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Abstract
Purpose
We evaluated the postoperative accuracy of intraocular lens power prediction for patients undergoing phacotrabeculectomy and identified preoperative factors associated with refractive outcome in those with primary open-angle glaucoma (POAG).
Methods
We retrospectively reviewed the medical records of 27 patients who underwent phacotrabeculectomy to treat POAG. We recorded all discrepancies between predicted and actual postoperative refractions. We compared the data to those of an age- and sex-matched control group that underwent uncomplicated cataract surgery during the same time period. Preoperative factors associated with the mean absolute error (MAE) were identified via multivariate regression analyses.
Results
The mean refractive error of the 27 eyes that underwent phacotrabeculectomy was comparable to that of the 27 eyes treated via phacoemulsification (+0.02 vs. −0.01 D, p = 0.802). The phacotrabeculectomy group exhibited a significantly higher MAE (0.65 vs. 0.35 D, p = 0.035) and more postoperative astigmatism (−1.07 vs. −0.66 D, p = 0.020) than the phacoemulsification group. The preoperative anterior chamber depth (ACD) and the changes in the postoperative intraocular pressure (IOP) were significantly associated with a greater MAE after phacotrabeculectomy.
Conclusions
POAG treatment via combined phacoemulsification/trabeculectomy was associated with greater error in terms of final refraction prediction, and more postoperative astigmatism. As both a shallow preoperative ACD and a greater postoperative change in IOP appear to increase the predictive error, these two factors should be considered when planning phacotrabeculectomy.
Figures and Tables
Figure 1
Distribution of the mean refractive error (preoperative target refraction subtracted from postoperative refraction) in the phacotrabeculectomy group and the phacoemulsification group. The phacotrabeculectomy group tends to have more refractive shift than phacoemulsification group. No. = number; D = diopter.
Figure 2
Schematic presentation of relationship between mean absolute error (MAE) and preoperative parameters. (A) Correlation between preoperative anterior chamber depth and the extent of MAE (｜ postoperative spherical equivalent refraction - preoperative predicted spherical equivalent refraction ｜). (B) Correlation between intraocular pressure (IOP) changes (preoperative IOP - postoperative IOP) and the extent of MAE in eyes that underwent phacotrabeculectomy.
Table 1
Patient demographics and preoperative clinical characteristics
Values are presented as mean ± standard deviation or number (%) unless otherwise indicated.
IOP = intraocular pressure; BCVA = best corrected visual acuity; SE = spherical equivalent in diopters; D = diopter; AL = axial length; ACD = anterior chamber depth.
*Mann-Whitney U-test between groups for variables, in case of numeric, Chi-square applied.
Table 2
Changes of best corrected visual acuity (BCVA), intraocular pressure (IOP), and refractive outcomes at 12 months postoperatively
Values are presented as mean ± SD unless otherwise indicated.
SE = spherical equivalent in diopters.
*Mann-Whitney U test; †Change in IOP = Preoperative IOP - Postoperative IOP; ‡Mean refractive error = postoperative spherical equivalent refraction - preoperative predicted spherical equivalent refraction; §Mean absolute error =｜postoperative spherical equivalent refraction - preoperative predicted spherical equivalent refraction｜.
References
1. Leske MC, Wu SY, Nemesure B, et al. Risk factors for incident nuclear opacities. Ophthalmology. 2002; 109:1303–1308.
2. Hylton C, Congdon N, Friedman D, et al. Cataract after glaucoma filtration surgery. Am J Ophthalmol. 2003; 135:231–232.
3. McCartney DL, Memmen JE, Stark WJ, et al. The efficacy and safety of combined trabeculectomy, cataract extraction, and intraocular lens implantation. Ophthalmology. 1988; 95:754–763.
4. Krupin T, Feitl ME, Bishop KI. Postoperative intraocular pressure rise in open-angle glaucoma patients after cataract or combined cataract-filtration surgery. Ophthalmology. 1989; 96:579–584.
5. Edwards RS. Trabeculectomy combined with cataract extraction: a follow-up study. Br J Ophthalmol. 1980; 64:720–724.
6. Allan BD, Barrett GD. Combined small incision phacoemulsification and trabeculectomy. J Cataract Refract Surg. 1993; 19:97–102.
7. Shin DH, Iskander NG, Ahee JA, et al. Long-term filtration and visual field outcomes after primary glaucoma triple procedure with and without mitomycin-C. Ophthalmology. 2002; 109:1607–1611.
