Journal List > J Korean Ophthalmol Soc > v.56(5) > 1010276

Han and Chung: Accuracy of Intraocular Lens Power Estimation in Eyes Undergoing Phacovitrectomy for Proliferative Diabetic Retinopathy



To evaluate the accuracy of intraocular lens (IOL) power estimation and the factors associated with outcome in eyes undergoing combined phacovitrectomy for proliferative diabetic retinopathy.


We performed a retrospective case review of 39 consecutive patients (44 eyes) that underwent phacovitrectomy for proliferative diabetic retinopathy. Axial lengths were measured using ultrasound (A-scan) and/or optical biometry (IOL Master). Achieved and predicted refractions were compared to calculate the mean postoperative refractive prediction error (ME) and the mean absolute prediction error (MAE). Systemic conditions of patients and several preoperative and postoperative factors related to the postoperative refraction were analyzed.


The ME of 44 eyes were −0.23 ± 0.52 diopters (D) and -0.23 ± 0.47 D after 3 and 6 months, respectively (range, -1.40~+0.79 D). There was no statistically significant difference in the refractive outcomes between the refractive errors ( p = 0.959). The MAEs were 0.45 ± 0.35 D and 0.40 ± 0.33 D after 3 and 6 months, respectively with no statistical significant difference between the results ( p = 0.196). When comparing ME in the 20 eyes that achieved both results, ultrasound was more accu-rate than optical biometry ( p = 0.002, 0.002). The factors associated with more inaccurate ME and MAE after phacovitrectomy were diabetic nephropathy and neovascular glaucoma.


Combined phacovitrectomy in proliferative diabetic retinopathy showed small biometric errors within the tolerable range in most cases. Patients with neovascular glaucoma and diabetic nephropathy had more inaccurate postoperative refractive power. Both optical biometry and ultrasound should be used to estimate axial lengths for improving the accuracy of IOL power calculation.


