Results of penetrating keratoplasty for pseudophakic corneal edema with retention of intraocular lens

Intraocular lens complications requiring removal or exchange

Intraocular lens (IOL)-related complications are caused primarily by mechanical trauma, inflammatory or infectious complications, or optical problems. Complications may occur at the time of surgery or be the result of an ongoing postoperative process. Mechanical and inflammatory injury may produce corneal decompensation, cystoid macular edema, hyphema, uveitis, and glaucoma, causing reduced vision and in some cases chronic pain. Optical problems may be due to a wrong power of the IOL or to postoperative decentration or dislocation of the lens. Ophthalmologists should be aware of the indications for IOL removal or exchange in those patients who have ongoing IOL-induced injury or impairment. Removal or exchange of an IOL frequently involves a complex decision-making process and is often associated with immense technical challenge. Various medical and surgical treatments may be tried to correct IOL problems before the decision is made to remove or exchange the lens.

Intraocular complications associated with the Dubroff anterior chamber lens

We examined a series of 53 consecutive eyes form which Dubroff-style anterior chamber lenses were explanted. The mean time from implantation to explantation was 46.21 months (range six to 99 months). Problems leading to explantation included bullous keratopathy (83%), glaucoma (51%), chronic cystoid macular edema (40%), and iritis (13%). Molteno valves were required in 9% of eyes. Progressive anterior synechias resulted in intraocular lens displacement against the cornea in 19%. The Dubroff lenses caused problems similar to those previously observed with closed-loop anterior chamber lenses but had a higher incidence of severe glaucoma and progressive peripheral anterior synechias.

Factors predictive of corneal graft survival. Report from the Australian Corneal Graft Registry

Risk factors for graft failure after penetrating keratoplasty were investigated in 961 patients from records collected prospectively by the Australian Corneal Graft Registry. The most common cause of graft failure was irreversible rejection. A multivariate proportional hazards regression analysis indicated that the key predictors of graft failure were: an indication for graft other than keratoconus or corneal dystrophy; a failed previous graft (ipsilateral eye); aphakia; inflammation at the time of graft; presence of an anterior chamber or iris-clip intraocular lens; graft size outside the range of 7.0 to 7.9 mm diameter; and corneal vascularization occurring in the postoperative period.

The corneal endothelium

The endothelium is a monolayer of cells on the posterior corneal surface that transports water from the stroma into the anterior chamber. This movement of water counters a natural tendency for the stroma to swell and is necessary to maintain a transparent cornea. Embryologic studies, in particular the demonstration of the derivation of the endothelium from the neural crest, have provided insight into the factors that govern the response of this tissue to disease. In some species the endothelium can regenerate after injury, but in man cellular enlargement is the main mechanism of repair after cell loss. A clinical estimate of endothelial cell density and function is provided by specular microscopy, fluorophotometry and pachymetry. In this paper we review the development, structure and function of the corneal endothelium, and then consider the pathological processes that can affect this tissue.

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.

Natural history of cystoid macular edema in pseudophakic bullous keratopathy

A retrospective review of 25 consecutive patients having penetrating keratoplasty (PKP) with the preoperative diagnoses of pseudophakic bullous keratopathy (PBK) and cystoid macular edema (CME) was undertaken to analyze the natural history of preoperative CME following keratoplasty. Follow-up ranged from 13 to 54 months with a mean of 27 months. All patients had intraocular lens exchanges with 24 receiving posterior chamber lenses; 23 had lenses sutured to the posterior iris. Sixteen patients (64%) recovered a visual acuity of 20/40 or better. The average time for visual recovery to 20/40 was nine months with a range of two to 45 months. Eighteen (72%) had resolution of angiographic CME. Three patients previously diagnosed as having chronic CME recovered visual acuity of 20/40 or better. Cases of PBK with CME may have an excellent visual prognosis if the IOL is managed properly at the time of PKP.

Visual results of suture-fixated posterior chamber lenses during penetrating keratoplasty

Between August 12, 1982, and June 30, 1987, 233 consecutive eyes had posterior chamber intraocular lenses (PC IOLs) suture-fixated to the posterior aspect of the iris during penetrating keratoplasty (PKP). In all cases, insufficient capsular material was present to provide adequate fixation for the implant. Lenses were placed in 72 aphakic eyes as a secondary implant, and 159 lenses were placed after removal of another implant. Follow-up ranged from 1 year to 68 months with 59.5% of patients achieving visual acuity of 20/40 or better, and 74% of 20/80 or better. Suture-fixating a PC IOL to the iris offers multiple advantages over placement of an anterior chamber lens during PKP. The complication rate appears low, and long-term problems with glaucoma and recurrent corneal decompensation should be reduced.

