Results of small incision extracapsular cataract surgery using the anterior chamber maintainer without viscoelastic

Corneal endothelial protection during manual small-incision cataract surgery: A narrative review

Cataract causes bilateral blindness in 20 million people globally, the vast majority of whom live in developing countries. Manual small-incision cataract surgery (MSICS) has emerged as an efficient and economical alternative to phacoemulsification, giving comparable results in terms of final visual gain. One of the important determinants of postoperative visual gain is the status of the corneal endothelium. Multiple factors such as corneal distortion, irrigation solution turbulence, mechanical trauma by instruments, nuclear fragments, intraocular lens contact, and free oxygen radicals, all have been implicated in causing corneal damage during cataract surgery. MSICS with posterior chamber intraocular lens implantation has been reported to cause an endothelial cell loss of 15.83%, which is comparable with other modes of cataract surgery like extracapsular cataract extraction and phacoemulsification. Thorough preoperative assessment of endothelial status and taking necessary steps for endothelial protection during surgery can decrease the endothelial cell loss and overall burden of pseudophakic bullous keratopathy. In addition to surgical techniques, the type of irrigating solutions, ocular viscoelastic devices, intracameral dyes, and drugs all affect the endothelial cell status. This review presents a summary of available literature on the protection of endothelial cells during different steps of MSICS. This is especially relevant for developing countries where large-scale MSICS cataract surgeries are performed to decrease the cataract blindness burden.

Corneal Endothelial Health after Phacoemulsification Cataract Surgery without Viscoelastic Substance

Purpose:

To evaluate corneal endothelial health after cataract surgery without viscoelastic substance (VS).

Methods:

A prospective, non-randomized, case-series study was developed, and phacoemulsification cataract surgery without VS was performed on 1324 eyes between September 2015 and September 2018. As main outcomes, mean endothelial cell density (ECD) and mean central corneal thickness (CCT) were assessed before surgery and then 6 and 12 months after surgery. Data are summarized as mean, standard deviation (SD), and 95% confidence intervals (CI).

Results:

A total of 1324 eyes were operated, and 31 were excluded by intraoperative complications. The mean ECD baseline was 2506 cells/mm² (SD = 215, CI = 2494–2518); 6 months after surgery, it was 2328 cells/mm² (SD = 213, CI = 2316–2340); and 1 year after surgery, it was 2265 cells/mm² (SD = 214, CI = 2253–2277). In terms of percentage differences, the mean ECD decrease was 9.4% after 1 year. The mean preoperative CCT was 531.6 μm (SD = 34.8, CI = 529.7–533.5); 6 months after surgery, it was 537.7 μm (SD = 38.2, CI = 535.6–539.8); and 1 year after surgery, it was 537.9 μm (SD = 37.9, CI = 535.8–540.0). The mean CCT increased 1.2% 1 year after surgery.

Conclusions:

Phacoemulsification cataract surgery can be completely performed without VS, with very low intraoperative complications. The postoperative ECD and CCT changes occurred primarily during the first 6 months, and the changes decreased during the second semester.

Efficacy of intracameral antibiotics following manual small incision cataract surgery in reducing the rates of endophthalmitis: A meta-analysis

BACKGROUND

Manual small incision cataract surgery (MSICS) is a widely used technique for cataract surgery in the developing world. Higher rates of postoperative endophthalmitis have been reported with this technique compared with phaco-emulsification. The purpose of this study was to evaluate the efficacy of prophylactic intracameral (IC) antibiotics in reducing the rates of postoperative endophthalmitis following MSICS.

METHODS

Systematic review and meta-analysis of patients undergoing MSICS. A literature search in PubMed and EMBASE databases was performed to identify studies published from October 1992 to April 2020 evaluating MSICS with a minimum of 500 eyes reported. Two authors independently assessed eligibility, extracted data and assessed the risk of bias. Heterogeneity was assessed using the I² test.

RESULTS

Twelve studies enrolling 1 494 307 eyes were included. IC antibiotics were used in 725 324 (48.5%) eyes. The risk ratio of developing endophthalmitis was 2.94 (95% CI, 1.07-8.12; P = .037) in eyes that did not receive IC antibiotics.