1. Thompson JT, Glaser BM, Sjaarda RN, Murphy RP. Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes. Am J Ophthalmol. 1995; 119:48–54.
2. Holekamp NM, Shui YB, Beebe DC. Vitrectomy surgery increases oxygen exposure to the lens: a possible mechanism for nuclear cataract formation. Am J Ophthalmol. 2005; 139:302–10.
3. Melberg NS, Thomas MA. Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age. Ophthalmology. 1995; 102:1466–71.
4. Jeoung JW, Chung H, Yu HG. Factors influencing refractive outcomes after combined phacoemulsification and pars plana vitrectomy: results of a prospective study. J Cataract Refract Surg. 2007; 33:108–14.
5. Chung TY, Chung H, Lee JH. Combined surgery and sequential surgery comprising phacoemulsification, pars plana vitrectomy, and intraocular lens implantation: comparison of clinical outcomes. J Cataract Refract Surg. 2002; 28:2001–5.
6. Patel D, Rahman R, Kumarasamy M. Accuracy of intraocular lens power estimation in eyes having phacovitrectomy for macular holes. J Cataract Refract Surg. 2007; 33:1760–2.
7. Manvikar SR, Allen D, Steel DH. Optical biometry in combined phacovitrectomy. J Cataract Refract Surg. 2009; 35:64–9.
8. Chylack LT Jr, Wolfe JK, Singer DM, et al. The lens opacities classification system III. The Longitudinal Study of Cataract Study Group. Arch Ophthalmol. 1993; 111:831–6.
9. Rice TA, Michels RG, Maguire MG, Rice EF. The effect of lensec-tomy on the incidence of iris neovascularization and neovascular glaucoma after vitrectomy for diabetic retinopathy. Am J Ophthalmol. 1983; 95:1–11.
10. Scharwey K, Pavlovic S, Jacobi KW. Combined clear corneal phacoemulsification, vitreoretinal surgery, and intraocular lens implantation. J Cataract Refract Surg. 1999; 25:693–8.
11. Demetriades AM, Gottsch JD, Thomsen R, et al. Combined phacoemulsification, intraocular lens implantation, and vitrectomy for eyes with coexisting cataract and vitreoretinal pathology. Am J Ophthalmol. 2003; 135:291–6.
12. Suzuki Y, Sakuraba T, Mizutani H, et al. Postoperative refractive error after simultaneous vitrectomy and cataract surgery. Ophthalmic Surg Lasers. 2000; 31:271–5.
13. Shioya M, Ogino N, Shinjo U. Change in postoperative refractive error when vitrectomy is added to intraocular lens implantation. J Cataract Refract Surg. 1997; 23:1217–20.
14. Falkner-Radler CI, Benesch T, Binder S. Accuracy of preoperative biometry in vitrectomy combined with cataract surgery for patients with epiretinal membranes and macular holes: results of a prospective controlled clinical trial. J Cataract Refract Surg. 2008; 34:1754–60.
15. Kucumen RB, Yenerel NM, Gorgun E, et al. Anterior segment optical coherence tomography measurement of anterior chamber depth and angle changes after phacoemulsification and intraocular lens implantation. J Cataract Refract Surg. 2008; 34:1694–8.
16. Díaz Lacalle V, Orbegozo Gárate FJ, Martinez Alday N, et al. Phacoemulsification cataract surgery in vitrectomized eyes. J Cataract Refract Surg. 1998; 24:806–9.
17. McDermott ML, Puklin JE, Abrams GW, Eliott D. Phacoemulsification for cataract following pars plana vitrectomy. Ophthalmic Surg Lasers. 1997; 28:558–64.
18. Rahman R, Bong CX, Stephenson J. Accuracy of intraocular lens power estimation in eyes having phacovitrectomy for rhegmatogenous retinal detachment. Retina. 2014; 34:1415–20.
19. Song WK, Kim SS, Kim SE, Lee SC. Refractive status and visual acuity changes after oil removal in eyes following phacovitrectomy, intraocular lens implantation, and silicone oil tamponade. Can J Ophthalmol. 2010; 45:616–20.
20. Lee DK, Lee SJ, You YS. Prediction of refractive error in combined vitrectomy and cataract surgery with one-piece acrylic intraocular lens. Korean J Ophthalmol. 2008; 22:214–9.
21. Findl O, Kriechbaum K, Sacu S, et al. Influence of operator experience on the performance of ultrasound biometry compared to optical biometry before cataract surgery. J Cataract Refract Surg. 2003; 29:1950–5.
22. Lee AC, Qazi MA, Pepose JS. Biometry and intraocular lens power calculation. Curr Opin Ophthalmol. 2008; 19:13–7.
23. Kunavisarut P, Poopattanakul P, Intarated C, Pathanapitoon K. Accuracy and reliability of IOL master and A-scan immersion biometry in silicone oil-filled eyes. Eye (Lond). 2012; 26:1344–8.
24. Findl O, Drexler W, Menapace R, et al. Improved prediction of intraocular lens power using partial coherence interferometry. J Cataract Refract Surg. 2001; 27:861–7.
25. Kovács I, Ferencz M, Nemes J, et al. Intraocular lens power calculation for combined cataract surgery, vitrectomy and peeling of epiretinal membranes for macular oedema. Acta Ophthalmol Scand. 2007; 85:88–91.
26. Sun HJ, Choi KS. Improving intraocular lens power prediction in combined phacoemulsification and vitrectomy in eyes with macular oedema. Acta Ophthalmol. 2011; 89:575–8.
27. Lim SS, Kim SD. Simulated operation of phacoemulsification, vitrectomy and posterior chamber intraocular lens implantation in proliferative diabetic retinopathy patients. J Korean Ophthalmol Soc. 1999; 40:2205–11.
28. Sung MS, Park TK, Ohn YH. Clinical analysis of combined vitrectomy and phacoemulsification with intraocular lens implantation for proliferative diabetic retinopathy. J Korean Ophthalmol Soc. 2005; 46:1333–41.
29. Christensen PK, Larsen S, Horn T, et al. Renal function and structure in albuminuric type 2 diabetic patients without retinopathy. Nephrol Dial Transplant. 2001; 16:2337–47.
30. Weinreb RN, Wasserstrom JP, Parker W. Neovascular glaucoma following neodymium-YAG laser posterior capsulotomy. Arch Ophthalmol. 1986; 104:730–1.
31. Blankenship GW, Machemer R. Long-term diabetic vitrectomy results. Report of 10 year follow-up. Ophthalmology. 1985; 92:503–6.
32. Benson WE, Brown GC, Tasman W, McNamara JA. Extracapsular cataract extraction, posterior chamber lens insertion, and pars plana vitrectomy in one operation. Ophthalmology. 1990; 97:918–21.
33. Chung HY, Chung HJ, Choi JY, et al. Risk factors for neovascular glaucoma after vitrectomy in patients with proliferative diabetic retinopathy. J Korean Ophthalmol Soc. 2013; 54:1868–74.
34. Lee JH, Kwon SJ, Shin JP, et al. Neovascular glaucoma after vitrectomy for proliferative diabetic retinopathy and the Ahmed valve implantation. J Korean Ophthalmol Soc. 2006; 47:1417–26.
35. Wand M, Madigan JC, Gaudio AR, Sorokanich S. Neovascular glaucoma following pars plana vitrectomy for complications of diabetic retinopathy. Ophthalmic Surg. 1990; 21:113–8.
36. Striga M, Ivanisević M. Comparison between efficacy of full-and mild-scatter (panretinal) photocoagulation on the course of diabetic rubeosis iridis. Ophthalmologica. 1993; 207:144–7.