Penetrating keratoplasty and intraocular lens exchange for pseudophakic bullous keratopathy associated with a closed-loop anterior chamber intraocular lens

We reviewed the records of 20 consecutive eyes with pseudophakic bullous keratopathy associated with a closed-loop anterior chamber lens that underwent penetrating keratoplasty, total anterior vitrectomy, and anterior chamber intraocular lens exchange. On reexamination, all corneal grafts had remained clear during an average follow-up period of 15 months (range, four to 45 months). Seven eyes (35%) attained a visual acuity of 20/40 or better with spectacle correction; however, 15 of 20 eyes (75%) attained a best-corrected visual acuity of 20/40 or better using a pinhole and a gas-permeable contact lens. In five eyes visual acuity was 20/400 or poorer because of cystoid macular edema, as documented by fluorescein angiography, age-related macular degeneration, or optic atrophy. Localized, minimal peripheral anterior synechiae were present on gonioscopy in seven eyes. The one-piece flexible anterior chamber lens implants used for exchange appeared to be well tolerated in this series of patients.

Penetrating keratoplasty for pseudophakic bullous keratopathy. Management of the intraocular lens

Management of the intraocular lens (IOL) at the time of penetrating keratoplasty (PK) for pseudophakic bullous keratopathy has been based on lens-related factors and coexisting anterior segment abnormalities. The authors reviewed the results of PK for 102 cases of pseudophakic bullous keratopathy (43 anterior chamber, 50 iris-supported, and 9 posterior chamber) with respect to: (1) the type of IOL, (2) coexisting abnormalities, and (3) management of the IOL at surgery. Graft failure after 2 years of follow-up was: (1) retained iris-supported IOLs, 9%; (2) retained anterior chamber IOLs, 60%; (3) retained posterior chamber intraocular lenses (PC IOL), 0%; (4) removed IOLs, 9%; and (5) exchanged IOLs, 20%. After 5 years of follow-up, 13 of 13 PKs with retained closed-loop anterior chamber IOLs had failed. Visual results were best in eyes with retained iris-supported, rigid anterior chamber or PC IOLs and when the IOL was removed without replacement. The authors recommend that closed-loop anterior chamber lenses and unstable lenses of any type be removed or exchanged and that well-fixated PC IOLs and iris-clip IOLs be retained at the time of PK for pseudophakic bullous keratopathy.

Visual results after keratoplasty in patients with posterior chamber intraocular lenses

We performed penetrating keratoplasty in 20 consecutive patients who had posterior chamber intraocular lenses and who developed pseudophakic bullous keratopathy. All patients received 8.0-mm grafts placed in 7.5-mm recipient beds. None of the intraocular lenses were removed. Final visual acuity was 20/40 or better in eight (40%) and 20/80 or better in 15 (75%) of the patients. Senile macular degeneration (one case), corneal graft rejection (two cases), and wound infection (one case) contributed to poor visual results in the remaining patients.

Results of anterior segment reconstruction for aphakic and pseudophakic corneal edema

The authors studied prospectively 59 eyes with corneal edema after cataract surgery that required reconstructive surgery; penetrating keratoplasty in 59 (100%), anterior vitrectomy in 42 (71%), intraocular lens removal or exchange in 33 (56%), gonioplasty in 32 (54%), and iridoplasty in 30 (51%). With an average follow-up of 9.9 months, the corneal transplant was clear in 56 eyes (95%). The corrected visual acuity was improved in 49 eyes (83%) and was the same in seven eyes (12%). Intraocular pressure was less than or equal to 21 mmHg in 47 eyes (80%) and 22 to 29 mmHg in nine eyes (15%). The peripheral anterior synechiae score was the same or improved in 56 eyes (95%). Cystoid macular edema was absent to mild in 52 eyes (88%). Anterior segment reconstruction improved both anatomic integrity and visual acuity of most eyes without increasing complications.

Penetrating keratoplasty for pseudophakic bullous keratopathy after extracapsular cataract extraction

Seventeen women underwent simple penetrating keratoplasty for pseudophakic bullous keratopathy after extracapsular cataract extraction. Corneal edema occurred an average of eight months after cataract surgery (range, zero to 32 months). Of 17 corneal grafts, 16 (94%) have remained clear during an average follow-up period of 14 months (range, two to 32 months). One eye had a nonimmunologic graft failure. Of 16 eyes with clear grafts, 14 (87%) achieved a visual acuity of 20/40 or better after surgery. Two eyes with a visual acuity of 20/50 and 20/200 had opacified posterior capsules and one demonstrated age-related macular degeneration. One eye with a postoperative visual acuity of 20/40 demonstrated cystoid macular edema. Fifteen of 17 contralateral eyes showed slit-lamp evidence of endothelial dystrophy.

Techniques of flexible intraocular lens insertion during keratoplasty

Aphakic and pseudophakic corneal edema have become the primary indication for corneal transplantation. At the time of this surgery, implantation of an intraocular lens (IOL) may be considered. We describe our technique for inserting a flexible anterior chamber IOL during keratoplasty to avoid any damage to intraocular structures.