CONCLUSIONS

Routine use of IC antibiotics may help to reduce the rates of endophthalmitis following MSICS and significantly improve the safety of this effective form of cataract surgery.

Hydroimplantation versus viscoimplantation: comparison of intraocular lens implantation with and without ophthalmic viscoelastic device in phacoemulsification

Purpose: To compare the efficacy and safety of intraocular lens implantation with and without ophthalmic viscoelastic device in phacoemulsification. Methods: A randomized prospective study was conducted on 84 eyes of 84 patients who underwent uneventful phacoemulsification by the same surgeon. Patients were divided into two groups after the completion of lens cortex removal. Intraocular lens implantation was performed with balanced salt solution irrigation in group H (n=42, hydroimplantation) and with ophthalmic viscoelastic device in group V (n=42, viscoimplantation). The main outcomes measured were postoperative changes of intraocular pressure (IOP), central corneal thickness (CCT), mean absolute refractive error, time of surgery, and the frequency of complications. Patients were evaluated 1 day, 1 week, and 1 month postoperatively. Results: There was no significant difference in mean age, gender, preoperative IOP and preoperative CCT between the two groups. IOP and CCT were not significantly different 1 day, 1 week, and 1 month postoperatively between the two groups. Mean absolute refractive error was also not significantly different between the two groups. Time of surgery was significantly lower in group H than in group V (953.81 ± 88.33 seconds, 1072.33 ± 172.16 seconds, respectively, p<0.001). No other complications were observed during the intraocular lens implantation in the two groups. Conclusions: Hydroimplantation technique is safe and effective in phacoemulsification. Furthermore, reduced time of surgery and reduced cost of ophthalmic viscoelastic devices are the advantages of this technique. Abbreviations: OVDs = ophthalmic viscosurgical devices; IOP = intraocular pressure; MARE = mean absolute refractive error; CCT = central corneal thickness; CDE = cumulative dissipated energy; AL = axial length; ACD = anterior chamber depth; ACM = anterior chamber maintainer; ECCE = extracapsular cataract extraction.

Review of manual small-incision cataract surgery

Cataract surgery has undergone many changes with the size of incision progressively decreasing over time with an incision of 12.0 mm for intracapsular cataract extraction to 2.2–2.8 mm in phacoemulsification. However, phacoemulsification due to high cost and equipment maintenance cannot be employed widely in developing countries. Manual small-incision cataract surgery (MSICS) offers similar advantages with the merits of wider applicability, less time consuming, a shorter learning curve, and lower cost. MSICS can be performed in high-volume setups due to fast technique. Here, we review the various techniques, safety and efficacy of MSICS, and its progress and utility in developing and underdeveloped countries.

Endothelial cells and central corneal thickness after modified sutureless manual small-incision cataract surgery

PURPOSE

Manual small-incision cataract surgery (MSICS) is a viable method for cataract surgery around the world. We evaluated the impact of a modification of MSICS, in which an anterior chamber maintainer is used throughout the surgery with the addition of ocular viscoelastic device prior to nucleus removal (M-MSICS), on the corneal endothelium.


METHODS

This prospective study comprised patients randomly assigned for cataract surgery who underwent M-MSICS. Patients underwent corneal endothelial counts by a noncontact specular microscopy in the center and at 12 and 6 o'clock position as well as central corneal pachymetry (CCT) preoperatively, and at 1 week and 1 and 3 months postoperatively. 


RESULTS

Twenty-one eyes were included, 16 of which completed the entire follow-up. There was a statistically significant difference in endothelial cell loss at the center of the cornea at 1 week postoperatively (p = 0.003). However, there was no significant difference in endothelial cell measurements between preoperative and other postoperative timepoints at the center of the cornea. In addition, no significant difference was found in the 12 and 6 o'clock measurements at all timepoints. There was a mild but statistically significant increase in CCT at the center of the cornea at 1-week and 1-month postoperative measurements as compared to preoperative measurement (p<0.05). By postoperative month 3, CCT had returned to baseline level. 


CONCLUSIONS

Modified MSICS offers a viable enhancement of MSICS, with mild and transient impact on the corneal endothelial cell density and corneal pachymetry.