Table 1.
Characteristics of Patients
Characteristics Results
Total number of eyes 44 eyes (39 patients)
  Male 24 eyes (22 patients)
  Female 20 eyes (17 patients)
Mean age (years) 53.86 ± 10.29
Duration of diabetes (years) 11.39 ± 6.92
Mean HbA1c (%) 8.90 ± 5.69
Associated systemic disease (n, %)  
  Diabetic nephropathy 26 of 39 patients (66.67)
  Hypertension 18 (46.15)
Associated ocular disease (n, %)  
  Vitreous hermorrhage 34 of 44 eyes (77.27)
  Retinal detachment 8 (18.18)
  Epiretinal membrane 24 (54.55)
  Diabetic macular edema 8 (18.18)
Mean axial length (measure by US, mm) 23.33 ± 1.25

Values are presented as mean ± SD unless otherwise indicated.

HbA1c = glycated hemoglobin; US = ultrasound (A-scan).

Table 2.
Mean prediction error (ME) and mean absolute prediction error (MAE)
Group ME MAE
All eyes (44 eyes)    
    After 3 months -0.23 (0.52) 0.45 (0.35)
    After 6 months -0.23 (0.47) 0.40 (0.33)
US and OB both group (20 eyes)    
    After 3 months -0.01 (0.46) 0.36 (0.27)
    After 6 months -0.05 (0.34) 0.25 (0.20)
    After 3 months 0.21 (0.36) 0.32 (0.25)
    After 6 months 0.17 (0.32) 0.27 (0.23)

Values are presented as mean (SD).

US = ultrasound (A-scan); OB = optical biometry (intraocular lens Master).

Table 3.
Descriptive summary of factors associated with refractive error
ME of 6 M MAE of 6 M
Preoperative factors    
  Duration of diabetes (years) 0.739 0.431
  Mean HbA1c (%) 0.870 0.916
  Diabetic nephropathy 0.021* 0.002*
  Hypertension 0.264 0.780
  Vitreous hermorrhage 0.351 0.222
  Retinal detachment 0.422 0.591
  Epiretinal membrane 0.736 0.615
  Diabetic macular edema 0.452 0.626
  Degree of cataract 0.645 0.302
  Axial length 0.098 0.358
Intraoperative factors    
  Posterior subtenon triamcinolone injection 0.907 0.138
  Membranectomy 0.769 0.910
  Panretinal photocoagulation (new or add) 0.839 0.440
  Silicone oil tamponade 0.422 0.591
  IOL (SN60WF or ZA9003) 0.199 0.725
Postoperative factors    
  Diabetic macular edema 0.532 0.329
  Neovascular glaucoma 0.043* 0.033*
  Rebleeding 0.317 0.494

ME = mean prediction error; MAE = mean absolute prediction error; HbA1c = glycated hemoglobin; IOL = intraocular lens.

* p < 0.05.

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