Cataract surgery in previously vitrectomized eyes

Challenges and outcomes of cataract surgery after vitrectomy

PURPOSE OF REVIEW

This review examines the challenges and outcomes of cataract surgery after pars plana vitrectomy (PPV), focusing on surgical techniques, timing, and complication management.

RECENT FINDINGS

Cataract formation remains the primary complication post-PPV, affecting approximately 80-100% of patients within two years. Nuclear sclerotic cataracts are most common, occurring in 60-100% of patients over 50, followed by posterior subcapsular cataracts (4-34%), which primarily affect younger and diabetic patients. PPV disrupts the normal oxygen gradient in the vitreous, resulting in a more uniform oxygen distribution and accelerating cataract formation.Post-PPV eyes present unique surgical challenges due to anatomical alterations, including zonular instability and capsular changes characterized by increased fragility, the potential for tears, and altered elasticity. Newer intraocular lens power calculations show promise, but unexpected refractive outcomes may occur. The choice between combined phacovitrectomy and sequential surgeries remains debated, with patient-specific factors guiding the approach. Visual outcomes vary depending on preexisting vitreoretinal pathologies and baseline vision before PPV. Further randomized controlled trials are needed to establish treatment guidelines and improve predictive models.

SUMMARY

Post-PPV cataract surgery presents unique challenges, including anatomical alterations and an increased risk of capsular complications. These necessitate careful consideration of the surgical approach and highlight the need for further research to optimize outcomes and establish treatment guidelines.

Assessment of Zonular Integrity in Phakic Eyes Following Pars Plana Vitrectomy Using Ultrasound Biomicroscopy: A Prospective Paired Eye Comparative Study

PURPOSE

To assess zonular integrity in phakic patients post vitrectomy using ultrasound biomicroscopy (UBM).

DESIGN

Prospective, comparative, nonrandomized, double-masked, paired eye study.

METHODS

We used ultrasound biomicroscopy (UBM) to evaluate phakic patients with a history of unilateral pars-plana vitrectomy.

INCLUSION CRITERIA

(1) phakic patients with history of pars plana vitrectomy in one eye as the only procedure; (2) normal unoperated fellow eye; and (3) complete gas or air resolution from the vitreous cavity at the time of UBM assessment.

EXCLUSION CRITERIA

(1) monocular patients; (2) history of intraoperative lenticular trauma; (3) the use of silicone oil tamponade; (4) history of trauma or pseudoexfoliation in either eye; (5) history of other ocular conditions that can affect the integrity of zonules, such as uveitis or ectopia lentis; (6) eyes with extreme myopia or long axial length (> -8.00 D or >30.0 mm); (7) history of intravitreal injection in either eye; (8) age <18 years.

TECHNIQUE

A high-frequency (50 MHz) UBM device was used by a masked technician to obtain radial section images from zonular bundles at 8 different clock positions. Image quality was assessed in real time, captured, and saved. Two experienced masked observers (H.C. and C.B.) then assessed the quality of the images and graded the zonular findings. Only patients with adequate studies have been included. A unique grading system that was specifically devised for this study was used as the following: (0) clear, well-defined zonule(s); (1) uneven, disrupted zonules or stretched zonules; and (2) extensive loss of zonules. Each clock hour was graded according to this system and the total score was then calculated for each eye. In the primary outcome, 2 main groups were analyzed: vitrectomized eyes and healthy contralateral nonvitrectomized eyes. The mean total UBM score (TUS) from each group was compared and analyzed.

RESULTS

Thirty-five patients were recruited into this study. Eleven patients were male and 24 were female. The mean age was 66.3 years. Thirty patients had vitrectomy for vitreomacular interface disorders (either macular hole or epiretinal membrane), 1 patient had vitreous hemorrhage and the remaining 4 patients had rhegmatogenous retinal detachments. With regard to tamponade agents, SF6 was used in 21 (60%) patients, air in 9 (26%) patients, and C3F8 in 5 (14%) patients. The mean TUS in the vitrectomized eyes was 2.28 (SD 1.83) vs 2.24 (SD 1.77) in the nonvitrectomized eyes (P = .9531). Overall, in the comparative analysis of mean scores based on 2 graders' assessments for each clock position in vitrectomized and nonvitrectomized eyes, there were no significant differences noted between the groups.

