A comparative study of the 91Z and other anterior chamber intraocular lenses

[Characteristics and management of Uveitis-Glaucoma-Hyphema syndrome]

INTRODUCTION

Uveitis-Glaucoma-Hyphema syndrome (UGH) is caused by mechanical chafing of anterior segment structures by an intraocular lens, especially an anterior chamber lens. The objective of this study was to characterise the clinical course and risk factors of UGH syndrome at a time when posterior chamber implantation is the gold standard.

PATIENTS AND METHODS

This was a retrospective study of 30 cases of UGH syndrome managed between January 2014 and September 2018. Data from the initial clinical examination, the type of implant involved and the clinical management were analysed.

RESULTS

Thirty eyes of 28 patients were included. Intra ocular lenses were iris-sutured (15/30, 50 %), in the bag (6/30, 20 %), scleral-fixated (4/30, 13.3 %), in the ciliary sulcus (3/30,10 %) or "in and out" (2/30, 6.7 %). Initial management was medical (18 eyes) or surgical (12 eyes). Surgical procedures were explantation (n=4), IOL repositioning (n=7) or trabeculectomy (n=1). Recurrences occurred with medical treatment (9/18), but not in the surgical group (p=0.02). Ocular hypertension became chronic in 19 cases out of 30 (63.3 %).

CONCLUSION

UGH syndrome can be caused by any type of pseudophakic lens. An intraocular lens in the bag should not rule out the diagnosis. Despite the decreasing popularity of anterior chamber intraocular lens implantation, UGH syndrome remains a current condition and must be recognised in order to adapt therapeutic management.

An unusual case of uveitis-glaucoma-hyphema syndrome

PURPOSE

To report a case of uveitis-glaucoma-hyphema (UGH) syndrome in which anterior chamber paracentesis led to the diagnosis of sickle cell trait.

DESIGN

Observational case report.

METHODS

A 43-year-old Cuban pseudophakic male was seen multiple times over a 3-year period complaining of floaters and blurry vision in his left eye. He was noted to have an inferotemporally displaced posterior chamber intraocular lens and recurrent microhyphemas with elevated intraocular pressure (IOP) readings between 29 and 46 mm Hg with each episode. He was diagnosed with UGH syndrome. Posterior chamber intraocular lens explantation and anterior chamber washout was performed. The aqueous fluid was submitted for cytopathologic examination.

RESULTS

Postoperatively, the patient's symptoms resolved and he had no further hemorrhages or elevated IOP readings. Cytopathology of the aspirate revealed sickled red blood cells.

CONCLUSIONS

Microscopic examination of aqueous fluid can be a valuable tool in diagnosing ophthalmic manifestations of systemic disease.

[History of the development of intraocular lenses]

Even though cataract surgery has been practiced for over 2000 years, modern cataract surgery started just some 50 years ago. with the first IOL implantation by Sir Harold Ridley. The development of intraocular lenses was accompanied by great successes and disasters. With the fast development of cataract surgical techniques over the past 15 years (ECCE, Phacoemulsification, Capsulorhexis) a successful marriage between IOL-developments and surgery was established. Indication profiles for cataract surgery and IOL implantation extended to more and more patient groups. At this time classical cataract surgery is further developing into refractive intraocular lens surgery to correct higher ametropia in clear lens or phakic eyes. This development was only possible because of the improvements of surgical techniques and implants in classical cataract surgery.

Are there acceptable anterior chamber intraocular lenses for clinical use in the 1990s? An analysis of 4104 explanted anterior chamber intraocular lenses

PURPOSE

The authors pose the question as to whether there are any anterior chamber intraocular lenses (AC IOLs) acceptable for clinical use in the 1990s.

METHODS

Data on the incidence and types of complications of 4104 AC IOLs that were submitted to the Center for IOL Research from 1982 to 1993 were retrieved from the laboratory database and analyzed using cumulative frequency calculations and the chi-square test. Normalized explantation rates were related to implantation rates that were derived from market-share analysis.

