Vision outcomes in dogs with primary glaucoma surgically treated with lensectomy and endolaser cyclophotocoagulation after an Ahmed valve gonioimplantation failure

OBJECTIVE

The aim of this study was to retrospectively evaluate vision outcomes of dogs with primary angle closure glaucoma (PACG) that underwent Ahmed valve gonioimplantation (AVG) followed by lensectomy and endolaser cyclophotocoagulation (ECP) with or without bleb resection after AVG failure.

PROCEDURE

Medical records from 2008 to April 2022 were reviewed. All patients selected had an AVG performed first. Following valve failure, lensectomy-ECP was performed in addition to bleb resection as indicated. Additional ECP and AVG replacement surgeries were performed as deemed medically necessary. Main outcomes evaluated included vision preservation, average IOP reduction, and the number of glaucoma medications (both oral and topical) at 6, 12, 24, and 36 months.

RESULTS

Fourteen eyes from 13 patients were included in the study. Females were predominant (n = 9) compared with males (n = 4). Mean age at initial glaucoma diagnosis was 6.82 years. Following AVG and lensectomy-ECP, vision was preserved in 93%, 84%, 60%, and 48% of eyes at 1, 2, 3, and 4 years respectively. Following lensectomy-ECP, there was a significant reduction in mean IOP of 9.64 mmHg (p = .015) and 9.71 mmHg (p = .016) at 2 and 6 months, respectively. There was a reduction in mean IOP of 2.45, 7.25, and 12.25 mmHg at 12, 24, and 36 months, respectively, which was not statistically significant. There was a significant decrease in the number of glaucoma medications at all evaluated time points except 24 months.

CONCLUSIONS

Combined AVG and lensectomy-ECP is successful in maintaining vision long term as well as decreasing IOP, and the number of glaucoma medications administered.

A New Technique of Pars Plana Vitrectomy With Microinterventional Nucleus Disassembly to Reduce the Energy of Fragmatome Lensectomy for Posteriorly Dislocated Crystalline Lens Removal

PURPOSE

To describe a novel technique of lens disassembly in posteriorly dislocated crystalline lens removal.

METHODS

A microinterventional microfilament loop device was introduced through the sclerotomy created for the fragmatome to cleave the lens into smaller, manageable pieces.

RESULTS

Five cases were performed with this technique with improved visual acuity and no complications.

CONCLUSION

The use of microinterventional nucleus disassembly during pars plana vitrectomy for retained lens material is a novel approach with potential advantages including decreased operating time and reduced complications secondary to excessive production of ultrasound energy.

Sulcus intraocular lens implantation in 17 dogs using a modified ab externo technique

OBJECTIVE

To describe a modified ab externo method of sulcus intraocular lens (IOL) fixation and report outcomes of eyes treated with this approach.

PROCEDURES

Records of patients with lens instability or luxation that underwent a lensectomy and sulcus IOL implantation from January 2004 to December 2020 were reviewed.

RESULTS

Nineteen eyes of 17 dogs had a sulcus IOL placed via a modified ab externo approach. The median follow-up time was 546 days (range 29-3387 days). Eight eyes (42.1%) developed POH. A total of six eyes (31.6%) developed glaucoma and required medical management long term to control IOP. The IOL position was satisfactory in most cases. Nine eyes developed superficial corneal ulcers within 4 weeks following surgery, all of which healed without complication. At the time of the last follow-up, 17 eyes were visual (89.5%).

CONCLUSIONS

The technique described represents a potentially less technically challenging option for sulcus IOL implantation. The success rate and complications are similar to previously described approaches.

