Intraocular pressure on the first postoperative day as a prognostic indicator in phacoemulsification combined with deep sclerectomy

ARTICLE

Intraocular pressure on the first postoperative day as a prognostic indicator in phacoemulsification combined with deep sclerectomy Jorge L. Garcı´a-Pe´rez, MD, Gema Rebolleda, MD, PhD, Francisco J. Mun˜oz-Negrete, MD, PhD

PURPOSE: To study the intraocular pressure (IOP) as a prognostic indicator on the first day after combined phacoemulsification and nonpenetrating deep sclerectomy. SETTING: Ramo´n y Cajal Hospital, Madrid, Spain. METHODS: This retrospective study included 70 eyes of 70 patients who had combined phacoemulsification–nonpenetrating deep sclerectomy with a reticulated hyaluronic acid implant. Visual acuity, IOP, and slitlamp examinations were performed preoperatively and 1 and 7 days and 1, 3, 6, 12, and 24 months postoperatively. A split point of 9.0 mm Hg on the first postoperative day was used. Success probability analysis was performed using a Kaplan-Meier survival curve. The need for medication and postoperative neodymium:YAG goniopuncture was also recorded. RESULTS: The mean preoperative IOP was 22.5 mm Hg G 5.2 (SD). The mean postoperative IOP was 11.6 G8.1 mm Hg, 16.4 G 4.7 mm Hg, and 17.0 G 5.3 SD mm Hg at 1 day, 12 months, and 24 months, respectively. A greater success rate was observed in terms of survival (P Z .006, log rank test) in patients with an IOP of 9 mm Hg or less on the first postoperative day; these patients also had a significantly reduced need for glaucoma treatment (P Z .015) and goniopuncture (P Z .009). CONCLUSION: An IOP of 9 mm Hg or less on the first postoperative day might serve as a positive prognostic indicator in combined phacoemulsification with deep sclerectomy. J Cataract Refract Surg 2008; 34:1374–1378 Q 2008 ASCRS and ESCRS

The incidence of open-angle glaucoma increases with patient age, and cataract and glaucoma frequently develop in the same patient. In addition, there is an increased risk for cataract in patients with glaucoma, and glaucoma surgery significantly increases the risk for development of cataracts.1 For these reasons, there has been an increasing trend toward performing

Accepted for publication April 14, 2008. Ramo´n y Cajal Hospital (Garcı´a-Pe´rez, Rebolleda, Mun˜oz-Negrete), Madrid, and Alcala´ University (Rebolleda, Mun˜oz-Negrete), Alcala´ de Henares, Spain. No author has a financial or proprietary interest in any material or method mentioned. Presented as a poster at the annual meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, USA, May 2007. Corresponding author: Jorge L. Garcı´a-Pe´rez, MD, c/Jazmı´n 52 B 1 3, 28033, Madrid, Spain. E-mail: [email protected].

1374

Q 2008 ASCRS and ESCRS Published by Elsevier Inc.

a combined procedure for both diseases. Nevertheless, the decision to do sequential or combined cataract and glaucoma surgery depends on several individual patient factors including the degree of visual impairment, target intraocular pressure (IOP), stage of glaucoma, and patient age and life expectancy.2 Deep sclerectomy and viscocanalostomy are nonpenetrating filtration procedures to surgically treat glaucoma. Isolated or combined with phacoemulsification, both procedures may offer good success rates, minimizing the risk for postoperative complications associated with trabeculectomy or phacotrabeculectomy.3–10 Regarding the efficacy of these nonpenetrating filtration procedures, the results are controversial.4,11 Recently, Shaarawy et al.12 found that variability in the results of deep sclerectomy was associated with differences in the mean IOP achieved on the first postoperative day. After a prospective study that included 105 patients with medically refractory glaucoma, the IOP on the first postoperative day was considered a prognostic indicator in isolated deep sclerectomy. 0886-3350/08/$dsee front matter doi:10.1016/j.jcrs.2008.04.025

