival flap method and drainage cannula diameter on bleb survival in the rabbit model.

PURPOSE: To examine the effect of cannula diameter and conjunctival flap method on bleb survival in rabbits undergoing cannula-based glaucoma filtration surgery (GFS). METHODS: Twelve New Zealand White rabbits underwent GFS in both eyes. The twenty-four eyes were divided into four groups. Two of the four groups (N = 12) received limbus-based conjunctival flaps (LBCF), and the other two (N = 12) received fornix-based conjunctival flaps (FBCF). Six FBCF rabbit eyes were implanted with 22-gauge drainage tubes, and the other six were implanted with 26-gauge tubes. Likewise, six LBCF rabbits received 22-gauge drainage tubes and six received 26-gauge tubes. Filtration blebs were evaluated every three days by a masked observer. Bleb failure was defined as the primary endpoint in this study and was recorded after two consecutive flat bleb evaluations. RESULTS: Group 1 (LBCF, 22- gauge cannula) had a mean bleb survival time (Mean ± SD) of 18.7 ± 2.9 days. Group 2 (LBCF, 26-gauge cannula) also had a mean bleb survival time of 18.7 ± 2.9 days. Group 3 (FBCF, 22-gauge cannula) had a mean bleb survival time of 19.2 ± 3.8 days. Group 4 (FBCF, 26-gauge cannula) had a mean bleb survival time of 19.7 ± 4.1 days. A 2-way analysis of variance showed that neither surgical approach nor cannula gauge made a statistically significant difference in bleb survival time (P = 0.634 and P = 0.874). Additionally, there was no significant interaction between cannula gauge and conjunctival flap approach (P = 0.874), suggesting that there was not a combination of drainage gauge and conjunctival flap method that produced superior bleb survival. CONCLUSION: Limbus and fornix-based conjunctival flaps are equally effective in promoting bleb survival using both 22 and 26-gauge cannulas in the rabbit model. The 26-gauge drainage tube may be preferred because its smaller size facilitates the implantation process, reducing the risk of corneal contact.

Comparing glaucomatous disc change using stereo disc viewing and the MatchedFlicker programme in glaucoma experts and trainees.

BACKGROUND/AIMS: The objective of this study is to evaluate the accuracy and speed of trainees and experienced glaucoma specialists using the MatchedFlicker software against the manual examination of stereoscopic disc photographs for detecting glaucomatous optic disc change. METHODS: Three experienced glaucoma specialists, two resident ophthalmologists and one glaucoma fellow from multiple institutions independently evaluated the same 140 image pairs from 100 glaucomatous/ocular hypertensive eyes using a handheld stereo viewer and the MatchedFlicker programme. Fifty had progression to glaucoma as determined by the Ocular Hypertension Treatment Study (OHTS) Optic Disc Reading Group and endpoint committee, and 50 more were negative controls for progression with photos taken a few minutes apart. Twenty photo pairs from each of the two groups were duplicated for reviewer variability analysis. The initial viewing method was randomised and then alternated for each group of 70 image pairs. Reviewer accuracy and evaluation time for each method were measured. RESULTS: Evaluators averaged 8.6 s faster per image pair (26%) with the MatchedFlicker programme than with the stereo viewer (p=0.0007). Evaluators correctly identified more image pairs when using the MatchedFlicker software over the stereo viewer (p=0.0003). There was no significant difference between the expert and trainee group in speed or overall accuracy for either method. Experts were significantly more consistent than trainees with the duplicate image pairs (p=0.029). Trainees appeared more reluctant to designate eyes as showing glaucoma progression than experts. CONCLUSIONS: Both expert glaucoma specialists and ophthalmologists in various stages of training had greater accuracy and speed with the MatchedFlicker programme than with a handheld stereoscopic viewer.

Retrospective Comparison of Intermediate-term Efficacy of 350 mm2 Glaucoma Drainage Implants and Medium-sized 230-250 mm2 Implants.