Management of Childhood Glaucoma Following Cataract Surgery

Glaucoma remains a frequent serious complication following cataract surgery in children. The optimal approach to management for 'glaucoma following cataract surgery' (GFCS), one of the paediatric glaucoma subtypes, is an ongoing debate. This review evaluates the various management options available and aims to propose a clinical management strategy for GFCS cases. A literature search was conducted in four large databases (Cochrane, PubMed, Embase, and Web of Science), from 1995 up to December 2021. Thirty-nine studies-presenting (1) eyes with GFCS; a disease entity as defined by the Childhood Glaucoma Research Network Classification, (2) data on treatment outcomes, and (3) follow-up data of at least 6 months-were included. Included papers report on GFCS treated with angle surgery, trabeculectomy, glaucoma drainage device implantation (GDD), and cyclodestructive procedures. Medical therapy is the first-line treatment in GFCS, possibly to bridge time to surgery. Multiple surgical procedures are often required to adequately control GFCS. Angle surgery (360 degree) may be considered before proceeding to GDD implantation, since this technique offers good results and is less invasive. Literature suggests that GDD implantation gives the best chance for long-term IOP control in childhood GFCS and some studies put this technique forward as a good choice for primary surgery. Cyclodestruction seems to be effective in some cases with uncontrolled IOP. Trabeculectomy should be avoided, especially in children under the age of one year and children that are left aphakic. The authors provide a flowchart to guide the management of individual GFCS cases.

Peripheral iridectomy for preventing iris-related complications in glued intraocular lens surgery in children

Purpose

To assess the role of surgical peripheral iridectomy (PI) in preventing iris-related complications associated with glued intraocular lens (GIOL) surgery in children with bilateral ectopia lentis.

Methods

Nonrandomized interventional case series of 34 eyes of 17 children (<15 years of age) who underwent pars plana lensectomy (PPL) and GIOL surgery between January 2013 and December 2016. Eyes with surgical PI (January 2013-June 2015) were compared with those without surgical PI (July 2015-December 2016). The primary outcome measure of the role of surgical PI in GIOL surgery was to account for complications such as optic capture, secondary glaucoma, intraocular lens (IOL) dislocation, or repeat surgery. The secondary outcomes were changes in the best-corrected visual acuity (BCVA).

Results

The mean age at surgery was 8.8 years (range: 3.5-15 years). Surgical PI was conducted in 15 eyes. Among the 19 eyes without PI, 9 eyes had complications (optic capture -6; rise in IOP -4; IOL subluxation -4; repeat surgery -5). The complications were significantly less in the PI group, P = 0.02. There was a statistically significant improvement in BCVA (P = 0.0001) in all the patients. The mean presenting BCVA was 0.99 (±0.79) logMAR (Snellen ≈ 20/200) and post BCVA was 0.40 (±0.50) (Snellen ≈ 20/50). The mean preoperative refraction was - 9 D (±8D) (range: -5 D to -23D) and postoperative was -1 (±1.15) D. The mean follow-up was 25.4 months.

Conclusion

Surgical PI along with GIOL surgery in children undergoing PPL is shown to reduce optic-capture-related complications.

Design Parameters for a Small-Gauge Fragmatome

Purpose

Manufacturers of surgical instrumentation have increasingly sought to decrease the size of ophthalmic surgical instruments. We have used finite element modeling to model the stress and strain present in a fragmatome as a function of driving frequency and fragmatome dimensions.

Methods

Finite element calculations using the COMSOL Multiphysics system v3.5 were used to elucidate the influence of wall thickness, length, and excitation frequency on a titanium fragmatome tube with outer diameters of 20, 23, 25, and 27 gauge.

Results

By coupling structural mechanics, fluid mechanics, and acoustical physics, we were able to determine the eigenfrequencies (resonant frequencies) as well as parameters in which the von Mises stress in a fragmatome tube exceeds the yield strength, leading to destruction of the instrument.

Conclusion

Solid fragmatomes have far fewer possible failure modes than fragmatomes with a standard wall thickness. Eigenfrequency analysis and finite element calculations can be critical in predicting potentially catastrophic designs in modern surgical instruments.

Translational Relevance

Instruments developed for microsurgical applications cannot always simply be scaled down versions of conventional instruments. Such an approach can lead to potentially dangerous intraoperative failures, such as a fragmatome shattering inside the eye. Modern engineering techniques are increasingly necessary to investigate potential instrument failure mechanisms and to optimize device performance in a design in silico before in vivo testing.