CONCLUSION

This study found no evidence for a difference in the mean total UBM score in eyes following vitrectomy when compared to their contralateral healthy, nonvitrectomized eyes. This likely indicates that vitrectomy may not affect the integrity of zonules in phakic patients, at least for patients with vitreomacular interface disorders undergoing uncomplicated surgery.

Application of the Active-Fluidics System in Phacoemulsification: A Review

The fluidics system is an indispensable and primary component of phacoemulsification. Both the gravity-fluidics system and active-fluidics system are commonly used in practice. The irrigation pressure of the gravity-fluidics system is determined by the bottle height, which is relatively constant, while the active-fluidics system is paired with a cassette that contains pressure sensors to monitor intraocular pressure changes. The active-fluidics system allows surgeons to preset a target intraocular pressure value, and it replenishes the fluids proactively; thus, the intraocular pressure is consistently maintained near the target value. Under such circumstances, stable intraocular pressure and anterior chamber volume values could be acquired. Research on surgical safety, efficiency and results have reported several strengths of the active-fluidics system. It is also advantageous in some complicated cataract surgeries. However, the system is not widely used at present, mainly due to its low penetration rate and high equipment cost. Some of its updates such as the new Active Sentry handpiece showed potential superiority in laboratory studies recently, but there is still further research to be conducted. This article gives an overview of the mechanism and performance of the active-fluidics system, and it is expected to provide clues for future research.

The Postvitrectomy Cataract

To review the recent literature regarding risk factors for cataract formation after vitrectomy, the challenges and management strategies for anterior segment surgeons when facing post-vitrectomy cataract surgery, and the visual outcomes of patients undergoing post-vitrectomy cataract surgery. Cataract surgery after vitrectomy can be safely performed to significantly improve the visual outcome in most post-vitrectomy patients, although final visual acuity is primarily limited by the patient’s underlying vitreoretinal pathology.

Application of prechop technique in phacoemulsification for cataract patients with highly liquefied vitreous: a retrospective study

Background

Phacoemulsification using phaco-chop technique has many challenging features in cataract patients with highly liquefied vitreous. This study aimed to compare the intraoperative parameters and safety between prechop technique and traditional phaco-chop in phacoemulsification for these patients.

Methods

A total of 54 eyes of 54 patients with high myopia-related or post-vitrectomy cataract that underwent phacoemulsification combined with intraocular lens implantation were included in this retrospective study. Of them, 25 eyes that received manual prechop were included in the prechop group, and 29 eyes with best match of age, axial length and nuclear opalescence (NO) that received standardized phaco-chop were included as the control group. The intraoperative complications and surgery parameters were compared between groups.

Results

No surgical complications were observed in the prechop group, while 2 eyes with posterior capsular rupture and 1 eye with a broken ciliary zonule (10.3%) were found in the control group. There was no significant difference in phaco time, average energy, and cumulative dissipated energy (CDE) between groups (all P > 0.05), but for hard nuclear cataracts with NO grading ≥ 5, prechop group required less phaco time (P = 0.008) and CDE (P = 0.029). There were significant correlations between phaco time vs. NO (r = 0.762 vs. 0.581, both P < 0.005) and CDE vs. NO (r = 0.717 vs. 0.668, both P < 0.001) in the prechop group and control group, respectively.

Conclusions

The prechop technique which seemed to have less intraoperative complications, reduced phaco time and CDE compared to standardized phaco-chop might be a good alternative for cataract patients with highly liquefied or vitrectomized vitreous, especially those with hard nuclear cataracts.

Prior pars plana vitrectomy and its association with adverse intraoperative events during cataract surgery

PURPOSE

To evaluate the risk of intraoperative complications during cataract surgery in eyes with a prior vitrectomy.

METHODS

A retrospective review of data from our cataract surgery registry of all patients undergoing cataract surgery between 2014 and 2018 at the University of Colorado Hospital. Univariate and multivariate analyses were conducted, accounting for intra-patient correlation in subjects who underwent two cataract surgeries. The three main outcomes of interest, zonulopathy, posterior capsule (PC) tears and dropped lens fragments, were analysed for their association with prior pars plana vitrectomy (PPV) and clinical characteristics of patients such as history of prior intravitreal injection and surgeon level of experience.

RESULTS

10 540 eyes of 6447 patients were included in the analysis. 371 (3.5%) eyes had a prior PPV. Eyes with a prior PPV experienced more zonulopathy during cataract surgery (adjusted OR 2.2, 95% confidence interval: 1.3-3.7, p = 0.002). Combined phacoemulsification/PPV were significantly more likely to experience all 3 complications, and this effect was even greater for eyes with a prior PPV.

