Single-piece AcrySof in the newborn rabbit eye

Ocular biometric changes following unilateral cataract surgery in children

Purpose

To analyze ocular biometric changes following unilateral cataract surgery in children.

Methods

A total of 57 children aged under 13 years who underwent unilateral cataract surgery were analyzed. Groups were classified according to their age at surgery: group I (age <3), II (3≤ age <6), III (6≤ age <9), and IV (age ≥9). The myopic shift, axial growth, and corneal curvature changes were compared between the pseudophakic eyes and the fellow phakic eyes.

Results

During 7.81 ± 4.39 years, the overall myopic shift (D) and the rate of myopic shift (D/year) were significantly higher at -3.25 ± 3.21 D and -0.45 ± 0.44 D/year in the pseudophakic eyes than -1.78 ± 2.10 D and -0.22 ± 0.29 D/year in the fellow phakic eyes (P = 0.01, 0.004). Group I (-1.14 ± 0.66 vs -0.02 ± 0.45 D/year) and group II (-0.63 ± 0.37 vs -0.31 ± 0.29 D/year) showed significantly higher rate of myopic shift in the pseudophakic eyes than in the phakic eyes. The rate of myopic shift in the pseudophakic eyes decreased in the older age groups (P = 0.001). There was no significant between-eye difference in the changes in axial length and keratometric values postoperatively.

Conclusion

Following unilateral cataract surgery, a significant postoperative myopic shift was noticed in the pseudophakic eyes compared to the fellow phakic eyes in groups under 6 years old. Postoperative myopic shift and the resultant anisometropia should be considered when selecting the optimal power of IOL in young children requiring unilateral cataract surgery.

INTRA-SCLERAL PARATHALAMUS IMPLANT: EFFICACY AND SAFETY IN RABBIT EYES

PURPOSE

A variety of anti-glaucomatous shunt designs have been proposed so far. This study evaluates the feasibility of a novel shunt design, the intra-scleral parathalamus implant (IPI), in a rabbit eye model.

METHODS

Ten healthy albino rabbits were included. Measurements of the IOP, using TonoPenXL, as well as ocular rigidity (OR) and aqueous outflow facility (AO), using a previously described methodology, were performed in both eyes of each animal. Subsequently, the IPI was implanted at the left eye of all animals whereas the right eye served as control. Measurements of IOP were repeated at weekly intervals for 2 months postoperatively whereas measurements of OR and AO were repeated at the 1st and 2nd postoperative week.

RESULTS

The IOP decreased significantly whereas the AO increased significantly postoperatively at the operated eyes. A significant postoperative decrease in OR was also recorded at the operated eyes. Respective differences at the fellow eyes were statistically not significant. Two animals developed postoperative complications and were excluded from follow-up.

CONCLUSIONS

Results imply that the implantation of the IPI is feasible in rabbit eyes with significant favorable effects on the IOP, AO and OR.

Intraocular lens as a drug delivery system for dexamethasone

PURPOSE

To evaluate the effect of an intraocular lens (IOL) coated with dexamethasone on postoperative inflammation after cataract surgery.

METHODS

Clear lens extraction was performed bilaterally in eight 8-week-old rabbits. An uncoated silicone IOL (CeeOn; AMO, Santa Ana, CA, USA) was implanted in one randomly selected eye. In the other eye, the same silicone IOL model was implanted but was coated with dexamethasone. Aqueous humour was obtained preoperatively and on days 1, 3, 7, 14 and 28 postoperatively. Three inflammatory parameters were measured and compared between the eyes: prostaglandin E2 (PGE2), white blood cell (WBC) count and protein content. The animals were killed on day 28 postoperatively.

RESULTS

PGE2 levels measured on days 1, 3 and 7 were significantly lower in eyes with a coated IOL compared to eyes with an uncoated IOL (p < 0.01). The WBC count was significantly lower in eyes with a coated IOL on days 1 (p < 0.01) and 3 (p < 0.05). There was significantly less protein in eyes with a coated IOL on days 1 and 3 (p < 0.01).

CONCLUSION

Coating a silicone IOL with dexamethasone significantly reduced postoperative inflammation after clear lens extraction in rabbits.

Single-piece AcrySof intraocular lens implantation in children with congenital and developmental cataract

PURPOSE

To evaluate surgical outcomes of 1-piece AcrySof SA30AL intraocular lens (IOL) (Alcon Laboratories) implantation in children having surgery for congenital and developmental cataracts.

SETTING

Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India.

METHODS

This prospective observational study comprised 134 consecutive eyes of 84 children from 2 to 15 years old who had surgery for congenital and developmental cataract. Two groups were formed depending on the age of the child at surgery. Primary posterior continuous curvilinear capsulorhexis (PCCC) was performed in children younger than 6 years (Group 1, 66 eyes), and no PCCC was performed in children older than 6 years (Group 2, 68 eyes). Vitrectomy was not performed. An AcrySof IOL was implanted in the bag in all eyes except 1 in Group 1, which received a sulcus-fixated IOL. The study's primary outcome measures were the incidence of visual axis obscuration and the need for a secondary procedure to clear the axis. Secondary observations included the incidence of posterior synechias, cell deposits, and haptic compression. A test of proportion was applied to determine whether age was a risk factor for the development of visual axis obscuration.