Visual outcome and surgical results in children with Marfan syndrome

IMPORTANCE

To determine visual and surgical results in children with Marfan syndrome.

BACKGROUND

Marfan syndrome involves ocular complications which can lead to visual disturbance and amblyopia. Data about the visual and surgical results in children with Marfan syndrome is vital for the clinical management of these patients.

DESIGN

Retrospective data analysis.

PARTICIPANTS

Eighty-two eyes of 41 patients with a genetically proved diagnosis of Marfan syndrome.

METHODS

Medical records of patients with Marfan syndrome were reviewed between 2007 and 2017. Ocular complications, visual acuity (VA) of patients with/without lensectomy and surgical method were evaluated.

MAIN OUTCOME MEASURES

VA outcomes of patients with Marfan syndrome with/without surgical repair of ectopia lentis.

RESULTS

In 27 (66%) of the 41 patients a bilateral subluxation of the lens was visible and 14 (52%) patients received lensectomy. The mean age at initial presentation was 12.3 ± 9 years and mean follow-up was 3 years (range 1-7). VA varied from 1.2 to -0.1 logMAR at first examination. At initial presentation, mean VA was 0.1 ± 0.7 logMAR in patients with a normal lens status (n = 14) and 0.3 ± 0.5 logMAR in patients with subluxation of the lens (n = 27) (P < .01). VA improved from 0.2 ± 0.5 logMAR to 0.1 ± 0.5 logMAR (P = .06) in children with subluxation of the lens who did not need a lensectomy (n = 12) and from 0.5 ± 0.5 logMAR to 0.2 ± 0.5 logMAR (P = .02) in patients who were referred to lensectomy with/without secondary lens implantation.

CONCLUSIONS AND RELEVANCE

In Marfan syndrome subluxation of the lens was found in the majority of children. Improvement of VA resulted in children with subluxation of the lens and following lensectomy.

Use of a Juvenile Rabbit Animal Model to Evaluate Therapeutic Interventions for Postoperative Inflammation and Fibrin Formation After Lensectomy

Purpose

We used the juvenile rabbit as a model for investigating therapeutic interventions for postoperative inflammation and fibrin formation following intraocular lens (IOL) insertion for management of pediatric cataracts.

Methods

Twelve 6- to 7-week-old, 600 to 900 g rabbits underwent bilateral clear-cornea lensectomy via irrigation and aspiration with IOL insertion. Following wound closure, enoxaparin 8 mg (n = 6 eyes), preservative-free triamcinolone 0.5 mg (n = 6), 8 mg enoxaparin plus 0.5 mg triamcinolone (n = 6), or balanced salt solution (n = 6) was injected into the anterior chamber. Slit-lamp examinations and optical coherence tomography (OCT) scans were performed postoperatively on days 3 through 7, and 14 to characterize levels of inflammation and fibrin. Using 17 additional rabbits, enzyme-linked immunosorbent assays (ELISAs) with 100 μL of aqueous humor were performed to quantify the amount of fibrinogen and fibrin preoperatively and on postoperative day 3. Immunohistochemistry was performed to confirm the presence of fibrin.

Results

Enoxaparin alone and combined with triamcinolone reduced the amount of fibrin present in the anterior chamber compared to untreated eyes, which corresponded to an increase in OCT signal strength. Despite the clear visual axis shown in clinical images, the combination treatment group had the highest levels of soluble fibrin when assessed by ELISA. Immunohistochemistry confirmed the presence of insoluble fibrin seen clinically.

Conclusions

A combination of enoxaparin and triamcinolone appears to provide the most therapeutic benefit by reducing fibrin formation and postoperative inflammation.

Translational Relevance

The juvenile rabbit is an excellent model to investigate inflammation and fibrin formation following lensectomy with IOL insertion and possibly any intraocular surgery in children.