IOP AFTER COMBINED PHACOEMULSIFICATION AND DEEP SCLERECTOMY

The purpose of the current study was to evaluate whether the IOP value 24 hours after combined phacoemulsification–nonpenetrating deep sclerectomy can also be considered a prognostic indicator. PATIENTS AND METHODS A retrospective study of 70 consecutive eyes of 70 patients who had combined phacoemulsification–nonpenetrating deep sclerectomy with a reticulated hyaluronic acid implant (SKGel, Laboratoires Corne´al) between April 2002 and October 2004 was performed. The indications for combined surgery included a best corrected visual acuity (BCVA) of 0.5 or worse, cataract, and medically uncontrolled glaucoma. Uncontrolled glaucoma was defined as IOP greater than 21 mm Hg on maximum tolerated medical treatment with well-documented progression of visual field defects and optic nerve morphology. Patients who were noncompliant with or intolerant of glaucoma medications were also scheduled for combined phacoemulsification–nonpenetrating deep sclerectomy, despite controlled IOP. Previously operated eyes and those with closed-angle, uveitic, juvenile, neovascular, or phacomorphic glaucoma were excluded as were eyes with a large intraoperative perforation of the trabeculo– Descemet membrane. The study was approved by the hospital’s institutional review board. The variables recorded were IOP using a Goldmann applanation tonometer, BCVA, and number of glaucoma medications preoperatively as well as 1 and 7 days and 1, 3, 6, 12, and 24 months postoperatively. The number of patients having neodymium:YAG (Nd:YAG) goniopuncture or starting medications postoperatively was also recorded. Patients were divided into 2 groups according to the IOP on the first postoperative day. The halfway point (the split point) in the distribution of IOP 24 hours after surgery was 9 mm Hg. Group 1 included patients whose day 1 postoperative IOP was 9 mm Hg or less. Group 2 included patients with an IOP greater than 9 mm Hg. Both groups comprised 35 patients. The 2 groups were examined in relation to the success rate and need for medication and subsequent Nd:YAG goniopuncture. Complete success was defined as an IOP less than 18 mm Hg without additional glaucoma medication. Failure was defined as an IOP exceeding 18 mm Hg, severe hypotony (IOP %4 mm Hg), the need for glaucoma medications, or the need for additional surgery. Intraoperative and postoperative complications were recorded. Patients with complications related to phacoemulsification were not excluded from the statistical analysis.

Surgical Technique All surgical procedures were performed by 1 of 2 surgeons (G.R., F.J.M.) using retrobulbar anesthesia. In all cases, a fornix-based conjunctival flap was created, the sclera exposed, and hemostasis by wet-field cautery performed. A one-third scleral thickness superficial flap (5.0 mm  5.0 mm) was dissected at the 12 o’clock position at least 1.0 mm into clear cornea. A second deep scleral flap was dissected and before Schlemm canal was entered, phacoemulsification was performed through a right horizontal clear corneal incision. A high-density ophthalmic viscosurgical device (OVD) (sodium hyaluronate 1% [Healon]) was used during all surgeries.

1375

After cataract surgery, Schlemm canal was deroofed and a trabeculo–Descemet membrane window created. The deep scleral flap was excised, the juxtacanalicular trabeculum and Schlemm endothelium were removed with a small blunt forceps (ab externo trabeculectomy), and a reticulated hyaluronic acid implant (SKGel) was placed on the scleral bed. The superficial scleral flap was sutured with 2 to 4 interrupted 10-0 nylon buried sutures. When a large intraoperative perforation of the trabeculo– Descemet membrane occurred, surgery was transformed into a standard trabeculectomy. The surgical outcomes in patients who had a large perforation of the trabeculo–Descemet membrane were not analyzed. When the IOP did not reach the preset target, goniopuncture was performed using an Nd:YAG laser in the thinnest anterior portion of the trabeculo–Descemet membrane.

Statistical Analysis The patients in both groups were compared to analyze differences in the proportion of men and woman, patient age, preoperative IOP, and medications used previously. The preoperative IOP, age, and number of glaucoma medications were compared, and longitudinal comparisons of the IOP values were performed using the Mann-Whitney U test. The chi-square test was used to compare the sex distribution and need for glaucoma medications and postoperative Nd:YAG goniopuncture between groups. A Kaplan-Meier survival curve was used for success probability analysis. SPSS for Windows (version 13.0 (SPSS, Inc.) was used in all statistical analyses. A P value of 0.05 or less was considered statistically significant.

