October 2020


EyeWorld journal club
Review of “Cataract surgery of eyes with previous vitrectomy – risks and benefits as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery”

by Shravan Savant, MD, Young Seol, MD, and Harsha Reddy, MD

Harsha Reddy, MD
Director of Residency Education
New York Eye and Ear Infirmary of Mount Sinai
New York, New York

Shravan Savant, MD
PGY-3 Ophthalmology Resident
New York Eye and Ear Infirmary of Mount Sinai

Young Seol, MD
PGY-3 Ophthalmology Resident
New York Eye and Ear Infirmary of Mount Sinai

Ophthalmology residents of New York Eye and Ear Infirmary of Mount Sinai
Source: New York Eye and Ear Infirmary of Mount Sinai

How does prior vitrectomy affect cataract surgical outcomes? This large registry study appearing in the October issue of JCRS was reviewed by the New York Eye and Ear residents.

—David F. Chang, MD EyeWorld Journal
Club Editor

Cataract extraction is one of the most common surgical procedures in the world. In an attempt to better risk-stratify patients and predict surgical outcomes, many studies have analyzed the relationships between cataract surgery and other ocular and systemic conditions. In this study, Lundstrom et al. assessed demographic data, preoperative and operative factors, and surgical outcomes of eyes that underwent cataract surgery after vitrectomy.
The authors collected data from the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO). This database was created by the European Society of Cataract and Refractive Surgeons as a quality registry of self-reported outcomes for cataract surgery. Preoperative data reported includes year of birth, sex, eye, best-corrected distance visual acuity, target refraction, co-existing eye diseases, surgical difficulties, and previous ophthalmic surgeries. Surgical data reported includes date of surgery, type of operation, intraocular lens material, and complications during surgery. Follow-up data includes date of examination, uncorrected distance visual acuity, best-corrected distance visual acuity, refraction, macular degeneration, and postoperative complications. From this database, the authors selected patients who had previous vitrectomy listed as part of the preoperative variables under previous ophthalmic surgeries. The authors included data from Jan. 1, 2008, to Dec. 31, 2018.
The dataset consisted of 19,416 eyes undergoing cataract extraction after vitrectomy (1.1% of the 1,715,348 patients in the database who had cataract extraction). The mean age of 64.1±10.1 years in the post-vitrectomy group was significantly younger than patients in the rest of the database (73.7±9.8 years). There was a significantly lower distribution of females in the post-vitrectomy group (47.5%) than in the rest of the database (58.1%). The preoperative visual acuity for eyes with previous vitrectomy was significantly worse, logMAR 0.61±0.35 (decimal 0.25) compared with 0.37±0.27 (decimal 0.45) for the non-vitrectomized eyes. Postoperative visual acuity was also significantly worse in vitrectomized eyes compared to controls. While mean postoperative logMAR was not provided, 82.8% of cases with previous vitrectomy achieved a postoperative visual acuity of logMAR 0.3 or better, compared to 95.6% for the rest of the database. The data also revealed that dropped nucleus and surgical complications listed under “other” in the reported surgical data were significantly more frequent in the post-vitrectomy eyes than in the rest of the database, though at a lower frequency than other comparable published studies. Interestingly, other surgical difficulties such as small pupils, corneal opacities, or pseudoexfoliation were significantly less common in the previous vitrectomy group.
The authors freely discussed many of the paper’s limitations, including firstly that the relationship between prior vitrectomy and cataract surgery outcomes is confounded by many variables. The clinical indication for prior vitrectomy was not documented in the EUREQUO, which is a limitation of the database itself rather than the paper. Vitrectomy for retinal detachment versus a non-clearing vitreous hemorrhage are two very different disease processes and would likely have different effects on final visual acuity. Further stratification of the vitrectomy group based on clinical indication would provide a clearer understanding of why preoperative visual acuity is worse in vitrectomized patients. Preoperative visual acuity in the setting of other pathology also skews the postoperative visual acuity, and the authors astutely noted that preoperative visual acuity prior to the onset of cataract was not available in the database. Vision that is limited by cataract and prior vitreoretinal disease would likely also be limited by the same disease process postoperatively, regardless of the efficacy of surgery. Secondly, the EUREQUO dataset posed significant limitations, including limited follow-up, with nearly 18% of patients missing postoperative data, a lack of detail in the database discussing surgical difficulties or surgical complications beyond simply labeling them as “other,” and biases in the data, which is generated from self-reporting by physicians or clinics. The authors reported significant differences in the rates of surgical difficulties and complications compared to previously published estimates in the literature, which may be the result of these limitations. Thirdly, a large database study may have produced statistically significant differences that are not clinically significant—the higher biometry-predicted refractive error in vitrectomized vs. non-vitrectomized eyes undergoing cataracts (0.52±0.75 D vs. 0.43±0.51) is one such result.
Lundstrom et al. conducted an important large European database study comparing cataract surgery outcomes in eyes that have undergone prior vitrectomy to those in non-vitrectomized eyes. Those with previous vitrectomy were younger and the majority were men, and had statistically significantly worse, though generally still clinically good, visual outcomes. Further research is necessary to differentiate complication rates and visual outcomes following cataract surgery in vitrectomized eyes depending on the indication for vitrectomy or the visual potential given existing comorbidities. Smaller studies with finer distinctions among “other” surgical difficulties or complications may also be helpful to the cataract surgeon in anticipating specific risks uniquely higher in vitrectomized eyes.


Reddy: hreddy@nyee.edu

Cataract surgery of eyes with previous vitrectomy – risks and benefits as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery

Mats Lundström, MD, Mor Dickman, MD, Ype Henry, MD, Sonia Manning, MD, Paul Rosen, FRCS, Marie-José Tassignon, MD, David Young, PhD, Ulf Stenevi, MD
J Cataract Refract Surg. 2020;46(10). Article in press.
• Purpose: The purpose of this study was to explore the frequency and outcomes of cataract surgery in eyes with previous vitrectomy.
• Setting: Patients who have received cataract surgery in 15 European countries.
• Design: Retrospective cross-sectional register-based study.
• Methods: The European Registry of Quality Outcomes of Cataract and Refractive Surgery (EUREQUO) contains data on baseline characteristics, surgery and follow-up for cataract surgeries. Previous vitrectomy is included as a mandatory parameter in baseline characteristics. According to the protocol for EUREQUO consecutive cases should be reported by participating units.
• Results: This study includes data from units in 15 European countries in the period 2008 to 2018. For this period 1,715,348 cataract extractions with follow-up data were reported to EUREQUO. Previous vitrectomy was reported in 19,416 eyes comprising 1.1% of all cases. This proportion was about the same for every single study year. The patients were in majority men and their mean age was 64.1 years compared with 73.7 years for the rest of the database. The preoperative visual acuity was modestly worse in post-vitrectomy eyes compared with the opposite (corrected distance visual acuity [CDVA] 0.45 vs. 0.25, respectively). A postoperative CDVA of 0.5 or better was achieved by 82.8% of the post-vitrectomy eyes compared with 95.6% for the non-post-vitrectomy eyes. The absolute mean biometry prediction error for the same groups were 0.52 diopters vs 0.43 diopters, respectively.
• Conclusion: Patients undergoing cataract extraction after previous vitrectomy were younger and in majority men. Their visual and refractive outcomes were slightly inferior compared to the non-vitrectomy patients.

Review of “Cataract surgery of eyes with previous vitrectomy – risks and benefits as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery” Review of “Cataract surgery of eyes with previous vitrectomy – risks and benefits as reflected in the
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