Purpose: When horizontal lid laxity is present, determining whether to perform a wedge resection horizontal shortening of the lid or a canthoplasty can be a difficult task. An analysis of patients with lower eyelid malpositions resulted in an algorithm to choose the most appropriate procedure based on specific anatomical deformities.
Techniques: 100 consecutive patients with lower eyelid malpositions were evaluated by 1) lamellar deformities (anterior, middle and posterior); 2) malar prominence to lower eyelid to globe spatial relationship (vector analysis); 3) globe and orbital volume approximation (soft tissue to bone distance); 4) tarsoligamentous integrity; 5) palpebral aperture; 6) lateral canthal to medial canthal position; and 7) lower eyelid and cheek junction (midface descent). Eight different methods of canthoplasty were utilized for reconstruction of the lower eyelid malpositions.
Results: An algorithm was developed to match the most appropriate canthoplasty technique to the specific anatomical findings:
| Canthoplasty Techniques | Indications | |
| IRLCx | LME I, B-STD < 1cm | |
| IRLC | LME I and II, B-STD < 1cm | |
| LME I and II, B-STD > 1cm | ||
| TSLC LME I | ||
| Lateral canthal laxity | ||
| Lateral canthal asymmetry | ||
| TSLC + HLS + VSG | LME II-IV with HLL | |
| LME II-IV with HLL and MLR | ||
| DOPLC | LME II-IV, B-STD > 1cm | |
| DOP + TSLC + HLS | LME II-IV with HLL, B-STD < 1 cm | |
| LME II-IV with HLL, B-STD > 1 cm | ||
| DOP + TSLC + HLS + VSG | LME III-IV with HLL and MLR, B-STD < 1 cm | |
| LME III-IV with HLL and MLR, B-STD > 1 cm | ||
| DOP + TSLC + HLS + VSG + midface | LME III-IV with HLL and MLR, midface descent, B-STD < 1 cm | |
| elevation/titanium screw fixation | LME III-IV with HLL and MLR, midface descent, B-STD > 1 cm | |
| *Abbreviations: IRLCx, inferior retinacular lateral canthopexy; IRLC, inferior retinacular lateral canthoplasty; TSLC, tarsal strip lateral canthoplasty; HLS, horizontal lid shortening; VSG, vertical skin graft; DOPLC, dermal-orbicular pennant lateral canthoplasty; DOP, dermal-orbicular pennant, LME, lid margin eversion; B-STD, bone to soft tissue distance; HLL, horizontal lid laxity; MLR, midlamellar retraction | ||
Conclusions: The authors describe a dependable, comprehensive algorithm for the diagnosis of patients with lower eyelid malpositions to be used to select the most appropriate corrective procedure based on specific anatomical deformities. By following this precise, systematic approach to determine which form of canthoplasty, if any, should be performed, a more reliable surgical outcome can be achieved.