CONCLUSIONS

All complications were rare; however, there was a significant association with prior PPV and intraoperative zonulopathy. Cataract surgeons must be aware of a patient's prior vitrectomy and plan accordingly for the increased risk of intraoperative complications.

Cataract Following Pars Plana Vitrectomy: A Review

Introduction: The indications for pars plana vitrectomy (PPV) have increased over the years. The vitreous is no longer considered an inert ocular structure and it is well known that its removal has anatomical and physiological consequences. The vitreous is no longer considered an inert ocular structure. The vitreous plays a key role as an intraocular physiologic oxygen regulator. In order to maintain its transparency, the crystalline lens needs protection from an excessive oxygen exposure. PPV leads to progression of nuclear sclerosis in most eyes.Methods: A systematic review of the literature was conducted using Embase and Medline databases. Articles studying the physiology, pathogenesis and surgical treatment of cataract after PPV were included in this review.Results: The pathogenesis of cataract formation after PPV remains unclear. Predisposing factors include advanced patient age, preexisting nuclear sclerosis, light toxicity, intraoperative oxidation of lens proteins, use of silicone oil or intravitreal gas, mechanical trauma and the duration of exposure to an irrigating solution.Conclusion: Cataract surgery in vitrectomized eyes presents with more technical difficulties, is more challenging and often has a higher risk of intraoperative and postoperative complications than in non vitrectomized eyes. There is no standardized technique or management in these cases; therefore, it requires more precautions during surgery.

Accuracy of Intraocular Lens Power Calculation in Children With Vitrectomized Eyes Undergoing Cataract Surgery

PURPOSE

To assess the predictability of desired postoperative refractive outcomes using the SRK-II formula for intraocular lens (IOL) power calculation in children undergoing cataract surgery in eyes with a previous pars plana vitrectomy (PPV).

METHODS

In this retrospective study, 68 eyes of 66 children who underwent cataract surgery and IOL implantation in eyes that had previous vitrectomy between January 2008 and December 2017 were included. Data were collected on preoperative and postoperative characteristics. The Mann-Whitney test, Kruskal-Wallis test, and multinominal logistic regression were used for comparing the results.

RESULTS

Absolute prediction error (APE) in the cohort was 1.29 ± 1.13. Desirable refractive outcome with insignificant prediction error of less than 0.50 diopters (D) was found in approximately one-third of the children. Patients were further subdivided by magnitude of APE as ≥ 0.50 to ≤ 1.00 D and > 1.00 D. Age at the time of surgery, axial length, mean keratometry, silicone oil removal, IOL position, scleral buckle, and corneal suture did not affect APE and there was no significant difference between the groups (P > .05).

CONCLUSIONS

The mean APE of the SRK-II formula for IOL power calculation in pediatric eyes that had vitrectomy is comparable to that reported in the literature for routine pediatric cataract surgeries. Factors such as age, axial length, corneal power, IOL position (bag/sulcus), scleral buckle, corneal suture, and silicone oil removal done prior to surgery or along with cataract surgery did not affect the APE. [J Pediatr Ophthalmol Strabismus. 2021;58(2):126-131.].

Phacoemulsification in vitrectomized eyes: Maintaining the stability of the anterior chamber via a new technique

Fluctuating anterior chamber depth and reverse pupillary block are the most common problems encountered during phacoemulsification following pars plana vitrectomy in cases of cataracts. The sudden deepening of the anterior chamber makes the surgical procedure more cumbersome and increases the risk of intraoperative complications. To solve this problem, we describe a method of balancing the pressure of the anterior and posterior chamber by using a syringe with a flushing needle to inject balanced salt solution into the posterior chamber via the gap between the iris and the anterior capsule of the lens. This technique is especially suitable for complicated cataracts following previous pars plana vitrectomy and high myopia-complicated cataracts. This technique yielded promising results in reducing the difficulties that occur during surgical procedures, reduced the risk of intraoperative complications and simplified the intraocular lens implantation.

Epiretinal membrane surgery: an analysis of 2-step sequential- or combined phacovitrectomy surgery on refraction and macular anatomy in a prospective trial

PURPOSE

To assess the impact of combined phacoemulsification-vitrectomy and sequential surgery for idiopathic epiretinal membrane (ERM) on refractive error (RE) and macular morphology.

