Nucleus fragmentation in a scleral pocket for small incision 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.

The Correlation of Age and Postoperative Visual Acuity for Age-Related Cataract

Purpose. Clinically, what is the best time for age-related cataract (ARC) patients to receive surgeries and get the most benefits is important. We explored the relationship between age and presenting postoperative visual acuity (POVA) in patients from rural China. Methods. Three Lifeline Express Hospital Eye-Train missions of Peking University People's Hospital were chosen. At the first day after surgery, 3452 ARC eyes with the presenting POVA ≥ 6/60 were enrolled. The relationship between age and POVA was analyzed statistically. Results. In these three missions, there were more female patients than males; the ratio of females to males was 1.71. The average age of females was older than males. Overall, the percentages of patients with good visual outcomes (≥6/18) were significantly decreased with aging. Different regions had variations, but the trends were the same. There was weak linear correlation between age and POVA. The correlations of females were stronger than males in Yuncheng and Sanmenxia and weaker than males in Zhoukou. Conclusion. The good visual outcomes of presenting POVA were significantly decreased with aging and there were weak linear correlations between age and POVA in rural China. The linear correlation might be influenced by the difference of gender and region.

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.

Nucleus management with irrigating vectis

The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS), incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost.

Small-incision manual extracapsular cataract surgery in Ghana, West Africa

PURPOSE

To evaluate the results of small-incision manual extracapsular cataract extraction surgery (ECCE) in a district hospital in West Africa.

SETTING

Margret Marquart Catholic Hospital, Ghana, West Africa.

METHODS

This prospective study consisted of 200 eyes of 193 patients who had small-incision manual ECCE between January 1999 and May 2000. For comparison, the charts of 32 patients (32 eyes) operated on between July and December 1998 using a limbal incision (control group) were retrospectively analyzed. Outcome measures included intraoperative and postoperative complications, postoperative visual acuity, and refractive astigmatism.

RESULTS

In the small-incision ECCE group, self-sealing wounds were achieved in 129 eyes (64.5%). Vitreous loss occurred in approximately 3% of eyes in both the small-incision and control groups. The final visual acuities were similar between the 2 groups, with more than 90% of eyes in both groups achieving a final best corrected visual acuity of at least 20/60. Eyes in the small-incision group had faster visual recovery (P <.001), a lower incidence of fibrinous iritis (P =.02), and were more likely to have round pupils (P <.001) than eyes in the control group. The main complication of small-incision surgery was moderate corneal edema, which persisted until at least the 1-week visit in 14 eyes (7%). At the most recent visit, 1 eye in the small-incision group (0.5%) had bullous keratopathy.

CONCLUSION

In a district hospital in West Africa, small-incision manual ECCE surgery yielded faster visual rehabilitation and had a lower incidence of fibrinous iritis than standard ECCE surgery.

Forceps-guided nuclear cleavage cataract extraction

We introduce a manual nuclear fragmentation technique, forceps-guided nuclear cleavage. A 5.5 to 7.0 mm superior scleral incision is started 1.5 mm posterior to the limbus. Two additional 1.0 mm paracenteses are made at 3 and 9 o'clock in clear cornea close to the limbus. A continuous curvilinear capsulorhexis (CCC) is created; in most cases, 4 to 5 radial relaxing incisions are made in the CCC. The anterior and equatorial cortex and epinucleus are removed with 2-handed irrigation/aspiration via the 2 paracenteses with the nucleus in the capsular bag. The nucleus is prolapsed into the anterior chamber. A nucleus hook is inserted via the 3 o'clock paracentesis and applied to the 6 o'clock nuclear equator to hold the nucleus. A nucleus cleaving forceps is inserted through the upper incision to the 12 o'clock equator of the nucleus and advanced to one-third depth of the nucleus. The forceps is relaxed while the nucleus is cleaved in half.

Minimal astigmatism after sutureless planned extracapsular cataract extraction

PURPOSE

To evaluate astigmatism after mini-nuc extracapsular cataract extraction (ECCE) in which a chevron incision is enlarged to 6.0 to 7.0 mm for easier nucleus removal and to compare the results with those using a 5.0 mm incision.

SETTING

Department of Ophthalmology, The Edith Wolfson Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Holon, Israel.