Manual Small Incision Cataract Surgery: A Review

We aim at reviewing published peer-reviewed studies that evaluate the safety and efficacy of manual small incision cataract surgery (MSICS). Literature searches of the PubMed and the Cochrane Library databases were conducted with no date restrictions; the searches were limited to articles published in English only. All publications with at least level II and III evidence were studied and surgical techniques were analyzed. MSICS was also compared with phacoemulsification and large incision extracapsular cataract surgery (ECCE) with respect to visual outcome, surgery time, cost, intra and postoperative complications and suitability for high volume surgical practices in the developing world.The overall safety profile of MSICS was found to be excellent with intra and postoperative complication rates comparable to phacoemulsification and ECCE. Multiple studies reported the safety and efficacy of MSICS for complicated cases, such as brunescent and white cataract and cataracts associated with phacolytic and phacomorphic glaucoma. Compared to phacoemulsification MSICS was associated with lower and shorter operative times. Visual outcomes were excellent and comparable to phacoemulsification with up to 6 months follow up.The literature provides outcome analysis of a variety of different MSICS techniques. As a whole, MSICS provides excellent outcomes with a low rate of surgical and postoperative complications. Particularly in the developing world, MSICS appears to provide outcomes that are of comparable quality to phacoemulsification at a much lower cost.

Cataract surgery in aged patients: phacoemulsification or small-incision extracapsular cataract surgery

AIM

To evaluate the effects and safety of phacoemulsification (Phaco) or small-incision extracapsular cataract surgery (SICS) and intraocular lens (IOL) implantation for aged patients.

METHODS

Totally 137 aged patients (149 eyes) underwent cataract operation in the case of stable systemic condition, the blood pressure less than 160/95mmHg, blood glucose less than 8mmol/L, and under the help of electrocardiogram surveillance by anesthesiologists during the operation. 106 aged patients (114 eyes) underwent Phaco while 31 aged patients (35 eyes) underwent SICS. The postoperative visual acuity, corneal endothelial cell loss, surgery time and major complications were observed and analyzed retrospectively.

RESULTS

The best-corrected visual acuity(BCVA) of ≥0.6 was achieved in 135 eyes (92.6%) at 1 month postoperatively (χ(2)=259.730, P<0.001). For aged patients, both Phaco and SICS could significantly improve visual acuity with no significant difference (χ(2)=4.535, P>0.05). Postoperative corneal endothelial cell loss was 18.6%, in PHACO group, the rate was 18.5%; in SICS group, the rate was 19.0%, the difference of which was no significant (χ(2)=0.102, P>0.05). The surgery time was different in two groups. No severe complications occurred.

CONCLUSION

Both Phaco and SICS combined with IOL implantation for aged patients are effective and safe. Before surgery, detailed physical examination should be performed. When the systemic condition is stable, cataract surgery for aged patients is safe.

Use of the anterior chamber maintainer in trabeculectomy following vitrectomy

PURPOSE

To retrospectively observe the effects of anterior chamber maintainer (ACM) placement in glaucoma patients undergoing trabeculectomy following vitrectomy.

METHODS

Trabeculectomy was performed on 51 secondary glaucoma patients (51 eyes), all of whom had undergone vitrectomy. During trabeculectomy, an ACM was placed in 27 eyes (group A), but not in the remaining 24 (group B). Intra- and post-operative complications were recorded. Intraocular pressure (IOP) measurements were recorded pre-operatively and repeated post-operatively on follow up days 1, 3, and 7, and months 1, 3, 6, 12, 18, and 24. Surgical success rates were recorded.

RESULTS

Mean pre-operative IOPs of groups A and B were 32.74 ± 11.25 and 34.29 ± 9.68 mmHg, respectively. In group A, anterior chamber bleeding (two cases), and choroidal detachment and/or ciliary detachment (four cases) occurred. In group B, anterior chamber bleeding (five cases), and choroidal detachment and/or ciliary detachment (11 cases) occurred. There was a statistically significant difference between the two groups. There also was statistically significant difference in post-operative IOPs between the two groups at 12 and 24 months. The surgical success rate of group A was higher than that of group B.

CONCLUSION

ACM is effective in maintaining IOP and reducing complications during trabeculectomy following vitrectomy, thereby increasing surgical success rates.

