Todd W. Perkins

Comparison of the Ahmed Glaucoma Valve, the Krupin Eye Valve with Disk, and the double-plate Molteno implant.

ObjectiveTo compare the efficacy of the nonvalved double-plate Molteno implant with two valved implants, the Krupin Eye Valve with Disc and the Ahmed Glaucoma Valve, in the treatment of recalcitrant glaucoma. Patients and MethodsThe authors performed a nonrandomized retrospective review of patients who received the Molteno implant (n = 27), Krupin Eye Valve with Disc (n = 13), or Ahmed Glaucoma Valve (n = 13), with adjunctive mitomycin C. ResultsKaplan-Meier life-table analysis showed that the Molteno implant patients were more likely to maintain an intraocular pressure between 5 and 15 mm Hg than Ahmed Glaucoma Valve patients (P = 0.03). Success rates at 1 year were 80% (95% CI, 66–97%) for the Molteno implant, 39% (19–77%) for the Krupin Eye Valve with Disc, and 35% (15–82%) for the Ahmed Glaucoma Valve. However, Ahmed Glaucoma Valve patients were less likely to experience complications requiring reoperation or loss of two or more lines of visual acuity (P < 0.01) than Molteno implant or Krupin Eye Valve with Disc patients. ConclusionsThis nonrandomized study suggests that the Molteno implant with mitomycin C is more likely to result in intraocular pressures in the lower teens than the Ahmed Glaucoma Valve with mitomycin C. The findings suggest that the Ahmed implant is less likely to create problems leading to reoperations or visual acuity loss than the Molteno or Krupin implants.

Krupin Eye Valve with Disk for Filtration Surgery

PURPOSE The authors evaluate a long posterior tube shunt device with a pressure sensitive valve for filtration surgery in eyes with recalcitrant glaucoma. METHODS The device consisted of an anterior chamber tube connected to an oval (13 x 18 mm) episcleral explant. The explant was designed to maximize the area of surrounding encapsulation while still allowing implantation within one quadrant. A pressure-sensitive and unidirectional slit valve in the tube provided resistance to aqueous humor flow. One-stage implantation without the use of restrictive sutures was performed in 50 eyes with various types of glaucoma unresponsive to prior glaucoma surgery. RESULTS Mean (+/- standard error of the mean) preoperative intraocular pressure (IOP) of 36.4 +/- 1.6 mmHg was reduced significantly (P < 0.001) to 8.3 +/- 1.3 mmHg on the first postoperative day. Mean anterior chamber depth (scale, 0-4+) was 3.4 +/- 0.1. Mean IOP 1 month after surgery was 14.1 +/- 1.3 mmHg. The implant was removed from four eyes due to IOP failure (1 eye), external erosion (2 eyes), or endophthalmitis (1 eye). A suprachoroidal hemorrhage occurred in one eye on the first postoperative day. Diplopia developed in one eye after surgery. Mean IOP at last follow-up examination (mean, 25.4 +/- 2.4 months; range, 16-36 months) was 13.1 +/- 1.3 mmHg. Intraocular pressure was 19 mmHg or lower in 80% of the eyes, 59% of which were without adjunctive antiglaucoma medications. CONCLUSIONS Design features of the Krupin Eye Valve with Disk result in a large area of encapsulation in a single ocular quadrant which functions as an external reservoir for passage of aqueous humor. The valve portion facilitates maintenance of anterior chamber depth during the early postoperative interval. This new therapeutic device can be effective in the long-term control of IOP in glaucomatous eyes not responsive to prior filtration surgery with adjunctive antimetabolite therapy.

Trabeculectomy with Mitomycin C: Intermediate-Term Results

PURPOSE This study was performed to provide results 2 to 3 years after trabeculectomy with mitomycin C (MMC). METHODS A consecutive series of all 68 patients who underwent trabeculectomy with MMC was analyzed using Kaplan-Meier life-table statistics and compared with other published retrospective analyses. RESULTS At 2- and 3-year follow-up examinations, 59% (95% confidence interval [CI], 44-70%) and 47% (95% CI, 32-61%) of patients, respectively, avoided an intraocular pressure (IOP) of more than 21 mmHg or less than 20% below their preoperative level without glaucoma medication on two consecutive occasions more than 1 month apart after 3 months follow-up (75% [95% CI, 60-84%] and 70% [95% CI, 53-81%], respectively, with medication) and avoided additional glaucoma surgery. Loss of more than three lines of visual acuity on two occasions more than 1 month apart after 3 months follow-up occurred in 28% of patients (> 2 lines in 44%) at 3 years. Nonreversible causes of loss of three lines of acuity occurred in 13% of patients. Complications requiring reoperation occurred in 16% of patients and included hypotony maculopathy (4%) and late bleb leaks (4%). CONCLUSIONS At the 3-year follow-up evaluation, trabeculectomy with MMC provided an approximately 50% chance of maintaining IOPs less than 21 mmHg and a more than 20% IOP reduction without concomitant use of glaucoma medication, which increased to 70% with the addition of medication. This procedure was associated with an approximately 30% risk of substantial visual loss (approximately 15% nonreversible) and a 15% chance of reoperation for complications.