METHODS

Thirty eyes of 29 patients were enrolled in this study. Keratometry was performed preoperatively and 3 to 9 months postoperatively. The incision length was 6.0 mm in 6 eyes, 6.5 mm in 10 eyes, and 7.0 mm in 14 eyes that had mature cataract.

RESULTS

The mean induced astigmatism calculated by simple subtraction was 0.12 diopter (D) +/- 0.51 (SD), 0.16 +/- 0.98 D, and 0.67 +/- 0.91 D for the 6.0 mm, 6.5 mm, and 7.0 mm incision, respectively. By vector analysis, the mean induced astigmatism was 0.60 +/- 0.30 D, 0.75 +/- 0.67 D, and 1.36 +/- 0.77 D, respectively. Results by both methods showed no significant difference between the previously reported 5.0 mm incision and the 6.0 mm and 6.5 mm incisions. The 7.0 mm group had statistically significantly greater induced astigmatism than the 5.0 mm group (P =.01, simple subtraction; P =.002, vector analysis).

CONCLUSIONS

Enlarging the size of the chevron incision up to 7.0 mm resulted in a small increase in induced astigmatism. The enlarged incision simplified the operative technique.

Small incision extracapsular cataract surgery with manual phacotrisection

PURPOSE

To evaluate the safety and efficacy of small incision extracapsular cataract extraction (ECCE) using the manual phacotrisection technique.

SETTING

Department of Ophthalmology, Turgut Ozal Medical Center, InönüUniversity, Malatya, Turkey.

METHODS

Fifty-nine eyes of 54 patients had small incision ECCE by the manual phacotrisection technique. Mean follow-up was 10 months. After capsulorhexis and hydrodissection were performed, the endonucleus was prolapsed into the anterior chamber and trisected using an anteriorly positioned triangular trisector and posteriorly placed solid vectis. Pieces were extracted with a forceps through a small incision.

RESULTS

Postoperatively, best spectacle-corrected visual acuity of 20/40 or better was achieved in 48 eyes (83%) and of 20/25 or better in 28 eyes (47%). The most frequent intraoperative complication was posterior capsule rupture (n = 5). Of eyes that developed posterior capsule rupture, 3 had vitreous loss and 2 had implantation of an anterior chamber intraocular lens (IOL). In 44 eyes, the IOL was implanted in the bag and in 12 eyes, in the ciliary sulcus. The most significant postoperative complication was transient corneal edema, which developed in 32 eyes (54%). No permanent complications (e.g., corneal endothelial decompensation) occurred in any case.

CONCLUSIONS

Manual phacotrisection has several advantages such as nucleus safety, less dependence on assistant personnel, the elimination of the phaco machine, and cost effectiveness.

Extracapsular cataract extraction with a sutureless incision for dense cataracts

PURPOSE

To evaluate the use of extracapsular cataract extraction (ECCE) via a sutureless incision for dense cataracts.

SETTING

Nagata Eye Clinic, Nara, Japan.

METHODS

This retrospective study comprised 51 eyes of 45 consecutive patients with dense cataracts who had ECCE with a sutureless incision between January 1996 and April 1998. A scleral incision from 6.0 to 8.5 mm was made at 12 o'clock or between 9 and 12 o'clock (oblique incision). Measures of outcome included postoperative visual acuity, surgically induced astigmatism (polar value method and vector analysis), complications, and changes in corneal endothelial cell density and morphology.

RESULTS

Self-sealing was achieved in 45 eyes (88.2%), but additional sutures were required in 6 (11.8%). Intraoperative complications included posterior capsule rupture in 3 eyes (5.9%) and iris prolapse in 2 (3.9%). Corneal flattening against the preoperative steep meridian was observed in the 12 o'clock incision group (0.24 diopter [D] +/- 1.23 [SD]) and in the oblique incision group (0.17 +/- 0.89 D). By vector analysis, the surgically induced vector was 1.41 +/- 0.72 D in the 12 o'clock incision group and 1.02 +/- 0.66 D in the oblique incision group. After surgery, the mean cell loss was 8.2% +/- 12.5%. There were no significant differences, however, between other preoperative and postoperative morphometric indexes.

CONCLUSION

This fast, safe, and inexpensive technique may be a viable treatment for dense cataracts with large, hard nuclei.