METHODS

In this prospective clinical trial, we allocated phakic eyes with ERM to (1) cataract surgery and subsequent pars plana vitrectomy (PPV) (CAT group), (2) PPV and subsequent cataract surgery (VIT group) or (3) phaco-vitrectomy (COMBI group). Examinations were at baseline, one month after each surgery, and at 3 months and 12 months of follow-up. Primary outcome was the RE (the difference between predicted and achieved spherical equivalent); secondary outcomes were best-corrected visual acuity (BCVA), and incidence of cystoid macular oedema (CME) defined as >10% increment of central subfield macular thickness (CSMT).

RESULTS

Sixty-two eyes were enrolled. The mean RE showed a small myopic shift of -0.36D in all groups 1 month after surgery, decreasing after 12 months to -0.17D. The absolute value of the RE (ARE) ranged 0.49-0.68D after 12 months. In the immediate postoperative period, there was a higher incidence of CME in the CAT group. There was no significant difference in final RE, ARE, BCVA and CSMT between the groups. Four cases (17%) in the CAT group had resolved visual complaints and improved BCVA after cataract surgery resulting in no need for PPV within the follow-up period.

CONCLUSION

Surgery for idiopathic ERM in phakic eyes with either phaco-vitrectomy or sequential surgery are equal approaches with respect to functional- (RE, BCVA) and anatomical outcomes (CME, CSMT). However, if starting with cataract surgery, 17% of the cases may not need subsequent PPV.

Phaco-emulsification in completely vitrectomized eyes: Intraoperative analysis of modified phaco sleeve

PURPOSE

The purpose was to evaluate the results of modified sleeve in phacoemulsification of cataract in completely vitrectomised eyes, Materials and Methods: Twenty-five previously completely vitrectomized eyes of 23 patients having visually significant cataract were included. After through evaluation they underwent phaco-emulsification by phaco chop with a modified sleeve via temporal clear corneal incision. The modified sleeve was made by creating a small round port of approximate 1 × 1 mm size at the proximate end of the sleeve in line with the already existing ports. This port faced the posterior capsule while performing phacoemulsification. Patients were observed for any intraoperative complications.

RESULT

The most common indication for pars plana vitrectomy in our study group was vitreous hemorrhage due to diabetic retinopathy [13 out of 25 eyes (52%)]. Intraoperative findings included miosis [seen in 3 (12%) eyes] and posterior capsular plaque [seen in 2(8%) eyes]. No other significant intraoperative complications (posterior capsular tear, dropped nucleus) were observed. Average effective phaco time was 33 sec. (±15.11).

CONCLUSION

Though cataract surgery in postvitrectomized eyes is a challenging situation, modified sleeve prevents anterior chamber fluctuation and avoids complications arising out of it, making the surgery safe.

Corneal endothelial cell loss and corneal biomechanical characteristics after two-step sequential or combined phaco-vitrectomy surgery for idiopathic epiretinal membrane

PURPOSE

To assess the impact of sequential and combined surgery [cataract surgery and 23-gauge pars plana vitrectomy (PPV) with peeling] on corneal endothelium cell density (CED) and corneal biomechanical characteristics.

METHODS

Phakic eyes with epiretinal membrane (ERM) were prospectively allocated to (i) cataract surgery and subsequent PPV (CAT group), (ii) PPV and subsequent cataract surgery (VIT group) or (iii) phacovitrectomy (COMBI group). Eyes were examined at baseline, 1 month after each surgery, and at 3 and 12 months follow-up. Corneal endothelium cell density (CED) was assessed with non-contact specular microscopy. Pachymetry [central cornea thickness (CCT)], keratometry and cornea volume (CV) were measured with Pentacam Scheimpflug camera. Primary outcome was change in CED after 12 months; secondary outcomes were changes in CCT and CV after 12 months.

RESULTS

Sixty-two eyes were enrolled and allocated to the three groups. The mean preoperative CED was 2776, 2794 and 2653 cells/mm^2, which decreased significantly at 12 months by 15.3, 20.0 and 19.3% in the CAT, VIT and COMBI group. There was no significant difference in percentage cell loss between the groups at final follow-up. The CED decreased significantly after cataract surgery, but was unaffected by PPV. Central cornea thickness (CCT) increased by 10 μm (p = 0.005) and CV by 1.38 mm³ (2.3%, p < 0.001) in the COMBI group. There were no significant differences in CCT or CV between the groups at final follow-up.