Molteno Implant With Mitomycin C: Intermediate-Term Results

PURPOSE The authors examine the intermediate-term effects of adjunctive intraoperative mitomycin C (MMC) in a cohort of patients who received double-plate Molteno implants for complicated glaucomas. METHODS A consecutive series of 21 patients who received MMC 0.5 mg/ml for 5 minutes as an adjunct to a double-plate Molteno implant was compared by life-table analysis to a historical control group of 18 patients who received either no adjunct or 5-fluorouracil (5-FU) but no MMC. RESULTS At three years follow-up, 35% (95% confidence interval (CI), 15-57%) of patients who received MMC avoided failure criteria of intraocular pressure (IOP) less than 6 mm Hg or more than 21 mm Hg, addition of glaucoma medication, reoperation for glaucoma, or tube removal. Seventeen percent (95% CI, 4-37%) of patients in the control group at three years follow-up met similar criteria (p = 0.039). No late complications of tube erosion were seen in the MMC group. CONCLUSION Intraoperative MMC offers an increased likelihood of a two- to three-year period of medication-free IOP control in patients undergoing double-plate Molteno implants, compared to similar patients receiving 5-FU or no adjunctive antimetabolite therapy.

The rarity of clinically significant rise in intraocular pressure after laser peripheral iridotomy with apraclonidine

OBJECTIVE To determine the incidence of intraocular pressure (IOP) rise of varying degrees after laser peripheral iridotomy (LPI) in patients with and without glaucoma treated perioperatively with pilocarpine and apraclonidine. DESIGN A retrospective chart review. PARTICIPANTS A total of 289 eyes in 179 patients with narrow occludable angles (NOA) (N = 148), open-angle glaucoma or ocular hypertension (OAG) (N = 115), or chronic-angle closure glaucoma (CACG) (N = 26) were reviewed. MAIN OUTCOME MEASURES The difference between preoperative and postoperative IOP, absolute postoperative IOP, and the need for acute IOP-lowering treatment was noted. RESULTS Only 1.1% (95% confidence interval [CI], 0.03%-5.8%; 1 of 94) of patients and 0.7% (95% CI, 0.02%-3.7%; 1 of 148) of eyes with NOA experienced a rise of more than 10 mmHg 1 to 2 hours after LPI. The incidence of postoperative IOP greater than 25 mmHg and acute postoperative IOP-lowering management was 0% (95% CI, 0%-3.8%). Intraocular pressure in 1 of 115 eyes (0.9%, 95% CI, 0.02%-4.7%) with OAG rose more than 10 mmHg, requiring acute treatment. None of the 26 CACG eyes experienced a rise of more than 10 mmHg (95% CI, 0%-13.2%). CONCLUSION The IOP rise that requires further intervention after LPI with the perioperative use of pilocarpine and apraclonidine is very uncommon. In patients with NOA, routine postiridotomy IOP monitoring may not be required.

Recalcitrant Diplopia After Implantation of a Krupin Valve With Disc

We report, to our knowledge, the first case of a patient experiencing recalcitrant diplopia after implantation of a Krupin valve with disc for uncontrolled glaucoma. Despite multiple surgeries and adjustments in her glasses, the patient was left with residual and intolerable diplopia.

Ocular motility defects in patients with the krupin valve implant

To determine the prevalence of ocular motility defects following placement of a Krupin valve with disk and adjunctive mitomycin-C in glaucoma patients, a retrospective case series of all patients receiving a Krupin valve with disk and intraoperative mitomycin-C in a university-based referral practice was conducted. Each of the seven consecutive patients undergoing placement of a Krupin valve with disk in one eye because of uncontrolled glaucoma, developed significant primary position heterotropia or limitation of ocular rotations. One patient had significant postoperative diplopia. We conclude that the Krupin valve with disk used with intraoperative mitomycin-C can be associated with the development of ocular motility defects. The limitation of rotations appears to relate to the combined mechanisms of implant and cyst bulk and the displacement of the oculorotary muscles by the encapsulating cyst.