Assessing the Role of Soft Contact Lenses Assessing the Role of Soft Contact Lenses in Preoperative Conditions Following in Preoperative Conditions Following

Keratoprosthesis ImplantationKeratoprosthesis Implantation

The authors have no financial interest in the subject matter of this poster.

Leah L. Kammerdiener, Miranda Lynch, Mona Harissi-Dagher, Claes H. Dohlman, James Aquavella, Joseph B. Ciolino, James Chodosh

Massachusetts Eye and Ear Infirmary, University of Rochester Flaum Eye Institute

The keratoprosthesis (Kpro), an artificial cornea, has proven effective at establishing a clear pathway for light through an opaque cornea.1 To qualify for the procedure, patients who underwent KPro surgery had poor prognoses for simple penetrating keratoplasty. These included patients with multiple graft rejection (54%), chemical injury (15%), and herpes simplex virus keratitis (7%) among others.2 The quality of life of the patients was increased with the restoration of vision, in some cases from light perception only to 20/400 vision1.

INTRODUCTONINTRODUCTON

Some of the difficulties arising from the KPro surgery have been desiccation by evaporative forces, epithelial defects, stromal thinning, and dellen formation.3 Problems caused by the physical presence of the device include instability of the KPro and aqueous humor leakage.4 To help protect the cornea from some of these complications, a soft contact lens (SCL) is routinely placed as the last step of surgery.3 The lens protects the corneal surface by diffusing the evaporative forces and maintaining a fluid meniscus at the edge of the front plate of the KPro. It also corrects postoperative refractive error, and can be used for cosmetic effect to match its paired eye.3,5,6

Photos: Keratoprosthesis with overlying soft contact lens on slit lamp exam

It has been recognized that pre-operative categories of patients, most broadly divided into autoimmune disorders, chemical injury, and “other” can be prognostic of post-surgical visual acuity outcomes.7 For the purposes of this study, the preoperative conditions have been grouped into autoimmune (Stevens-Johnson Syndrome, ocular cicatricial pemphigoid, rheumatoid arthritis, and uveitis), chemical injury, and “other” (infection and non-inflammatory conditions such as dystropheis, trauma, keratopathies, and keratoconus). There is however, a scarcity of data evaluating the pre-operative groups for prognostic value in the management of post-operative SCL use and complications.

To evaluate associations between patient pre-operative diagnosis with SCL retention, complications, and outcomes.

A retrospective chart review was conducted of 92 patients’ (103 eyes) charts who underwent a Boston KPro Type I at the Massachusetts Eye and Ear Infirmary (MEEI) or the University of Rochester Flaum Eye Institute (UREI) by one of two surgeons (J.V.A, or C.H.D) between August 1995 and June 2008. The medical records were reviewed and analyzed for pre-operative diagnosis, past ocular surgical history, SCL retention, and subsequent complications and outcomes.

PURPOSEPURPOSE

METHODSMETHODS

• Preoperative categories included 16 patients with autoimmune disease (Stevens Johnson Syndrome, ocular cicatritial pemphigoid, rheumatoid arthritis, and uveitis), 9 with chemical injury, and 67 “other” (aniridia, infection, trauma, dystrophies, and keratopathies).

• Among these groups, the time to first soft contact lens (SCL) loss was shortest for chemical injury and longest for autoimmune patients.

Figure: Time (in months) until first soft contact lens loss in each preoperative group. Vertical dashes mark where a censored data point occurs (time when patient follow-up ended, but no SCL loss was experienced).

RESULTSRESULTS

• Chemical injury had more SCL losses while autoimmune had fewest.• A small subset (n=17) of the population experienced more than 2

SCL losses per year. These patients comprised 6% of the autoimmune group, 22% of the chemical injury group, and 21% of the “other” group.

Soft Contact Lens Losses By Preoperative Diagnosis

0

5

10

15

20

25

30

1

Autoimmune Chemical Injury Other

Figure: Number of soft contact lens (SCL) losses per 10 years SCL wear.

• Autoimmune experienced the highest yearly complication rate and “other” the lowest rate.

• Among all three categories, complication rates were highest when patients were not wearing their contact lenses. The most common complication experienced was corneal melt resulting in aqueous humor leak.

• Patients over the age of 70 years were significantly less likely to experience a complication compared to those younger than 70.

Complications By Preoperative Diagnosis

0

1

2

3

4

5

6

Autoimmune Chemical Injury Other

Number ofComplications with SCL(per 10 patient-years)

Number ofComplications withoutSCL (per 10 patient-years)

Figure: Number of complications experienced while wearing SCL and without SCL per 10 patient-years of follow-up.

• Even with a trend toward higher lens retention, some patients with autoimmune disease are destined to develop corneal complications after implantation. The chronic inflammatory response present in eyes affected by autoimmune diseases is responsible for increased complication rates, predisposing the corneal surface to sterile corneal ulcers and infections.6

• Chemically injured eyes experienced the most rapid initial soft contact lens loss which may be due to poor tear production, ocular surface disease, symblepharon formation, and lid abnormalities that are associated with these injuries.8

• Non-autoimmune and non-chemical injury patients may have less inflammation, and typically have normal tear production and normal eyelid function. The difficulty in lens fitting in some non-chemical injury and non-autoimmune disorder patients may account for the slightly higher rate of contact lens loss.

CONCLUSIONCONCLUSION

1 Aquavella, JV., Y. Qian, GJ. McCormick, and JR. Palakuru. "Keratoprosthesis: The Dohlman-Doane Device." American Journal of Ophthalmology 6 (2005): 1032-038.

2 Zerbe, B., M. Belin, and J. Ciolino. "Results from the Multicenter Boston Type 1 Keratoprosthesis Study." Ophthalmology 113 (2006): 1779-784.

3 Harissi-Dagher, M., J. Beyer, and CH. Dohlman. "The Role of Soft Contact Lenses as an Adjunct to the Boston Keratoprothesis." International Opthalmology Clinic 2 (2008): 43-51.

4 Khan, BF., M. Harissi-Dagher, DM. Khan, and CH. Dohlman. "Advances in Boston Keratoprosthesis: Enhancing Retention and Prevention of Infection and Inflammation." International Ophthalmology Clinic 2 (2007): 61-71.

5 Macsai, MS. "The Management of Corneal Trauma: Advances in the Past Twenty-five Year." Cornea 5 (2000): 617-24.

6 Dohlman, CH., EJ. Dudenhoefer, BF. Khan, and S. Morneault. "Protection of the Ocular Surface After Keratoprosthesis Surgery: The Role of Soft Contact Lenses." CLAO J. 2 (2002): 72-74.

7 Yaghouti, F., M. Nouri, JC. Abad, WJ. Power, MG. Doane, CH. Dohlman. “Keratoprothesis: Preoperative Prognostic Categories.” Cornea 20 (2001): 19-23. There are no commercial relationships or any financial disclosures.

8 Kadar T, Dachir S, Cohen L, et al. Ocular injuries following sulfur mustard exposure--pathological mechanism and potential therapy. Toxicology. Sep 1 2009;263(1):59-69.

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