Nucleus management with Blumenthal technique: anterior chamber maintainer

The Blumenthal's ‘Mininuc’ technique enables nuclear expression through a 5-6.5-mm sclerocorneal tunnel incision using a Sheet's lens glide and anterior chamber maintainer (ACM). A 6-mm or larger capsulorrhexis, reduction in nuclear size by hydroprocedure and its manipulation manually into the anterior chamber are performed. The nucleus is expressed out of the chamber by use of hydrostatic pressure created by balanced salt solution delivered continuously through the ACM. This continuous flow from ACM to anterior chamber keeps the eye under positive pressure physiological state besides clearing the chamber of cortex, blood and pigments offering excellent visualization. The procedure, with an initial learning curve, is highly effective, applicable to all grades of cataracts, has minimum intraocular instrumentation resulting in an early rehabilitation of the patient.

Viscoexpression technique in manual small incision cataract surgery

Viscoexpression method of nucleus delivery in manual small incision cataract surgery is described in this article. The practical modifications to the conventional technique in special situations are presented. Intraoperative and postoperative problems likely to be encountered and the steps to avoid them and tackle them effectively are discussed.

Comparison of endothelial cell loss and surgically induced astigmatism following conventional extracapsular cataract surgery, manual small-incision surgery and phacoemulsification

PURPOSE

To compare the surgically induced astigmatism (SIA) and endothelial cell loss following conventional extracapsular cataract surgery (ECCE), manual small-incision cataract surgery (Blumenthal technique)(SICS) and phacoemulsification (PE) with non-foldable intraocular lens implantation.

METHODS

186 cataractous eyes with nuclear sclerosis grade 3 or less were randomized to undergo ECCE, SICS or PE with intraocular lens (non-foldable) implantation after a detailed pre-operative assessment. Keratometry and specular microscopy were performed pre-operatively and 6 weeks postoperatively. Surgically induced astigmatism was calculated using the rectangular coordinate method (Holladay et al.).

RESULTS

Mean endothelial cell loss was similar for all three groups (p = 0.855); ECCE induced a loss of 4.72% (SD: 13.07); SICS 4.21% (SD: 10.29) and PE 5.41% (SD: 10.99). Mean SIA was 1.77D (1.61D) for the ECCE group, 1.17D (0.95D) for the SICS group and 0.77D (0.65D) for the PE group (p = 0.001). The magnitude of the difference between the SICS and the PE group was 0.4D.

CONCLUSION

PE induced less astigmatism than SICS and ECCE in this study but the magnitude of the difference between SICS and PE was small. There was no significant difference in endothelial cell loss between the three groups.

Small incision clear lens extraction for correction of high myopia

PURPOSE

To evaluate the effectiveness, predictability, and safety of clear lens extraction in the correction of high myopia.

SETTING

Kartal Education and Research Hospital, Istanbul, Turkey.

METHODS

This retrospective study comprised 56 eyes of 30 patients who had clear lens extraction to correct myopia of 12.00 diopters (D) or more. Small incision clear lens extraction using an anterior chamber maintainer was performed and low-power posterior chamber intraocular lens (IOL) was implanted. The mean postoperative follow-up was 40.2 +/- 11.9 months.

RESULTS

Uncorrected visual acuity improved in 94.6% of eyes. Best-corrected visual acuity (BCVA) improved in 37 eyes (66%); 27 (48.2%) gained two or more lines. The percentage of eyes achieving a BCVA of 20/40 or better increased from 26.7% preoperatively to 58.9% postoperatively. Of the eyes, 38 (67.8%) were within +/- 1.00 D of targeted refractive error and 52 (92.8%) were within +/- 2.00 D. Posterior capsule tear with vitreous loss occurred in one eye (1.7%). During the follow-up, retinal detachment (RD) occurred in 2 eyes (3.5%).

CONCLUSIONS

Clear lens extraction and IOL implantation was effective and had an acceptable predictability and a low morbidity in correcting high myopia. Regular retinal examination is necessary to prevent postoperative RD.

Posterior capsule rupture and vitreous loss during phacoemulsification with or without the use of an anterior chamber maintainer

PURPOSE

To compare the incidence of posterior capsule rupture and vitreous loss during phacoemulsification with and without the use of an anterior chamber maintainer (ACM) SETTING: Aristotle University Eye Clinic, Thessaloniki, Greece.