Current concepts and techniques of vitrectomy for retinopathy of prematurity

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. ROP screening and interventions (e.g., laser ablation and anti-vascular endothelial growth factor [VEGF] therapy) at the right time can reduce disease activity and prevent retinal detachment. However, sometimes, ROP is refractory to treatment, leading to tractional retinal detachment (TRD), requiring surgical intervention, such as vitrectomy. Vitrectomy for Stage 5 ROP (total retinal detachment) is beneficial in preventing total blindness in some patients. However, it has poor anatomical and functional results. Vitrectomy (lens-sparing vitrectomy, if possible) should be performed at Stage 4A ROP (partial TRD not involving the macula) because the anatomical and functional results are much better.

Surgical treatment and visual outcomes of cataract with persistent hyperplastic primary vitreous

AIM

To evaluate the surgical treatment and visual outcomes of eyes with cataract and persistent hyperplastic primary vitreous (PHPV).

METHODS

This retrospective study included patients with cataract and PHPV treated with various strategies. Anterior PHPV was treated using phacoemulsification with underwater electric coagulation on posterior capsule neovascularization, posterior capsulotomy, anterior vitrectomy, and intraocular lens (IOL) implantation. Posterior PHPV was treated with lensectomy, posterior vitrectomy, retinal photocoagulation, and IOL implantation or silicone oil tamponade. Visual acuity (VA), pattern visual evoked potential (P-VEP), anatomic recovery, postoperative complications, and amblyopia outcome were examined. Subjects were followed-up for 3-48mo after surgery.

RESULTS

Of the 30 patients (33 eyes) with congenital cataract and PHPV included (average age, 39.30±35.47mo), 9 eyes had anterior PHPV and 24 had posterior PHPV. Thirty-two eyes were surgically treated. Eyes with anterior PHPV received an IOL during one-stage (6 eyes) and two-stage (3 eyes) implantation. Postoperative complications included retinal detachment (1 eye) and recurrent anterior chamber hemorrhage (1 eye). In eyes with posterior PHPV, 6 and 11 eyes received IOLs in one- and two-stage procedures, respectively. Silicone oil was retained in 2 eyes, and IOLs were not implanted in 4 eyes. VA significantly improved in 25 eyes following operations and 3-48mo of amblyopia treatment. P-VEP P₁₀₀ was improved following surgery in both PHPV types.

CONCLUSION

Our surgical strategies are appropriate and effective for anterior and posterior PHPV. Early surgical intervention and amblyopia therapy result in positive treatment outcomes.

Anterior iris-claw intraocular lens implantation for the management of nontraumatic ectopia lentis: long-term outcomes in a paediatric cohort

PURPOSE

To report the feasibility and long-term safety of lensectomy and iris-claw intraocular lens (IOL) implantation to treat children with severe ectopia lentis in a paediatric tertiary hospital.

METHODS

Prospective cohort study of 21 eyes from 12 patients with severe ectopia lentis and visual acuity <20/63. All eyes underwent 23-gauge pars plana vitrectomy, lensectomy, iridectomy and Artisan IOL implantation in the anterior chamber with iris-claw enclavation via pars plana. Mean age at surgery was 8.0 ± 5.3 yo (range 3-17 years). A full ophthalmologic examination including best-corrected visual acuity (BCVA), biomicroscopy, intraocular pressure (IOP) measurement, fundus evaluation and central endothelial cell count (cECC) was performed pretreatment, at 3 months' postsurgery, and every 6 months thereafter. Ultrasound biomicroscopy (UBM) was performed 12 months after surgery.

RESULTS

Mean follow-up was 39.3 ± 13.0 months. Best-corrected visual acuity (BCVA) (mean ± SD) improved from 0.91 ± 0.29 logMar preoperatively to 0.18 ± 0.23 logMar at final follow-up (p < 0.0001). Mean distance from the endothelium to the anterior IOL surface after surgery was 3.11 ± 0.61 mm. Postsurgically, cECC loss was 5.04% ± 9.58% with an annual cECC loss rate of 3.16% ± 4.46%. One patient developed IOL dislocation and retinal detachment after severe ocular contusion requiring vitrectomy, IOL refixation and gas tamponade. Another patient developed cystoid macular oedema, managed with intravitreal dexamethasone.