8. Husain R, Li W, Gazzard G, et al. Longitudinal changes in anterior chamber depth and axial length in Asian subjects after trabeculectomy surgery. Br J Ophthalmol. 2013; 97:852–856.
9. Claridge KG, Galbraith JK, Karmel V, Bates AK. The effect of trabeculectomy on refraction, keratometry and corneal topography. Eye (Lond). 1995; 9(Pt 3):292–298.
10. Kara N, Baz O, Altan C, et al. Changes in choroidal thickness, axial length, and ocular perfusion pressure accompanying successful glaucoma filtration surgery. Eye (Lond). 2013; 27:940–945.
11. Vaideanu D, Mandal K, Hildreth A, et al. Visual and refractive outcome of one-site phacotrabeculectomy compared with temporal approach phacoemulsification. Clin Ophthalmol. 2008; 2:569–574.
12. Tzu JH, Shah CT, Galor A, et al. Refractive outcomes of combined cataract and glaucoma surgery. J Glaucoma. 2015; 24:161–164.
13. Rasmussen CA, Kaufman PL. Primate glaucoma models. J Glaucoma. 2005; 14:311–314.
14. Tham CC, Kwong YY, Leung DY, et al. Phacoemulsification vs phacotrabeculectomy in chronic angle-closure glaucoma with cataract: complications [corrected]. Arch Ophthalmol. 2010; 128:303–311.
15. Lochhead J, Casson RJ, Salmon JF. Long term effect on intraocular pressure of phacotrabeculectomy compared to trabeculectomy. Br J Ophthalmol. 2003; 87:850–852.
16. Murthy SK, Damji KF, Pan Y, Hodge WG. Trabeculectomy and phacotrabeculectomy, with mitomycin-C, show similar two-year target IOP outcomes. Can J Ophthalmol. 2006; 41:51–59.
17. Chang L, Thiagarajan M, Moseley M, et al. Intraocular pressure outcome in primary 5FU phacotrabeculectomies compared with 5FU trabeculectomies. J Glaucoma. 2006; 15:475–481.
18. Ong C, Nongpiur M, Peter L, Perera SA. Combined approach to phacoemulsification and trabeculectomy results in less ideal refractive outcomes compared with the sequential approach. J Glaucoma. 2016; 25:e873–e878.
19. Martínez-Belló C, Rodriguez-Ares T, Pazos B, et al. Changes in anterior chamber depth and angle width after filtration surgery: a quantitative study using ultrasound biomicroscopy. J Glaucoma. 2000; 9:51–55.
20. Francis BA, Wang M, Lei H, et al. Changes in axial length following trabeculectomy and glaucoma drainage device surgery. Br J Ophthalmol. 2005; 89:17–20.
21. Uretmen O, Ateş H, Andaç K, Deli B. Axial length changes accompanying successful nonpenetrating glaucoma filtration surgery. Ophthalmologica. 2003; 217:199–203.
22. Cashwell LF, Martin CA. Axial length decrease accompanying successful glaucoma filtration surgery. Ophthalmology. 1999; 106:2307–2311.
23. Lee YE, Choi KR, Jun RM. Accuracy of intraocular lens power calculations according to the formulas and anterior chamber depth in short eyes. J Korean Ophthalmol Soc. 2010; 51:1338–1344.
24. Maeng HS, Ryu EH, Chung TY, Chung ES. Effects of anterior chamber depth and axial length on refractive error after intraocular lens implantation. J Korean Ophthalmol Soc. 2010; 51:195–202.
25. Dietze PJ, Oram O, Kohnen T, et al. Visual function following trabeculectomy: effect on corneal topography and contrast sensitivity. J Glaucoma. 1997; 6:99–103.
26. Kook MS, Kim HB, Lee SU. Short-term effect of mitomycin-C augmented trabeculectomy on axial length and corneal astigmatism. J Cataract Refract Surg. 2001; 27:518–523.
27. Cunliffe IA, Dapling RB, West J, Longstaff S. A prospective study examining the changes in factors that affect visual acuity following trabeculectomy. Eye (Lond). 1992; 6(Pt 6):618–622.
28. Hugkulstone CE. Changes in keratometry following trabeculectomy. Br J Ophthalmol. 1991; 75:217–218.
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