RESULTS

Of 4104 explanted IOLs, 50% were closed-loop designs (n = 2095/4104); 26% (1100/4104) were miscellaneous, older designs; and 22% (919/4104) were open-loop lenses. The most important complications were corneal pathology (2065/4104) and inflammation (1370/4104). Closed-loop designs were responsible for almost 80% of corneal pathology, with an increasing complication rate with ongoing implant duration (P < 0.0001). Open-loop AC IOLs showed, in relation to their normalized rate of implantation, a significantly lower rate of complications and explantations (P < 0.01).

CONCLUSION

Complication rates of flexible, open-loop AC IOLs are much lower than previously assumed. They should be distinguished clearly from most older AC IOL designs. Consideration of these lenses as an alternative to sutured posterior chamber IOLs for secondary or exchange implantation may be warranted for selected clinical indications. They also could provide an alternative to the aphakic spectacle rehabilitation program in developing countries, which will have a positive impact on the overwhelming backlog of patients with cataract in the underprivileged world.

The Binkhorst Medal Lecture. Biologic relationship between poly(methyl methacrylate) intraocular lenses and uveal tissue

Implantation of a poly(methyl methacrylate) (PMMA) intraocular lens (IOL) after cataract surgery is associated with breakdown of the blood-ocular barrier and a foreign body inflammatory response. Although the material is biocompatible, it is not inert. The history of PMMA IOL implantation has reflected mechanical, chemical, and immunological interactions between the IOL and ocular tissues. The common link in these events is instability of the blood-ocular barrier. In this lecture, I discuss the nature of these interactions and present evidence that currently investigated methods of surface modification and capsular bag IOL implantation are effective in stabilizing the blood-ocular barrier.

An analysis of flexible anterior chamber lenses with special reference to the normalized rate of lens explantation

A survey of 1204 closed-loop anterior chamber intraocular lenses (AC-IOLs) and 310 open-loop AC-IOLs accessioned between November 1982 and January 1990 was conducted at the Center for Intraocular Lens Research. An analysis of complication rates was done after normalization of data with respect to market share totals. The results establish that an unacceptable complication rate is associated with the closed-loop design when compared with either the tripod or quadripod lens styles. Furthermore, the closed-loop designs, while comprising an estimated 45% of the total number of AC-IOLs estimated to be implanted in the United States (n = 674,000), were responsible for 80% of the AC-IOLs explanted after complications and accessioned at the authors' center. A rethinking of the extreme condemnation of all anterior chamber IOLs that has surfaced in recent years is warranted. This is particularly true with respect to indications for use of sutured posterior chamber (PC) IOLs as well as with regard to possible use of open-loop AC-IOLs in less-industrialized nations.

Complications of sulcus-supported intraocular lenses with iris sutures, implanted during penetrating keratoplasty after intracapsular cataract extraction

In a retrospective study, the authors analyzed visual results and postoperative complications in a series of 14 consecutive patients who had undergone penetrating keratoplasty and implantation of a posterior chamber intraocular lens (PC IOL) in the absence of the posterior capsule. Seven patients suffered from aphakic bullous keratopathy and seven from pseudophakic bullous keratopathy. Postoperative follow-up was 7.6 months on the average. Best-corrected postoperative visual acuity was 20/60 or better in four cases and 20/200 or better in eight. Glaucoma was present before surgery in four eyes, which persisted in all cases and developed in four new cases. Results of gonioscopic examination showed the postoperative development of goniosynechiae in four eyes. Pseudophakodonesis of various extent was present in ten eyes. Preoperatively, cystoid macular edema was diagnosed angiographically in one case. It did not improve after surgery and was seen in three additional eyes postoperatively. Causes for postoperative visual acuity lower than 20/200 were cystoid macular edema in three cases, graft rejection in one case, central retinal scar in one case, and optic nerve atrophy in one case. A distortion of the pupil was seen in three eyes in miosis and in four additional eyes in mydriasis. Corneal thickness as well as anterior chamber depth were within normal limits. Fluorophotometric evaluation of the blood-aqueous barrier showed values comparable with those obtained after intracapsular cataract extraction and implantation of an iris-fixated IOL. Despite the relatively good visual results, the high postoperative incidence of cystoid macular edema and/or glaucoma may discourage the use of this technique.