CONCLUSION

This technique is both feasible and effective to manage severe ectopia lentis in children. Lifetime ophthalmic follow-up including cECC measurement, IOL position monitoring and fundus examination is mandatory in these patients.

Safety of Simultaneous Bilateral Intraocular Surgery Under General Anesthesia in Pediatric Patients

Objective:

To evaluate the risks and benefits of simultaneous bilateral intraocular surgery (SBIS) in pediatric patients at a university hospital in the Kingdom of Saudi Arabia, who are placed under general anesthesia for the procedure.

Methods:

This retrospective, noncomparative case study comprised 15 children, who underwent bilateral cataract surgery and/or primary or secondary intraocular lens (IOL) implantation in one sitting between November 2008 and July 2014. Seven patients had bilateral lensectomy primary posterior capsulotomy and anterior vitrectomy, and the remaining eight patients had bilateral IOL implantation at the capsular bag either primarily IOL implantation (two cases) at the time of cataract extraction or secondary IOL implantation at the capsular bag (six cases). Bilateral surgeries were performed sequentially by the same surgeon, with strict aseptic separation of the two surgeries, while the patient was under general anesthesia.

Results:

The age of the patients at the time of the surgery ranged from 7 months to 9 years (mean age 2.13 years). The patients were followed up approximately for 4 months postsurgery. There were no catastrophic complications from the anesthesia (death, asphyxia, cardiac or respiratory arrest, or seizures) nor were there any intraoperative complications that necessitated cancelation of surgery in the second eye. Postoperatively, one patient was noted to have reproliferation of lens material in one eye. However, no serious postoperative complications such as endophthalmitis, aphakic glaucoma, and hyphema were noted.

Conclusion:

SBIS conducted during the same operative procedure is an alternative to sequential surgery in selected pediatric patients if operative guidelines and surgical asepsis are strictly followed.

Primary angle-closure glaucoma: an update

Primary angle-closure glaucoma is potentially a devastating disease, responsible for half of glaucoma-related blindness worldwide. Angle closure is characterized by appositional approximation or contact between the iris and trabecular meshwork. It tends to develop in eyes with shallow anterior chambers, anteriorly positioned or pushed lenses, and angle crowding. Risk of primary angle-closure glaucoma is high among women, the elderly and the hyperopic, and it is most prevalent in Asia. Investigation into genetic mechanisms of glaucoma inheritance is underway. Diagnosis relies on gonioscopy and may be aided by anterior segment optical coherence tomography and ultrasound biomicroscopy. Treatment is designed to control intraocular pressure while monitoring changes to the angle and optic nerve head. Treatment typically begins with medical management through pressure-reducing topical medications. Peripheral iridotomy is often performed to alleviate pupillary block, while laser iridoplasty has been found effective for mechanisms of closure other than pupillary block, such as plateau iris syndrome. Phacoemulsification, with or without goniosynechialysis, both in eyes with existing cataracts and in those with clear lenses, is thus far a viable treatment alternative. Long-term research currently underway will examine its efficacy in cases of angle closure in early stages of the disease. Endoscopic cyclophotocoagulation is another treatment option, which can be combined with cataract surgery. Trabeculectomy remains effective therapy for more advanced cases.

Serum levels of intravitreal bevacizumab after vitrectomy, lensectomy and non-surgical controls

PURPOSE

To determine serum level differences of intravitreally-placed bevacizumab after vitrectomy and lensectomy-vitrectomy and to compare these with non-operated eyes in a rabbit model.