RESULTS The mean preoperative IOP in all eyes was 22.5 mm Hg G 5.2 (SD). The decrease in IOP was statistically significant at all follow-up time points (P Z .000). Postoperatively, IOP decreased by a mean of 10.9 G 9.4 mm Hg at 1 day, 7.24 G 5.9 mm Hg at 6 months, 6.13 G 5.2 mm Hg at 12 months, and 5.51 G 4.3 mm Hg at 24 months. The need for glaucoma medications decreased from 1.90 G 0.75 to 0.38 G 0.68 after 2 years of follow-up (P Z .000). Forty-four eyes (62.8%) did not require treatment at the last follow-up. Goniopuncture was performed in 22 eyes (31.4%). Table 1 shows the preoperative patient data. There were no statistically significant differences between groups in mean age, sex, preoperative IOP, or number of medications used. Figure 1 shows the evolution of mean IOP in both groups over time. At the last visit, the mean IOP was 15.34 G 3.66 mm Hg in Group 1 (IOP 1 day postoperatively % 9 mm Hg) and 18.8 G 4.35 mm Hg in Group 2 (IOP 1 day postoperatively O9 mm Hg) (P Z .010). The IOP remained significantly lower in Group 1 than in Group 2 at all follow-up time points (P%.05). Figure 2 show the long-term success probabilities using a Kaplan-Meier survival curve. In Group 1, the complete success rate was 89.4%, 81.3%, and 73.5% at 6 months, 12 months, and 24 months, respectively.

J CATARACT REFRACT SURG - VOL 34, AUGUST 2008

1376

IOP AFTER COMBINED PHACOEMULSIFICATION AND DEEP SCLERECTOMY

Table 1. Preoperative patient characteristics by group.

Parameter Eyes, n Sex, n Female Male Age (y) Mean G (SD) Range Type of glaucoma, n (%) POAG PEXG NTG Preop IOP (mm Hg) Mean G (SD) Range Preop medications, n Mean G (SD) Range

Group 1 Group 2 (1 D IOP (1 D IOP P %9 mm Hg) O9 mm Hg) Value 35

35

1

12 23

14 21

.81 .76 .34

81 G 8.3 49–91

79.1 G 7.7 50–88

30 (85.7) 5 (14.2) 0

31 (88.5) 3 (8.5) 1 (2.8)

22.7 G 6.7 16–48

23.16 G 7.3 15–51

1.93 G 0.7 0–3

1.87 G 0.6 0–3

.82 .13 1 .42

.75

IOP Z intraocular pressure; PEXG Z pseudoexfoliation glaucoma; POAG Z primary open-angle glaucoma

In Group 2, the complete success rate was 52.6%, 48.4%, and 45.3%, respectively. The P value for the log rank test was 0.006. At the end of follow-up, patients with an IOP of 9 mm Hg or lower on the first postoperative day required fewer antiglaucoma medications (6 patients, 17%) than those with an IOP exceeding 9 mm Hg (13 patients, 37%) (P Z .015). Goniopuncture was performed in 5 patients (14%) in Group 1 and 15 patients (43%) in Group 2 (P Z .009). Table 2 shows the intraoperative and postoperative complications. There was no statistically significant difference in the rate of complications between the 2 groups.

Figure 1. Mean IOP G SD before and after combined phacoemulsification–nonpenetrating deep sclerectomy in Group 1 (24 h IOP %9 mm Hg) and Group 2 (24 h IOP O9 mm Hg) (IOP Z intraocular pressure).

DISCUSSION Deep sclerectomy alone or combined with phacoemulsification can achieve success rates comparable to those of trabeculectomy or phacotrabeculectomy with less risk for postoperative complications.3–10 There is no evidence of differences in the success rates or postoperative IOP between phacoemulsification combined with viscocanalostomy or with deep sclerectomy or with trabeculectomy.2,6–10 In contrast to trabeculectomy, nonpenetrating filtering surgery does not appear to be compromised in IOP-lowering efficacy or success rates when combined with phacoemulsification and intraocular lens implantation.13 In the current study, combined phacoemulsification–nonpenetrating deep sclerectomy was found to be a successful filtering procedure. There was a significant reduction in IOP at all postoperative visits. The mean IOP reduction was 10.9 mm Hg on the first postoperative day and 7.24 mm Hg, 6.13 mm Hg, and 5.51 mm Hg at 6 months, 12 months, and 24 months, respectively. The use of glaucoma medications also decreased significantly after surgery. These results are similar to those described previously.14 In a prospective trial of deep sclerectomy, Shaarawy et al.12 found that patients with an IOP of 5 mm Hg or lower on the first postoperative day had a longer mean time to failure and significantly fewer Nd:YAG goniopunctures. We evaluated 70 consecutive eyes to analyze whether the IOP value 24 hours after combined phacoemulsification–nonpenetrating deep sclerectomy could be used similarly as a prognostic indicator. In this sample, the median IOP on the first postoperative day was 9 mm Hg. A possible explanation for this

Figure 2. Kaplan-Meier survival curve of long-term success probabilities.