AIM: To compare the intermediate-term efficacy of a large surface area Baerveldt 350 mm2 glaucoma drainage device (GDD) with medium surface area implants (Baerveldt 250 mm2 and Molteno 3, 230, or 245 mm2). DESIGN: This is a retrospective, nonrandomized comparative trial. MATERIALS AND METHODS: A total of 94 eyes of 94 patients of mixed glaucoma diagnoses without any prior glaucoma surgical procedures and who had undergone a glaucoma drainage implant surgery with either a large Baerveldt 350 mm2 GDD or a medium-sized GDD (Baerveldt 250 mm2 or Molteno 230 or 245 mm2) were reviewed for intraocular pressure (IOP), number of glaucoma medications, and visual acuity (VA) preoperatively, and at 1, 2, and 3 years postprocedure. RESULTS: No significant differences were found in mean IOP, number of glaucoma medications used, and VA at 1, 2, and 3 years postoperatively. The rate of additional glaucoma procedures was similar between the two groups. CONCLUSION: There is no clear evidence that a larger implant surface area beyond 230 to 250 mm2 is advantageous in providing intermediate-term IOP control. CLINICAL SIGNIFICANCE: It may be technically easier to surgically place a GDD that does not need to have its wings placed underneath the recti muscles, and the IOP results are similar. HOW TO CITE THIS ARTICLE: Meyer AM, Rodgers CD, Zou B, Rosenberg NC, Webel AD, Sherwood MB. Retrospective Comparison of Intermediate-term Efficacy of 350 mm2 Glaucoma Drainage Implants and Medium-sized 230-250 mm2 Implants. J Curr Glaucoma Pract 2017;11(1):8-15.

Relationship between Glaucoma Drainage Device Size and Intraocular Pressure Control: Does Size Matter?

There is ambiguity in the literature regarding whether a larger glaucoma drainage device (GDD) achieves a lower long-term intraocular pressure (IOP). There is some evidence on both sides, but overall there seems to be an optimal surface area of approximately 200-250 mm2 beyond which there may be little advantage to increasing the plate size for most patients. HOW TO CITE THIS ARTICLE: Rodgers CD, Meyer AM, Sherwood MB. Relationship between Glaucoma Drainage Device Size and Intraocular Pressure Control: Does Size Matter? J Curr Glaucoma Pract 2017;11(1):1-2.

Comparing Glaucomatous Disc Change Using Stereo Disc Viewing and the MatchedFlicker Software Program in Ophthalmologists-in-Training.

PURPOSE: To compare the accuracy and speed of using the computerized MatchedFlicker software program (EyeIC Inc, Narberth, Pennsylvania, USA) to evaluate glaucomatous optic disc change against the traditional gold standard of manually examining stereoscopic disc photographs. DESIGN: A prospective evaluation of diagnostic technology. METHODS: Two resident ophthalmologists and 1 glaucoma fellow at the University of Florida independently evaluated 140 image pairs from 100 glaucomatous/ocular hypertensive patient eyes using a handheld stereo viewer and the MatchedFlicker program. Fifty had progression to glaucoma as determined by the Ocular Hypertension Treatment Study (OHTS) Optic Disc Reading Group and the OHTS Endpoint Committee in the OHTS, and 50 more had photographs taken a few minutes apart, which were negative controls with no progression. Twenty photograph pairs from each group were duplicated to determine reviewer variability. Photographs were examined in alternating blocks of 70 photograph pairs for each method, with the starting viewing method randomized. Reviewer accuracy and time to review for each method were measured. RESULTS: Using the handheld stereo viewer, the reviewers correctly identified progression or nonprogression in 76.0% of the slide pairs. Using the MatchedFlicker software, 87.6% were correctly identified (P = .011). Evaluator speed averaged 34.1 seconds per image pair with the stereo viewer vs 24.9 seconds with the MatchedFlicker program (P = .044). Overall, Flicker was significantly more specific but less sensitive than stereo slides. Trainees appeared more reluctant to identify glaucoma progression from slides than from Flicker. For the 2 less experienced trainees Flicker was significantly more accurate. CONCLUSION: The MatchedFlicker software had a greater accuracy and was quicker to perform than using a handheld stereoscopic viewer.