METHODS

Five Dutch-belted rabbits underwent pars plana vitrectomy (PPV), five rabbits underwent pars plana lensectomy (PPL) and five rabbits served as non-surgical controls. Twelve days following the surgical procedures, each operated eye underwent an intravitreal injection consisting of 1.25 mg/0.05 mL bevacizumab. Serum levels from each rabbit were drawn on days 2, 4, 7, 10, 14, 21, 28 and 35 and were measured with ELISA immunoassay.

RESULTS

The average peak serum concentration (Cmax) was highest for the PPL group (11.33 μg ± 3.48 mL), and was similar between the PPV (5.35 μg ± 2.69 mL) and non-surgical control groups (5.35 μg ± 0.69 mL). The average time to maximal plasma concentration (Tmax) in days was earliest for the PPL group (2.8 ± 0.47), followed by the PPV (5.6 ± 0.84) and non-surgical control groups (6.4 ± 0.71). The PPL group had higher serum levels than the other two groups until day 7 that was significant only at day 2 (p < 0.0001). After day 4, there were no significant differences or trends between any of the three groups. The half-life (T1/2) was fastest for the PPL group (1.41 ± 0.21 d) followed by the PPV (2.80 ± 3.35 d) and non-surgical control groups (6.69 ± 10.4 d).

CONCLUSIONS

Serum bevacizumab levels were initially elevated following lensectomy and vitrectomy compared to non-surgical eyes following intravitreal injection. The half-life of bevacizumab was prolonged in non-surgical eyes presumably due to a slower release from the vitreous cavity.

Vitrectomy, lensectomy and silicone oil tamponade in the management of retinal detachment associated with choroidal detachment

AIM

To report the results of combined vitrectomy, lensectomy and silicone oil (SO) tamponade in treating primary rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD).

METHODS

A retrospective, consecutive and case series study of 21 subjects with concurrent RRD associated with CD was conducted. All subjects underwent a standard three-port 20G pars plana vitrectomy (PPV) with lensectomy and silicone oil tamponade. Mean follow-up time was 8 months (rang from 4 to 19 months). The primary and final anatomic success rate, visual acuity and final intraocular pressure(IOP) were recorded and analyzed.

RESULTS

Of 21 subjects, 8 were women and 13 were men. Age at presentation ranged from 22 to 75 years (mean 57.4 years). The presenting vision ranged from light perception to 0.15. The initial IOP ranged from 3mmHg to 12mmHg (mean 6.2mmHg). All eyes were phakic except one pseudophakic. No intraocular lens was implanted during the primary surgical intervention. Fifteen of 21 (71.4%) eyes had retina reattached after one operation. Six eyes had recurrent inferior retinal detachment due to proliferation. Five of them were successfully reattached after one or more additional operations. Mean IOP at final follow-up was 15.2mmHg (range from 8mmHg to 20mmHg). One case declined for further operation. The final reattachment rate was 95.2%. Visual acuity improved in 19 (90.5%) eyes, was unchanged in 1 (4.8%) eye and decreased in 1 (4.8%) eye.

CONCLUSION

Combination of vitrectomy, lensectomy and silicone tamponade is an effective method in treating RRD associated with CD, reducing the incidence of postoperative hypotony.

Optic capture pars plana lensectomy

Objective

To describe an optic capture pars plana lensectomy technique.

Methods

After core vitrectomy, pars plana lensectomy is performed with preservation of the anterior capsule. Capsulorhexis is performed on the preserved anterior capsule through a 2.8 mm clear corneal incision. An intraocular lens (IOL) is placed in the ciliary sulcus, and then the optic of the IOL is pushed back to the vitreous cavity so that the optic is captured by the surrounding capsulorhexis margin.

Results

The captured IOL-capsule diaphragm remained stable during air–fluid exchange and prevented air prolapse to the anterior chamber. IOL stability and a clear visual axis were preserved during the follow-up period.

Conclusion

With this modified pars plana lensectomy technique, stable IOL position and clear visual axis can be maintained when a pars plana approach is needed during combined cataract and vitreoretinal surgery.