J CATARACT REFRACT SURG - VOL 34, AUGUST 2008

IOP AFTER COMBINED PHACOEMULSIFICATION AND DEEP SCLERECTOMY

Table 2. Surgical complications after phacoemulsification combined with nonpenetrating deep sclerectomy. Number (%)

Complication Posterior capsule rupture Iris incarceration Shallow anterior chamber Fibrin Hyphema Transient wound leak Serous choroidal detachment Hypotony

Group 1 Group 2 (1 D IOP (1 D IOP P %9 mmHg) O9 mm Hg) Value 2 (5.7) 0 1 (2.8) 0 2 (5.7) 3 (8.5) 4 (11.4) 4 (11.4)

1 (2.8) 2 (5.7) 1 (2.8) 2 (5.7) 3 (8.5) 2 (5.7) 2 (5.7) 1 (2.8)

.6 .4 1 .4 .7 .6 .2 .09

IOP Z intraocular pressure

greater value in combined glaucoma and cataract surgery might be OVD retention after phacoemulsification. Histopathologic studies of the trabeculo– Descemet membrane in enucleated eyes show that aqueous percolation mainly occurs at the level of the trabeculum and to a much lower extent at Descemet membrane.12 In the current study, a high-density OVD was used in all cataract surgeries. The trabeculo–Descemet membrane offers outflow resistance that may delay the exit of the remaining high-density OVD after combined phacoemulsification–nonpenetrating deep sclerectomy; thus, the immediate postoperative IOP could be higher after combined surgery. Our results showed that the IOP remained significantly lower in patients in Group 1 (first postoperative day IOP %9 mm Hg) at all follow-up evaluations. The mean postoperative IOP in this group was 5.1 mm Hg. In these patients, there was also a significantly longer time to failure, fewer antiglaucoma medications required, and a lower likelihood of a need for Nd:YAG goniopuncture. As with isolated deep sclerectomy, a possible explanation is that after nonperforating filtration surgery, the main postoperative outflow resistance is at the trabeculo–Descemet membrane, which offers a reproducible postoperative IOP (Mermoud A, Vandaux J. IOVS 1997; 38(4):ARVO Abstract 4967).15 Therefore, the low IOP on the first postoperative day probably signifies adequate inner scleral flap dissection and juxtacanalicular trabecular meshwork removal. However, we lack histopathologic or ultrasonic biomicroscopic studies to support this hypothesis. Recently, a significant inverse correlation between the mean postoperative IOP 6 months after deep sclerectomy or combined phacoemulsification–nonpenetrating deep sclerectomy and the surface, volume,

1377

and weight of the deep scleral flap has been reported.16 Those preliminary results suggest that, at least in the early postoperative period, the mean postoperative IOP could be an indicator of adequate inner scleral flap dissection. Other surgical features may be related to a lower mean IOP in the first postoperative day. These include the presence of microperforations of the trabeculo– Descemet membrane and a larger than usual trabeculo– Descemet membrane window. Future studies are required to prove these hypotheses. The presence of postoperative complications can influence the final results. However, there was no significant difference in the rate of intraoperative and postoperative complications between the 2 groups in our study. The only trend we observed was a greater rate of hypotony in Group 1, and the trend was not significant. Surgeon experience is another important issue. There is a long learning curve for this surgical procedure, fundamentally because of the difficulty of achieving an adequate surgical dissection.17 To define complete success, we used strict criteria (ie, a postoperative IOP of 18 mm Hg or less without medication) because higher levels of IOP may not be sufficient to control progression in eyes with advanced glaucoma.18 The current study was limited by the retrospective design. Nevertheless, based on our results, it appears that the IOP on the first postoperative day could be considered a prognostic indicator in combined phacoemulsification with deep sclerectomy. In the present study, the SKGel implant was used in all cases. It would be interesting to know whether first-day IOP could also be considered a prognostic factor when other implants with or without antimetabolites are used. A prospective trial with long-term follow-up is required to confirm these findings. The trial should also evaluate potential intraoperative factors related to lower postoperative IOP such as the size of the trabeculo–Descemet window or the presence of intraoperative microperforations. REFERENCES 1. Verges C, Cazal J, Lavin C. Surgical strategies in patients with cataract and glaucoma. Curr Opin Ophthalmol 2005; 16:44–52 2. Funnell CL, Clowes M, Anand N. Combined cataract and glaucoma surgery with mitomycin C: phacoemulsification-trabeculectomy compared to phacoemulsification-deep sclerectomy. Br J Ophthalmol 2005; 89:694–698 3. Lachkar Y, Hamard P. Nonpenetrating filtering surgery. Curr Opin Ophthalmol 2002; 13:110–115 4. El Sayyad F, Helal M, El-Kholify H, Khalil M, El-Maghraby A. Nonpenetrating deep sclerectomy versus trabeculectomy in bilateral primary open-angle glaucoma. Ophthalmology 2000; 107:1671–1674