CONCLUSION

Combined and sequential surgery in ERM leads to a small decrease in CED. Performing cataract surgery before, after or in combination with vitrectomy did not make any significant difference with respect to final CED, CCT or CV.

Refractive change after vitrectomy for epiretinal membrane in pseudophakic eyes

PURPOSE

To report the change in refraction in pseudophakic eyes following 23-gauge vitrectomy for epiretinal membrane (ERM), without use of silicone oil, intraocular gas or scleral buckling.

METHODS

Retrospective review of the records of 28 pseudophakic eyes in 28 patients undergoing 23-gauge pars plana vitrectomy for ERM. All 28 eyes had a measured preoperative refraction in their records and were seen minimum 2 months after vitrectomy for measuring their refraction. Fellow eyes (28 eyes) were used as controls.

RESULTS

The mean preoperative refraction was -0.15 ± 0.85 dioptre (D), and the mean postoperative refraction was -0.41 ± 0.93 D. Thus, a myopic shift was observed following vitrectomy with a mean change in refraction of -0.26 ± 0.60 D (range +0.75 to -2.13 D, p = 0.032). The postoperative change in refraction was within ±0.25, ±0.50 and ±1.00 D in 39%, 68% and 96% of the eyes, respectively. The mean absolute refractive error was 0.47 ± 0.44 D. The change in refraction in fellow eyes was +0.01 D (p = 0.82).

CONCLUSION

The change in refraction following 23-gauge pars plana vitrectomy for ERM in pseudophakic eyes was -0.26 D.

Outcome of phacoemulsification in previously vitrectomized myopic eyes with axial length greater than 26 mm

PURPOSE

To determine the outcome, including the intraoperative and postoperative complications, of phacoemulsification with intraocular lens (IOL) implantation in myopic eyes with axial length of 26 mm or more that had undergone previous pars plana vitrectomy (PPV).

METHODS

This prospective study comprised 37 highly myopic eyes (axial length over 26 mm) with previous vitrectomy that underwent phacoemulsification and were reviewed at a mean postoperative follow-up of 3-6 weeks. The main outcome measures were preoperative and postoperative spherical equivalent, preoperative and postoperative visual acuity, difference between intended and achieved refraction, and any complications during cataract surgery.

RESULTS

The mean age for cataract surgery was 61.5 years. Nuclear sclerosis was present in 91.89% of patients. The mean axial length was 27.53 mm (range 26.03-30.52 mm). The most common indication for vitrectomy in our study was retinal detachment surgery (35 out of 37). Postoperatively, 34 patients (91.89%) had a visual acuity improvement of 2 or more Snellen lines and the best-corrected visual acuity at final refraction was 6/9 (0.2 logMAR) or better in 30 patients (81.08%). Two patients had perioperative complications (5.4%).

CONCLUSIONS

Cataract surgery with IOL implantation can be performed safely in highly myopic eyes after PPV and the final visual acuity outcomes appear to be dependent on the preoperative status of the retina. Our study suggests that the incidence of intraoperative and postoperative complications can be reduced to a minimum with proper planning and meticulous attention to detail during cataract surgery.

Cataract surgery after pars plana vitrectomy

PURPOSE OF REVIEW

To review recent studies and advances and their possible implications in the care of patients undergoing cataract surgery after pars plana vitrectomy.

RECENT FINDINGS

Optical biometry has shown to be superior to ultrasound biometry in vitrectomized eyes but still not achieving as good results as it does in nonvitrectomized eyes. Blue light-filter intraocular lenses, with their possible advantage of macular protection, have shown no operative or functional disadvantages in vitrectomized eyes, and thus their routine use can be justified. However, presbyopia-correcting intraocular lenses, at least at their current stage of development, generally, are still not accepted for vitrectomized eyes. Combining cataract surgery with intravitreal injections of bevacizumab or triamcinolone acetonide in patients with macular edema and cataract is advisable to avoid exacerbation of the condition and improve visual outcome. Despite the recent advances, incidences of posterior capsular opacification and retinal detachment are still considerable.

SUMMARY

Understanding ocular anatomical alterations imposed by the previous pars plana vitrectomy surgery and the underlying vitreoretinal disease will allow the surgeon to address the special challenges. Despite that, recent advances in techniques and instrumentation have improved the surgical safety and outcomes, reported complications rates are still relatively high.