23-gauge pars plana vitrectomy for management of posteriorly dislocated crystalline lens

Purpose

Management of posteriorly dislocated crystalline lens has traditionally been performed with a standard 20-gauge vitrectomy system. This study demonstrates the use of a 23-gauge vitrectomy system for removal of retained lens fragments secondary to spontaneous dislocation or complicated cataract extraction.

Methods

A retrospective, noncomparative, interventional consecutive case series at a single university medical center.

Results

Fourteen eyes of 14 patients underwent a 23-gauge vitrectomy for removal of retained lens. Mean age was 75 years. Mean logMAR (logarithm of minimum angle of resolution) visual acuity was 1.47 (Snellen equivalent 20/600) preoperatively and 0.37 (Snellen equivalent 20/50) postoperatively. A 20-gauge fragmatome was used in 64% of cases. The mean time to the best post-vitrectomy acuity was 4.9 weeks. The mean healing time was 25 days (6–48 days). Post- vitrectomy complications included choroidal detachment (two patients), vitreous hemorrhage (two patients), and acute ocular hypertension (two patients). The mean length of follow-up was 6.2 months (1–13 months).

Conclusion

A 23-gauge vitrectomy system alone or in combination with the 20-gauge fragmatome is a safe and efficacious option for removal of dense posteriorly dislocated crystalline lens material.

Combined 20-gauge and 23-gauge pars plana vitrectomy for the management of posteriorly dislocated lens: a case series

Objective:

To present a new surgical approach for the management of posteriorly dislocated lens by using a combination of 20-gauge (20G) and 23-gauge (23G) pars plana vitrectomy.

Design:

An interventional case series

Methods:

This technique was performed on six patients (five men, one woman; mean age, 66.67 years; range, 66–72 years). Two 23G trans-conjunctival sclerotomy ports were created for infusion and illumination along with a 20G sclerotomy port for introducing the vitrectomy probe or fragmatome.

Results:

This procedure was successfully performed on six eyes. On postoperative day one, the media were clear and the retina could be seen by indirect ophthalmoscopy. Hyphema developed in one eye and resolved within a week. There were no observed cases of retinal tear, wound leakage, hypotony, or endophthalmitis. The post-operative follow-up period ranged from three to twelve months (mean, 8.1 months). By the final visit, two patients had achieved a visual acuity of 20/40 or better, three patients, 20/70, and one patient, 20/200.

Conclusion:

The combination of 20G and 23G pars plana vitrectomy is an efficacious and safe procedure for management of posteriorly dislocated lens.

Deposition of silicone oil droplets in the residual anterior lens capsule after vitrectomy and lensectomy in rabbits

AIM

To examine the histology of preserved anterior lens capsule in vitrectomised and lensectomised rabbit eyes with and without silicone oil tamponade.

METHODS

Forty adult Japanese albino rabbits received two port vitrectomy and lensectomy with or without silicone oil tamponade in one eye under both general and topical anaesthesia. Anterior lens capsule was preserved during operation. After healing intervals residual anterior capsule was histologically observed under light or electron microscopy.

RESULTS

Immediately after operation, cuboidal lens epithelial cells were observed on the posterior surface of the preserved anterior capsule. During healing intervals in eyes with or without silicone oil tamponade, regenerated lens structure of Sommerring's ring and fibrous tissue formed in the peripheral and central areas of the residual capsule, respectively. Ultrastructural observation revealed the presence of many vacuoles amid matrix accumulation on the posterior capsular surface, suggesting the deposition of emulsified silicone oil droplets.

CONCLUSION

Lens epithelial cells produce regenerated lenticular structure and fibrous tissue on the residual capsule following vitrectomy and lensectomy in rabbits. Silicone oil droplets formed by its emulsification deposit in extracellular matrix accumulated on the posterior surface of the anterior capsule. Emulsified silicone may potentially enhance opacification of residual anterior capsule following pars plana vitrectomy by silicone oil deposition and subsequent activation of lens epithelial cells.