J CATARACT REFRACT SURG - VOL 34, AUGUST 2008

1378

IOP AFTER COMBINED PHACOEMULSIFICATION AND DEEP SCLERECTOMY

5. Mermoud A, Schnyder CC, Sickenberg M, Chiou AGY, He´diguer SEA, Faggioni R. Comparison of deep sclerectomy with collagen implant and trabeculectomy in open-angle glaucoma. J Cataract Refract Surg 1999; 25:323–331 6. Gianoli F, Schnyder CC, Bovey E, Mermoud A. Combined surgery for cataract and glaucoma: phacoemulsification and deep sclerectomy compared with phacoemulsification and trabeculectomy. J Cataract Refract Surg 1999; 25:340–346 7. Di Staso S, Taverniti L, Genitti G, Marangolo L, Aiello A, Giuffre´ L, Balestrazzi E. Combined phacoemulsification and deep sclerectomy vs phacoemulsification and trabeculectomy. Acta Ophthalmol Scand 2000; 232:59–60 8. Cillino S, Di Pace F, Casuccio A, Calvaruso L, Morreale D, Vadala` M, Lodato G. Deep sclerectomy versus punch trabeculectomy with or without phacoemulsification; a randomized clinical trial. J Glaucoma 2004; 13:500–506 9. Wishart MS, Shergill T, Porooshani H. Viscocanalostomy and phacoviscocanalostomy: long-term results. J Cataract Refract Surg 2002; 28:745–751 10. Gimbel HV, Anderson Penno EE, Ferensowicz M. Combined cataract surgery, intraocular lens implantation, and viscocanalostomy. J Cataract Refract Surg 1999; 25:1370–1375 11. Chiselita D. Non-penetrating deep sclerectomy versus trabeculectomy in primary open-angle glaucoma surgery. Eye 2001; 15:197–201 12. Shaarawy T, Flammer J, Smits G, Mermoud A. Low first postoperative day intraocular pressure as a positive prognostic indicator in deep sclerectomy. Br J Ophthalmol 2004; 88:658–661 13. D’Eliseo D, Pastena B, Longanesi L, Grisanti F, Negrini V. Comparison of deep sclerectomy with implant and combined glaucoma surgery. Ophthalmologica 2003; 217:208–211

14. Mun˜oz-Negrete FJ, Rebolleda G, Noval S. Facoesclerectomı´a profunda no perforante. Resultados y complicaciones [Non-penetrating deep sclerectomy combined with phacoemulsification. Results and complications.]. Arch Soc Esp Oftalmol 2003; 78:499–506 15. Rossier A, Uffer S, Mermoud A. Aqueous dynamics in experimental ab externo trabeculectomy. Ophthalmic Res 2000; 32:165–171 16. Torres-Suarez E, Rebolleda G, Munoz-Negrete FJ, Cabarga C, Rivas L. Influence of deep scleral flap size on intraocular pressure after deep sclerectomy. Eur J Ophthalmol 2007; 17:350– 356 17. Bauchiero L, Demarie A, Belli L, Brogliatti B. Deep sclerectomy and viscocanalostomy: critical revision of the results obtaining during the learning curve. Acta Ophthalmol Scand Suppl 2002; 236:64–66. Available at: http://www.blackwell-synergy.com/ doi/pdf/10.1034/j.1600-0420.80.s236.41.x. Accessed May 5, 2008 18. The AGIS Investigators. The advanced glaucoma intervention study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration. Am J Ophthalmol 2000; 130:429–440

J CATARACT REFRACT SURG - VOL 34, AUGUST 2008

First author: Jorge L. Garcı´a-Pe´rez, MD Ramo´n y Cajal Hospital, Madrid, Spain