METHODS

The surgical records of patients who had phacoemulsification by experienced surgeons over a 2-year period were reviewed. The cases were divided into 2 groups: surgery performed without the use of an ACM (no-ACM group) and surgery performed with the use of an ACM (ACM group).

RESULTS

The no-ACM group comprised 231 cases and the ACM group, 312 cases. Posterior capsule rupture occurred in 19 cases (8.22%) and 22 cases (7.05%), respectively. Of the patients with posterior capsule rupture, 6 (31.57%) in the no-ACM group and 16 (72.72%) in the ACM group had vitreous loss and required an anterior vitrectomy; the difference between the 2 groups was statistically significant (P =.03).

CONCLUSIONS

The use of an ACM in phacoemulsification provided a consistently deep anterior chamber and approximately the same rate of complications as with a standard technique in the hands of experienced surgeons. However, when posterior capsule rupture occurred, the incidence of vitreous loss was significantly higher in eyes with an ACM.

Sutureless cataract surgery with nucleus extraction: outcome of a prospective study in Nepal

AIM

To report the short and medium term outcome of a prospective series of sutureless manual extracapsular cataract extractions (ECCE) at a high volume surgical centre in Nepal.

METHODS

Cataract surgery was carried out, on eyes with no co-existing diseases, in 500 consecutive patients who were likely to return for follow up. The technique involved sclerocorneal tunnel, capsulotomy, hydrodissection, nucleus extraction with a bent needle tip hook, and posterior chamber intraocular lens (PC-IOL) implantation according to biometry findings. Surgical complications, visual acuity at discharge, 6 weeks, and 1 year follow up, and surgically induced astigmatism are reported.

RESULTS

The uncorrected visual acuity at discharge was 6/18 or better in 76.8% of eyes, and declined to 70.5% at 6 weeks' follow up, and 64.9% at 1 year. The best corrected visual acuity was 6/18 or better in 96.2% of eyes at 6 weeks and in 95.9% at 1 year. Poor visual outcome (<6/60) occurred in less than 2%. Intraoperative complications included 47 (9.4%) eyes with hyphaema, and one eye (0.2%) with posterior capsule rupture and vitreous in the anterior chamber. Surgery led to an increase in against the rule astigmatism, which was the major cause of uncorrected visual acuity less than 6/18. Six weeks postoperatively, 85.5% of eyes had against the rule astigmatism, with a mean induced cylinder of 1.41 D (SD 0.8). There was a further small increase in against the rule astigmatism of 0.66 D (SD 0.41) between 6 weeks and 1 year. The mean duration of surgery was 4 minutes and the average cost of consumables, including the IOL, was less than $10.

CONCLUSION

Rapid recovery of good vision can be achieved with sutureless manual ECCE at low cost in areas where there is a need for high volume cataract surgery. Further work is required to reduce significant postoperative astigmatism, which was the major cause of uncorrected acuity less than 6/18.

Simultaneous bilateral cataract extraction

PURPOSE

To assess the visual outcome and safety of simultaneous bilateral cataract extraction.

SETTING

Department of Ophthalmology, Queen's Hospital, Burton on Trent, Staffordshire, United Kingdom.

METHODS

Simultaneous bilateral cataract extraction was performed in 288 eyes of 144 patients over 10 years in a single department in selected cases. Case notes were retrospectively analyzed for final best corrected visual acuity (BCVA) and intraoperative and postoperative complication rates.

RESULTS

The final BCVA was 6/9 or better in 87.0% of eyes. The incidence of intraoperative complications was 2.42%. These included posterior capsule rupture without vitreous loss (0.69%) and with vitreous loss (1.04%). Postoperative complications occurred in 10.05% of eyes and included raised intraocular pressure (IOP) (3.82%), iris prolapse (0.69%), uveitis (0.69%), and suture abscess (0.35%). There were no major bilateral complications such as endophthalmitis or corneal decompensation.

CONCLUSION

The outcome of simultaneous bilateral cataract extraction was comparable to that of single-eye cataract surgery, indicating that the procedure is safe under strict surgical protocol and beneficial in selected cases.