RESULTS

The mean age at surgery was 6.0 years +/- 3.2 (SD). The mean follow-up was 2.6 +/- 0.6 years. In Group 1, 20 eyes (30.3%) developed visual axis obscuration but only 6 (9.1%) required a secondary procedure. In Group 2, 20 eyes (29.4%) developed visual axis obscuration and 10 (14.7%) required secondary procedures. Posterior synechias were observed in 2 eyes (3.0%) in Group 1 and none in Group 2. Cell deposits were seen in 8 eyes (12.1%) in Group 1 and 8 eyes (11.8%) in Group 2. Haptic compression was noted in 1 eye in Group 2. Mild IOL decentration was observed in the 1 eye with a sulcus-fixated IOL.

CONCLUSION

The 1-piece AcrySof IOL provided satisfactory visual axis clarity, produced an acceptable inflammatory response, and maintained centration in pediatric eyes.

Implantation of single-piece foldable acrylic IOLs in small children in the Ukraine

PURPOSE

To evaluate the efficacy and outcome of implantation of a single-piece foldable acrylic intraocular lens (IOL) in children younger than 2 years in the Ukraine.

METHODS

A total of 31 children from all over the Ukraine with a median age of 11 months (range 2-28 months) underwent cataract surgery with anterior and posterior capsulorhexis, implantation of a single-piece AcrySof SA30AL IOL and anterior dry vitrectomy. Of these, 22 patients attended the last follow-up. Ten patients had follow-up periods of 12 months; 12 had follow-up periods of 18 months. At the postoperative visits, we investigated visual acuity (VA), whether or not the subject had strabismus, lens epithelial cell migration and signs of secondary glaucoma.

RESULTS

The single-piece IOL remained clinically centred in all eyes. No secondary glaucoma was detected. Eleven patients needed surgery for after-cataract. All but two patients achieved better VA after surgery. Many patients suffered from deprivation amblyopia as quite a few cataracts were probably congenital; however, the improvement in VA shows that cataract surgery was worth performing despite the late intervention.

CONCLUSION

The foldable single-piece acrylic IOL seems to be well tolerated by children aged 0-2 years. No serious complications were seen and no patient developed secondary glaucoma within the follow-up time. However, lens epithelial cells are very lively in this age group.

Cataracts in children

Bilateral congenital cataract is the most common cause of treatable childhood blindness. Nuclear cataract is usually present at birth and is nonprogressive, whereas lamellar cataract usually develops later and is progressive. Surgery must be performed promptly in cases with dense congenital cataract; if nystagmus has developed, the amblyopia is irreversible. A treatment regimen based on surgery within 2 months of birth combined with prompt optical correction of the aphakia and aggressive occlusion therapy with frequent follow-up has been successful in unilateral and bilateral cases. Both anterior and posterior capsulorhexes are performed in most children. Intraocular lens implantation can be performed safely in children older than 1 year. Anterior dry vitrectomy is recommended in preschool children to avoid after-cataract. Opacification of the visual axis is the most common complication of cataract surgery in children. Secondary glaucoma is the most sight-threatening complication and is common if surgery is performed early. Life-long follow-up is essential in these cases.

After-cataract in children having cataract surgery with or without anterior vitrectomy implanted with a single-piece AcrySof IOL

PURPOSE

To evaluate whether cataract surgery in children should be performed with anterior vitrectomy and to examine the properties of the AcrySof SA30AL intraocular lens (IOL) in the pediatric eye.

SETTING

Filatov Institute, Odessa, Ukraine.

METHODS

Cataract surgery was performed in 66 children aged 3 to 15 years. They were randomized to surgery with or without anterior vitrectomy. All eyes were implanted with the single-piece AcrySof SA30AL IOL (Alcon). During the study, the patients who needed surgery for after-cataract had a second surgical procedure. Two years after surgery, the surgical method was evaluated using exact logistic regression. Also, the Evaluation of Posterior Capsule Opacification (EPCO) score was compared between the patients who had surgery for after-cataract and the patients who did not need this. The presence of posterior synechias and centration of the IOL were assessed.

RESULTS

Children in the younger age group (</=62 months at surgery) had surgery for after-cataract more often than children in the older age group (P<.01). Patients who did not receive an anterior vitrectomy had surgery for after-cataract more often (P<.01). Age at surgery and whether an anterior vitrectomy was performed did not significantly affect the EPCO score. The patients who had surgery for after-cataract had a significantly higher EPCO score (P<.001). The IOL remained centered in all eyes; no eye developed posterior synechias.

CONCLUSIONS

This prospective study shows that cataract surgery with anterior vitrectomy is advantageous in younger patients concerning after-cataract formation. The AcrySof SA30AL maintains good centration, produces minimal inflammation, and is well tolerated in the pediatric eye.