Graft failure after penetrating keratoplasty

Despite the improving results that have been noted with penetrating keratoplasty, graft failure remains a significant problem. The causes of graft failure are quite varied. Primary donor failure, surgical complications, intraocular lens complications, persistent epithelial defects, allograft rejection, infection, glaucoma, trauma, and recurrences of primary corneal dystrophies are common etiologies. In this article, a critical review of the available literature concerned with the factors influencing the many causes of graft failure and their management is provided.

Intraocular lens removal for chronic cystoid macular edema

Intraocular lenses were removed from ten eyes with chronic cystoid macular edema demonstrated by fluorescein angiography. No corneal transplantation was done at the time of intraocular lens removal. Five eyes achieved a visual acuity of 20/50 or better. Exchange for a posterior chamber intraocular lens did not appear to have an adverse affect compared to simple intraocular lens removal.

Intraocular lens removal during penetrating keratoplasty for pseudophakic bullous keratopathy

Pseudophakic bullous keratopathy is now the most common reason for penetrating keratoplasty. In previous reports, the type of intraocular lens (IOL) most frequently encountered in these eyes was the iris plane IOL. The authors reviewed 27 cases of IOL removal during penetrating keratoplasty. Lenses were removed if they were dislocated or associated with iritis, recurrent hyphema, glaucoma, or persistent cystoid macular edema. The IOL encountered most often was the anterior chamber lens (in 22 eyes); closed thin loop, semiflexible or flexible anterior chamber lenses accounted for 19 of these. Iris plane lenses were removed from five eyes. No posterior chamber lenses were removed. Clear grafts were obtained in 24 of 27 cases (89%); visual acuity improved or remained the same in 24 cases, to 20/60 in 11 cases. The most common causes of poor postoperative vision were retinal disease (6/27 cases) and glaucoma (6/27 cases). The association between anterior chamber lenses and pseudophakic bullous keratopathy is probably the result of both the increase in use of these lenses and the documented propensity of the closed loop semiflexible anterior chamber lenses to cause complications.

Additional long-term follow-up on the IOLAB Azar 91Z anterior chamber intraocular lens

A retrospective study of 98 91Z anterior chamber intraocular lenses used with intracapsular cataract extraction was performed. Minimum follow-up was 12 months and average follow-up was two years seven months. These patients were part of a group of 113 91Z patients previously reported with minimum six-months follow-up and an average of one year follow-up. Comparing the two groups showed the number of patients with 20/40 visual acuity declined from 84.1% to 67.4% and those with visual acuity less than 20/400 increased from 0.9% to 5.1%. The number of 91Zs explanted more than doubled from five (4.4%) to 11 (11.2%). Pseudophakic bullous keratopathy not present in the one-year follow-up group is occurring with longer follow-up. This study demonstrates an increasing incidence of inflammatory - hemorrhagic and corneal complications in 91Z patients.

Complications of intraocular lenses. A historical and histopathological review

Recent improvements in intraocular lens (IOL) design, manufacturing techniques, and surgical techniques have greatly reduced the incidence of complications following implantation, and many authors now consider IOL implantation to be among the most safe and effective major surgical procedures. However, adverse reactions are still seen--some as late sequelae of earlier IOL designs and implantation techniques and some as sequelae of more recent implantations using "state-of-the-art" lenses and surgical techniques. Complications may be due to various factors, including surgical technique, IOL design, or the inability of some eyes with preexisting disease to tolerate an implant. The authors trace the evolution of IOLs since Ridley's first implant, summarizing the modifications in lenses and surgical techniques that were made as complications were recognized. They then review the clinical and histopathological features of selected cases from more than 200 IOLs and/or globes removed due to IOL-related complications and studied in the University of Utah Ocular Pathology Laboratory. It is hoped that this review will provide insights into the pathogenesis of IOL complications, enhancing the current success of implant procedures and stimulating further basic and clinical research in this area.